Merge branch 'rickard/r16/port-optimizations/OTP-10336'

* rickard/r16/port-optimizations/OTP-10336:
  Change annotate level for emacs-22 in cerl
  Update etp-commands
  Add documentation on communication in Erlang
  Add support for busy port message queue
  Add driver callback epilogue
  Implement true asynchronous signaling between processes and ports
  Add erl_drv_[send|output]_term
  Move busy port flag
  Use rwlock for driver list
  Optimize management of port tasks
  Improve configuration of process and port tables
  Remove R9 compatibility features
  Use ptab functionality also for ports
  Prepare for use of ptab functionality also for ports
  Atomic port state
  Generalize process table implementation
  Implement functionality for delaying thread progress from unmanaged threads

82 files changed, 12099 insertions, 6857 deletions

diff --git a/erts/emulator/Makefile.in b/erts/emulator/Makefile.in
index 7e966c81bb..67320697ef 100644
--- a/erts/emulator/Makefile.in
+++ b/erts/emulator/Makefile.in
@@ -560,7 +560,8 @@ $(PRELOAD_SRC): $(ERL_TOP)/erts/preloaded/ebin/otp_ring0.beam \
 			$(ERL_TOP)/erts/preloaded/ebin/zlib.beam \
 			$(ERL_TOP)/erts/preloaded/ebin/prim_zip.beam \
 			$(ERL_TOP)/erts/preloaded/ebin/erl_prim_loader.beam \
-			$(ERL_TOP)/erts/preloaded/ebin/erlang.beam
+			$(ERL_TOP)/erts/preloaded/ebin/erlang.beam \
+			$(ERL_TOP)/erts/preloaded/ebin/erts_internal.beam
 	LANG=C $(PERL) utils/make_preload $(MAKE_PRELOAD_EXTRA) -rc $^ > $@
 else
 PRELOAD_OBJ = $(OBJDIR)/preload.o
@@ -572,7 +573,8 @@ $(PRELOAD_SRC): $(ERL_TOP)/erts/preloaded/ebin/otp_ring0.beam \
 			$(ERL_TOP)/erts/preloaded/ebin/zlib.beam \
 			$(ERL_TOP)/erts/preloaded/ebin/prim_zip.beam \
 			$(ERL_TOP)/erts/preloaded/ebin/erl_prim_loader.beam \
-			$(ERL_TOP)/erts/preloaded/ebin/erlang.beam
+			$(ERL_TOP)/erts/preloaded/ebin/erlang.beam \
+			$(ERL_TOP)/erts/preloaded/ebin/erts_internal.beam
 	LANG=C $(PERL) utils/make_preload -old $^ > $@
 endif
 
@@ -735,7 +737,8 @@ RUN_OBJS = \
 	$(OBJDIR)/packet_parser.o	$(OBJDIR)/safe_hash.o \
 	$(OBJDIR)/erl_zlib.o		$(OBJDIR)/erl_nif.o \
 	$(OBJDIR)/erl_bif_binary.o      $(OBJDIR)/erl_ao_firstfit_alloc.o \
-	$(OBJDIR)/erl_thr_queue.o	$(OBJDIR)/erl_sched_spec_pre_alloc.o
+	$(OBJDIR)/erl_thr_queue.o	$(OBJDIR)/erl_sched_spec_pre_alloc.o \
+	$(OBJDIR)/erl_ptab.o
 
 ifeq ($(TARGET),win32)
 DRV_OBJS = \
diff --git a/erts/emulator/beam/atom.names b/erts/emulator/beam/atom.names
index afcbd732df..c47a608215 100644
--- a/erts/emulator/beam/atom.names
+++ b/erts/emulator/beam/atom.names
@@ -94,6 +94,7 @@ atom asynchronous
 atom atom
 atom atom_used
 atom attributes
+atom await_port_send_result
 atom await_proc_exit
 atom await_sched_wall_time_modifications
 atom awaiting_load
@@ -152,6 +153,7 @@ atom connection_closed
 atom cons
 atom const
 atom context_switches
+atom control
 atom copy
 atom cpu
 atom cpu_timestamp
@@ -204,6 +206,7 @@ atom erlang
 atom ERROR='ERROR'
 atom error_handler
 atom error_logger
+atom erts_internal
 atom ets
 atom ETS_TRANSFER='ETS-TRANSFER'
 atom event
@@ -237,6 +240,7 @@ atom gc_end
 atom gc_start
 atom Ge='>='
 atom generational
+atom get_data
 atom get_seq_token
 atom get_tcw
 atom getenv
@@ -408,6 +412,7 @@ atom overlapped_io
 atom owner
 atom packet
 atom packet_size
+atom parallelism
 atom Plus='+'
 atom pause
 atom pending
@@ -419,12 +424,12 @@ atom pid
 atom port
 atom ports
 atom port_count
+atom port_limit
 atom print
 atom priority
 atom private
 atom process
 atom processes
-atom processes_trap
 atom processes_used
 atom process_count
 atom process_display
@@ -434,6 +439,7 @@ atom procs
 atom profile
 atom protected
 atom protection
+atom ptab_list_continue
 atom public
 atom purify
 atom quantify
@@ -481,6 +487,7 @@ atom sequential_trace_token
 atom serial
 atom set
 atom set_cpu_topology
+atom set_data
 atom set_on_first_link
 atom set_on_first_spawn
 atom set_on_link
diff --git a/erts/emulator/beam/beam_bif_load.c b/erts/emulator/beam/beam_bif_load.c
index 9e4add823d..e0a4f86d2d 100644
--- a/erts/emulator/beam/beam_bif_load.c
+++ b/erts/emulator/beam/beam_bif_load.c
@@ -438,8 +438,7 @@ check_process_code_2(BIF_ALIST_2)
     if (is_internal_pid(BIF_ARG_1)) {
 	Eterm res;
 	ErtsCodeIndex code_ix;
-	if (internal_pid_index(BIF_ARG_1) >= erts_max_processes)
-	    goto error;
+
 	code_ix = erts_active_code_ix();
 	modp = erts_get_module(BIF_ARG_2, code_ix);
 	if (modp == NULL) {		/* Doesn't exist. */
diff --git a/erts/emulator/beam/beam_bp.c b/erts/emulator/beam/beam_bp.c
index 58e0090a76..2168d410b5 100644
--- a/erts/emulator/beam/beam_bp.c
+++ b/erts/emulator/beam/beam_bp.c
@@ -714,7 +714,7 @@ erts_bif_trace(int bif_index, Process* p, Eterm* args, BeamInstr* I)
 	IS_TRACED_FL(p, F_TRACE_CALLS)) {
 	int local = !!(bp_flags & ERTS_BPF_LOCAL_TRACE);
 	flags = erts_call_trace(p, ep->code, bp->local_ms, args,
-				local, &p->tracer_proc);
+				local, &ERTS_TRACER_PROC(p));
     }
     if (bp_flags & ERTS_BPF_META_TRACE) {
 	Eterm tpid1, tpid2;
@@ -800,7 +800,7 @@ erts_bif_trace(int bif_index, Process* p, Eterm* args, BeamInstr* I)
 	    }
 	    if (flags & MATCH_SET_EXCEPTION_TRACE) {
 		erts_trace_exception(p, ep->code, class, value,
-				     &p->tracer_proc);
+				     &ERTS_TRACER_PROC(p));
 	    }
 	    if ((flags & MATCH_SET_RETURN_TO_TRACE) && p->catches > 0) {
 		/* can only happen if(local)*/
@@ -825,7 +825,7 @@ erts_bif_trace(int bif_index, Process* p, Eterm* args, BeamInstr* I)
 	    UnUseTmpHeapNoproc(3);
 	    if ((flags_meta|flags) & MATCH_SET_EXCEPTION_TRACE) {
 		erts_smp_proc_lock(p, ERTS_PROC_LOCKS_ALL_MINOR);
-		p->trace_flags |= F_EXCEPTION_TRACE;
+		ERTS_TRACE_FLAGS(p) |= F_EXCEPTION_TRACE;
 		erts_smp_proc_unlock(p, ERTS_PROC_LOCKS_ALL_MINOR);
 	    }
 	}
@@ -835,7 +835,7 @@ erts_bif_trace(int bif_index, Process* p, Eterm* args, BeamInstr* I)
 	}
 	/* MATCH_SET_RETURN_TO_TRACE cannot occur if(meta) */
 	if (flags & MATCH_SET_RX_TRACE) {
-	    erts_trace_return(p, ep->code, result, &p->tracer_proc);
+	    erts_trace_return(p, ep->code, result, &ERTS_TRACER_PROC(p));
 	}
 	if (flags & MATCH_SET_RETURN_TO_TRACE) {
 	    /* can only happen if(local)*/
@@ -935,7 +935,7 @@ do_call_trace(Process* c_p, BeamInstr* I, Eterm* reg,
 	c_p->cp = (flags & MATCH_SET_EXCEPTION_TRACE) ?
 	    beam_exception_trace : beam_return_trace;
 	erts_smp_proc_lock(c_p, ERTS_PROC_LOCKS_ALL_MINOR);
-	c_p->trace_flags |= F_EXCEPTION_TRACE;
+	ERTS_TRACE_FLAGS(c_p) |= F_EXCEPTION_TRACE;
 	erts_smp_proc_unlock(c_p, ERTS_PROC_LOCKS_ALL_MINOR);
     }
     c_p->stop = E;
@@ -974,7 +974,7 @@ erts_trace_time_call(Process* c_p, BeamInstr* I, BpDataTime* bdt)
 	ASSERT(pbt->pc);
 	/* add time to previous code */
 	bp_time_diff(&sitem, pbt, ms, s, us);
-	sitem.pid = c_p->id;
+	sitem.pid = c_p->common.id;
 	sitem.count = 0;
 
 	/* previous breakpoint */
@@ -997,7 +997,7 @@ erts_trace_time_call(Process* c_p, BeamInstr* I, BpDataTime* bdt)
     }
 
     /* Add count to this code */
-    sitem.pid     = c_p->id;
+    sitem.pid     = c_p->common.id;
     sitem.count   = 1;
     sitem.s_time  = 0;
     sitem.us_time = 0;
@@ -1055,7 +1055,7 @@ erts_trace_time_return(Process *p, BeamInstr *pc)
 	ASSERT(pbt->pc);
 
 	bp_time_diff(&sitem, pbt, ms, s, us);
-	sitem.pid   = p->id;
+	sitem.pid   = p->common.id;
 	sitem.count = 0;
 
 	/* previous breakpoint */
@@ -1386,7 +1386,7 @@ void erts_schedule_time_break(Process *p, Uint schedule) {
 	    if (pbdt) {
 		get_sys_now(&ms,&s,&us);
 		bp_time_diff(&sitem, pbt, ms, s, us);
-		sitem.pid   = p->id;
+		sitem.pid   = p->common.id;
 		sitem.count = 0;
 
 		h = &(pbdt->hash[bp_sched2ix_proc(p)]);
diff --git a/erts/emulator/beam/beam_emu.c b/erts/emulator/beam/beam_emu.c
index 7b1ae624ce..0e9d140908 100644
--- a/erts/emulator/beam/beam_emu.c
+++ b/erts/emulator/beam/beam_emu.c
@@ -516,7 +516,7 @@ extern int count_instructions;
 #  define Dispatchfun() DispatchMacroFun()
 #endif
 
-#define Self(R) R = c_p->id
+#define Self(R) R = c_p->common.id
 #define Node(R) R = erts_this_node->sysname
 
 #define Arg(N)       I[(N)+1]
@@ -1074,11 +1074,11 @@ init_emulator(void)
 void
 dtrace_drvport_str(ErlDrvPort drvport, char *port_buf)
 {
-    Port *port = erts_drvport2port(drvport);
+    Port *port = erts_drvport2port(drvport, NULL);
 
     erts_snprintf(port_buf, DTRACE_TERM_BUF_SIZE, "#Port<%lu.%lu>",
-                  port_channel_no(port->id),
-                  port_number(port->id));
+                  port_channel_no(port->common.id),
+                  port_number(port->common.id));
 }
 #endif
 /*
@@ -1195,7 +1195,7 @@ void process_main(void)
     c_p = schedule(c_p, reds_used);
     ERTS_VERIFY_UNUSED_TEMP_ALLOC(c_p);
 #ifdef DEBUG
-    pid = c_p->id; /* Save for debugging purpouses */
+    pid = c_p->common.id; /* Save for debugging purpouses */
 #endif
     ERTS_SMP_REQ_PROC_MAIN_LOCK(c_p);
     PROCESS_MAIN_CHK_LOCKS(c_p);
@@ -1227,7 +1227,7 @@ void process_main(void)
 
 	reds = c_p->fcalls;
 	if (ERTS_PROC_GET_SAVED_CALLS_BUF(c_p)
-	    && (c_p->trace_flags & F_SENSITIVE) == 0) {
+	    && (ERTS_TRACE_FLAGS(c_p) & F_SENSITIVE) == 0) {
 	    neg_o_reds = -reds;
 	    FCALLS = REDS_IN(c_p) = 0;
 	} else {
@@ -1591,6 +1591,7 @@ void process_main(void)
      reg[0] = r(0);
      result = erl_send(c_p, r(0), x(1));
      PreFetch(0, next);
+     ERTS_VERIFY_UNUSED_TEMP_ALLOC(c_p);
      ERTS_SMP_REQ_PROC_MAIN_LOCK(c_p);
      PROCESS_MAIN_CHK_LOCKS(c_p);
      if (c_p->mbuf || MSO(c_p).overhead >= BIN_VHEAP_SZ(c_p)) {
@@ -1866,14 +1867,14 @@ void process_main(void)
 		     erts_fprintf(stderr,
 				  "Dtrace -> (%T) stop spreading "
 				  "tag %T with message %T\r\n",
-				  c_p->id,DT_UTAG(c_p),ERL_MESSAGE_TERM(msgp));
+				  c_p->common.id,DT_UTAG(c_p),ERL_MESSAGE_TERM(msgp));
 #endif
 	     } else {
 #ifdef DTRACE_TAG_HARDDEBUG
 		 erts_fprintf(stderr,
 			      "Dtrace -> (%T) kill tag %T with "
 			      "message %T\r\n",
-			      c_p->id,DT_UTAG(c_p),ERL_MESSAGE_TERM(msgp));
+			      c_p->common.id,DT_UTAG(c_p),ERL_MESSAGE_TERM(msgp));
 #endif
 		 DT_UTAG(c_p) = NIL;
 		 SEQ_TRACE_TOKEN(c_p) = NIL;
@@ -1898,7 +1899,7 @@ void process_main(void)
 	     erts_fprintf(stderr,
 			  "Dtrace -> (%T) receive tag (%T) "
 			  "with message %T\r\n",
-			  c_p->id, DT_UTAG(c_p), ERL_MESSAGE_TERM(msgp));
+			  c_p->common.id, DT_UTAG(c_p), ERL_MESSAGE_TERM(msgp));
 #endif
 	 } else {
 #endif
@@ -1914,7 +1915,7 @@ void process_main(void)
 	     }
 	     msg = ERL_MESSAGE_TERM(msgp);
 	     seq_trace_output(SEQ_TRACE_TOKEN(c_p), msg, SEQ_TRACE_RECEIVE, 
-			      c_p->id, c_p);
+			      c_p->common.id, c_p);
 #ifdef USE_VM_PROBES
 	 }
 #endif
@@ -2567,6 +2568,7 @@ void process_main(void)
 	reg[0] = r(0);
 	result = (*bf)(c_p, reg, I);
 	ASSERT(!ERTS_PROC_IS_EXITING(c_p) || is_non_value(result));
+	ERTS_VERIFY_UNUSED_TEMP_ALLOC(c_p);
 	ERTS_HOLE_CHECK(c_p);
 	ERTS_SMP_REQ_PROC_MAIN_LOCK(c_p);
 	PROCESS_MAIN_CHK_LOCKS(c_p);
@@ -3301,7 +3303,6 @@ void process_main(void)
 	    PROCESS_MAIN_CHK_LOCKS(c_p);
 	    bif_nif_arity = I[-1];
 	    ERTS_SMP_UNREQ_PROC_MAIN_LOCK(c_p);
-	    ERTS_VERIFY_UNUSED_TEMP_ALLOC(c_p);
 
 	    ASSERT(!ERTS_PROC_IS_EXITING(c_p));
 	    {
@@ -3346,7 +3347,6 @@ void process_main(void)
 	    bif_nif_arity = I[-1];
 	    ASSERT(bif_nif_arity <= 3);
 	    ERTS_SMP_UNREQ_PROC_MAIN_LOCK(c_p);
-	    ERTS_VERIFY_UNUSED_TEMP_ALLOC(c_p);
 	    reg[0] = r(0);
 	    {
 		Eterm (*bf)(Process*, Eterm*, BeamInstr*) = vbf;
@@ -5257,7 +5257,7 @@ terminate_proc(Process* c_p, Eterm Value)
     /* EXF_LOG is a primary exception flag */
     if (c_p->freason & EXF_LOG) {
 	erts_dsprintf_buf_t *dsbufp = erts_create_logger_dsbuf();
-	erts_dsprintf(dsbufp, "Error in process %T ", c_p->id);
+	erts_dsprintf(dsbufp, "Error in process %T ", c_p->common.id);
 	if (erts_is_alive)
 	    erts_dsprintf(dsbufp, "on node %T ", erts_this_node->sysname);
 	erts_dsprintf(dsbufp,"with exit value: %0.*T\n", display_items, Value);
@@ -6186,7 +6186,7 @@ new_fun(Process* p, Eterm* reg, ErlFunEntry* fe, int num_free)
     MSO(p).first = (struct erl_off_heap_header*) funp;
     funp->fe = fe;
     funp->num_free = num_free;
-    funp->creator = p->id;
+    funp->creator = p->common.id;
 #ifdef HIPE
     funp->native_address = fe->native_address;
 #endif
diff --git a/erts/emulator/beam/bif.c b/erts/emulator/beam/bif.c
index 1cdce49eef..98dc9a3902 100644
--- a/erts/emulator/beam/bif.c
+++ b/erts/emulator/beam/bif.c
@@ -37,10 +37,13 @@
 #include "erl_db_util.h"
 #include "register.h"
 #include "erl_thr_progress.h"
+#define ERTS_PTAB_WANT_BIF_IMPL__
+#include "erl_ptab.h"
 
 static Export* flush_monitor_message_trap = NULL;
 static Export* set_cpu_topology_trap = NULL;
 static Export* await_proc_exit_trap = NULL;
+static Export* await_port_send_result_trap = NULL;
 Export* erts_format_cpu_topology_trap = NULL;
 
 static Export *await_sched_wall_time_mod_trap;
@@ -83,8 +86,10 @@ static int insert_internal_link(Process* p, Eterm rpid)
     ASSERT(is_internal_pid(rpid));
 
 #ifdef ERTS_SMP
-    if (IS_TRACED(p) && (p->trace_flags & (F_TRACE_SOL|F_TRACE_SOL1)))
+    if (IS_TRACED(p)
+	&& (ERTS_TRACE_FLAGS(p) & (F_TRACE_SOL|F_TRACE_SOL1))) {
 	rp_locks = ERTS_PROC_LOCKS_ALL;
+    }
 
     erts_smp_proc_lock(p, ERTS_PROC_LOCK_LINK);
 #endif
@@ -100,27 +105,27 @@ static int insert_internal_link(Process* p, Eterm rpid)
     }
 
     if (p != rp) {
-	erts_add_link(&(p->nlinks), LINK_PID, rp->id);
-	erts_add_link(&(rp->nlinks), LINK_PID, p->id);
+	erts_add_link(&ERTS_P_LINKS(p), LINK_PID, rp->common.id);
+	erts_add_link(&ERTS_P_LINKS(rp), LINK_PID, p->common.id);
 
-	ASSERT(is_nil(p->tracer_proc)
-	       || is_internal_pid(p->tracer_proc)
-	       || is_internal_port(p->tracer_proc));
+	ASSERT(is_nil(ERTS_TRACER_PROC(p))
+	       || is_internal_pid(ERTS_TRACER_PROC(p))
+	       || is_internal_port(ERTS_TRACER_PROC(p)));
 
 	if (IS_TRACED(p)) {
-	    if (p->trace_flags & (F_TRACE_SOL|F_TRACE_SOL1))  {
-		rp->trace_flags |= (p->trace_flags & TRACEE_FLAGS);
-		rp->tracer_proc = p->tracer_proc; /* maybe steal */
+	    if (ERTS_TRACE_FLAGS(p) & (F_TRACE_SOL|F_TRACE_SOL1))  {
+		ERTS_TRACE_FLAGS(rp) |= (ERTS_TRACE_FLAGS(p) & TRACEE_FLAGS);
+		ERTS_TRACER_PROC(rp) = ERTS_TRACER_PROC(p); /* maybe steal */
 
-		if (p->trace_flags & F_TRACE_SOL1)  { /* maybe override */
-		    rp->trace_flags &= ~(F_TRACE_SOL1 | F_TRACE_SOL);
-		    p->trace_flags &= ~(F_TRACE_SOL1 | F_TRACE_SOL);
+		if (ERTS_TRACE_FLAGS(p) & F_TRACE_SOL1) { /* maybe override */
+		    ERTS_TRACE_FLAGS(rp) &= ~(F_TRACE_SOL1 | F_TRACE_SOL);
+		    ERTS_TRACE_FLAGS(p) &= ~(F_TRACE_SOL1 | F_TRACE_SOL);
 		}
 	    }
 	}
     }
     if (IS_TRACED_FL(rp, F_TRACE_PROCS))
-	trace_proc(p, rp, am_getting_linked, p->id);
+	trace_proc(p, rp, am_getting_linked, p->common.id);
 
     if (p == rp)
 	erts_smp_proc_unlock(p, rp_locks & ~ERTS_PROC_LOCK_MAIN);
@@ -144,10 +149,6 @@ BIF_RETTYPE link_1(BIF_ALIST_1)
     /* check that the pid or port which is our argument is OK */
 
     if (is_internal_pid(BIF_ARG_1)) {
-	if (internal_pid_index(BIF_ARG_1) >= erts_max_processes) {
-	    BIF_ERROR(BIF_P, BADARG);
-	}
-
 	if (insert_internal_link(BIF_P, BIF_ARG_1)) {
 	    BIF_RET(am_true);
 	}
@@ -157,19 +158,37 @@ BIF_RETTYPE link_1(BIF_ALIST_1)
     }
 
     if (is_internal_port(BIF_ARG_1)) {
-	Port *pt = erts_id2port(BIF_ARG_1, BIF_P, ERTS_PROC_LOCK_MAIN);
-	if (!pt) {
+	int send_link_signal = 0;
+	Port *prt = erts_port_lookup(BIF_ARG_1, ERTS_PORT_SFLGS_INVALID_LOOKUP);
+	if (!prt) {
 	    goto res_no_proc;
 	}
 
 	erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_LINK);
 	
-	if (erts_add_link(&(BIF_P->nlinks), LINK_PID, BIF_ARG_1) >= 0)
-	    erts_add_link(&(pt->nlinks), LINK_PID, BIF_P->id);
+	if (erts_add_link(&ERTS_P_LINKS(BIF_P), LINK_PID, BIF_ARG_1) >= 0)
+	    send_link_signal = 1;
 	/* else: already linked */
 
 	erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_LINK);
-	erts_smp_port_unlock(pt);
+
+	if (send_link_signal) {
+	    Eterm ref;
+	    Eterm *refp = erts_port_synchronous_ops ? &ref : NULL;
+
+	    switch (erts_port_link(BIF_P, prt, BIF_P->common.id, refp)) {
+	    case ERTS_PORT_OP_DROPPED:
+	    case ERTS_PORT_OP_BADARG:
+		goto res_no_proc;
+	    case ERTS_PORT_OP_SCHEDULED:
+		if (refp) {
+		    ASSERT(is_internal_ref(ref));
+		    BIF_TRAP3(await_port_send_result_trap, BIF_P, ref, am_true, am_true);
+		}
+	    default:
+		break;
+	    }
+	}
 	BIF_RET(am_true);
     }
     else if (is_external_port(BIF_ARG_1)
@@ -182,7 +201,7 @@ BIF_RETTYPE link_1(BIF_ALIST_1)
 	erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_LINK);
 
 	/* We may earn time by checking first that we're not linked already */
-	if (erts_lookup_link(BIF_P->nlinks, BIF_ARG_1) != NULL) {
+	if (erts_lookup_link(ERTS_P_LINKS(BIF_P), BIF_ARG_1) != NULL) {
 	    erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_LINK);
 	    BIF_RET(am_true);
 	}
@@ -209,10 +228,10 @@ BIF_RETTYPE link_1(BIF_ALIST_1)
 
 		erts_smp_de_links_lock(dep);
 
-		erts_add_link(&(BIF_P->nlinks), LINK_PID, BIF_ARG_1);
+		erts_add_link(&ERTS_P_LINKS(BIF_P), LINK_PID, BIF_ARG_1);
 		lnk = erts_add_or_lookup_link(&(dep->nlinks),
 					      LINK_PID,
-					      BIF_P->id);
+					      BIF_P->common.id);
 		ASSERT(lnk != NULL);
 		erts_add_link(&ERTS_LINK_ROOT(lnk), LINK_PID, BIF_ARG_1);
 
@@ -220,7 +239,7 @@ BIF_RETTYPE link_1(BIF_ALIST_1)
 		erts_smp_de_runlock(dep);
 		erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_LINK);
 
-		code = erts_dsig_send_link(&dsd, BIF_P->id, BIF_ARG_1);
+		code = erts_dsig_send_link(&dsd, BIF_P->common.id, BIF_ARG_1);
 		if (code == ERTS_DSIG_SEND_YIELD)
 		    ERTS_BIF_YIELD_RETURN(BIF_P, am_true);
 		BIF_RET(am_true);
@@ -289,7 +308,7 @@ remote_demonitor(Process *c_p, DistEntry *dep, Eterm ref, Eterm to)
 	    if (dmon)
 		erts_destroy_monitor(dmon);
 	}
-	mon = erts_remove_monitor(&c_p->monitors, ref);
+	mon = erts_remove_monitor(&ERTS_P_MONITORS(c_p), ref);
 	erts_smp_proc_unlock(c_p, ERTS_PROC_LOCK_LINK);
 
 	res = ERTS_DEMONITOR_TRUE;
@@ -298,7 +317,7 @@ remote_demonitor(Process *c_p, DistEntry *dep, Eterm ref, Eterm to)
     case ERTS_DSIG_PREP_CONNECTED:
 
 	erts_smp_de_links_lock(dep);
-	mon = erts_remove_monitor(&c_p->monitors, ref);
+	mon = erts_remove_monitor(&ERTS_P_MONITORS(c_p), ref);
 	dmon = erts_remove_monitor(&dep->monitors, ref);
 	erts_smp_de_links_unlock(dep);
 	erts_smp_de_runlock(dep);
@@ -325,7 +344,7 @@ remote_demonitor(Process *c_p, DistEntry *dep, Eterm ref, Eterm to)
 	     * the atom is stored there. Yield if necessary.
 	     */
 	    code = erts_dsig_send_demonitor(&dsd,
-					    c_p->id, 
+					    c_p->common.id, 
 					    (mon->name != NIL
 					     ? mon->name
 					     : mon->pid), 
@@ -387,7 +406,7 @@ static int demonitor(Process *c_p, Eterm ref)
        goto done; /* Cannot be this monitor's ref */
    }
 
-   mon = erts_lookup_monitor(c_p->monitors, ref);
+   mon = erts_lookup_monitor(ERTS_P_MONITORS(c_p), ref);
    if (!mon) {
        res = ERTS_DEMONITOR_FALSE;
        goto done;
@@ -426,7 +445,7 @@ static int demonitor(Process *c_p, Eterm ref)
 			      to,
 			      ERTS_PROC_LOCK_LINK,
 			      ERTS_P2P_FLG_ALLOW_OTHER_X);
-       mon = erts_remove_monitor(&c_p->monitors, ref);
+       mon = erts_remove_monitor(&ERTS_P_MONITORS(c_p), ref);
 #ifndef ERTS_SMP
        ASSERT(mon);
 #else
@@ -440,7 +459,7 @@ static int demonitor(Process *c_p, Eterm ref)
        }
        if (rp) {
 	   ErtsMonitor *rmon;
-	   rmon = erts_remove_monitor(&(rp->monitors), ref);
+	   rmon = erts_remove_monitor(&ERTS_P_MONITORS(rp), ref);
 	   if (rp != c_p)
 	       erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_LINK);
 	   if (rmon != NULL)
@@ -582,7 +601,7 @@ local_pid_monitor(Process *p, Eterm target)
 
     mon_ref = erts_make_ref(p);
     ERTS_BIF_PREP_RET(ret, mon_ref);
-    if (target == p->id) {
+    if (target == p->common.id) {
 	return ret;
     }
 
@@ -599,8 +618,8 @@ local_pid_monitor(Process *p, Eterm target)
     else {
 	ASSERT(rp != p);
 
-	erts_add_monitor(&(p->monitors), MON_ORIGIN, mon_ref, target, NIL);
-	erts_add_monitor(&(rp->monitors), MON_TARGET, mon_ref, p->id, NIL);
+	erts_add_monitor(&ERTS_P_MONITORS(p), MON_ORIGIN, mon_ref, target, NIL);
+	erts_add_monitor(&ERTS_P_MONITORS(rp), MON_TARGET, mon_ref, p->common.id, NIL);
 
 	erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_LINK);
     }
@@ -635,9 +654,9 @@ local_name_monitor(Process *p, Eterm target_name)
 	UnUseTmpHeap(3,p);
     }
     else if (rp != p) {
-	erts_add_monitor(&(p->monitors), MON_ORIGIN, mon_ref, rp->id,
+	erts_add_monitor(&ERTS_P_MONITORS(p), MON_ORIGIN, mon_ref, rp->common.id,
 			 target_name);
-	erts_add_monitor(&(rp->monitors), MON_TARGET, mon_ref, p->id,
+	erts_add_monitor(&ERTS_P_MONITORS(rp), MON_TARGET, mon_ref, p->common.id,
 			 target_name);
 	erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_LINK);
     }
@@ -689,16 +708,16 @@ remote_monitor(Process *p, Eterm bifarg1, Eterm bifarg2,
 
 	    erts_smp_de_links_lock(dep);
 
-	    erts_add_monitor(&(p->monitors), MON_ORIGIN, mon_ref, p_trgt,
+	    erts_add_monitor(&ERTS_P_MONITORS(p), MON_ORIGIN, mon_ref, p_trgt,
 			     p_name);
-	    erts_add_monitor(&(dep->monitors), MON_TARGET, mon_ref, p->id,
+	    erts_add_monitor(&(dep->monitors), MON_TARGET, mon_ref, p->common.id,
 			     d_name);
 
 	    erts_smp_de_links_unlock(dep);
 	    erts_smp_de_runlock(dep);
 	    erts_smp_proc_unlock(p, ERTS_PROC_LOCK_LINK);
 
-	    code = erts_dsig_send_monitor(&dsd, p->id, target, mon_ref);
+	    code = erts_dsig_send_monitor(&dsd, p->common.id, target, mon_ref);
 	    if (code == ERTS_DSIG_SEND_YIELD)
 		ERTS_BIF_PREP_YIELD_RETURN(ret, p, mon_ref);
 	    else
@@ -941,36 +960,39 @@ BIF_RETTYPE unlink_1(BIF_ALIST_1)
     }
 
     if (is_internal_port(BIF_ARG_1)) {
-	Port *pt = erts_id2port_sflgs(BIF_ARG_1,
-				      BIF_P,
-				      ERTS_PROC_LOCK_MAIN,
-				      ERTS_PORT_SFLGS_DEAD);
-
 	erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_LINK|ERTS_PROC_LOCK_STATUS);
 #ifdef ERTS_SMP
-	if (ERTS_PROC_PENDING_EXIT(BIF_P)) {
-	    if (pt)
-		erts_smp_port_unlock(pt);
+	if (ERTS_PROC_PENDING_EXIT(BIF_P))
 	    goto handle_pending_exit;
-	}
 #endif
 
-	l = erts_remove_link(&BIF_P->nlinks, BIF_ARG_1);
-
-	ASSERT(pt || !l);
-
-	if (pt) {
-	    rl = erts_remove_link(&pt->nlinks, BIF_P->id);
-	    erts_smp_port_unlock(pt);
-	    if (rl)
-		erts_destroy_link(rl);
-	}
+	l = erts_remove_link(&ERTS_P_LINKS(BIF_P), BIF_ARG_1);
 
 	erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_LINK|ERTS_PROC_LOCK_STATUS);
 
-	if (l)
+	if (l) {
+	    Port *prt;
+
 	    erts_destroy_link(l);
 
+	    /* Send unlink signal */
+	    prt = erts_port_lookup(BIF_ARG_1, ERTS_PORT_SFLGS_DEAD);
+	    if (prt) {
+		ErtsPortOpResult res;
+		Eterm ref;
+		Eterm *refp = erts_port_synchronous_ops ? &ref : NULL;
+#ifdef DEBUG
+		ref = NIL;
+#endif
+		res = erts_port_unlink(BIF_P, prt, BIF_P->common.id, refp);
+
+		if (refp && res == ERTS_PORT_OP_SCHEDULED) {
+		    ASSERT(is_internal_ref(ref));
+		    BIF_TRAP3(await_port_send_result_trap, BIF_P, ref, am_true, am_true);
+		}
+	    }
+	}
+
 	BIF_RET(am_true);
     }
     else if (is_external_port(BIF_ARG_1)
@@ -993,7 +1015,7 @@ BIF_RETTYPE unlink_1(BIF_ALIST_1)
 	if (ERTS_PROC_PENDING_EXIT(BIF_P))
 	    goto handle_pending_exit;
 #endif
-	l = erts_remove_link(&BIF_P->nlinks,BIF_ARG_1);
+	l = erts_remove_link(&ERTS_P_LINKS(BIF_P), BIF_ARG_1);
 
 	erts_smp_proc_unlock(BIF_P,
 			     ERTS_PROC_LOCK_LINK|ERTS_PROC_LOCK_STATUS);
@@ -1022,8 +1044,8 @@ BIF_RETTYPE unlink_1(BIF_ALIST_1)
 #endif
 
 	case ERTS_DSIG_PREP_CONNECTED:
-	    erts_remove_dist_link(&dld, BIF_P->id, BIF_ARG_1, dep);
-	    code = erts_dsig_send_unlink(&dsd, BIF_P->id, BIF_ARG_1);
+	    erts_remove_dist_link(&dld, BIF_P->common.id, BIF_ARG_1, dep);
+	    code = erts_dsig_send_unlink(&dsd, BIF_P->common.id, BIF_ARG_1);
 	    erts_destroy_dist_link(&dld);
 	    if (code == ERTS_DSIG_SEND_YIELD)
 		ERTS_BIF_YIELD_RETURN(BIF_P, am_true);
@@ -1037,10 +1059,6 @@ BIF_RETTYPE unlink_1(BIF_ALIST_1)
 
     /* Internal pid... */
 
-     /* process ok ? */
-    if (internal_pid_index(BIF_ARG_1) >= erts_max_processes)
-	BIF_ERROR(BIF_P, BADARG);
-
     erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_LINK|ERTS_PROC_LOCK_STATUS);
 
     /* get process struct */
@@ -1059,7 +1077,7 @@ BIF_RETTYPE unlink_1(BIF_ALIST_1)
 #endif
 
     /* unlink and ignore errors */
-    l = erts_remove_link(&BIF_P->nlinks,BIF_ARG_1);
+    l = erts_remove_link(&ERTS_P_LINKS(BIF_P), BIF_ARG_1);
     if (l != NULL)
 	erts_destroy_link(l);
 
@@ -1067,12 +1085,12 @@ BIF_RETTYPE unlink_1(BIF_ALIST_1)
 	ERTS_SMP_ASSERT_IS_NOT_EXITING(BIF_P);
     }
     else {
-	rl = erts_remove_link(&(rp->nlinks),BIF_P->id);
+	rl = erts_remove_link(&ERTS_P_LINKS(rp), BIF_P->common.id);
 	if (rl != NULL)
 	    erts_destroy_link(rl);
 
 	if (IS_TRACED_FL(rp, F_TRACE_PROCS) && rl != NULL) {
-	    trace_proc(BIF_P, rp, am_getting_unlinked, BIF_P->id);
+	    trace_proc(BIF_P, rp, am_getting_unlinked, BIF_P->common.id);
 	}
 
 	if (rp != BIF_P)
@@ -1345,15 +1363,28 @@ BIF_RETTYPE exit_2(BIF_ALIST_2)
       */
 
      if (is_internal_port(BIF_ARG_1)) {
-	 Port *prt;
-	 erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_MAIN);
-	 prt = erts_id2port(BIF_ARG_1, NULL, 0);
+	 Port *prt = erts_port_lookup(BIF_ARG_1, ERTS_PORT_SFLGS_INVALID_LOOKUP);
+
 	 if (prt) {
-	     erts_do_exit_port(prt, BIF_P->id, BIF_ARG_2);
-	     erts_port_release(prt);
+	     Eterm ref;
+	     Eterm *refp = erts_port_synchronous_ops ? &ref : NULL;
+	     ErtsPortOpResult res;
+
+#ifdef DEBUG
+	     ref = NIL;
+#endif
+
+	     res = erts_port_exit(BIF_P, 0, prt, BIF_P->common.id, BIF_ARG_2, refp);
+
+	     ERTS_BIF_CHK_EXITED(BIF_P);
+
+	     if (refp && res == ERTS_PORT_OP_SCHEDULED) {
+		 ASSERT(is_internal_ref(ref));
+		 BIF_TRAP3(await_port_send_result_trap, BIF_P, ref, am_true, am_true);
+	     }
+
 	 }
-	 erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_MAIN);
-	 ERTS_BIF_CHK_EXITED(BIF_P);
+
 	 BIF_RET(am_true);
      }
      else if(is_external_port(BIF_ARG_1)
@@ -1379,7 +1410,7 @@ BIF_RETTYPE exit_2(BIF_ALIST_2)
 	 case ERTS_DSIG_PREP_NOT_CONNECTED:
 	     BIF_TRAP2(dexit_trap, BIF_P, BIF_ARG_1, BIF_ARG_2);
 	 case ERTS_DSIG_PREP_CONNECTED:
-	     code = erts_dsig_send_exit2(&dsd, BIF_P->id, BIF_ARG_1, BIF_ARG_2);
+	     code = erts_dsig_send_exit2(&dsd, BIF_P->common.id, BIF_ARG_1, BIF_ARG_2);
 	     if (code == ERTS_DSIG_SEND_YIELD)
 		 ERTS_BIF_YIELD_RETURN(BIF_P, am_true);
 	     BIF_RET(am_true);
@@ -1397,9 +1428,7 @@ BIF_RETTYPE exit_2(BIF_ALIST_2)
 	  */
 	 ErtsProcLocks rp_locks;
 
-	 if (internal_pid_index(BIF_ARG_1) >= erts_max_processes)
-	     BIF_ERROR(BIF_P, BADARG);
-	 if (BIF_ARG_1 == BIF_P->id) {
+	 if (BIF_ARG_1 == BIF_P->common.id) {
 	     rp_locks = ERTS_PROC_LOCKS_ALL;
 	     rp = BIF_P;
 	     erts_smp_proc_lock(rp, ERTS_PROC_LOCKS_ALL_MINOR);
@@ -1417,7 +1446,7 @@ BIF_RETTYPE exit_2(BIF_ALIST_2)
 	  * Send an exit signal.
 	  */
 	 erts_send_exit_signal(BIF_P,
-			       BIF_P->id,
+			       BIF_P->common.id,
 			       rp,
 			       &rp_locks,
 			       BIF_ARG_2,
@@ -1519,22 +1548,24 @@ BIF_RETTYPE process_flag_2(BIF_ALIST_2)
        }
        /*
 	* NOTE: It is important that we check for pending exit signals
-	*       and handle them before flag trap_exit is set to true.
-	*       For more info, see implementation of erts_send_exit_signal().
+	*       and handle them before returning if trap_exit is set to
+	*       true. For more info, see implementation of
+	*       erts_send_exit_signal().
 	*/
-       erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_STATUS);
-       ERTS_SMP_LC_ASSERT((ERTS_PROC_LOCK_MAIN|ERTS_PROC_LOCK_STATUS)
-			  & erts_proc_lc_my_proc_locks(BIF_P));
-       ERTS_SMP_BIF_CHK_PENDING_EXIT(BIF_P,
-				     ERTS_PROC_LOCK_MAIN|ERTS_PROC_LOCK_STATUS);
        if (trap_exit)
-	   state = erts_smp_atomic32_read_bor_nob(&BIF_P->state,
-						  ERTS_PSFLG_TRAP_EXIT);
+	   state = erts_smp_atomic32_read_bor_mb(&BIF_P->state,
+						 ERTS_PSFLG_TRAP_EXIT);
        else
-	   state = erts_smp_atomic32_read_band_nob(&BIF_P->state,
-						   ~ERTS_PSFLG_TRAP_EXIT);
+	   state = erts_smp_atomic32_read_band_mb(&BIF_P->state,
+						  ~ERTS_PSFLG_TRAP_EXIT);
+#ifdef ERTS_SMP
+       if (ERTS_PROC_PENDING_EXIT(BIF_P)) {
+	   erts_handle_pending_exit(BIF_P, ERTS_PROC_LOCK_MAIN);
+	   ERTS_BIF_EXITED(BIF_P);
+       }
+#endif
+
        old_value = (state & ERTS_PSFLG_TRAP_EXIT) ? am_true : am_false;
-       erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_STATUS);
        BIF_RET(old_value);
    }
    else if (BIF_ARG_1 == am_scheduler) {
@@ -1617,11 +1648,13 @@ BIF_RETTYPE process_flag_2(BIF_ALIST_2)
 	   goto error;
        }
        erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCKS_ALL_MINOR);
-       old_value = BIF_P->trace_flags & F_SENSITIVE ? am_true : am_false;
+       old_value = (ERTS_TRACE_FLAGS(BIF_P) & F_SENSITIVE
+		    ? am_true
+		    : am_false);
        if (is_sensitive) {
-	   BIF_P->trace_flags |= F_SENSITIVE;
+	   ERTS_TRACE_FLAGS(BIF_P) |= F_SENSITIVE;
        } else {
-	   BIF_P->trace_flags &= ~F_SENSITIVE;
+	   ERTS_TRACE_FLAGS(BIF_P) &= ~F_SENSITIVE;
        }
        erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCKS_ALL_MINOR);
        BIF_RET(old_value);
@@ -1747,8 +1780,9 @@ ebif_bang_2(BIF_ALIST_2)
 #define SEND_BADARG		(-4)
 #define SEND_USER_ERROR		(-5)
 #define SEND_INTERNAL_ERROR	(-6)
+#define SEND_AWAIT_RESULT	(-7)
 
-Sint do_send(Process *p, Eterm to, Eterm msg, int suspend);
+Sint do_send(Process *p, Eterm to, Eterm msg, int suspend, Eterm *refp);
 
 static Sint remote_send(Process *p, DistEntry *dep,
 			Eterm to, Eterm full_to, Eterm msg, int suspend)
@@ -1802,7 +1836,7 @@ static Sint remote_send(Process *p, DistEntry *dep,
 }
 
 Sint
-do_send(Process *p, Eterm to, Eterm msg, int suspend) {
+do_send(Process *p, Eterm to, Eterm msg, int suspend, Eterm *refp) {
     Eterm portid;
     Port *pt;
     Process* rp;
@@ -1814,16 +1848,10 @@ do_send(Process *p, Eterm to, Eterm msg, int suspend) {
 	    trace_send(p, to, msg);
 	if (ERTS_PROC_GET_SAVED_CALLS_BUF(p))
 	    save_calls(p, &exp_send);
-	
-	if (internal_pid_index(to) >= erts_max_processes)
-	    return SEND_BADARG;
 
-	rp = erts_proc_lookup_raw(to);
-	
-	if (!rp) {
-	    ERTS_SMP_ASSERT_IS_NOT_EXITING(p);
+	rp = erts_proc_lookup_raw(to);	
+	if (!rp)
 	    return 0;
-	}
     } else if (is_external_pid(to)) {
 	dep = external_pid_dist_entry(to);
 	if(dep == erts_this_dist_entry) {
@@ -1832,7 +1860,7 @@ do_send(Process *p, Eterm to, Eterm msg, int suspend) {
 			  "Discarding message %T from %T to %T in an old "
 			  "incarnation (%d) of this node (%d)\n",
 			  msg,
-			  p->id,
+			  p->common.id,
 			  to,
 			  external_pid_creation(to),
 			  erts_this_node->creation);
@@ -1841,45 +1869,24 @@ do_send(Process *p, Eterm to, Eterm msg, int suspend) {
 	}
 	return remote_send(p, dep, to, to, msg, suspend);
     } else if (is_atom(to)) {
-	
-	/* Need to virtual schedule out sending process
-	 * because of lock wait. This is only necessary
-	 * for internal port calling but the lock is bundled
-	 * with name lookup.
-	 */
-	    
-	if (IS_TRACED_FL(p, F_TRACE_SCHED_PROCS)) {
-	    trace_virtual_sched(p, am_out);
-	}
-	if (erts_system_profile_flags.runnable_procs && erts_system_profile_flags.exclusive) {
-	    profile_runnable_proc(p, am_inactive);
-	}
-	erts_whereis_name(p, ERTS_PROC_LOCK_MAIN,
-			  to,
-			  &rp, 0, 0,
-			  &pt);
+	Eterm id = erts_whereis_name_to_id(p, to);
+
+	rp = erts_proc_lookup(id);
+	if (rp)
+	    goto send_message;
 
+	pt = erts_port_lookup(id, ERTS_PORT_SFLGS_INVALID_LOOKUP);
 	if (pt) {
-	    portid = pt->id;
+	    portid = id;
 	    goto port_common;
 	}
-	
-	/* Not a port virtually schedule the process back in */
-	if (IS_TRACED_FL(p, F_TRACE_SCHED_PROCS)) {
-	    trace_virtual_sched(p, am_in);
-	}
-	if (erts_system_profile_flags.runnable_procs && erts_system_profile_flags.exclusive) {
-	    profile_runnable_proc(p, am_active);
-	}
 
 	if (IS_TRACED(p))
 	    trace_send(p, to, msg);
 	if (ERTS_PROC_GET_SAVED_CALLS_BUF(p))
 	    save_calls(p, &exp_send);
 	
-	if (!rp) {
-	    return SEND_BADARG;
-	}
+	return SEND_BADARG;
     } else if (is_external_port(to)
 	       && (external_port_dist_entry(to)
 		   == erts_this_dist_entry)) {
@@ -1888,50 +1895,56 @@ do_send(Process *p, Eterm to, Eterm msg, int suspend) {
 		      "Discarding message %T from %T to %T in an old "
 		      "incarnation (%d) of this node (%d)\n",
 		      msg,
-		      p->id,
+		      p->common.id,
 		      to,
 		      external_port_creation(to),
 		      erts_this_node->creation);
 	erts_send_error_to_logger(p->group_leader, dsbufp);
 	return 0;
     } else if (is_internal_port(to)) {
+	int ret_val;
 	portid = to;
-	/* schedule out calling process, waiting for lock*/
-	if (IS_TRACED_FL(p, F_TRACE_SCHED_PROCS)) {
-	    trace_virtual_sched(p, am_out);
-	}
-	if (erts_system_profile_flags.runnable_procs && erts_system_profile_flags.exclusive) {
-	    profile_runnable_proc(p, am_inactive);
-	}
-	pt = erts_id2port(to, p, ERTS_PROC_LOCK_MAIN);
+
+	pt = erts_port_lookup(portid, ERTS_PORT_SFLGS_INVALID_LOOKUP);
+
       port_common:
-	ERTS_SMP_LC_ASSERT(!pt || erts_lc_is_port_locked(pt));
+	ret_val = 0;
         
-	/* We have waited for locks, trace schedule ports */
-	if (pt && IS_TRACED_FL(pt, F_TRACE_SCHED_PORTS)) {
-	    trace_sched_ports_where(pt, am_in, am_command);
-	}
-	if (pt && erts_system_profile_flags.runnable_ports && !erts_port_is_scheduled(pt)) {
-	    profile_runnable_port(pt, am_active);
-	}
-	
-	/* XXX let port_command handle the busy stuff !!! */
-	if (pt && (pt->status & ERTS_PORT_SFLG_PORT_BUSY)) {
-	    if (suspend) {
-		erts_suspend(p, ERTS_PROC_LOCK_MAIN, pt);
-		if (erts_system_monitor_flags.busy_port) {
-		    monitor_generic(p, am_busy_port, portid);
+	if (pt) {
+	    int ps_flags = suspend ? 0 : ERTS_PORT_SIG_FLG_NOSUSPEND;
+	    *refp = NIL;
+
+	    switch (erts_port_command(p, ps_flags, pt, msg, refp)) {
+	    case ERTS_PORT_OP_CALLER_EXIT:
+		/* We are exiting... */
+		return SEND_USER_ERROR;
+	    case ERTS_PORT_OP_BUSY:
+		/* Nothing has been sent */
+		if (suspend)
+		    erts_suspend(p, ERTS_PROC_LOCK_MAIN, pt);
+		return SEND_YIELD;
+	    case ERTS_PORT_OP_BUSY_SCHEDULED:
+		/* Message was sent */
+		if (suspend) {
+		    erts_suspend(p, ERTS_PROC_LOCK_MAIN, pt);
+		    ret_val = SEND_YIELD_RETURN;
+		    break;
 		}
+		/* Fall through */
+	    case ERTS_PORT_OP_SCHEDULED:
+		if (is_not_nil(*refp)) {
+		    ASSERT(is_internal_ref(*refp));
+		    ret_val = SEND_AWAIT_RESULT;
+		}
+		break;
+	    case ERTS_PORT_OP_DROPPED:
+	    case ERTS_PORT_OP_BADARG:
+	    case ERTS_PORT_OP_DONE:
+		break;
+	    default:
+		ERTS_INTERNAL_ERROR("Unexpected erts_port_command() result");
+		break;
 	    }
-	    /* Virtually schedule out the port before releasing */
-	    if (IS_TRACED_FL(pt, F_TRACE_SCHED_PORTS)) {
-	    	trace_sched_ports_where(pt, am_out, am_command);
-	    }
-	    if (erts_system_profile_flags.runnable_ports && !erts_port_is_scheduled(pt)) {
-	    	profile_runnable_port(pt, am_inactive);
-	    }
-	    erts_port_release(pt);
-	    return SEND_YIELD;
 	}
 	
 	if (IS_TRACED(p)) 	/* trace once only !! */
@@ -1949,30 +1962,11 @@ do_send(Process *p, Eterm to, Eterm msg, int suspend) {
 			     SEQ_TRACE_SEND, portid, p);
 	}	    
 	
-	/* XXX NO GC in port command */
-	erts_port_command(p, p->id, pt, msg);
-	if (pt) {
-	    /* Virtually schedule out the port before releasing */
-	    if (IS_TRACED_FL(pt, F_TRACE_SCHED_PORTS)) {
-	    	trace_sched_ports_where(pt, am_out, am_command);
-	    }
-	    if (erts_system_profile_flags.runnable_ports && !erts_port_is_scheduled(pt)) {
-	    	profile_runnable_port(pt, am_inactive);
-	    }
-	    erts_port_release(pt);
-	}
-	/* Virtually schedule in process */
-	if (IS_TRACED_FL(p, F_TRACE_SCHED_PROCS)) {
-	    trace_virtual_sched(p, am_in);
-	}
-	if (erts_system_profile_flags.runnable_procs && erts_system_profile_flags.exclusive) {
-	    profile_runnable_proc(p, am_active);
-	}
 	if (ERTS_PROC_IS_EXITING(p)) {
 	    KILL_CATCHES(p); /* Must exit */
 	    return SEND_USER_ERROR;
 	}
-	return 0;
+	return ret_val;
     } else if (is_tuple(to)) { /* Remote send */
 	int ret;
 	tp = tuple_val(to);
@@ -1988,47 +1982,24 @@ do_send(Process *p, Eterm to, Eterm msg, int suspend) {
 	dep = erts_sysname_to_connected_dist_entry(tp[2]);
 
 	if (dep == erts_this_dist_entry) {
+	    Eterm id;
 	    erts_deref_dist_entry(dep);
 	    if (IS_TRACED(p))
 		trace_send(p, to, msg);
 	    if (ERTS_PROC_GET_SAVED_CALLS_BUF(p))
 		save_calls(p, &exp_send);
-	    
-	    /* Need to virtual schedule out sending process
-	     * because of lock wait. This is only necessary
-	     * for internal port calling but the lock is bundled.
-	     */
-	    
-	    if (IS_TRACED_FL(p, F_TRACE_SCHED_PROCS)) {
-	    	trace_virtual_sched(p, am_out);
-	    }
-	    if (erts_system_profile_flags.runnable_procs && erts_system_profile_flags.exclusive) {
-	    	profile_runnable_proc(p, am_inactive);
-	    }
 
-	    erts_whereis_name(p, ERTS_PROC_LOCK_MAIN,
-			      tp[1],
-			      &rp, 0, 0,
-			      &pt);
+	    id = erts_whereis_name_to_id(p, tp[1]);
+
+	    rp = erts_proc_lookup_raw(id);
+	    if (rp)
+		goto send_message;
+	    pt = erts_port_lookup(id, ERTS_PORT_SFLGS_INVALID_LOOKUP);
 	    if (pt) {
-		portid = pt->id;
+		portid = id;
 		goto port_common;
 	    }
-	    /* Port lookup failed, virtually schedule the process
-	     * back in.
-	     */
-
-	    if (IS_TRACED_FL(p, F_TRACE_SCHED_PROCS)) {
-	    	trace_virtual_sched(p, am_in);
-	    }
-	    if (erts_system_profile_flags.runnable_procs && erts_system_profile_flags.exclusive) {
-	    	profile_runnable_proc(p, am_active);
-	    }
-
-	    if (!rp) {
-		return 0;
-	    }
-	    goto send_message;
+	    return 0;
 	}
 
 	ret = remote_send(p, dep, tp[1], to, msg, suspend);
@@ -2067,6 +2038,7 @@ do_send(Process *p, Eterm to, Eterm msg, int suspend) {
 
 BIF_RETTYPE send_3(BIF_ALIST_3)
 {
+    Eterm ref;
     Process *p = BIF_P;
     Eterm to = BIF_ARG_1;
     Eterm msg = BIF_ARG_2;
@@ -2090,12 +2062,18 @@ BIF_RETTYPE send_3(BIF_ALIST_3)
     if(!is_nil(l)) {
 	BIF_ERROR(p, BADARG);
     }
-    
-    result = do_send(p, to, msg, suspend);
+
+#ifdef DEBUG
+    ref = NIL;
+#endif
+
+    result = do_send(p, to, msg, suspend, &ref);
     if (result > 0) {
 	ERTS_VBUMP_REDS(p, result);
 	BIF_RET(am_ok);
-    } else switch (result) {
+    }
+
+    switch (result) {
     case 0:
 	BIF_RET(am_ok); 
 	break;
@@ -2118,6 +2096,9 @@ BIF_RETTYPE send_3(BIF_ALIST_3)
 	    ERTS_BIF_YIELD_RETURN(p, am_ok);
 	else
 	    BIF_RET(am_nosuspend);
+    case SEND_AWAIT_RESULT:
+	ASSERT(is_internal_ref(ref));
+	BIF_TRAP3(await_port_send_result_trap, p, ref, am_nosuspend, am_ok);
     case SEND_BADARG:
 	BIF_ERROR(p, BADARG); 
 	break;
@@ -2142,12 +2123,21 @@ BIF_RETTYPE send_2(BIF_ALIST_2)
 
 Eterm erl_send(Process *p, Eterm to, Eterm msg)
 {
-    Sint result = do_send(p, to, msg, !0);
+    Eterm ref;
+    Sint result;
+
+#ifdef DEBUG
+    ref = NIL;
+#endif
+
+    result = do_send(p, to, msg, !0, &ref);
     
     if (result > 0) {
 	ERTS_VBUMP_REDS(p, result);
 	BIF_RET(msg);
-    } else switch (result) {
+    }
+
+    switch (result) {
     case 0:
 	BIF_RET(msg); 
 	break;
@@ -2159,6 +2149,9 @@ Eterm erl_send(Process *p, Eterm to, Eterm msg)
 	break;
     case SEND_YIELD_RETURN:
 	ERTS_BIF_YIELD_RETURN(p, msg);
+    case SEND_AWAIT_RESULT:
+	ASSERT(is_internal_ref(ref));
+	BIF_TRAP3(await_port_send_result_trap, p, ref, msg, msg);
     case SEND_BADARG:
 	BIF_ERROR(p, BADARG); 
 	break;
@@ -3126,7 +3119,7 @@ BIF_RETTYPE list_to_tuple_1(BIF_ALIST_1)
 
 BIF_RETTYPE self_0(BIF_ALIST_0)
 {
-     BIF_RET(BIF_P->id);
+     BIF_RET(BIF_P->common.id);
 }
 
 /**********************************************************************/
@@ -3163,11 +3156,9 @@ static erts_smp_spinlock_t make_ref_lock;
 static erts_smp_mtx_t ports_snapshot_mtx;
 erts_smp_atomic_t erts_dead_ports_ptr; /* To store dying ports during snapshot */
 
-Eterm erts_make_ref_in_buffer(Eterm buffer[REF_THING_SIZE])
+void
+erts_make_ref_in_array(Uint32 ref[ERTS_MAX_REF_NUMBERS])
 {
-    Eterm* hp = buffer;
-    Uint32 ref0, ref1, ref2;
-
     erts_smp_spin_lock(&make_ref_lock);
 
     reference0++;
@@ -3179,24 +3170,36 @@ Eterm erts_make_ref_in_buffer(Eterm buffer[REF_THING_SIZE])
 	}
     }
 
-    ref0 = reference0;
-    ref1 = reference1;
-    ref2 = reference2;
+    ref[0] = reference0;
+    ref[1] = reference1;
+    ref[2] = reference2;
 
     erts_smp_spin_unlock(&make_ref_lock);
+}
+
+Eterm erts_make_ref_in_buffer(Eterm buffer[REF_THING_SIZE])
+{
+    Eterm* hp = buffer;
+    Uint32 ref[ERTS_MAX_REF_NUMBERS];
 
-    write_ref_thing(hp, ref0, ref1, ref2);
+    erts_make_ref_in_array(ref);
+    write_ref_thing(hp, ref[0], ref[1], ref[2]);
     return make_internal_ref(hp);
 }
 
 Eterm erts_make_ref(Process *p)
 {
     Eterm* hp;
+    Uint32 ref[ERTS_MAX_REF_NUMBERS];
 
     ERTS_SMP_LC_ASSERT(ERTS_PROC_LOCK_MAIN & erts_proc_lc_my_proc_locks(p));
 
     hp = HAlloc(p, REF_THING_SIZE);
-    return erts_make_ref_in_buffer(hp);
+
+    erts_make_ref_in_array(ref);
+    write_ref_thing(hp, ref[0], ref[1], ref[2]);
+
+    return make_internal_ref(hp);
 }
 
 BIF_RETTYPE make_ref_0(BIF_ALIST_0)
@@ -3460,7 +3463,7 @@ BIF_RETTYPE garbage_collect_1(BIF_ALIST_1)
 	BIF_ERROR(BIF_P, BADARG);
     }
 
-    if (BIF_P->id == BIF_ARG_1)
+    if (BIF_P->common.id == BIF_ARG_1)
 	rp = BIF_P;
     else {
 #ifdef ERTS_SMP
@@ -3500,71 +3503,23 @@ BIF_RETTYPE garbage_collect_0(BIF_ALIST_0)
 }
 
 /**********************************************************************/
-/* Return a list of active ports */
+/*
+ * The erlang:processes/0 BIF.
+ */
 
-BIF_RETTYPE ports_0(BIF_ALIST_0)
+BIF_RETTYPE processes_0(BIF_ALIST_0)
 {
-    Eterm res = NIL;
-    Eterm* port_buf = erts_alloc(ERTS_ALC_T_TMP,
-				 sizeof(Eterm)*erts_max_ports);
-    Eterm* pp = port_buf;
-    Eterm* dead_ports;
-    int alive, dead;
-    Uint32 next_ss;
-    int i;
-
-    /* To get a consistent snapshot... 
-     * We add alive ports from start of the buffer
-     * while dying ports are added from the other end by the killing threads.
-     */
-
-    erts_smp_mtx_lock(&ports_snapshot_mtx); /* One snapshot at a time */
-
-    erts_smp_atomic_set_nob(&erts_dead_ports_ptr,
-			    (erts_aint_t) (port_buf + erts_max_ports));
-
-    next_ss = erts_smp_atomic32_inc_read_relb(&erts_ports_snapshot);
-
-    for (i = erts_max_ports-1; i >= 0; i--) {
-	Port* prt = &erts_port[i];
-	erts_smp_port_state_lock(prt);
-	if (!(prt->status & ERTS_PORT_SFLGS_DEAD)
-	    && prt->snapshot != next_ss) {
-	    ASSERT(prt->snapshot == next_ss - 1);
-	    *pp++ = prt->id;		
-	    prt->snapshot = next_ss; /* Consumed by this snapshot */
-	}
-	erts_smp_port_state_unlock(prt);
-    }
-
-    dead_ports = (Eterm*)erts_smp_atomic_xchg_nob(&erts_dead_ports_ptr,
-						  (erts_aint_t) NULL);
-    erts_smp_mtx_unlock(&ports_snapshot_mtx);
-
-    ASSERT(pp <= dead_ports);
-
-    alive = pp - port_buf;
-    dead = port_buf + erts_max_ports - dead_ports;
-
-    ASSERT((alive+dead) <= erts_max_ports);
-
-    if (alive+dead > 0) {
-	erts_aint_t i;
-	Eterm *hp = HAlloc(BIF_P, (alive+dead)*2);
-
-	for (i = 0; i < alive; i++) {
-	    res = CONS(hp, port_buf[i], res);	    
-	    hp += 2;
-	}
-	for (i = 0; i < dead; i++) {
-	    res = CONS(hp, dead_ports[i], res);
-	    hp += 2;
-	}
-    }
+    return erts_ptab_list(BIF_P, &erts_proc);
+}
 
-    erts_free(ERTS_ALC_T_TMP, port_buf);
+/**********************************************************************/
+/*
+ * The erlang:ports/0 BIF.
+ */
 
-    BIF_RET(res);
+BIF_RETTYPE ports_0(BIF_ALIST_0)
+{
+    return erts_ptab_list(BIF_P, &erts_port);
 }
 
 /**********************************************************************/
@@ -4194,12 +4149,13 @@ BIF_RETTYPE system_flag_2(BIF_ALIST_2)
 	    BIF_RET(old_value);
 	}
     } else if (BIF_ARG_1 == make_small(1)) {
-	Uint i;
+	int i, max;
 	ErlMessage* mp;
 	erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_MAIN);
 	erts_smp_thr_progress_block();
 
-	for (i = 0; i < erts_max_processes; i++) {
+	max = erts_ptab_max(&erts_proc);
+	for (i = 0; i < max; i++) {
 	    Process *p = erts_pix2proc(i);
 	    if (p) {
 #ifdef USE_VM_PROBES
@@ -4546,6 +4502,8 @@ void erts_init_bif(void)
 						    am_format_cpu_topology,
 						    1);
     await_proc_exit_trap = erts_export_put(am_erlang,am_await_proc_exit,3);
+    await_port_send_result_trap
+	= erts_export_put(am_erts_internal, am_await_port_send_result, 3);
     await_sched_wall_time_mod_trap
 	= erts_export_put(am_erlang, am_await_sched_wall_time_modifications, 2);
     erts_smp_atomic32_init_nob(&sched_wall_time, 0);
@@ -4561,19 +4519,18 @@ bif erlang:send_to_logger/2
 BIF_RETTYPE send_to_logger_2(BIF_ALIST_2)
 {
     byte *buf;
-    int len;
+    ErlDrvSizeT len;
     if (!is_atom(BIF_ARG_1) || !(is_list(BIF_ARG_2) ||
 				 is_nil(BIF_ARG_1))) {
 	BIF_ERROR(BIF_P,BADARG);
     }
-    len = io_list_len(BIF_ARG_2);
-    if (len < 0)
+    if (erts_iolist_size(BIF_ARG_2, &len) != 0)
 	BIF_ERROR(BIF_P,BADARG);
     else if (len == 0)
 	buf = "";
     else {
 #ifdef DEBUG
-	int len2;
+	ErlDrvSizeT len2;
 #endif
 	buf = (byte *) erts_alloc(ERTS_ALC_T_TMP, len+1);
 #ifdef DEBUG
@@ -4581,7 +4538,7 @@ BIF_RETTYPE send_to_logger_2(BIF_ALIST_2)
 #else
 	(void)
 #endif
-	    io_list_to_buf(BIF_ARG_2, buf, len);
+	    erts_iolist_to_buf(BIF_ARG_2, buf, len);
 	ASSERT(len2 == len);
 	buf[len] = '\0';
 	switch (BIF_ARG_1) {
@@ -4675,7 +4632,6 @@ BIF_RETTYPE dt_prepend_vm_tag_data_1(BIF_ALIST_1)
 #ifdef USE_VM_PROBES
     Eterm b; 
     Eterm *hp;
-    hp = HAlloc(BIF_P,2);
     if (is_binary((DT_UTAG(BIF_P)))) {
 	Uint sz = binary_size(DT_UTAG(BIF_P));
 	int i;
@@ -4692,6 +4648,7 @@ BIF_RETTYPE dt_prepend_vm_tag_data_1(BIF_ALIST_1)
     } else {
 	b = new_binary(BIF_P,(byte *)"\0",1);
     }
+    hp = HAlloc(BIF_P,2);
     BIF_RET(CONS(hp,b,BIF_ARG_1));
 #else
     BIF_RET(BIF_ARG_1);
@@ -4702,7 +4659,6 @@ BIF_RETTYPE dt_append_vm_tag_data_1(BIF_ALIST_1)
 #ifdef USE_VM_PROBES
     Eterm b; 
     Eterm *hp;
-    hp = HAlloc(BIF_P,2);
     if (is_binary((DT_UTAG(BIF_P)))) {
 	Uint sz = binary_size(DT_UTAG(BIF_P));
 	int i;
@@ -4719,6 +4675,7 @@ BIF_RETTYPE dt_append_vm_tag_data_1(BIF_ALIST_1)
     } else {
 	b = new_binary(BIF_P,(byte *)"\0",1);
     }
+    hp = HAlloc(BIF_P,2);
     BIF_RET(CONS(hp,BIF_ARG_1,b));
 #else
     BIF_RET(BIF_ARG_1);
@@ -4742,14 +4699,14 @@ BIF_RETTYPE dt_spread_tag_1(BIF_ALIST_1)
 #ifdef DTRACE_TAG_HARDDEBUG
 	    erts_fprintf(stderr,
 			 "Dtrace -> (%T) start spreading tag %T\r\n",
-			 BIF_P->id,DT_UTAG(BIF_P));
+			 BIF_P->common.id,DT_UTAG(BIF_P));
 #endif
 	} else {
 	    DT_UTAG_FLAGS(BIF_P) &= ~DT_UTAG_SPREADING;
 #ifdef DTRACE_TAG_HARDDEBUG
 	    erts_fprintf(stderr,
 			 "Dtrace -> (%T) stop spreading tag %T\r\n",
-			 BIF_P->id,DT_UTAG(BIF_P));
+			 BIF_P->common.id,DT_UTAG(BIF_P));
 #endif
 	}
     }
@@ -4775,7 +4732,7 @@ BIF_RETTYPE dt_restore_tag_1(BIF_ALIST_1)
 #ifdef DTRACE_TAG_HARDDEBUG
 	    erts_fprintf(stderr,
 			 "Dtrace -> (%T) restore Killing tag!\r\n",
-			 BIF_P->id);
+			 BIF_P->common.id);
 #endif
 	}
 	DT_UTAG(BIF_P) = NIL;
@@ -4792,12 +4749,12 @@ BIF_RETTYPE dt_restore_tag_1(BIF_ALIST_1)
 	    erts_fprintf(stderr,
 			 "Dtrace -> (%T) restore stop spreading "
 			 "tag %T\r\n",
-			 BIF_P->id, tpl[2]);
+			 BIF_P->common.id, tpl[2]);
 	} else if ((x & DT_UTAG_SPREADING) && 
 		   !(DT_UTAG_FLAGS(BIF_P) & DT_UTAG_SPREADING)) {
 	    erts_fprintf(stderr,
 			 "Dtrace -> (%T) restore start spreading "
-			 "tag %T\r\n",BIF_P->id,tpl[2]);
+			 "tag %T\r\n",BIF_P->common.id,tpl[2]);
 	}
 #endif
 	DT_UTAG_FLAGS(BIF_P) = x;
diff --git a/erts/emulator/beam/bif.h b/erts/emulator/beam/bif.h
index 7cb2c78815..71f232035d 100644
--- a/erts/emulator/beam/bif.h
+++ b/erts/emulator/beam/bif.h
@@ -322,27 +322,6 @@ do {					\
 	ERTS_BIF_EXITED((PROC));	\
 } while (0)
 
-#ifdef ERTS_SMP
-#define ERTS_SMP_BIF_CHK_PENDING_EXIT(P, L)				\
-do {									\
-    ERTS_SMP_LC_ASSERT((L) == erts_proc_lc_my_proc_locks((P)));		\
-    ERTS_SMP_LC_ASSERT(ERTS_PROC_LOCK_MAIN & (L));			\
-    if (!((L) & ERTS_PROC_LOCK_STATUS))					\
-	erts_smp_proc_lock((P), ERTS_PROC_LOCK_STATUS);			\
-    if (ERTS_PROC_PENDING_EXIT((P))) {					\
-	erts_handle_pending_exit((P), (L)|ERTS_PROC_LOCK_STATUS);	\
-	erts_smp_proc_unlock((P),					\
-			     (((L)|ERTS_PROC_LOCK_STATUS)		\
-			      & ~ERTS_PROC_LOCK_MAIN));			\
-	ERTS_BIF_EXITED((P));						\
-    }									\
-    if (!((L) & ERTS_PROC_LOCK_STATUS))					\
-	erts_smp_proc_unlock((P), ERTS_PROC_LOCK_STATUS);		\
-} while (0)
-#else
-#define ERTS_SMP_BIF_CHK_PENDING_EXIT(P, L)
-#endif
-
 /*
  * The ERTS_BIF_*_AWAIT_X_*_TRAP makros either exits the caller, or
  * sets up a trap to erlang:await_proc_exit/3.
diff --git a/erts/emulator/beam/bif.tab b/erts/emulator/beam/bif.tab
index f7dad2767f..9a1a25031c 100644
--- a/erts/emulator/beam/bif.tab
+++ b/erts/emulator/beam/bif.tab
@@ -180,10 +180,6 @@ bif 'erl.lang.port':open/2		ebif_open_port_2 open_port_2
 
 bif erlang:pid_to_list/1
 bif 'erl.lang.proc':pid_to_string/1	ebif_pid_to_string_1 pid_to_list_1
-bif erlang:port_info/1
-bif 'erl.lang.port':info/1		ebif_port_info_1
-bif erlang:port_info/2
-bif 'erl.lang.port':info/2		ebif_port_info_2
 bif erlang:ports/0
 bif 'erl.lang.node':ports/0		ebif_ports_0
 bif erlang:pre_loaded/0
@@ -252,24 +248,16 @@ bif erlang:setnode/2
 bif erlang:setnode/3
 bif erlang:dist_exit/3
 
-bif erlang:port_call/2
-bif 'erl.lang.port':call/2		ebif_port_call_2
-bif erlang:port_call/3
-bif 'erl.lang.port':call/3		ebif_port_call_3
-bif erlang:port_command/2
-bif 'erl.lang.port':command/2		ebif_port_command_2
-bif erlang:port_command/3
-bif 'erl.lang.port':command/3		ebif_port_command_3
-bif erlang:port_control/3
-bif 'erl.lang.port':control/3		ebif_port_control_3
-bif erlang:port_close/1
-bif 'erl.lang.port':close/1		ebif_port_close_1
-bif erlang:port_connect/2
-bif 'erl.lang.port':connect/2		ebif_port_connect_2
-bif erlang:port_set_data/2
-bif 'erl.lang.port':set_data/2		ebif_port_set_data_2
-bif erlang:port_get_data/1
-bif 'erl.lang.port':get_data/1		ebif_port_get_data_1
+# Static native functions in erts_internal
+bif erts_internal:port_info/1
+bif erts_internal:port_info/2
+bif erts_internal:port_call/3
+bif erts_internal:port_command/3
+bif erts_internal:port_control/3
+bif erts_internal:port_close/1
+bif erts_internal:port_connect/2
+bif erts_internal:port_set_data/2
+bif erts_internal:port_get_data/1
 
 # Tracing & debugging.
 bif erlang:trace_pattern/2
diff --git a/erts/emulator/beam/binary.c b/erts/emulator/beam/binary.c
index 3d2725e239..4441dab181 100644
--- a/erts/emulator/beam/binary.c
+++ b/erts/emulator/beam/binary.c
@@ -355,10 +355,10 @@ BIF_RETTYPE bitstring_to_list_1(BIF_ALIST_1)
 BIF_RETTYPE erts_list_to_binary_bif(Process *p, Eterm arg)
 {
     Eterm bin;
-    Uint size;
+    ErlDrvSizeT size;
     byte* bytes;
 #ifdef DEBUG
-    int offset;
+    ErlDrvSizeT offset;
 #endif
 
     if (is_nil(arg)) {
@@ -377,7 +377,7 @@ BIF_RETTYPE erts_list_to_binary_bif(Process *p, Eterm arg)
 #ifdef DEBUG
     offset = 
 #endif
-	io_list_to_buf(arg, (char*) bytes, size);
+	erts_iolist_to_buf(arg, (char*) bytes, size);
 
     ASSERT(offset == 0);
     BIF_RET(bin);
diff --git a/erts/emulator/beam/break.c b/erts/emulator/beam/break.c
index c1e9fe536d..9aa1e5f30d 100644
--- a/erts/emulator/beam/break.c
+++ b/erts/emulator/beam/break.c
@@ -61,16 +61,19 @@ extern char* erts_system_version[];
 static void
 port_info(int to, void *to_arg)
 {
-    int i;
-    for (i = 0; i < erts_max_ports; i++)
-	print_port_info(to, to_arg, i);
+    int i, max = erts_ptab_max(&erts_port);
+    for (i = 0; i < max; i++) {
+	Port *p = erts_pix2port(i);
+	if (p)
+	    print_port_info(p, to, to_arg);
+    }
 }
 
 void
 process_info(int to, void *to_arg)
 {
-    int i;
-    for (i = 0; i < erts_max_processes; i++) {
+    int i, max = erts_ptab_max(&erts_proc);
+    for (i = 0; i < max; i++) {
 	Process *p = erts_pix2proc(i);
 	if (p && p->i != ENULL) {
 	    if (!ERTS_PROC_IS_EXITING(p))
@@ -84,12 +87,12 @@ process_info(int to, void *to_arg)
 static void
 process_killer(void)
 {
-    int i, j;
+    int i, j, max = erts_ptab_max(&erts_proc);
     Process* rp;
 
     erts_printf("\n\nProcess Information\n\n");
     erts_printf("--------------------------------------------------\n");
-    for (i = erts_max_processes-1; i >= 0; i--) {
+    for (i = max-1; i >= 0; i--) {
 	rp = erts_pix2proc(i);
 	if (rp && rp->i != ENULL) {
 	    int br;
@@ -196,7 +199,7 @@ print_process_info(int to, void *to_arg, Process *p)
     erts_aint32_t state;
 
     /* display the PID */
-    erts_print(to, to_arg, "=proc:%T\n", p->id);
+    erts_print(to, to_arg, "=proc:%T\n", p->common.id);
 
     /* Display the state */
     erts_print(to, to_arg, "State: ");
@@ -226,8 +229,8 @@ print_process_info(int to, void *to_arg, Process *p)
      * If the process is registered as a global process, display the
      * registered name
      */
-    if (p->reg != NULL)
-	erts_print(to, to_arg, "Name: %T\n", p->reg->name);
+    if (p->common.u.alive.reg)
+	erts_print(to, to_arg, "Name: %T\n", p->common.u.alive.reg->name);
 
     /*
      * Display the initial function name
@@ -301,11 +304,11 @@ print_process_info(int to, void *to_arg, Process *p)
     }
 
     /* display the links only if there are any*/
-    if (p->nlinks != NULL || p->monitors != NULL) {
+    if (ERTS_P_LINKS(p) || ERTS_P_MONITORS(p)) {
 	PrintMonitorContext context = {1,to}; 
 	erts_print(to, to_arg,"Link list: [");
-	erts_doforall_links(p->nlinks, &doit_print_link, &context);	
-	erts_doforall_monitors(p->monitors, &doit_print_monitor, &context);
+	erts_doforall_links(ERTS_P_LINKS(p), &doit_print_link, &context);	
+	erts_doforall_monitors(ERTS_P_MONITORS(p), &doit_print_monitor, &context);
 	erts_print(to, to_arg,"]\n");
     }
 
@@ -625,9 +628,9 @@ bin_check(void)
 {
     Process  *rp;
     struct erl_off_heap_header* hdr;
-    int i, printed = 0;
+    int i, printed = 0, max = erts_ptab_max(&erts_proc);
 
-    for (i=0; i < erts_max_processes; i++) {
+    for (i=0; i < max; i++) {
 	rp = erts_pix2proc(i);
 	if (!rp)
 	    continue;
@@ -635,7 +638,7 @@ bin_check(void)
 	    if (hdr->thing_word == HEADER_PROC_BIN) {
 		ProcBin *bp = (ProcBin*) hdr;
 		if (!printed) {
-		    erts_printf("Process %T holding binary data \n", rp->id);
+		    erts_printf("Process %T holding binary data \n", rp->common.id);
 		    printed = 1;
 		}
 		erts_printf("%p orig_size: %bpd, norefs = %bpd\n",
@@ -766,7 +769,7 @@ erl_crash_dump_v(char *file, int line, char* fmt, va_list args)
     erts_print_nif_taints(fd, NULL);
     erts_fdprintf(fd, "Atoms: %d\n", atom_table_size());
     info(fd, NULL); /* General system info */
-    if (erts_proc.tab)
+    if (erts_ptab_initialized(&erts_proc))
 	process_info(fd, NULL); /* Info about each process and port */
     db_info(fd, NULL, 0);
     erts_print_bif_timer_info(fd, NULL);
diff --git a/erts/emulator/beam/copy.c b/erts/emulator/beam/copy.c
index 36eda04de2..23c0fca6aa 100644
--- a/erts/emulator/beam/copy.c
+++ b/erts/emulator/beam/copy.c
@@ -47,7 +47,7 @@ copy_object(Eterm obj, Process* to)
     if (DTRACE_ENABLED(copy_object)) {
         DTRACE_CHARBUF(proc_name, 64);
 
-        erts_snprintf(proc_name, sizeof(proc_name), "%T", to->id);
+        erts_snprintf(proc_name, sizeof(proc_name), "%T", to->common.id);
         DTRACE2(copy_object, proc_name, size);
     }
 #endif
diff --git a/erts/emulator/beam/dist.c b/erts/emulator/beam/dist.c
index 28c4621ff2..f169a1a34a 100644
--- a/erts/emulator/beam/dist.c
+++ b/erts/emulator/beam/dist.c
@@ -124,6 +124,13 @@ static void send_nodes_mon_msgs(Process *, Eterm, Eterm, Eterm, Eterm);
 static void init_nodes_monitors(void);
 
 static erts_smp_atomic_t no_caches;
+static erts_smp_atomic_t no_nodes;
+
+struct {
+    Eterm reason;
+    ErlHeapFragment *bp;
+} nodedown;
+
 
 static void
 delete_cache(ErtsAtomCache *cache)
@@ -144,7 +151,7 @@ create_cache(DistEntry *dep)
 
     ERTS_SMP_LC_ASSERT(
 	is_internal_port(dep->cid)
-	&& erts_lc_is_port_locked(&erts_port[internal_port_index(dep->cid)]));
+	&& erts_lc_is_port_locked(erts_port_lookup_raw(dep->cid)));
     ASSERT(!dep->cache);
 
     dep->cache = cp = (ErtsAtomCache*) erts_alloc(ERTS_ALC_T_DCACHE,
@@ -171,11 +178,10 @@ get_suspended_on_de(DistEntry *dep, Uint32 unset_qflgs)
 	return NULL;
     }
     else {
-	ErtsProcList *plp;
-	plp = dep->suspended.first;
-	dep->suspended.first = NULL;
-	dep->suspended.last = NULL;
-	return plp;
+	ErtsProcList *suspended = dep->suspended;
+	dep->suspended = NULL;
+	erts_proclist_fetch(&suspended, NULL);
+	return suspended;
     }
 }
 
@@ -252,7 +258,7 @@ static void doit_monitor_net_exits(ErtsMonitor *mon, void *vnecp)
 
     if (mon->type == MON_ORIGIN) {
 	/* local pid is beeing monitored */
-	rmon = erts_remove_monitor(&(rp->monitors),mon->ref);
+	rmon = erts_remove_monitor(&ERTS_P_MONITORS(rp), mon->ref);
 	/* ASSERT(rmon != NULL); nope, can happen during process exit */
 	if (rmon != NULL) {
 	    erts_destroy_monitor(rmon);
@@ -262,7 +268,7 @@ static void doit_monitor_net_exits(ErtsMonitor *mon, void *vnecp)
 	Eterm watched;
 	UseTmpHeapNoproc(3);
 	ASSERT(mon->type == MON_TARGET);
-	rmon = erts_remove_monitor(&(rp->monitors),mon->ref);
+	rmon = erts_remove_monitor(&ERTS_P_MONITORS(rp), mon->ref);
 	/* ASSERT(rmon != NULL); can happen during process exit */
 	if (rmon != NULL) {
 	    ASSERT(is_atom(rmon->name) || is_nil(rmon->name));
@@ -311,7 +317,7 @@ static void doit_link_net_exits_sub(ErtsLink *sublnk, void *vlnecp)
 	    goto done;
 	}
 
-	rlnk = erts_remove_link(&(rp->nlinks), sublnk->pid);
+	rlnk = erts_remove_link(&ERTS_P_LINKS(rp), sublnk->pid);
 	xres = erts_send_exit_signal(NULL,
 				     sublnk->pid,
 				     rp,
@@ -370,7 +376,7 @@ static void doit_node_link_net_exits(ErtsLink *lnk, void *vnecp)
 	if (!rp) {
 	    goto done;
 	}
-	rlnk = erts_remove_link(&(rp->nlinks), name);
+	rlnk = erts_remove_link(&ERTS_P_LINKS(rp), name);
 	if (rlnk != NULL) {
 	    ASSERT(is_atom(rlnk->pid) && (rlnk->type == LINK_NODE));
 	    erts_destroy_link(rlnk);
@@ -394,6 +400,47 @@ static void doit_node_link_net_exits(ErtsLink *lnk, void *vnecp)
     erts_destroy_link(lnk);
 }
 
+static void
+set_node_not_alive(void *unused)
+{
+    ErlHeapFragment *bp;
+    Eterm nodename = erts_this_dist_entry->sysname;
+
+    ASSERT(erts_smp_atomic_read_nob(&no_nodes) == 0);
+
+    erts_smp_thr_progress_block();
+    erts_set_this_node(am_Noname, 0);
+    erts_is_alive = 0;
+    send_nodes_mon_msgs(NULL, am_nodedown, nodename, am_visible, nodedown.reason);
+    nodedown.reason = NIL;
+    bp = nodedown.bp;
+    nodedown.bp = NULL;
+    erts_smp_thr_progress_unblock();
+    if (bp)
+	free_message_buffer(bp);
+}
+
+static ERTS_INLINE void
+dec_no_nodes(void)
+{
+    erts_aint_t no = erts_smp_atomic_dec_read_mb(&no_nodes);
+    ASSERT(no >= 0);
+    ASSERT(erts_get_scheduler_id()); /* Need to be a scheduler */
+    if (no == 0)
+	erts_schedule_misc_aux_work(erts_get_scheduler_id(),
+				    set_node_not_alive,
+				    NULL);
+}
+
+static ERTS_INLINE void
+inc_no_nodes(void)
+{
+#ifdef DEBUG
+    erts_aint_t no = erts_smp_atomic_read_nob(&no_nodes);
+    ASSERT(erts_is_alive ? no > 0 : no == 0);
+#endif
+    erts_smp_atomic_inc_mb(&no_nodes);
+}
 	
 /*
  * proc is currently running or exiting process.
@@ -403,47 +450,76 @@ int erts_do_net_exits(DistEntry *dep, Eterm reason)
     Eterm nodename;
 
     if (dep == erts_this_dist_entry) {  /* Net kernel has died (clean up!!) */
+	DistEntry *tdep;
+	int no_dist_port = 0;
 	Eterm nd_reason = (reason == am_no_network
 			   ? am_no_network
 			   : am_net_kernel_terminated);
 	erts_smp_rwmtx_rwlock(&erts_dist_table_rwmtx);
 
+	for (tdep = erts_hidden_dist_entries; tdep; tdep = tdep->next)
+	    no_dist_port++;
+	for (tdep = erts_visible_dist_entries; tdep; tdep = tdep->next)
+	    no_dist_port++;
+
 	/* KILL all port controllers */
-	while(erts_visible_dist_entries || erts_hidden_dist_entries) {
-	    DistEntry *tdep;
-	    Eterm prt_id;
-	    Port *prt;
-	    if(erts_hidden_dist_entries)
-		tdep = erts_hidden_dist_entries;
-	    else
-		tdep = erts_visible_dist_entries;
-	    prt_id = tdep->cid;
-	    ASSERT(is_internal_port(prt_id));
+	if (no_dist_port == 0)
 	    erts_smp_rwmtx_rwunlock(&erts_dist_table_rwmtx);
+	else {
+	    Eterm def_buf[128];
+	    int i = 0;
+	    Eterm *dist_port;
 
-	    prt = erts_id2port(prt_id, NULL, 0);
-	    if (prt) {
-		ASSERT(prt->status & ERTS_PORT_SFLG_DISTRIBUTION);
-		ASSERT(prt->dist_entry);
-		/* will call do_net_exists !!! */
-		erts_do_exit_port(prt, prt_id, nd_reason);
-		erts_port_release(prt);
+	    if (no_dist_port <= sizeof(def_buf)/sizeof(def_buf[0]))
+		dist_port = &def_buf[0];
+	    else
+		dist_port = erts_alloc(ERTS_ALC_T_TMP,
+				       sizeof(Eterm)*no_dist_port);
+	    for (tdep = erts_hidden_dist_entries; tdep; tdep = tdep->next) {
+		ASSERT(is_internal_port(tdep->cid));
+		dist_port[i++] = tdep->cid;
+	    }
+	    for (tdep = erts_visible_dist_entries; tdep; tdep = tdep->next) {
+		ASSERT(is_internal_port(tdep->cid));
+		dist_port[i++] = tdep->cid;
 	    }
+	    erts_smp_rwmtx_rwunlock(&erts_dist_table_rwmtx);
 
-	    erts_smp_rwmtx_rwlock(&erts_dist_table_rwmtx);
-	}
+	    for (i = 0; i < no_dist_port; i++) {
+		Port *prt = erts_port_lookup(dist_port[i],
+					     ERTS_PORT_SFLGS_INVALID_LOOKUP);
+		if (!prt)
+		    continue;
+		ASSERT(erts_atomic32_read_nob(&prt->state)
+		       & ERTS_PORT_SFLG_DISTRIBUTION);
 
-	erts_smp_rwmtx_rwunlock(&erts_dist_table_rwmtx);
+		erts_port_exit(NULL, ERTS_PORT_SIG_FLG_FORCE_SCHED,
+			       prt, dist_port[i], nd_reason, NULL);
+	    }
 
-	nodename = erts_this_dist_entry->sysname;
-	erts_smp_thr_progress_block();
-	erts_set_this_node(am_Noname, 0);
-	erts_is_alive = 0;
-	send_nodes_mon_msgs(NULL, am_nodedown, nodename, am_visible, nd_reason);
-	erts_smp_thr_progress_unblock();
+	    if (dist_port != &def_buf[0])
+		erts_free(ERTS_ALC_T_TMP, dist_port);
+	}
 
+	/*
+	 * When last dist port exits, node will be taken
+	 * from alive to not alive.
+	 */
+	ASSERT(is_nil(nodedown.reason) && !nodedown.bp);
+	if (is_immed(nd_reason))
+	    nodedown.reason = nd_reason;
+	else {
+	    Eterm *hp;
+	    Uint sz = size_object(nd_reason);
+	    nodedown.bp = new_message_buffer(sz);
+	    hp = nodedown.bp->mem;
+	    nodedown.reason = copy_struct(nd_reason,
+					  sz,
+					  &hp,
+					  &nodedown.bp->off_heap);
+	}
     }
-    else { /* recursive call via erts_do_exit_port() will end up here */
+    else { /* Call from distribution port */
 	NetExitsContext nec = {dep};
 	ErtsLink *nlinks;
 	ErtsLink *node_links;
@@ -454,10 +530,10 @@ int erts_do_net_exits(DistEntry *dep, Eterm reason)
 	erts_smp_de_rwlock(dep);
 
 	ERTS_SMP_LC_ASSERT(is_internal_port(dep->cid)
-			   && erts_lc_is_port_locked(&erts_port[internal_port_index(dep->cid)]));
+			   && erts_lc_is_port_locked(erts_port_lookup_raw(dep->cid)));
 
 	if (erts_port_task_is_scheduled(&dep->dist_cmd))
-	    erts_port_task_abort(dep->cid, &dep->dist_cmd);
+	    erts_port_task_abort(&dep->dist_cmd);
 
 	if (dep->status & ERTS_DE_SFLG_EXITING) {
 #ifdef DEBUG
@@ -503,6 +579,9 @@ int erts_do_net_exits(DistEntry *dep, Eterm reason)
 	clear_dist_entry(dep);
 
     }
+
+    dec_no_nodes();
+
     return 1;
 }
 
@@ -516,6 +595,10 @@ void init_dist(void)
 {
     init_nodes_monitors();
 
+    nodedown.reason = NIL;
+    nodedown.bp = NULL;
+
+    erts_smp_atomic_init_nob(&no_nodes, 0);
     erts_smp_atomic_init_nob(&no_caches, 0);
 
     /* Lookup/Install all references to trap functions */
@@ -769,7 +852,7 @@ erts_dsig_send_msg(ErtsDSigData *dsdp, Eterm remote, Eterm message)
     *node_name = *sender_name = *receiver_name = '\0';
     if (DTRACE_ENABLED(message_send) || DTRACE_ENABLED(message_send_remote)) {
         erts_snprintf(node_name, sizeof(node_name), "%T", dsdp->dep->sysname);
-        erts_snprintf(sender_name, sizeof(sender_name), "%T", sender->id);
+        erts_snprintf(sender_name, sizeof(sender_name), "%T", sender->common.id);
         erts_snprintf(receiver_name, sizeof(receiver_name), "%T", remote);
         msize = size_object(message);
         if (token != NIL && token != am_have_dt_utag) {
@@ -826,7 +909,7 @@ erts_dsig_send_reg_msg(ErtsDSigData *dsdp, Eterm remote_name, Eterm message)
     *node_name = *sender_name = *receiver_name = '\0';
     if (DTRACE_ENABLED(message_send) || DTRACE_ENABLED(message_send_remote)) {
         erts_snprintf(node_name, sizeof(node_name), "%T", dsdp->dep->sysname);
-        erts_snprintf(sender_name, sizeof(sender_name), "%T", sender->id);
+        erts_snprintf(sender_name, sizeof(sender_name), "%T", sender->common.id);
         erts_snprintf(receiver_name, sizeof(receiver_name),
                       "{%T,%s}", remote_name, node_name);
         msize = size_object(message);
@@ -840,10 +923,10 @@ erts_dsig_send_reg_msg(ErtsDSigData *dsdp, Eterm remote_name, Eterm message)
 
     if (token != NIL)
 	ctl = TUPLE5(&ctl_heap[0], make_small(DOP_REG_SEND_TT),
-		     sender->id, am_Cookie, remote_name, token);
+		     sender->common.id, am_Cookie, remote_name, token);
     else
 	ctl = TUPLE4(&ctl_heap[0], make_small(DOP_REG_SEND),
-		     sender->id, am_Cookie, remote_name);
+		     sender->common.id, am_Cookie, remote_name);
     DTRACE6(message_send, sender_name, receiver_name,
             msize, tok_label, tok_lastcnt, tok_serial);
     DTRACE7(message_send_remote, sender_name, node_name, receiver_name,
@@ -889,7 +972,7 @@ erts_dsig_send_exit_tt(ErtsDSigData *dsdp, Eterm local, Eterm remote,
     *node_name = *sender_name = *remote_name = '\0';
     if (DTRACE_ENABLED(process_exit_signal_remote)) {
         erts_snprintf(node_name, sizeof(node_name), "%T", dsdp->dep->sysname);
-        erts_snprintf(sender_name, sizeof(sender_name), "%T", sender->id);
+        erts_snprintf(sender_name, sizeof(sender_name), "%T", sender->common.id);
         erts_snprintf(remote_name, sizeof(remote_name),
                       "{%T,%s}", remote, node_name);
         erts_snprintf(reason_str, sizeof(reason), "%T", reason);
@@ -1141,7 +1224,7 @@ int erts_net_message(Port *prt,
 	}
 
 	erts_smp_de_links_lock(dep);
-	res = erts_add_link(&(rp->nlinks), LINK_PID, from);
+	res = erts_add_link(&ERTS_P_LINKS(rp), LINK_PID, from);
 
 	if (res < 0) {
 	    /* It was already there! Lets skip the rest... */
@@ -1149,7 +1232,7 @@ int erts_net_message(Port *prt,
 	    erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_LINK);
 	    break;
 	}
-	lnk = erts_add_or_lookup_link(&(dep->nlinks), LINK_PID, rp->id);
+	lnk = erts_add_or_lookup_link(&(dep->nlinks), LINK_PID, rp->common.id);
 	erts_add_link(&(ERTS_LINK_ROOT(lnk)), LINK_PID, from);
 	erts_smp_de_links_unlock(dep);
 
@@ -1176,7 +1259,7 @@ int erts_net_message(Port *prt,
 	if (!rp)
 	    break;
 
-	lnk = erts_remove_link(&(rp->nlinks), from);
+	lnk = erts_remove_link(&ERTS_P_LINKS(rp), from);
 
 	if (IS_TRACED_FL(rp, F_TRACE_PROCS) && lnk != NULL) {
 	    trace_proc(NULL, rp, am_getting_unlinked, from);
@@ -1233,10 +1316,10 @@ int erts_net_message(Port *prt,
 	}
 	else {
 	    if (is_atom(watched))
-		watched = rp->id;
+		watched = rp->common.id;
 	    erts_smp_de_links_lock(dep);
 	    erts_add_monitor(&(dep->monitors), MON_ORIGIN, ref, watched, name);
-	    erts_add_monitor(&(rp->monitors), MON_TARGET, ref, watcher, name);
+	    erts_add_monitor(&ERTS_P_MONITORS(rp), MON_TARGET, ref, watcher, name);
 	    erts_smp_de_links_unlock(dep);
 	    erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_LINK);
 	}
@@ -1275,7 +1358,7 @@ int erts_net_message(Port *prt,
 	if (!rp) {
 	    break;
 	}
-	mon = erts_remove_monitor(&(rp->monitors),ref);
+	mon = erts_remove_monitor(&ERTS_P_MONITORS(rp), ref);
 	erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_LINK);
 	ASSERT(mon != NULL);
 	if (mon == NULL) {
@@ -1432,7 +1515,7 @@ int erts_net_message(Port *prt,
 
 	erts_destroy_monitor(mon);
 
-	mon = erts_remove_monitor(&(rp->monitors),ref);
+	mon = erts_remove_monitor(&ERTS_P_MONITORS(rp), ref);
 
 	if (mon == NULL) {
 	    erts_smp_proc_unlock(rp, rp_locks);
@@ -1483,7 +1566,7 @@ int erts_net_message(Port *prt,
 	if (!rp)
 	    lnk = NULL;
 	else {
-	    lnk = erts_remove_link(&(rp->nlinks), from);
+	    lnk = erts_remove_link(&ERTS_P_LINKS(rp), from);
 
 	    /* If lnk == NULL, we have unlinked on this side, i.e.
 	     * ignore exit.
@@ -1597,7 +1680,7 @@ int erts_net_message(Port *prt,
 	erts_free(ERTS_ALC_T_DCTRL_BUF, (void *) ctl);
     }
     UnUseTmpHeapNoproc(DIST_CTL_DEFAULT_SIZE);
-    erts_do_exit_port(prt, dep->cid, am_killed);
+    erts_deliver_port_exit(prt, dep->cid, am_killed, 0);
     ERTS_SMP_CHK_NO_PROC_LOCKS;
     return -1;
 }
@@ -1693,7 +1776,6 @@ dsig_send(ErtsDSigData *dsdp, Eterm ctl, Eterm msg, int force_busy)
 	    erts_smp_mtx_unlock(&dep->qlock);
 
 	    plp = erts_proclist_create(c_p);
-	    plp->next = NULL;
 	    erts_suspend(c_p, ERTS_PROC_LOCK_MAIN, NULL);
 	    suspended = 1;
 	    erts_smp_mtx_lock(&dep->qlock);
@@ -1726,11 +1808,7 @@ dsig_send(ErtsDSigData *dsdp, Eterm ctl, Eterm msg, int force_busy)
 	    else {
 		/* Enqueue suspended process on dist entry */
 		ASSERT(plp);
-		if (dep->suspended.last)
-		    dep->suspended.last->next = plp;
-		else
-		    dep->suspended.first = plp;
-		dep->suspended.last = plp;
+		erts_proclist_store_last(&dep->suspended, plp);
 	    }
 	}
 
@@ -1779,7 +1857,7 @@ dsig_send(ErtsDSigData *dsdp, Eterm ctl, Eterm msg, int force_busy)
 
             erts_snprintf(port_str, sizeof(port_str), "%T", cid);
             erts_snprintf(remote_str, sizeof(remote_str), "%T", dep->sysname);
-            erts_snprintf(pid_str, sizeof(pid_str), "%T", c_p->id);
+            erts_snprintf(pid_str, sizeof(pid_str), "%T", c_p->common.id);
             DTRACE4(dist_port_busy, erts_this_node_sysname,
                     port_str, remote_str, pid_str);
         }
@@ -1812,7 +1890,7 @@ dist_port_command(Port *prt, ErtsDistOutputBuf *obuf)
         DTRACE_CHARBUF(port_str, 64);
         DTRACE_CHARBUF(remote_str, 64);
 
-        erts_snprintf(port_str, sizeof(port_str), "%T", prt->id);
+        erts_snprintf(port_str, sizeof(port_str), "%T", prt->common.id);
         erts_snprintf(remote_str, sizeof(remote_str),
                       "%T", prt->dist_entry->sysname);
         DTRACE4(dist_output, erts_this_node_sysname, port_str,
@@ -1866,7 +1944,7 @@ dist_port_commandv(Port *prt, ErtsDistOutputBuf *obuf)
         DTRACE_CHARBUF(port_str, 64);
         DTRACE_CHARBUF(remote_str, 64);
 
-        erts_snprintf(port_str, sizeof(port_str), "%T", prt->id);
+        erts_snprintf(port_str, sizeof(port_str), "%T", prt->common.id);
         erts_snprintf(remote_str, sizeof(remote_str),
                       "%T", prt->dist_entry->sysname);
         DTRACE4(dist_outputv, erts_this_node_sysname, port_str,
@@ -1903,13 +1981,13 @@ int
 erts_dist_command(Port *prt, int reds_limit)
 {
     Sint reds = ERTS_PORT_REDS_DIST_CMD_START;
-    int prt_busy;
     Uint32 status;
     Uint32 flags;
     Sint obufsize = 0;
     ErtsDistOutputQueue oq, foq;
     DistEntry *dep = prt->dist_entry;
     Uint (*send)(Port *prt, ErtsDistOutputBuf *obuf);
+    erts_aint32_t sched_flags;
 
     ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
 
@@ -1925,7 +2003,7 @@ erts_dist_command(Port *prt, int reds_limit)
     erts_smp_de_runlock(dep);
 
     if (status & ERTS_DE_SFLG_EXITING) {
-	erts_do_exit_port(prt, prt->id, am_killed);
+	erts_deliver_port_exit(prt, prt->common.id, am_killed, 0);
 	erts_deref_dist_entry(dep);
 	return reds + ERTS_PORT_REDS_DIST_CMD_EXIT;
     }
@@ -1952,12 +2030,12 @@ erts_dist_command(Port *prt, int reds_limit)
     dep->finalized_out_queue.first = NULL;
     dep->finalized_out_queue.last = NULL;
 
+    sched_flags = erts_smp_atomic32_read_nob(&prt->sched.flags);
+
     if (reds > reds_limit)
 	goto preempted;
 
-    prt_busy = (int) (prt->status & ERTS_PORT_SFLG_PORT_BUSY);
-
-    if (!prt_busy && foq.first) {
+    if (!(sched_flags & ERTS_PTS_FLG_BUSY_PORT) && foq.first) {
 	int preempt = 0;
 	do {
 	    Uint size;
@@ -1974,11 +2052,10 @@ erts_dist_command(Port *prt, int reds_limit)
 	    obufsize += size_obuf(fob);
 	    foq.first = foq.first->next;
 	    free_dist_obuf(fob);
-	    preempt = reds > reds_limit || (prt->status & ERTS_PORT_SFLGS_DEAD);
-	    if (prt->status & ERTS_PORT_SFLG_PORT_BUSY) {
-		prt_busy = 1;
+	    sched_flags = erts_smp_atomic32_read_nob(&prt->sched.flags);
+	    preempt = reds > reds_limit || (sched_flags & ERTS_PTS_FLG_EXIT);
+	    if (sched_flags & ERTS_PTS_FLG_BUSY_PORT)
 		break;
-	    }
 	} while (foq.first && !preempt);
 	if (!foq.first)
 	    foq.last = NULL;
@@ -1986,7 +2063,7 @@ erts_dist_command(Port *prt, int reds_limit)
 	    goto preempted;
     }
 
-    if (prt_busy) {
+    if (sched_flags & ERTS_PTS_FLG_BUSY_PORT) {
 	if (oq.first) {
 	    ErtsDistOutputBuf *ob;
 	    int preempt;
@@ -2058,12 +2135,10 @@ erts_dist_command(Port *prt, int reds_limit)
 	    obufsize += size_obuf(fob);
 	    oq.first = oq.first->next;
 	    free_dist_obuf(fob);
-	    preempt = reds > reds_limit || (prt->status & ERTS_PORT_SFLGS_DEAD);
-	    if (prt->status & ERTS_PORT_SFLG_PORT_BUSY) {
-		prt_busy = 1;
-		if (oq.first && !preempt)
-		    goto finalize_only;
-	    }
+	    sched_flags = erts_smp_atomic32_read_nob(&prt->sched.flags);
+	    preempt = reds > reds_limit || (sched_flags & ERTS_PTS_FLG_EXIT);
+	    if ((sched_flags & ERTS_PTS_FLG_BUSY_PORT) && oq.first && !preempt)
+		goto finalize_only;
 	}
 
 	ASSERT(!oq.first || preempt);
@@ -2091,7 +2166,7 @@ erts_dist_command(Port *prt, int reds_limit)
 	ASSERT(dep->qsize >= obufsize);
 	dep->qsize -= obufsize;
 	obufsize = 0;
-	if (!prt_busy
+	if (!(sched_flags & ERTS_PTS_FLG_BUSY_PORT)
 	    && (dep->qflgs & ERTS_DE_QFLG_BUSY)
 	    && dep->qsize < erts_dist_buf_busy_limit) {
 	    ErtsProcList *suspendees;
@@ -2137,11 +2212,15 @@ erts_dist_command(Port *prt, int reds_limit)
     return reds;
 
  preempted:
+    /*
+     * Here we assume that state has been read
+     * since last call to driver.
+     */
 
     ASSERT(oq.first || !oq.last);
     ASSERT(!oq.first || oq.last);
 
-    if (prt->status & ERTS_PORT_SFLGS_DEAD) {
+    if (sched_flags & ERTS_PTS_FLG_EXIT) {
 	/*
 	 * Port died during port command; clean up 'oq'
 	 * and 'foq'. Things buffered in dist entry after
@@ -2199,7 +2278,7 @@ erts_dist_port_not_busy(Port *prt)
         DTRACE_CHARBUF(port_str, 64);
         DTRACE_CHARBUF(remote_str, 64);
 
-        erts_snprintf(port_str, sizeof(port_str), "%T", prt->id);
+        erts_snprintf(port_str, sizeof(port_str), "%T", prt->common.id);
         erts_snprintf(remote_str, sizeof(remote_str),
                       "%T", prt->dist_entry->sysname);
         DTRACE3(dist_port_not_busy, erts_this_node_sysname,
@@ -2241,7 +2320,7 @@ static void doit_print_monitor_info(ErtsMonitor *mon, void *vptdp)
     Process *rp;
     ErtsMonitor *rmon;
     rp = erts_proc_lookup(mon->pid);
-    if (!rp || (rmon = erts_lookup_monitor(rp->monitors, mon->ref)) == NULL) {
+    if (!rp || (rmon = erts_lookup_monitor(ERTS_P_MONITORS(rp), mon->ref)) == NULL) {
 	erts_print(to, arg, "Warning, stray monitor for: %T\n", mon->pid);
     } else if (mon->type == MON_ORIGIN) {
 	/* Local pid is being monitored */
@@ -2486,6 +2565,7 @@ BIF_RETTYPE setnode_2(BIF_ALIST_2)
 
     erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_MAIN);
     erts_smp_thr_progress_block();
+    inc_no_nodes();
     erts_set_this_node(BIF_ARG_1, (Uint32) creation);
     erts_is_alive = 1;
     send_nodes_mon_msgs(NULL, am_nodeup, BIF_ARG_1, am_visible, NIL);
@@ -2554,9 +2634,9 @@ BIF_RETTYPE setnode_3(BIF_ALIST_3)
     /* DFLAG_EXTENDED_REFERENCES is compulsory from R9 and forward */
     if (!(DFLAG_EXTENDED_REFERENCES & flags)) {
 	erts_dsprintf_buf_t *dsbufp = erts_create_logger_dsbuf();
-	erts_dsprintf(dsbufp, "%T", BIF_P->id);
-	if (BIF_P->reg)
-	    erts_dsprintf(dsbufp, " (%T)", BIF_P->reg->name);
+	erts_dsprintf(dsbufp, "%T", BIF_P->common.id);
+	if (BIF_P->common.u.alive.reg)
+	    erts_dsprintf(dsbufp, " (%T)", BIF_P->common.u.alive.reg->name);
 	erts_dsprintf(dsbufp,
 		      " attempted to enable connection to node %T "
 		      "which is not able to handle extended references.\n",
@@ -2576,10 +2656,14 @@ BIF_RETTYPE setnode_3(BIF_ALIST_3)
     else if (!dep)
 	goto system_limit; /* Should never happen!!! */
 
-    pp = erts_id2port(BIF_ARG_2, BIF_P, ERTS_PROC_LOCK_MAIN);
+    pp = erts_id2port_sflgs(BIF_ARG_2,
+			    BIF_P,
+			    ERTS_PROC_LOCK_MAIN,
+			    ERTS_PORT_SFLGS_INVALID_LOOKUP);
     erts_smp_de_rwlock(dep);
 
-    if (!pp || (pp->status & ERTS_PORT_SFLG_EXITING))
+    if (!pp || (erts_atomic32_read_nob(&pp->state)
+		& ERTS_PORT_SFLG_EXITING))
 	goto badarg;
 
     if ((pp->drv_ptr->flags & ERL_DRV_FLAG_SOFT_BUSY) == 0)
@@ -2594,11 +2678,7 @@ BIF_RETTYPE setnode_3(BIF_ALIST_3)
 	plp->next = NULL;
 	erts_suspend(BIF_P, ERTS_PROC_LOCK_MAIN, NULL);
 	erts_smp_mtx_lock(&dep->qlock);
-	if (dep->suspended.last)
-	    dep->suspended.last->next = plp;
-	else
-	    dep->suspended.first = plp;
-	dep->suspended.last = plp;
+	erts_proclist_store_last(&dep->suspended, plp);
 	erts_smp_mtx_unlock(&dep->qlock);
 	goto yield;
     }
@@ -2608,7 +2688,16 @@ BIF_RETTYPE setnode_3(BIF_ALIST_3)
     if (pp->dist_entry || is_not_nil(dep->cid))
 	goto badarg;
 
-    erts_port_status_bor_set(pp, ERTS_PORT_SFLG_DISTRIBUTION);
+    erts_atomic32_read_bor_nob(&pp->state, ERTS_PORT_SFLG_DISTRIBUTION);
+
+    /*
+     * Dist-ports do not use the "busy port message queue" functionality, but
+     * instead use "busy dist entry" functionality.
+     */
+    {
+	ErlDrvSizeT disable = ERL_DRV_BUSY_MSGQ_DISABLED;
+	erl_drv_busy_msgq_limits((ErlDrvPort) pp, &disable, NULL);
+    }
 
     pp->dist_entry = dep;
 
@@ -2640,6 +2729,8 @@ BIF_RETTYPE setnode_3(BIF_ALIST_3)
     erts_smp_de_rwunlock(dep);
     dep = NULL; /* inc of refc transferred to port (dist_entry field) */
 
+    inc_no_nodes();
+
     send_nodes_mon_msgs(BIF_P,
 			am_nodeup,
 			BIF_ARG_1,
@@ -2653,7 +2744,7 @@ BIF_RETTYPE setnode_3(BIF_ALIST_3)
     }
 
     if (pp)
-	erts_smp_port_unlock(pp);
+	erts_port_release(pp);
 
     return ret;
 
@@ -2697,7 +2788,7 @@ BIF_RETTYPE dist_exit_3(BIF_ALIST_3)
     if (is_internal_pid(local)) {
 	Process *lp;
 	ErtsProcLocks lp_locks;
-	if (BIF_P->id == local) {
+	if (BIF_P->common.id == local) {
 	    lp_locks = ERTS_PROC_LOCKS_ALL;
 	    lp = BIF_P;
 	    erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCKS_ALL_MINOR);
@@ -2725,11 +2816,17 @@ BIF_RETTYPE dist_exit_3(BIF_ALIST_3)
 #endif
 	erts_smp_proc_unlock(lp, lp_locks);
 	if (lp == BIF_P) {
+	    erts_aint32_t state = erts_smp_atomic32_read_acqb(&BIF_P->state);
 	    /*
 	     * We may have exited current process and may have to take action.
 	     */
-	    ERTS_BIF_CHK_EXITED(BIF_P);
-	    ERTS_SMP_BIF_CHK_PENDING_EXIT(BIF_P, ERTS_PROC_LOCK_MAIN);
+	    if (state & (ERTS_PSFLG_EXITING|ERTS_PSFLG_PENDING_EXIT)) {
+#ifdef ERTS_SMP
+		if (state & ERTS_PSFLG_PENDING_EXIT)
+		    erts_handle_pending_exit(BIF_P, ERTS_PROC_LOCK_MAIN);
+#endif
+		ERTS_BIF_EXITED(BIF_P);
+	    }
 	}
     }
     else if (is_external_pid(local)
@@ -2927,23 +3024,23 @@ monitor_node(Process* p, Eterm Node, Eterm Bool, Eterm Options)
     if (Bool == am_true) {
 	ASSERT(dep->cid != NIL);
 	lnk = erts_add_or_lookup_link(&(dep->node_links), LINK_NODE, 
-				      p->id);
+				      p->common.id);
 	++ERTS_LINK_REFC(lnk);
-	lnk = erts_add_or_lookup_link(&(p->nlinks), LINK_NODE, Node);
+	lnk = erts_add_or_lookup_link(&ERTS_P_LINKS(p), LINK_NODE, Node);
 	++ERTS_LINK_REFC(lnk);
     }
     else  {
-	lnk = erts_lookup_link(dep->node_links, p->id);
+	lnk = erts_lookup_link(dep->node_links, p->common.id);
 	if (lnk != NULL) {
 	    if ((--ERTS_LINK_REFC(lnk)) == 0) {
 		erts_destroy_link(erts_remove_link(&(dep->node_links), 
-						   p->id));
+						   p->common.id));
 	    }
 	}
-	lnk = erts_lookup_link(p->nlinks, Node);
+	lnk = erts_lookup_link(ERTS_P_LINKS(p), Node);
 	if (lnk != NULL) {
 	    if ((--ERTS_LINK_REFC(lnk)) == 0) {
-		erts_destroy_link(erts_remove_link(&(p->nlinks),
+		erts_destroy_link(erts_remove_link(&ERTS_P_LINKS(p),
 						   Node));
 	    }
 	}
@@ -3505,7 +3602,7 @@ erts_processes_monitoring_nodes(Process *c_p)
 		olist = erts_bld_cons(hpp, szp, am_nodedown_reason, olist);
 	    res = erts_bld_cons(hpp, szp,
 				erts_bld_tuple(hpp, szp, 2,
-					       nmp->proc->id,
+					       nmp->proc->common.id,
 					       olist),
 				res);
 	}
diff --git a/erts/emulator/beam/dist.h b/erts/emulator/beam/dist.h
index 845151c895..2bc3d9c881 100644
--- a/erts/emulator/beam/dist.h
+++ b/erts/emulator/beam/dist.h
@@ -187,11 +187,12 @@ void erts_schedule_dist_command(Port *prt, DistEntry *dist_entry)
 
     if (prt) {
 	ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
-	ASSERT((erts_port_status_get(prt) & ERTS_PORT_SFLGS_DEAD) == 0);
+	ASSERT((erts_atomic32_read_nob(&prt->state)
+		& ERTS_PORT_SFLGS_DEAD) == 0);
 	ASSERT(prt->dist_entry);
 
 	dep = prt->dist_entry;
-	id = prt->id;
+	id = prt->common.id;
     }
     else {
 	ASSERT(dist_entry);
@@ -203,13 +204,8 @@ void erts_schedule_dist_command(Port *prt, DistEntry *dist_entry)
 	id = dep->cid;
     }
 
-    if (!erts_smp_atomic_xchg_mb(&dep->dist_cmd_scheduled, 1)) {
-	(void) erts_port_task_schedule(id,
-				       &dep->dist_cmd,
-				       ERTS_PORT_TASK_DIST_CMD,
-				       (ErlDrvEvent) -1,
-				       NULL);
-    }
+    if (!erts_smp_atomic_xchg_mb(&dep->dist_cmd_scheduled, 1))
+	erts_port_task_schedule(id, &dep->dist_cmd, ERTS_PORT_TASK_DIST_CMD);
 }
 
 #endif
diff --git a/erts/emulator/beam/erl_alloc.c b/erts/emulator/beam/erl_alloc.c
index 3eee53eba3..04d807b780 100644
--- a/erts/emulator/beam/erl_alloc.c
+++ b/erts/emulator/beam/erl_alloc.c
@@ -2128,6 +2128,7 @@ erts_memory(int *print_to_p, void *print_to_arg, void *proc, Eterm earg)
 
 
     if (want_tot_or_sys || want.processes || want.processes_used) {
+	int max_processes = erts_ptab_max(&erts_proc);
 	UWord tmp;
 
 	if (ERTS_MEM_NEED_ALL_ALCU)
@@ -2137,7 +2138,7 @@ erts_memory(int *print_to_p, void *print_to_arg, void *proc, Eterm earg)
 		      fi, ERTS_ALC_NO_FIXED_SIZES);
 	    tmp = alcu_size(ERTS_ALC_A_EHEAP, NULL, 0);
 	}
-	tmp += erts_max_processes*sizeof(Process*);
+	tmp += max_processes*sizeof(erts_smp_atomic_t);
 	tmp += erts_bif_timer_memory_size();
 	tmp += erts_tot_link_lh_size();
 
@@ -2268,6 +2269,8 @@ erts_allocated_areas(int *print_to_p, void *print_to_arg, void *proc)
     Eterm res = THE_NON_VALUE;
     int i, length;
     Uint reserved_atom_space, atom_space;
+    int max_processes = erts_ptab_max(&erts_proc);
+    int max_ports = erts_ptab_max(&erts_port);
 
     if (proc) {
 	ERTS_SMP_LC_ASSERT(ERTS_PROC_LOCK_MAIN
@@ -2299,7 +2302,7 @@ erts_allocated_areas(int *print_to_p, void *print_to_arg, void *proc)
     values[i].arity = 2;
     values[i].name = "static";
     values[i].ui[0] = 
-	erts_max_ports*sizeof(Port)		/* Port table */
+	max_ports*sizeof(erts_smp_atomic_t)	/* Port table */
 	+ erts_timer_wheel_memory_size();	/* Timer wheel */
     i++;
 
@@ -2378,7 +2381,7 @@ erts_allocated_areas(int *print_to_p, void *print_to_arg, void *proc)
 
     values[i].arity = 2;
     values[i].name = "process_table";
-    values[i].ui[0] = erts_max_processes*sizeof(Process*);
+    values[i].ui[0] = max_processes*sizeof(Process*);
     i++;
 
     values[i].arity = 2;
diff --git a/erts/emulator/beam/erl_alloc.h b/erts/emulator/beam/erl_alloc.h
index e475f9d8a2..ba5ec9c367 100644
--- a/erts/emulator/beam/erl_alloc.h
+++ b/erts/emulator/beam/erl_alloc.h
@@ -267,6 +267,8 @@ typedef void (*erts_alloc_verify_func_t)(Allctr_t *);
 erts_alloc_verify_func_t
 erts_alloc_get_verify_unused_temp_alloc(Allctr_t **allctr);
 
+#define ERTS_ALC_DATA_ALIGN_SIZE(SZ) \
+  (((((SZ) - 1) / 8) + 1) * 8)
 
 #define ERTS_ALC_CACHE_LINE_ALIGN_SIZE(SZ) \
   (((((SZ) - 1) / ERTS_CACHE_LINE_SIZE) + 1) * ERTS_CACHE_LINE_SIZE)
diff --git a/erts/emulator/beam/erl_alloc.types b/erts/emulator/beam/erl_alloc.types
index 0a4407f009..d4de0d076a 100644
--- a/erts/emulator/beam/erl_alloc.types
+++ b/erts/emulator/beam/erl_alloc.types
@@ -146,6 +146,7 @@ class	SYSTEM		system_data
 
 type	SBMBC		SBMBC		SYSTEM		small_block_mbc
 type	PROC		FIXED_SIZE	PROCESSES	proc
+type	PORT		DRIVER		SYSTEM		port
 type	ATOM		LONG_LIVED	ATOM		atom_entry
 type	MODULE		LONG_LIVED	CODE		module_entry
 type	REG_PROC	STANDARD	PROCESSES	reg_proc
@@ -189,7 +190,10 @@ type	PORT_TABLE	LONG_LIVED	SYSTEM		port_tab
 type	TIMER_WHEEL	LONG_LIVED	SYSTEM		timer_wheel
 type	DRV		DRIVER		SYSTEM		drv_internal
 type	DRV_BINARY	BINARY		BINARIES	drv_binary
-type	DRIVER		STANDARD	SYSTEM		driver
+type	DRIVER		DRIVER		SYSTEM		driver
+type	DRV_CMD_DATA	DRIVER		SYSTEM		driver_command_data
+type	DRV_CTRL_DATA	DRIVER		SYSTEM		driver_control_data
+type	DRV_CALL_DATA	DRIVER		SYSTEM		driver_call_data
 type	NIF		DRIVER		SYSTEM		nif_internal
 type	BINARY		BINARY		BINARIES	binary
 type	NBIF_TABLE	SYSTEM		SYSTEM		nbif_tab
@@ -197,14 +201,12 @@ type	ARG_REG		STANDARD	PROCESSES	arg_reg
 type	PROC_DICT	STANDARD	PROCESSES	proc_dict
 type	CALLS_BUF	STANDARD	PROCESSES	calls_buf
 type	BPD		STANDARD	SYSTEM		bpd
-type	PORT_NAME	STANDARD	SYSTEM		port_name
 type	LINEBUF		STANDARD	SYSTEM		line_buf
 type	IOQ		STANDARD	SYSTEM		io_queue
 type	BITS_BUF	STANDARD	SYSTEM		bits_buf
 type	TMP_DIST_BUF	TEMPORARY	SYSTEM		tmp_dist_buf
 type	ASYNC_DATA	LONG_LIVED	SYSTEM		internal_async_data
 type	ESTACK		TEMPORARY	SYSTEM		estack
-type	PORT_CALL_BUF	TEMPORARY	SYSTEM		port_call_buf
 type	DB_TABLE	ETS		ETS		db_tab
 type	DB_FIXATION	SHORT_LIVED	ETS		db_fixation
 type	DB_FIX_DEL	SHORT_LIVED	ETS		fixed_del
@@ -234,14 +236,14 @@ type	DDLL_HANDLE	STANDARD	SYSTEM		ddll_handle
 type	DDLL_ERRCODES	LONG_LIVED	SYSTEM		ddll_errcodes
 type	DDLL_TMP_BUF	TEMPORARY	SYSTEM		ddll_tmp_buf
 type	PORT_TASK	SHORT_LIVED	SYSTEM		port_task
-type	PORT_TASKQ	SHORT_LIVED	SYSTEM		port_task_queue
+type	PT_HNDL_LIST	SHORT_LIVED	SYSTEM		port_task_handle_list
 type	MISC_OP_LIST	SHORT_LIVED	SYSTEM		misc_op_list
 type	PORT_NAMES	SHORT_LIVED	SYSTEM		port_names
-type	PORT_DATA_LOCK	STANDARD	SYSTEM		port_data_lock
+type	PORT_DATA_LOCK	DRIVER		SYSTEM		port_data_lock
 type	NODES_MON	STANDARD	PROCESSES	nodes_monitor
-type	PROCS_TPROC_EL	SHORT_LIVED	PROCESSES	processes_term_proc_el
-type	PROCS_CNKINF	SHORT_LIVED	PROCESSES	processes_chunk_info
-type	PROCS_PIDS	SHORT_LIVED	PROCESSES	processes_pids
+type	PTAB_LIST_DEL	SHORT_LIVED	PROCESSES	ptab_list_deleted_el
+type	PTAB_LIST_CNKI	SHORT_LIVED	PROCESSES	ptab_list_chunk_info
+type	PTAB_LIST_PIDS	SHORT_LIVED	PROCESSES	ptab_list_pids
 type	RE_TMP_BUF	TEMPORARY	SYSTEM		re_tmp_buf
 type    RE_SUBJECT      SHORT_LIVED     SYSTEM          re_subject
 type  	RE_HEAP 	STANDARD	SYSTEM		re_heap
@@ -266,6 +268,8 @@ type	AUX_WORK_TMO	LONG_LIVED	SYSTEM		aux_work_timeouts
 type	MISC_AUX_WORK_Q	LONG_LIVED	SYSTEM		misc_aux_work_q
 type	CODE_IX_LOCK_Q  SHORT_LIVED	SYSTEM		code_ix_lock_q
 type	PROC_INTERVAL	LONG_LIVED	SYSTEM		process_interval
+type    BUSY_CALLER_TAB	SHORT_LIVED	SYSTEM		busy_caller_table
+type    BUSY_CALLER	SHORT_LIVED	SYSTEM		busy_caller
 
 +if threads_no_smp
 # Need thread safe allocs, but std_alloc and fix_alloc are not;
diff --git a/erts/emulator/beam/erl_async.c b/erts/emulator/beam/erl_async.c
index c5f432bea1..f2ca193ace 100644
--- a/erts/emulator/beam/erl_async.c
+++ b/erts/emulator/beam/erl_async.c
@@ -382,10 +382,15 @@ static ERTS_INLINE ErtsAsync *async_get(ErtsThrQ_t *q,
 
 static ERTS_INLINE void call_async_ready(ErtsAsync *a)
 {
+#if ERTS_USE_ASYNC_READY_Q
     Port *p = erts_id2port_sflgs(a->port,
 				 NULL,
 				 0,
 				 ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP);
+#else
+    Port *p = erts_thr_id2port_sflgs(a->port,
+				     ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP);
+#endif
     if (!p) {
 	if (a->async_free)
 	    a->async_free(a->async_data);
@@ -395,7 +400,11 @@ static ERTS_INLINE void call_async_ready(ErtsAsync *a)
 	    if (a->async_free)
 		a->async_free(a->async_data);
 	}
+#if ERTS_USE_ASYNC_READY_Q
 	erts_port_release(p);
+#else
+	erts_thr_port_release(p);
+#endif
     }
     if (a->pdl)
 	driver_pdl_dec_refc(a->pdl);
@@ -603,7 +612,7 @@ long driver_async(ErlDrvPort ix, unsigned int* key,
 	sched_id = 1;
 #endif
 
-    prt = erts_drvport2port(ix);
+    prt = erts_drvport2port(ix, NULL);
     if (!prt)
 	return -1;
 
@@ -615,7 +624,7 @@ long driver_async(ErlDrvPort ix, unsigned int* key,
     a->sched_id = sched_id;
 #endif
     a->hndl = (DE_Handle*)prt->drv_ptr->handle;
-    a->port = prt->id;
+    a->port = prt->common.id;
     a->pdl = NULL;
     a->async_data = async_data;
     a->async_invoke = async_invoke;
diff --git a/erts/emulator/beam/erl_bif_ddll.c b/erts/emulator/beam/erl_bif_ddll.c
index 7f7c975e78..7cbea55eac 100644
--- a/erts/emulator/beam/erl_bif_ddll.c
+++ b/erts/emulator/beam/erl_bif_ddll.c
@@ -104,16 +104,49 @@ static void dereference_all_processes(DE_Handle *dh);
 static void restore_process_references(DE_Handle *dh);
 static void ddll_no_more_references(void *vdh);
 
-#define lock_drv_list() erts_smp_mtx_lock(&erts_driver_list_lock)
-#define unlock_drv_list() erts_smp_mtx_unlock(&erts_driver_list_lock)
+#define lock_drv_list() erts_smp_rwmtx_rwlock(&erts_driver_list_lock)
+#define unlock_drv_list() erts_smp_rwmtx_rwunlock(&erts_driver_list_lock)
 #define assert_drv_list_locked() \
-    ERTS_SMP_LC_ASSERT(erts_smp_lc_mtx_is_locked(&erts_driver_list_lock))
+    ERTS_SMP_LC_ASSERT(erts_smp_lc_rwmtx_is_rwlocked(&erts_driver_list_lock) \
+		       || erts_smp_lc_rwmtx_is_rlocked(&erts_driver_list_lock))
+#define assert_drv_list_rwlocked() \
+    ERTS_SMP_LC_ASSERT(erts_smp_lc_rwmtx_is_rwlocked(&erts_driver_list_lock))
+#define assert_drv_list_rlocked() \
+    ERTS_SMP_LC_ASSERT(erts_smp_lc_rwmtx_is_rlocked(&erts_driver_list_lock))
 #define assert_drv_list_not_locked() \
-    ERTS_SMP_LC_ASSERT(!erts_smp_lc_mtx_is_locked(&erts_driver_list_lock))
+    ERTS_SMP_LC_ASSERT(!erts_smp_lc_rwmtx_is_rwlocked(&erts_driver_list_lock) \
+		       && !erts_smp_lc_rwmtx_is_rlocked(&erts_driver_list_lock))
 
 
 #define FREE_PORT_FLAGS (ERTS_PORT_SFLGS_DEAD & (~ERTS_PORT_SFLG_INITIALIZING))
 
+static void
+kill_ports_driver_unloaded(DE_Handle *dh)
+{
+    int ix, max = erts_ptab_max(&erts_port);
+
+    for (ix = 0; ix < max; ix++) {
+	erts_aint32_t state;
+	Port* prt = erts_pix2port(ix);
+	if (!prt)
+	    continue;
+
+	ERTS_SMP_DATA_DEPENDENCY_READ_MEMORY_BARRIER;
+
+	state = erts_atomic32_read_nob(&prt->state);
+	if (state & FREE_PORT_FLAGS)
+	    continue;
+
+	erts_smp_port_lock(prt);
+
+	state = erts_atomic32_read_nob(&prt->state);
+	if (!(state & ERTS_PORT_SFLGS_DEAD) && prt->drv_ptr->handle == dh)
+	    driver_failure_atom((ErlDrvPort) prt, "driver_unloaded");
+
+	erts_port_release(prt);
+    }
+}
+
 /*
  *    try_load(Path, Name, OptionList) -> {ok,Status} | 
  *                                        {ok, PendingStatus, Ref} | 
@@ -149,7 +182,7 @@ BIF_RETTYPE erl_ddll_try_load_3(BIF_ALIST_3)
     Eterm name_term = BIF_ARG_2;
     Eterm options = BIF_ARG_3;
     char *path = NULL;
-    Uint path_len;
+    ErlDrvSizeT path_len;
     char *name = NULL;
     DE_Handle *dh;
     erts_driver_t *drv;
@@ -228,7 +261,7 @@ BIF_RETTYPE erl_ddll_try_load_3(BIF_ALIST_3)
 	goto error;
     }
     path = erts_alloc(ERTS_ALC_T_DDLL_TMP_BUF, path_len + 1 /* might need path separator */ + sys_strlen(name) + 1);
-    if (io_list_to_buf(path_term, path, path_len) != 0) {
+    if (erts_iolist_to_buf(path_term, path, path_len) != 0) {
 	goto error;
     }
     while (path_len > 0 && (path[path_len-1] == '\\' || path[path_len-1] == '/')) {
@@ -356,40 +389,16 @@ BIF_RETTYPE erl_ddll_try_load_3(BIF_ALIST_3)
 	    ok_term = mkatom("loaded");
 	}
     }
-    assert_drv_list_locked();
+    assert_drv_list_rwlocked();
     if (kill_ports) {
-	int j;
-	/* Avoid closing the driver by referencing it */
+ 	/* Avoid closing the driver by referencing it */
 	erts_ddll_reference_driver(dh);
 	ASSERT(dh->status == ERL_DE_RELOAD);
 	dh->status = ERL_DE_FORCE_RELOAD;
 #if DDLL_SMP
 	unlock_drv_list();
 #endif
-	for (j = 0; j < erts_max_ports; j++) {
-	    Port* prt = &erts_port[j];
-	    erts_smp_port_state_lock(prt);
-	    if (!(prt->status & FREE_PORT_FLAGS) &&
-		prt->drv_ptr->handle == dh) {
-		erts_smp_atomic_inc_nob(&prt->refc);
-#if DDLL_SMP
-		/* Extremely rare spinlock */
-		while(prt->status & ERTS_PORT_SFLG_INITIALIZING) {
-		       erts_smp_port_state_unlock(prt);
-		       erts_smp_port_state_lock(prt);
-	        }
-		erts_smp_port_state_unlock(prt);
-		erts_smp_mtx_lock(prt->lock);
-		if (!(prt->status & ERTS_PORT_SFLGS_DEAD)) {
-		    driver_failure_atom(j, "driver_unloaded");
-		}
-#else
-		driver_failure_atom(j, "driver_unloaded");
-#endif
-		erts_port_release(prt);
-	    }
-	    else erts_smp_port_state_unlock(prt);
-	}
+	kill_ports_driver_unloaded(dh);
 	/* Dereference, eventually causing driver destruction */
 #if DDLL_SMP
 	lock_drv_list(); 
@@ -579,45 +588,21 @@ Eterm erl_ddll_try_unload_2(BIF_ALIST_2)
 	dh->reload_full_path = dh->reload_driver_name = NULL; 
 	dh->reload_flags = 0;
     } 
-    if (dh->port_count > 0) {
+    if (erts_smp_atomic32_read_nob(&dh->port_count) > 0) {
 	++kill_ports;
     }
     dh->status = ERL_DE_UNLOAD;
     ok_term = am_pending_driver;
 done:
-    assert_drv_list_locked();
+    assert_drv_list_rwlocked();
     if (kill_ports > 1) {
-	int j;
 	/* Avoid closing the driver by referencing it */
 	erts_ddll_reference_driver(dh);
 	dh->status = ERL_DE_FORCE_UNLOAD;
 #if DDLL_SMP
 	unlock_drv_list();
 #endif
-	for (j = 0; j < erts_max_ports; j++) {
-	    Port* prt = &erts_port[j];
-	    erts_smp_port_state_lock(prt);
-	    if (!(prt->status &  FREE_PORT_FLAGS) 
-		&& prt->drv_ptr->handle == dh) {
-		erts_smp_atomic_inc_nob(&prt->refc);
-#if DDLL_SMP
-		/* Extremely rare spinlock */
-		while(prt->status & ERTS_PORT_SFLG_INITIALIZING) {
-		       erts_smp_port_state_unlock(prt);
-		       erts_smp_port_state_lock(prt);
-	        }
-		erts_smp_port_state_unlock(prt);
-		erts_smp_mtx_lock(prt->lock);
-		if (!(prt->status & ERTS_PORT_SFLGS_DEAD)) {
-		    driver_failure_atom(j, "driver_unloaded");
-		}
-#else
-		driver_failure_atom(j, "driver_unloaded");
-#endif
-		erts_port_release(prt);
-	    }
-	    else erts_smp_port_state_unlock(prt);
-	}
+	kill_ports_driver_unloaded(dh);
 #if DDLL_SMP
 	lock_drv_list(); 
 #endif
@@ -787,7 +772,7 @@ BIF_RETTYPE erl_ddll_info_2(BIF_ALIST_2)
 	} else if (drv->handle->status == ERL_DE_PERMANENT) {
 	    res = am_permanent;
 	} else {
-	    res = make_small(drv->handle->port_count);
+	    res = make_small(erts_smp_atomic32_read_nob(&drv->handle->port_count));
 	}
 	goto done;
     case am_linked_in_driver:
@@ -1045,38 +1030,16 @@ void erts_ddll_proc_dead(Process *p, ErtsProcLocks plocks)
 		} 
 		dh->status = ERL_DE_UNLOAD;
 	    }
-	    if (!left && drv->handle->port_count > 0) {
+	    if (!left
+		&& erts_smp_atomic32_read_nob(&drv->handle->port_count) > 0) {
 		if (kill_ports) {
-		    int j;
 		    DE_Handle *dh = drv->handle;
 		    erts_ddll_reference_driver(dh);
 		    dh->status = ERL_DE_FORCE_UNLOAD;
 #if DDLL_SMP
 		    unlock_drv_list();
 #endif
-		    for (j = 0; j < erts_max_ports; j++) {
-			Port* prt = &erts_port[j];
-			erts_smp_port_state_lock(prt);
-			if (!(prt->status & FREE_PORT_FLAGS) &&
-			    prt->drv_ptr->handle == dh) {
-			    erts_smp_atomic_inc_nob(&prt->refc);
-#if DDLL_SMP
-			    while(prt->status & ERTS_PORT_SFLG_INITIALIZING) {
-				erts_smp_port_state_unlock(prt);
-				erts_smp_port_state_lock(prt);
-			    }
-			    erts_smp_port_state_unlock(prt);
-			    erts_smp_mtx_lock(prt->lock);
-			    if (!(prt->status & ERTS_PORT_SFLGS_DEAD)) {
-				driver_failure_atom(j, "driver_unloaded");
-			    }
-#else
-			    driver_failure_atom(j, "driver_unloaded");
-#endif
-			    erts_port_release(prt);
-			}
-			else erts_smp_port_state_unlock(prt);
-		    } 
+		    kill_ports_driver_unloaded(dh);
 #if DDLL_SMP
 		    lock_drv_list(); /* Needed for future list operations */
 #endif
@@ -1098,7 +1061,7 @@ void erts_ddll_proc_dead(Process *p, ErtsProcLocks plocks)
 void erts_ddll_lock_driver(DE_Handle *dh, char *name)
 {
     DE_ProcEntry *p,*q;
-    assert_drv_list_locked();
+    assert_drv_list_rwlocked();
     notify_all(dh, name, 
 	       ERL_DE_PROC_AWAIT_LOAD, am_UP, am_permanent);
     notify_all(dh, name, 
@@ -1121,19 +1084,22 @@ void erts_ddll_lock_driver(DE_Handle *dh, char *name)
 void erts_ddll_increment_port_count(DE_Handle *dh) 
 {
     assert_drv_list_locked();
-    dh->port_count++;
+    erts_smp_atomic32_inc_nob(&dh->port_count);
 }
 
 void erts_ddll_decrement_port_count(DE_Handle *dh)
 {
     assert_drv_list_locked();
-    ASSERT(dh->port_count > 0);
-    dh->port_count--;
+#if DEBUG
+    ASSERT(erts_smp_atomic32_dec_read_nob(&dh->port_count) >= 0);
+#else
+    erts_smp_atomic32_dec_nob(&dh->port_count);
+#endif
 }
 
 static void first_ddll_reference(DE_Handle *dh) 
 {
-    assert_drv_list_locked();
+    assert_drv_list_rwlocked();
     erts_refc_init(&(dh->refc),1);
 }
 
@@ -1161,7 +1127,7 @@ void erts_ddll_dereference_driver(DE_Handle *dh)
 static void dereference_all_processes(DE_Handle *dh) 
 {
     DE_ProcEntry *p;
-    assert_drv_list_locked();
+    assert_drv_list_rwlocked();
     for(p  = dh->procs;p != NULL; p = p->next) {
 	if (p->awaiting_status == ERL_DE_PROC_LOADED) {
 	    ASSERT(!(p->flags & ERL_DE_FL_DEREFERENCED));
@@ -1174,7 +1140,7 @@ static void dereference_all_processes(DE_Handle *dh)
 static void restore_process_references(DE_Handle *dh) 
 {
     DE_ProcEntry *p;
-    assert_drv_list_locked();
+    assert_drv_list_rwlocked();
     ASSERT(erts_refc_read(&(dh->refc),0) == 0);
     for(p  = dh->procs;p != NULL; p = p->next) {
 	if (p->awaiting_status == ERL_DE_PROC_LOADED) {
@@ -1402,7 +1368,7 @@ static int is_last_user(DE_Handle *dh, Process *proc) {
     DE_ProcEntry *p = dh->procs;
     int found = 0;
 
-    assert_drv_list_locked();
+    assert_drv_list_rwlocked();
 
     while (p != NULL) {
 	if (p->proc == proc && p->awaiting_status == ERL_DE_PROC_LOADED) {
@@ -1423,7 +1389,7 @@ static DE_ProcEntry *find_proc_entry(DE_Handle *dh, Process *proc, Uint status)
 {
     DE_ProcEntry *p = dh->procs;
 
-    assert_drv_list_locked();
+    assert_drv_list_rwlocked();
 
     while (p != NULL) {
 	if (p->proc == proc && p->awaiting_status == status) {
@@ -1450,7 +1416,7 @@ static int num_procs(DE_Handle *dh, Uint status) {
     DE_ProcEntry *p = dh->procs;
     int i = 0;
 
-    assert_drv_list_locked();
+    assert_drv_list_rwlocked();
 
     while (p != NULL) {
 	if (p->awaiting_status == status) {
@@ -1465,7 +1431,7 @@ static int num_entries(DE_Handle *dh, Process *proc, Uint status) {
     DE_ProcEntry *p = dh->procs;
     int i = 0;
 
-    assert_drv_list_locked();
+    assert_drv_list_rwlocked();
     while (p != NULL) {
 	if (p->awaiting_status == status && p->proc == proc) {
 	    ++i;
@@ -1478,7 +1444,7 @@ static int num_entries(DE_Handle *dh, Process *proc, Uint status) {
 static void add_proc_loaded(DE_Handle *dh, Process *proc) 
 {
     DE_ProcEntry *p;
-    assert_drv_list_locked();
+    assert_drv_list_rwlocked();
     p = erts_alloc(ERTS_ALC_T_DDLL_PROCESS, sizeof(DE_ProcEntry));
     p->proc = proc;
     p->flags = 0;
@@ -1490,7 +1456,7 @@ static void add_proc_loaded(DE_Handle *dh, Process *proc)
 static void add_proc_loaded_deref(DE_Handle *dh, Process *proc) 
 {
     DE_ProcEntry *p;
-    assert_drv_list_locked();
+    assert_drv_list_rwlocked();
     p = erts_alloc(ERTS_ALC_T_DDLL_PROCESS, sizeof(DE_ProcEntry));
     p->proc = proc;
     p->awaiting_status = ERL_DE_PROC_LOADED;
@@ -1510,7 +1476,7 @@ static void add_proc_waiting(DE_Handle *dh, Process *proc,
 			     Uint status, Eterm ref) 
 {
     DE_ProcEntry *p;
-    assert_drv_list_locked();
+    assert_drv_list_rwlocked();
     p = erts_alloc(ERTS_ALC_T_DDLL_PROCESS, sizeof(DE_ProcEntry));
     p->proc = proc;
     p->flags = 0;
@@ -1524,7 +1490,7 @@ static Eterm add_monitor(Process *p, DE_Handle *dh, Uint status)
 {
     Eterm r;
 
-    assert_drv_list_locked();
+    assert_drv_list_rwlocked();
     r = erts_make_ref(p);
     add_proc_waiting(dh, p, status, r);
     return r;
@@ -1535,7 +1501,7 @@ static void set_driver_reloading(DE_Handle *dh, Process *proc, char *path, char
 {
     DE_ProcEntry *p;
 
-    assert_drv_list_locked();
+    assert_drv_list_rwlocked();
     p = erts_alloc(ERTS_ALC_T_DDLL_PROCESS, sizeof(DE_ProcEntry));
     p->proc = proc;
     p->awaiting_status = ERL_DE_OK;
@@ -1556,7 +1522,7 @@ static int do_load_driver_entry(DE_Handle *dh, char *path, char *name)
     int res;
     ErlDrvEntry *dp;
 
-    assert_drv_list_locked();
+    assert_drv_list_rwlocked();
 
     if ((res =  erts_sys_ddll_open(path, &(dh->handle))) != ERL_DE_NO_ERROR) {
 	return res;
@@ -1594,7 +1560,7 @@ static int do_load_driver_entry(DE_Handle *dh, char *path, char *name)
 	goto error;
     }
     erts_smp_atomic_init_nob(&(dh->refc), (erts_aint_t) 0);
-    dh->port_count = 0;
+    erts_smp_atomic32_init_nob(&dh->port_count, 0);
     dh->full_path = erts_alloc(ERTS_ALC_T_DDLL_HANDLE, sys_strlen(path) + 1);
     sys_strcpy(dh->full_path, path);
     dh->flags = 0;
@@ -1620,7 +1586,7 @@ static int do_unload_driver_entry(DE_Handle *dh, Eterm *save_name)
 {
     erts_driver_t *q, *p = driver_list;
 
-    assert_drv_list_locked();
+    assert_drv_list_rwlocked();
 
     while (p != NULL) {
 	if (p->handle == dh) {
@@ -1660,11 +1626,11 @@ static int load_driver_entry(DE_Handle **dhp, char *path, char *name)
     int res;
     DE_Handle *dh = erts_alloc(ERTS_ALC_T_DDLL_HANDLE, sizeof(DE_Handle));
 
-    assert_drv_list_locked();
+    assert_drv_list_rwlocked();
 
     dh->handle = NULL;
     dh->procs = NULL;
-    dh->port_count = 0;
+    erts_smp_atomic32_init_nob(&dh->port_count, 0);
     erts_refc_init(&(dh->refc), (erts_aint_t) 0);
     dh->status = -1;
     dh->reload_full_path = NULL;
@@ -1698,7 +1664,7 @@ static int reload_driver_entry(DE_Handle *dh)
     int loadres;
     Uint flags = dh->reload_flags;
 
-    assert_drv_list_locked();
+    assert_drv_list_rwlocked();
 
     dh->reload_full_path = NULL;
     dh->reload_driver_name = NULL;
@@ -1736,7 +1702,7 @@ static void notify_proc(Process *proc, Eterm ref, Eterm driver_name, Eterm type,
     ErtsProcLocks rp_locks = 0;
     ERTS_SMP_CHK_NO_PROC_LOCKS;
 
-    assert_drv_list_locked();
+    assert_drv_list_rwlocked();
     if (errcode != 0) {
 	int need = load_error_need(errcode);
 	Eterm e;
@@ -1769,7 +1735,7 @@ static void notify_all(DE_Handle *dh, char *name, Uint awaiting, Eterm type, Ete
 {
     DE_ProcEntry **p;
 
-    assert_drv_list_locked();
+    assert_drv_list_rwlocked();
 
     p = &(dh->procs);
     while (*p != NULL) {
@@ -1875,7 +1841,7 @@ static Eterm mkatom(char *str)
 static char *pick_list_or_atom(Eterm name_term)
 { 
     char *name = NULL;
-    Uint name_len;
+    ErlDrvSizeT name_len;
     if (is_atom(name_term)) {
 	Atom *ap = atom_tab(atom_val(name_term));
 	if (ap->len == 0) {
@@ -1891,7 +1857,7 @@ static char *pick_list_or_atom(Eterm name_term)
 	    goto error;
 	}
 	name = erts_alloc(ERTS_ALC_T_DDLL_TMP_BUF, name_len + 1);
-	if (io_list_to_buf(name_term, name, name_len) != 0) {
+	if (erts_iolist_to_buf(name_term, name, name_len) != 0) {
 	    goto error;
 	}
 	name[name_len] = '\0';
@@ -1912,10 +1878,10 @@ static int build_proc_info(DE_Handle *dh, ProcEntryInfo **out_pei, Uint filter)
     int i;
     DE_ProcEntry *pe;
 
-    assert_drv_list_locked();
+    assert_drv_list_rwlocked();
 
     for (pe = dh->procs; pe != NULL; pe = pe->next) {
-	Eterm id = pe->proc->id;
+	Eterm id = pe->proc->common.id;
 	Uint stat = pe->awaiting_status;
 	if (stat == ERL_DE_PROC_AWAIT_UNLOAD_ONLY) {
 	    stat = ERL_DE_PROC_AWAIT_UNLOAD;
diff --git a/erts/emulator/beam/erl_bif_info.c b/erts/emulator/beam/erl_bif_info.c
index a3811ccdb0..fabddffc68 100755
--- a/erts/emulator/beam/erl_bif_info.c
+++ b/erts/emulator/beam/erl_bif_info.c
@@ -40,6 +40,8 @@
 #include "erl_cpu_topology.h"
 #include "erl_async.h"
 #include "erl_thr_progress.h"
+#define ERTS_PTAB_WANT_DEBUG_FUNCS__
+#include "erl_ptab.h"
 #ifdef HIPE
 #include "hipe_arch.h"
 #endif
@@ -128,8 +130,6 @@ static char erts_system_version[] = ("Erlang " ERLANG_OTP_RELEASE
 static Eterm os_type_tuple;
 static Eterm os_version_tuple;
 
-static BIF_RETTYPE port_info(Process* p, Eterm portid, Eterm item);
-
 static Eterm
 current_function(Process* p, Process* rp, Eterm** hpp, int full_info);
 static Eterm current_stacktrace(Process* p, Process* rp, Eterm** hpp);
@@ -873,8 +873,7 @@ BIF_RETTYPE process_info_1(BIF_ALIST_1)
 	&& external_pid_dist_entry(BIF_ARG_1) == erts_this_dist_entry)
 	BIF_RET(am_undefined);
 	
-    if (is_not_internal_pid(BIF_ARG_1)
-	|| internal_pid_index(BIF_ARG_1) >= erts_max_processes) {
+    if (is_not_internal_pid(BIF_ARG_1)) {
 	BIF_ERROR(BIF_P, BADARG);
     }
 
@@ -909,8 +908,7 @@ BIF_RETTYPE process_info_2(BIF_ALIST_2)
 	&& external_pid_dist_entry(pid) == erts_this_dist_entry)
 	BIF_RET(am_undefined);
 	
-    if (is_not_internal_pid(pid)
-	|| internal_pid_index(BIF_ARG_1) >= erts_max_processes) {
+    if (is_not_internal_pid(pid)) {
 	BIF_ERROR(BIF_P, BADARG);
     }
 
@@ -1002,9 +1000,9 @@ process_info_aux(Process *BIF_P,
     switch (item) {
 
     case am_registered_name:
-	if (rp->reg != NULL) {
+	if (rp->common.u.alive.reg) {
 	    hp = HAlloc(BIF_P, 3);
-	    res = rp->reg->name;
+	    res = rp->common.u.alive.reg->name;
 	} else {
 	    if (always_wrap) {
 		hp = HAlloc(BIF_P, 3);
@@ -1050,7 +1048,7 @@ process_info_aux(Process *BIF_P,
 	ERTS_SMP_MSGQ_MV_INQ2PRIVQ(rp);
 	n = rp->msg.len;
 
-	if (n == 0 || rp->trace_flags & F_SENSITIVE) {
+	if (n == 0 || ERTS_TRACE_FLAGS(rp) & F_SENSITIVE) {
 	    hp = HAlloc(BIF_P, 3);
 	} else {
 	    int remove_bad_messages = 0;
@@ -1209,7 +1207,7 @@ process_info_aux(Process *BIF_P,
 
 	INIT_MONITOR_INFOS(mic);
 
-	erts_doforall_links(rp->nlinks,&collect_one_link,&mic);
+	erts_doforall_links(ERTS_P_LINKS(rp),&collect_one_link,&mic);
 
 	hp = HAlloc(BIF_P, 3 + mic.sz);
 	res = NIL;
@@ -1227,7 +1225,7 @@ process_info_aux(Process *BIF_P,
 	int i;
 
 	INIT_MONITOR_INFOS(mic);
-	erts_doforall_monitors(rp->monitors,&collect_one_origin_monitor,&mic);
+	erts_doforall_monitors(ERTS_P_MONITORS(rp),&collect_one_origin_monitor,&mic);
 	hp = HAlloc(BIF_P, 3 + mic.sz);
 	res = NIL;
 	for (i = 0; i < mic.mi_i; i++) {
@@ -1264,7 +1262,7 @@ process_info_aux(Process *BIF_P,
 	Eterm item;
 
 	INIT_MONITOR_INFOS(mic);
-	erts_doforall_monitors(rp->monitors,&collect_one_target_monitor,&mic);
+	erts_doforall_monitors(ERTS_P_MONITORS(rp),&collect_one_target_monitor,&mic);
 	hp = HAlloc(BIF_P, 3 + mic.sz);
 
 	res = NIL;
@@ -1330,7 +1328,7 @@ process_info_aux(Process *BIF_P,
     }
 
     case am_dictionary:
-	if (rp->trace_flags & F_SENSITIVE) {
+	if (ERTS_TRACE_FLAGS(rp) & F_SENSITIVE) {
 	    res = NIL;
 	} else {
 	    res = erts_dictionary_copy(BIF_P, rp->dictionary);
@@ -1426,8 +1424,8 @@ process_info_aux(Process *BIF_P,
 
 	ERTS_SMP_MSGQ_MV_INQ2PRIVQ(rp);
 
-	erts_doforall_links(rp->nlinks, &one_link_size, &size);
-	erts_doforall_monitors(rp->monitors, &one_mon_size, &size);
+	erts_doforall_links(ERTS_P_LINKS(rp), &one_link_size, &size);
+	erts_doforall_monitors(ERTS_P_MONITORS(rp), &one_mon_size, &size);
 	size += (rp->heap_sz + rp->mbuf_sz) * sizeof(Eterm);
 	if (rp->old_hend && rp->old_heap)
 	    size += (rp->old_hend - rp->old_heap) * sizeof(Eterm);
@@ -1500,7 +1498,7 @@ process_info_aux(Process *BIF_P,
 
     case am_trace:
 	hp = HAlloc(BIF_P, 3);
-	res = make_small(rp->trace_flags & TRACEE_FLAGS);
+	res = make_small(ERTS_TRACE_FLAGS(rp) & TRACEE_FLAGS);
 	break;
 
     case am_binary: {
@@ -1605,7 +1603,7 @@ current_function(Process* BIF_P, Process* rp, Eterm** hpp, int full_info)
 	}
     }
 
-    if (BIF_P->id == rp->id) {
+    if (BIF_P == rp) {
 	FunctionInfo fi2;
 
 	/*
@@ -1837,17 +1835,17 @@ info_1_tuple(Process* BIF_P,	/* Pointer to current process. */
 #    define ERTS_ERROR_CHECKER_PRINTF_XML VALGRIND_PRINTF_XML
 #  endif
 #endif
-	    Uint buf_size = 8*1024; /* Try with 8KB first */
+	    ErlDrvSizeT buf_size = 8*1024; /* Try with 8KB first */
 	    char *buf = erts_alloc(ERTS_ALC_T_TMP, buf_size);
-	    int r = io_list_to_buf(*tp, (char*) buf, buf_size - 1);
-	    if (r < 0) {
+	    ErlDrvSizeT r = erts_iolist_to_buf(*tp, (char*) buf, buf_size - 1);
+	    if (ERTS_IOLIST_TO_BUF_FAILED(r)) {
 		erts_free(ERTS_ALC_T_TMP, (void *) buf);
 		if (erts_iolist_size(*tp, &buf_size)) {
 		    goto badarg;
 		}
 		buf_size++;
 		buf = erts_alloc(ERTS_ALC_T_TMP, buf_size);
-		r = io_list_to_buf(*tp, (char*) buf, buf_size - 1);
+		r = erts_iolist_to_buf(*tp, (char*) buf, buf_size - 1);
 		ASSERT(r == buf_size - 1);
 	    }
 	    buf[buf_size - 1 - r] = '\0';
@@ -2159,9 +2157,13 @@ BIF_RETTYPE system_info_1(BIF_ALIST_1)
 	res = TUPLE2(hp, am_min_bin_vheap_size,make_small(BIN_VH_MIN_SIZE));
 	BIF_RET(res);
     } else if (BIF_ARG_1 == am_process_count) {
-	BIF_RET(make_small(erts_process_count()));
+	BIF_RET(make_small(erts_ptab_count(&erts_proc)));
     } else if (BIF_ARG_1 == am_process_limit) {
-	BIF_RET(make_small(erts_max_processes));
+	BIF_RET(make_small(erts_ptab_max(&erts_proc)));
+    } else if (BIF_ARG_1 == am_port_count) {
+	BIF_RET(make_small(erts_ptab_count(&erts_port)));
+    } else if (BIF_ARG_1 == am_port_limit) {
+	BIF_RET(make_small(erts_ptab_max(&erts_port)));
     } else if (BIF_ARG_1 == am_info
 	       || BIF_ARG_1 == am_procs
 	       || BIF_ARG_1 == am_loaded
@@ -2534,6 +2536,9 @@ BIF_RETTYPE system_info_1(BIF_ALIST_1)
     } else if (ERTS_IS_ATOM_STR("run_queues", BIF_ARG_1)) {
 	res = make_small(erts_no_run_queues);
 	BIF_RET(res);
+    } else if (ERTS_IS_ATOM_STR("port_parallelism", BIF_ARG_1)) {
+	res = erts_port_parallelism ? am_true : am_false;
+	BIF_RET(res);
     } else if (ERTS_IS_ATOM_STR("c_compiler_used", BIF_ARG_1)) {
 	Eterm *hp = NULL;
 	Uint sz = 0;
@@ -2701,66 +2706,6 @@ BIF_RETTYPE system_info_1(BIF_ALIST_1)
     BIF_ERROR(BIF_P, BADARG);
 }
 
-BIF_RETTYPE
-port_info_1(BIF_ALIST_1)
-{
-    Process* p = BIF_P;
-    Eterm pid = BIF_ARG_1;
-    static Eterm keys[] = {
-	am_name,
-	am_links,
-	am_id,
-	am_connected,
-	am_input,
-	am_output,
-	am_os_pid
-    };
-    Eterm items[ASIZE(keys)];
-    Eterm result = NIL;
-    Eterm reg_name;
-    Eterm* hp;
-    Uint need;
-    int i;
-
-    /*
-     * Collect all information about the port.
-     */
-
-    for (i = 0; i < ASIZE(keys); i++) {
-	Eterm item;
-
-	item = port_info(p, pid, keys[i]);
-	if (is_non_value(item)) {
-	    return THE_NON_VALUE;
-	}
-	if (item == am_undefined) {
-	    return am_undefined;
-	}
-	items[i] = item;
-    }
-    reg_name = port_info(p, pid, am_registered_name);
-
-    /*
-     * Build the resulting list.
-     */
-
-    need = 2*ASIZE(keys);
-    if (is_tuple(reg_name)) {
-	need += 2;
-    }
-    hp = HAlloc(p, need);
-    for (i = ASIZE(keys) - 1; i >= 0; i--) {
-	result = CONS(hp, items[i], result);
-	hp += 2;
-    }
-    if (is_tuple(reg_name)) {
-	result = CONS(hp, reg_name, result);
-    }
-
-    return result;
-}
-
-
 /**********************************************************************/ 
 /* Return information on ports */
 /* Info:
@@ -2773,38 +2718,20 @@ port_info_1(BIF_ALIST_1)
 **    os_pid      The child's process ID
 */
 
-BIF_RETTYPE port_info_2(BIF_ALIST_2)
-{
-    return port_info(BIF_P, BIF_ARG_1, BIF_ARG_2);
-}
-
-static BIF_RETTYPE port_info(Process* p, Eterm portid, Eterm item)
+Eterm
+erts_bld_port_info(Eterm **hpp, ErlOffHeap *ohp, Uint *szp, Port *prt, Eterm item)
 {
-    BIF_RETTYPE ret;
-    Port *prt;
-    Eterm res;
-    Eterm* hp;
-    int count;
-
-    if (is_internal_port(portid))
-	prt = erts_id2port(portid, p, ERTS_PROC_LOCK_MAIN);
-    else if (is_atom(portid))
-	erts_whereis_name(p, ERTS_PROC_LOCK_MAIN,
-			  portid, NULL, 0, 0, &prt);
-    else if (is_external_port(portid)
-	     && external_port_dist_entry(portid) == erts_this_dist_entry)
-	BIF_RET(am_undefined);
-    else {
-	BIF_ERROR(p, BADARG);
-    }
+    Eterm res = THE_NON_VALUE;
 
-    if (!prt) {
-	BIF_RET(am_undefined);
-    }
+    ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
 
     if (item == am_id) {
-	hp = HAlloc(p, 3);
-	res = make_small(internal_port_number(portid));
+	if (hpp)
+	    res = make_small(internal_port_index(prt->common.id));
+	if (szp) {
+	    res = am_true;
+	    goto done;
+	}
     }
     else if (item == am_links) {
 	MonitorInfoCollection mic;
@@ -2813,17 +2740,26 @@ static BIF_RETTYPE port_info(Process* p, Eterm portid, Eterm item)
 
 	INIT_MONITOR_INFOS(mic);
 
-	erts_doforall_links(prt->nlinks, &collect_one_link, &mic);
+	erts_doforall_links(ERTS_P_LINKS(prt), &collect_one_link, &mic);
 
-	hp = HAlloc(p, 3 + mic.sz);
-	res = NIL;
-	for (i = 0; i < mic.mi_i; i++) {
-	    item = STORE_NC(&hp, &MSO(p), mic.mi[i].entity);
-	    res = CONS(hp, item, res);
-	    hp += 2;
+	if (szp)
+	    *szp += mic.sz;
+
+	if (hpp) {
+	    res = NIL;
+	    for (i = 0; i < mic.mi_i; i++) {
+		item = STORE_NC(hpp, ohp, mic.mi[i].entity);
+		res = CONS(*hpp, item, res);
+		*hpp += 2;
+	    }
 	}
+
 	DESTROY_MONITOR_INFOS(mic);
 
+	if (szp) {
+	    res = am_true;
+	    goto done;
+	}
     }
     else if (item == am_monitors) {
 	MonitorInfoCollection mic;
@@ -2832,79 +2768,96 @@ static BIF_RETTYPE port_info(Process* p, Eterm portid, Eterm item)
 
 	INIT_MONITOR_INFOS(mic);
 
-	erts_doforall_monitors(prt->monitors, &collect_one_origin_monitor, &mic);
+	erts_doforall_monitors(ERTS_P_MONITORS(prt), &collect_one_origin_monitor, &mic);
 
-	hp = HAlloc(p, 3 + mic.sz);
-	res = NIL;
-	for (i = 0; i < mic.mi_i; i++) {
-	    Eterm t;
-	    item = STORE_NC(&hp, &MSO(p), mic.mi[i].entity);
-	    t = TUPLE2(hp, am_process, item);
-	    hp += 3;
-	    res = CONS(hp, t, res);
-	    hp += 2;
+	if (szp)
+	    *szp += mic.sz;
+
+	if (hpp) {
+	    res = NIL;
+	    for (i = 0; i < mic.mi_i; i++) {
+		Eterm t;
+		item = STORE_NC(hpp, ohp, mic.mi[i].entity);
+		t = TUPLE2(*hpp, am_process, item);
+		*hpp += 3;
+		res = CONS(*hpp, t, res);
+		*hpp += 2;
+	    }
 	}
+
 	DESTROY_MONITOR_INFOS(mic);
 
+	if (szp) {
+	    res = am_true;
+	    goto done;
+	}
     }
     else if (item == am_name) {
-	count = sys_strlen(prt->name);
+	int count = sys_strlen(prt->name);
+
+	if (hpp)
+	    res = buf_to_intlist(hpp, prt->name, count, NIL);
 
-	hp = HAlloc(p, 3 + 2*count);
-	res = buf_to_intlist(&hp, prt->name, count, NIL);
+	if (szp) {
+	    *szp += 2*count;
+	    res = am_true;
+	    goto done;
+	}
     }
     else if (item == am_connected) {
-	hp = HAlloc(p, 3);
-	res = prt->connected; /* internal pid */
+	if (hpp)
+	    res = ERTS_PORT_GET_CONNECTED(prt); /* internal pid */
+	if (szp) {
+	    res = am_true;
+	    goto done;
+	}
     }
     else if (item == am_input) {
-	Uint hsz = 3;
-	Uint n = prt->bytes_in;
-	(void) erts_bld_uint(NULL, &hsz, n);
-	hp = HAlloc(p, hsz);
-	res = erts_bld_uint(&hp, NULL, n);
+	res = erts_bld_uint(hpp, szp, prt->bytes_in);
+	if (szp) {
+	    res = am_true;
+	    goto done;
+	}
     }
     else if (item == am_output) {
-	Uint hsz = 3;
-	Uint n = prt->bytes_out;
-	(void) erts_bld_uint(NULL, &hsz, n);
-	hp = HAlloc(p, hsz);
-	res = erts_bld_uint(&hp, NULL, n);
+	res = erts_bld_uint(hpp, szp, prt->bytes_out);
+	if (szp) {
+	    res = am_true;
+	    goto done;
+	}
     }
     else if (item == am_os_pid) {
-        if (prt->os_pid >= 0) {
-            Uint hsz = 3;
-            UWord n = prt->os_pid;
-            (void) erts_bld_uword(NULL, &hsz, n);
-            hp = HAlloc(p, hsz);
-            res = erts_bld_uword(&hp, NULL, n);
-        } else {
-	    hp = HAlloc(p, 3);
-	    res = am_undefined;
-        }
+	res = (prt->os_pid < 0
+	       ? am_undefined
+	       : erts_bld_uword(hpp, szp, (UWord) prt->os_pid));
+	if (szp) {
+	    res = am_true;
+	    goto done;
+	}
     }
     else if (item == am_registered_name) {
-	RegProc *reg;
-	reg = prt->reg;
-	if (reg == NULL) {
-	    ERTS_BIF_PREP_RET(ret, NIL);
-	    goto done;
-	} else {
-	    hp = HAlloc(p, 3);
+	RegProc *reg = prt->common.u.alive.reg;
+	if (reg) {
 	    res = reg->name;
+	    if (szp) {
+		res = am_true;
+		goto done;
+	    }
+	}
+	else {
+	    if (szp)
+		return am_undefined;
+	    return NIL;
 	}
     }
     else if (item == am_memory) {
 	/* All memory consumed in bytes (the Port struct should not be
 	   included though).
 	 */
-	Uint hsz = 3;
 	Uint size = 0;
 	ErlHeapFragment* bp;
 
-	hp = HAlloc(p, 3);
-
-	erts_doforall_links(prt->nlinks, &one_link_size, &size);
+	erts_doforall_links(ERTS_P_LINKS(prt), &one_link_size, &size);
 
 	for (bp = prt->bp; bp; bp = bp->next)
 	    size += sizeof(ErlHeapFragment) + (bp->alloc_size - 1)*sizeof(Eterm);
@@ -2918,51 +2871,72 @@ static BIF_RETTYPE port_info(Process* p, Eterm portid, Eterm item)
 	/* All memory allocated by the driver should be included, but it is
 	   hard to retrieve... */
 	
-	(void) erts_bld_uint(NULL, &hsz, size);
-	hp = HAlloc(p, hsz);
-	res = erts_bld_uint(&hp, NULL, size);
+	res = erts_bld_uint(hpp, szp, size);
+	if (szp) {
+	    res = am_true;
+	    goto done;
+	}
     }
     else if (item == am_queue_size) {
 	Uint ioq_size = erts_port_ioq_size(prt);
-	Uint hsz = 3;
-	(void) erts_bld_uint(NULL, &hsz, ioq_size);
-	hp = HAlloc(p, hsz);
-	res = erts_bld_uint(&hp, NULL, ioq_size);
+	res = erts_bld_uint(hpp, szp, ioq_size);
+	if (szp) {
+	    res = am_true;
+	    goto done;
+	}
     }
     else if (ERTS_IS_ATOM_STR("locking", item)) {
-	hp = HAlloc(p, 3);
+	if (hpp) {
 #ifndef ERTS_SMP
-	res = am_false;
+	    res = am_false;
 #else
-	if (prt->status & ERTS_PORT_SFLG_PORT_SPECIFIC_LOCK) {
-	    DECL_AM(port_level);
-	    ASSERT(prt->drv_ptr->flags
-		   & ERL_DRV_FLAG_USE_PORT_LOCKING);
-	    res = AM_port_level;
+	    if (erts_atomic32_read_nob(&prt->state)
+		& ERTS_PORT_SFLG_PORT_SPECIFIC_LOCK) {
+		DECL_AM(port_level);
+		ASSERT(prt->drv_ptr->flags
+		       & ERL_DRV_FLAG_USE_PORT_LOCKING);
+		res = AM_port_level;
+	    }
+	    else {
+		DECL_AM(driver_level);
+		ASSERT(!(prt->drv_ptr->flags
+			 & ERL_DRV_FLAG_USE_PORT_LOCKING));
+		res = AM_driver_level;
+	    }
+#endif
 	}
-	else {
-	    DECL_AM(driver_level);
-	    ASSERT(!(prt->drv_ptr->flags
-		     & ERL_DRV_FLAG_USE_PORT_LOCKING));
-	    res = AM_driver_level;
+	if (szp) {
+	    res = am_true;
+	    goto done;
 	}
-#endif
+    }
+    else if (item == am_parallelism) {
+	if (szp) {
+	    res = am_true;
+	    goto done;
+	}
+	res = ((ERTS_PTS_FLG_PARALLELISM &
+		erts_smp_atomic32_read_nob(&prt->sched.flags))
+	       ? am_true
+	       : am_false);
     }
     else {
-	ERTS_BIF_PREP_ERROR(ret, p, BADARG);
-	goto done;
+	if (szp)
+	    return am_false;
+	return THE_NON_VALUE;
     }
 
-    ERTS_BIF_PREP_RET(ret, TUPLE2(hp, item, res));
-
- done:
-
-    erts_smp_port_unlock(prt);
+done:
+    if (szp)
+	*szp += 3;
+    if (hpp) {
+	res = TUPLE2(*hpp, item, res);
+	*hpp += 3;
+    }
 
-    return ret;
+    return res;
 }
 
-
 BIF_RETTYPE
 fun_info_2(BIF_ALIST_2)
 {
@@ -3094,12 +3068,9 @@ BIF_RETTYPE is_process_alive_1(BIF_ALIST_1)
    if(is_internal_pid(BIF_ARG_1)) {
        Process *rp;
 
-       if (BIF_ARG_1 == BIF_P->id)
+       if (BIF_ARG_1 == BIF_P->common.id)
 	   BIF_RET(am_true);
 
-       if(internal_pid_index(BIF_ARG_1) >= erts_max_processes)
-	   BIF_ERROR(BIF_P, BADARG);
-
        rp = erts_proc_lookup(BIF_ARG_1);
        if (!rp) {
 	   BIF_RET(am_false);
@@ -3317,10 +3288,9 @@ BIF_RETTYPE erts_debug_get_internal_state_1(BIF_ALIST_1)
 	    /* Used by node_container_SUITE (emulator) */
 	    Eterm res;
 	    if (ERTS_IS_ATOM_STR("next_pid", BIF_ARG_1))
-		res = erts_test_next_pid(0, 0);
-	    else {
-		res = erts_test_next_port(0, 0);
-	    }
+		res = erts_ptab_test_next_id(&erts_proc, 0, 0);
+	    else
+		res = erts_ptab_test_next_id(&erts_port, 0, 0);
 	    if (res < 0)
 		BIF_RET(am_false);
 	    BIF_RET(erts_make_integer(res, BIF_P));
@@ -3356,11 +3326,11 @@ BIF_RETTYPE erts_debug_get_internal_state_1(BIF_ALIST_1)
 	}
 	else if (ERTS_IS_ATOM_STR("processes", BIF_ARG_1)) {
 	    /* Used by process_SUITE (emulator) */
-	    BIF_RET(erts_debug_processes(BIF_P));
+	    BIF_RET(erts_debug_ptab_list(BIF_P, &erts_proc));
 	}
 	else if (ERTS_IS_ATOM_STR("processes_bif_info", BIF_ARG_1)) {
 	    /* Used by process_SUITE (emulator) */
-	    BIF_RET(erts_debug_processes_bif_info(BIF_P));
+	    BIF_RET(erts_debug_ptab_list_bif_info(BIF_P, &erts_proc));
 	}
 	else if (ERTS_IS_ATOM_STR("max_atom_out_cache_index", BIF_ARG_1)) {
 	    /* Used by distribution_SUITE (emulator) */
@@ -3421,17 +3391,20 @@ BIF_RETTYPE erts_debug_get_internal_state_1(BIF_ALIST_1)
 			ERTS_SMP_ASSERT_IS_NOT_EXITING(BIF_P);
 			BIF_RET(am_undefined);
 		    }
-		    res = make_link_list(BIF_P, p->nlinks, NIL);
+		    res = make_link_list(BIF_P, ERTS_P_LINKS(p), NIL);
 		    erts_smp_proc_unlock(p, ERTS_PROC_LOCK_LINK);
 		    BIF_RET(res);
 		}
 		else if(is_internal_port(tp[2])) {
 		    Eterm res;
-		    Port *p = erts_id2port(tp[2], BIF_P, ERTS_PROC_LOCK_MAIN);
+		    Port *p = erts_id2port_sflgs(tp[2],
+						 BIF_P,
+						 ERTS_PROC_LOCK_MAIN,
+						 ERTS_PORT_SFLGS_INVALID_LOOKUP);
 		    if(!p)
 			BIF_RET(am_undefined);
-		    res = make_link_list(BIF_P, p->nlinks, NIL);
-		    erts_smp_port_unlock(p);
+		    res = make_link_list(BIF_P, ERTS_P_LINKS(p), NIL);
+		    erts_port_release(p);
 		    BIF_RET(res);
 		}
 		else if(is_node_name_atom(tp[2])) {
@@ -3463,7 +3436,7 @@ BIF_RETTYPE erts_debug_get_internal_state_1(BIF_ALIST_1)
 			ERTS_SMP_ASSERT_IS_NOT_EXITING(BIF_P);
 			BIF_RET(am_undefined);
 		    }
-		    res = make_monitor_list(BIF_P, p->monitors);
+		    res = make_monitor_list(BIF_P, ERTS_P_MONITORS(p));
 		    erts_smp_proc_unlock(p, ERTS_PROC_LOCK_LINK);
 		    BIF_RET(res);
 		} else if(is_node_name_atom(tp[2])) {
@@ -3606,7 +3579,7 @@ BIF_RETTYPE erts_debug_set_internal_state_2(BIF_ALIST_2)
 	erts_aint_t prev_on = erts_smp_atomic_xchg_nob(&available_internal_state, on);
 	if (on) {
 	    erts_dsprintf_buf_t *dsbufp = erts_create_logger_dsbuf();
-	    erts_dsprintf(dsbufp, "Process %T ", BIF_P->id);
+	    erts_dsprintf(dsbufp, "Process %T ", BIF_P->common.id);
 	    if (erts_is_alive)
 		erts_dsprintf(dsbufp, "on node %T ", erts_this_node->sysname);
 	    erts_dsprintf(dsbufp,
@@ -3674,10 +3647,9 @@ BIF_RETTYPE erts_debug_set_internal_state_2(BIF_ALIST_2)
 		Eterm res;
 
 		if (ERTS_IS_ATOM_STR("next_pid", BIF_ARG_1))
-		    res = erts_test_next_pid(1, next);
-		else {
-		    res = erts_test_next_port(1, next);
-		}
+		    res = erts_ptab_test_next_id(&erts_proc, 1, next);
+		else
+		    res = erts_ptab_test_next_id(&erts_port, 1, next);
 		if (res < 0)
 		    BIF_RET(am_false);
 		BIF_RET(erts_make_integer(res, BIF_P));
@@ -3948,8 +3920,8 @@ static Eterm lcnt_build_lock_term(Eterm **hpp, Uint *szp, erts_lcnt_lock_t *lock
     } else if (lock->flag & ERTS_LCNT_LT_PROCLOCK) {
 	/* use registered names as id's for process locks if available */
 	proc  = erts_proc_lookup(lock->id);
-	if (proc && proc->reg) {
-	    id = proc->reg->name;
+	if (proc && proc->common.u.alive.reg) {
+	    id = proc->common.u.alive.reg->name;
 	} else {
 	    /* otherwise use process id */
 	    id = lock->id;
diff --git a/erts/emulator/beam/erl_bif_port.c b/erts/emulator/beam/erl_bif_port.c
index f9009166c0..81146e38d7 100644
--- a/erts/emulator/beam/erl_bif_port.c
+++ b/erts/emulator/beam/erl_bif_port.c
@@ -42,28 +42,26 @@
 #include "erl_bits.h"
 #include "dtrace-wrapper.h"
 
-static int open_port(Process* p, Eterm name, Eterm settings, int *err_nump);
+static Port *open_port(Process* p, Eterm name, Eterm settings, int *err_typep, int *err_nump);
 static byte* convert_environment(Process* p, Eterm env);
 static char **convert_args(Eterm);
 static void free_args(char **);
 
 char *erts_default_arg0 = "default";
 
-static BIF_RETTYPE
-port_call(Process* p, Eterm arg1, Eterm arg2, Eterm arg3);
-
 BIF_RETTYPE open_port_2(BIF_ALIST_2)
 {
-    int port_num;
-    Eterm port_val;
+    Port *port;
+    Eterm port_id;
     char *str;
-    int err_num;
+    int err_type, err_num;
 
-    if ((port_num = open_port(BIF_P, BIF_ARG_1, BIF_ARG_2, &err_num)) < 0) {
-	if (port_num == -3) {
+    port = open_port(BIF_P, BIF_ARG_1, BIF_ARG_2, &err_type, &err_num);
+    if (!port) {
+	if (err_type == -3) {
 	    ASSERT(err_num == BADARG || err_num == SYSTEM_LIMIT);
 	    BIF_ERROR(BIF_P, err_num);
-	} else if (port_num == -2) {
+	} else if (err_type == -2) {
 	    str = erl_errno_id(err_num);
 	} else {
 	    str = "einval";
@@ -74,546 +72,408 @@ BIF_RETTYPE open_port_2(BIF_ALIST_2)
 
     erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_LINK);
 
-    port_val = erts_port[port_num].id;
-    erts_add_link(&(erts_port[port_num].nlinks), LINK_PID, BIF_P->id);
-    erts_add_link(&(BIF_P->nlinks), LINK_PID, port_val);
+    port_id = port->common.id;
+    erts_add_link(&ERTS_P_LINKS(port), LINK_PID, BIF_P->common.id);
+    erts_add_link(&ERTS_P_LINKS(BIF_P), LINK_PID, port_id);
 
     erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_LINK);
 
-    erts_port_release(&erts_port[port_num]);
+    erts_port_release(port);
 
-    BIF_RET(port_val);
+    BIF_RET(port_id);
 }
 
-/****************************************************************************
-
-  PORT BIFS:
-
-           port_command/2   -- replace Port ! {..., {command, Data}}
-               port_command(Port, Data) -> true
-               when port(Port), io-list(Data)
-
-           port_control/3   -- new port_control(Port, Ctl, Data) -> Reply
-	      port_control(Port, Ctl, Data) -> Reply
-              where integer(Ctl), io-list(Data), io-list(Reply)
-
-           port_close/1     -- replace Port ! {..., close}
-             port_close(Port) -> true
-             when port(Port)
-
-           port_connect/2   -- replace Port ! {..., {connect, Pid}}
-              port_connect(Port, Pid) 
-              when port(Port), pid(Pid)
-
- ***************************************************************************/
-
-static Port*
-id_or_name2port(Process *c_p, Eterm id)
+static ERTS_INLINE Port *
+lookup_port(Process *c_p, Eterm id_or_name)
 {
-    Port *port;
-    if (is_not_atom(id))
-	port = erts_id2port(id, c_p, ERTS_PROC_LOCK_MAIN);
+    /* TODO: Implement nicer lookup in register... */
+    Eterm id;
+    if (is_atom(id_or_name))
+	id = erts_whereis_name_to_id(c_p, id_or_name);
     else
-	erts_whereis_name(c_p, ERTS_PROC_LOCK_MAIN, id, NULL, 0, 0, &port);
-    return port;
+	id = id_or_name;
+    return erts_port_lookup(id, ERTS_PORT_SFLGS_INVALID_LOOKUP);
 }
 
-#define ERTS_PORT_COMMAND_FLAG_FORCE		(((Uint32) 1) << 0)
-#define ERTS_PORT_COMMAND_FLAG_NOSUSPEND	(((Uint32) 1) << 1)
+/*
+ * erts_internal:port_command/3 is used by the
+ * erlang:port_command/2 and erlang:port_command/3
+ * BIFs.
+ */
 
-static BIF_RETTYPE
-do_port_command(Process *BIF_P, Eterm arg1, Eterm arg2, Eterm arg3,
-		Uint32 flags)
+BIF_RETTYPE erts_internal_port_command_3(BIF_ALIST_3)
 {
     BIF_RETTYPE res;
-    Port *p;
-
-    /* Trace sched out before lock check wait */    
-    if (IS_TRACED_FL(BIF_P, F_TRACE_SCHED_PROCS)) {
-	trace_virtual_sched(BIF_P, am_out);
-    }
-    
-    if (erts_system_profile_flags.runnable_procs && erts_system_profile_flags.exclusive) {
-    	profile_runnable_proc(BIF_P, am_inactive);
-    }
-
-    p = id_or_name2port(BIF_P, arg1);
-    if (!p) {
-    	if (IS_TRACED_FL(BIF_P, F_TRACE_SCHED_PROCS)) {
-	    trace_virtual_sched(BIF_P, am_in);
+    Port *prt;
+    int flags = 0;
+    Eterm ref;
+
+    if (is_not_nil(BIF_ARG_3)) {
+	Eterm l = BIF_ARG_3;
+	while (is_list(l)) {
+	    Eterm* cons = list_val(l);
+	    Eterm car = CAR(cons);
+	    if (car == am_force)
+		flags |= ERTS_PORT_SIG_FLG_FORCE;
+	    else if (car == am_nosuspend)
+		flags |= ERTS_PORT_SIG_FLG_NOSUSPEND;
+	    else
+		BIF_RET(am_badarg);
+	    l = CDR(cons);
 	}
-    	if (erts_system_profile_flags.runnable_procs && erts_system_profile_flags.exclusive) {
-    	    profile_runnable_proc(BIF_P, am_active);
-    	}
-	BIF_ERROR(BIF_P, BADARG);
+	if (!is_nil(l))
+	    BIF_RET(am_badarg);
     }
-    
-    /* Trace port in, id_or_name2port causes wait */
 
-    if (IS_TRACED_FL(p, F_TRACE_SCHED_PORTS)) {
-	trace_sched_ports_where(p, am_in, am_command);
-    }
-    if (erts_system_profile_flags.runnable_ports && !erts_port_is_scheduled(p)) {
-    	profile_runnable_port(p, am_active);
+    prt = lookup_port(BIF_P, BIF_ARG_1);
+    if (!prt)
+	BIF_RET(am_badarg);
+
+    if (flags & ERTS_PORT_SIG_FLG_FORCE) {
+	if (!(prt->drv_ptr->flags & ERL_DRV_FLAG_SOFT_BUSY))
+	    BIF_RET(am_notsup);
     }
 
-    ERTS_BIF_PREP_RET(res, am_true);
+#ifdef DEBUG
+    ref = NIL;
+#endif
 
-    if ((flags & ERTS_PORT_COMMAND_FLAG_FORCE)
-	&& !(p->drv_ptr->flags & ERL_DRV_FLAG_SOFT_BUSY)) {
-	ERTS_BIF_PREP_ERROR(res, BIF_P, EXC_NOTSUP);
-    }
-    else if (!(flags & ERTS_PORT_COMMAND_FLAG_FORCE)
-	     && p->status & ERTS_PORT_SFLG_PORT_BUSY) {
-	if (flags & ERTS_PORT_COMMAND_FLAG_NOSUSPEND) {
+    switch (erts_port_output(BIF_P, flags, prt, prt->common.id, BIF_ARG_2, &ref)) {
+    case ERTS_PORT_OP_CALLER_EXIT:
+    case ERTS_PORT_OP_BADARG:
+    case ERTS_PORT_OP_DROPPED:
+ 	ERTS_BIF_PREP_RET(res, am_badarg);
+	break;
+    case ERTS_PORT_OP_BUSY:
+	ASSERT(!(flags & ERTS_PORT_SIG_FLG_FORCE));
+	if (flags & ERTS_PORT_SIG_FLG_NOSUSPEND)
 	    ERTS_BIF_PREP_RET(res, am_false);
-	}
 	else {
-	    erts_suspend(BIF_P, ERTS_PROC_LOCK_MAIN, p);
-	    if (erts_system_monitor_flags.busy_port) {
-		monitor_generic(BIF_P, am_busy_port, p->id);
-	    }
-	    ERTS_BIF_PREP_YIELD3(res, bif_export[BIF_port_command_3], BIF_P,
-				 arg1, arg2, arg3);
-	}
-    } else {
-	int wres;
-	erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_MAIN);
-	ERTS_SMP_CHK_NO_PROC_LOCKS;
-	wres = erts_write_to_port(BIF_P->id, p, arg2);
-	erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_MAIN);
-	if (wres != 0) {
-	    ERTS_BIF_PREP_ERROR(res, BIF_P, BADARG);
+	    erts_suspend(BIF_P, ERTS_PROC_LOCK_MAIN, prt);
+	    ERTS_BIF_PREP_YIELD3(res, bif_export[BIF_erts_internal_port_command_3],
+				 BIF_P, BIF_ARG_1, BIF_ARG_2, BIF_ARG_3);
 	}
-    }
-    
-    if (IS_TRACED_FL(p, F_TRACE_SCHED_PORTS)) {
-	trace_sched_ports_where(p, am_out, am_command);
-    }
-    if (erts_system_profile_flags.runnable_ports && !erts_port_is_scheduled(p)) {
-    	profile_runnable_port(p, am_inactive);
+	break;
+    case ERTS_PORT_OP_BUSY_SCHEDULED:
+	ASSERT(!(flags & ERTS_PORT_SIG_FLG_FORCE));
+	/* Fall through... */
+    case ERTS_PORT_OP_SCHEDULED:
+	ASSERT(is_internal_ref(ref));
+	ERTS_BIF_PREP_RET(res, ref);
+	break;
+    case ERTS_PORT_OP_DONE:
+	ERTS_BIF_PREP_RET(res, am_true);
+	break;
+    default:
+	ERTS_INTERNAL_ERROR("Unexpected erts_port_output() result");
+	break;
     }
 
-    erts_port_release(p);
-    /* Trace sched in after port release */
-    if (IS_TRACED_FL(BIF_P, F_TRACE_SCHED_PROCS)) {
-	trace_virtual_sched(BIF_P, am_in);
-    }
-    if (erts_system_profile_flags.runnable_procs && erts_system_profile_flags.exclusive) {
-    	profile_runnable_proc(BIF_P, am_active);
-    }
-    
     if (ERTS_PROC_IS_EXITING(BIF_P)) {
 	KILL_CATCHES(BIF_P);	/* Must exit */
 	ERTS_BIF_PREP_ERROR(res, BIF_P, EXC_ERROR);
     }
-    return res;
-}
 
-BIF_RETTYPE port_command_2(BIF_ALIST_2)
-{
-    return do_port_command(BIF_P, BIF_ARG_1, BIF_ARG_2, NIL, 0);
+    return res;
 }
 
-BIF_RETTYPE port_command_3(BIF_ALIST_3)
+BIF_RETTYPE erts_internal_port_call_3(BIF_ALIST_3)
 {
-    Eterm l = BIF_ARG_3;
-    Uint32 flags = 0;
-    while (is_list(l)) {
-	Eterm* cons = list_val(l);
-	Eterm car = CAR(cons);
-	if (car == am_force) {
-	    flags |= ERTS_PORT_COMMAND_FLAG_FORCE;
-	} else if (car == am_nosuspend) {
-	    flags |= ERTS_PORT_COMMAND_FLAG_NOSUSPEND;
-	} else {
-	    BIF_ERROR(BIF_P, BADARG);
-	}
-	l = CDR(cons);
-    }
-    if(!is_nil(l)) {
-	BIF_ERROR(BIF_P, BADARG);
+    Port* prt;
+    Eterm retval;
+    Uint uint_op;
+    unsigned int op;
+    erts_aint32_t state;
+
+    prt = lookup_port(BIF_P, BIF_ARG_1);
+    if (!prt)
+	BIF_RET(am_badarg);
+
+    if (!term_to_Uint(BIF_ARG_2, &uint_op))
+	BIF_RET(am_badarg);
+
+    if (uint_op > (Uint) UINT_MAX)
+	BIF_RET(am_badarg);
+
+    op = (unsigned int) uint_op;
+
+    switch (erts_port_call(BIF_P, prt, op, BIF_ARG_3, &retval)) {
+    case ERTS_PORT_OP_CALLER_EXIT:
+    case ERTS_PORT_OP_DROPPED:
+    case ERTS_PORT_OP_BADARG:
+	retval = am_badarg;
+	break;
+    case ERTS_PORT_OP_SCHEDULED:
+	ASSERT(is_internal_ref(retval));
+	break;
+    case ERTS_PORT_OP_DONE:
+	ASSERT(is_not_internal_ref(retval));
+	break;
+    default:
+	ERTS_INTERNAL_ERROR("Unexpected erts_port_call() result");
+	retval = am_internal_error;
+	break;
     }
-    return do_port_command(BIF_P, BIF_ARG_1, BIF_ARG_2, BIF_ARG_3, flags);
-}
 
-BIF_RETTYPE port_call_2(BIF_ALIST_2)
-{
-    return port_call(BIF_P,BIF_ARG_1, make_small(0), BIF_ARG_2);
-}
+    state = erts_smp_atomic32_read_acqb(&BIF_P->state);
+    if (state & (ERTS_PSFLG_EXITING|ERTS_PSFLG_PENDING_EXIT)) {
+#ifdef ERTS_SMP
+	if (state & ERTS_PSFLG_PENDING_EXIT)
+	    erts_handle_pending_exit(BIF_P, ERTS_PROC_LOCK_MAIN);
+#endif
+	ERTS_BIF_EXITED(BIF_P);
+    }
 
-BIF_RETTYPE port_call_3(BIF_ALIST_3)
-{
-    return port_call(BIF_P, BIF_ARG_1, BIF_ARG_2, BIF_ARG_3);
+    BIF_RET(retval);
 }
 
-static BIF_RETTYPE
-port_call(Process* c_p, Eterm arg1, Eterm arg2, Eterm arg3)
+BIF_RETTYPE erts_internal_port_control_3(BIF_ALIST_3)
 {
-    Uint op;
-    Port *p;
-    Uint size;
-    byte *bytes;
-    byte *endp;
-    ErlDrvSizeT real_size;
-    erts_driver_t *drv;
-    byte port_input[256];	/* Default input buffer to encode in */
-    byte port_result[256];	/* Buffer for result from port. */
-    byte* port_resp;		/* Pointer to result buffer. */
-    char *prc;
-    ErlDrvSSizeT ret;
-    Eterm res;
-    Sint result_size;
-    Eterm *hp;
-    Eterm *hp_end;
-    unsigned ret_flags = 0U;
-    int fpe_was_unmasked;
-
-    bytes = &port_input[0];
-    port_resp = port_result;
-    /* trace of port scheduling with virtual process descheduling
-     * lock wait 
-     */
-    if (IS_TRACED_FL(c_p, F_TRACE_SCHED_PROCS)) {
-	trace_virtual_sched(c_p, am_out);
-    }
-
-    if (erts_system_profile_flags.runnable_procs && erts_system_profile_flags.exclusive) {
-	profile_runnable_proc(c_p, am_inactive);
+    Port* prt;
+    Eterm retval;
+    Uint uint_op;
+    unsigned int op;
+    erts_aint32_t state;
+
+    prt = lookup_port(BIF_P, BIF_ARG_1);
+    if (!prt)
+	BIF_RET(am_badarg);
+
+    if (!term_to_Uint(BIF_ARG_2, &uint_op))
+	BIF_RET(am_badarg);
+
+    if (uint_op > (Uint) UINT_MAX)
+	BIF_RET(am_badarg);
+
+    op = (unsigned int) uint_op;
+
+    switch (erts_port_control(BIF_P, prt, op, BIF_ARG_3, &retval)) {
+    case ERTS_PORT_OP_CALLER_EXIT:
+    case ERTS_PORT_OP_BADARG:
+    case ERTS_PORT_OP_DROPPED:
+	retval = am_badarg;
+	break;
+    case ERTS_PORT_OP_SCHEDULED:
+	ASSERT(is_internal_ref(retval));
+	break;
+    case ERTS_PORT_OP_DONE:
+	ASSERT(is_not_internal_ref(retval));
+	break;
+    default:
+	ERTS_INTERNAL_ERROR("Unexpected erts_port_control() result");
+	retval = am_internal_error;
+	break;
     }
 
-    p = id_or_name2port(c_p, arg1);
-    if (!p) {
-    error:
-	if (port_resp != port_result && 
-	    !(ret_flags & DRIVER_CALL_KEEP_BUFFER)) {
-	    driver_free(port_resp);
-	}
-	if (bytes != &port_input[0])
-	    erts_free(ERTS_ALC_T_PORT_CALL_BUF, bytes);
-	/* Need to virtual schedule in the process if there
-	 * was an error.
-	 */
-	if (IS_TRACED_FL(c_p, F_TRACE_SCHED_PROCS)) {
-	    trace_virtual_sched(c_p, am_in);
-    	}
-
-	if (erts_system_profile_flags.runnable_procs && erts_system_profile_flags.exclusive) {
-	    profile_runnable_proc(c_p, am_active);
-    	}
-
-	if (p)
-	    erts_port_release(p);
+    state = erts_smp_atomic32_read_acqb(&BIF_P->state);
+    if (state & (ERTS_PSFLG_EXITING|ERTS_PSFLG_PENDING_EXIT)) {
 #ifdef ERTS_SMP
-	ERTS_SMP_BIF_CHK_PENDING_EXIT(c_p, ERTS_PROC_LOCK_MAIN);
-#else
-	ERTS_BIF_CHK_EXITED(c_p);
+	if (state & ERTS_PSFLG_PENDING_EXIT)
+	    erts_handle_pending_exit(BIF_P, ERTS_PROC_LOCK_MAIN);
 #endif
-	BIF_ERROR(c_p, BADARG);
-    }
-
-    if ((drv = p->drv_ptr) == NULL) {
-	goto error;
-    }
-    if (drv->call == NULL) {
-	goto error;
-    }
-    if (!term_to_Uint(arg2, &op)) {
-	goto error;
-    }
-    p->caller = c_p->id;
-    
-    /* Lock taken, virtual schedule of port */
-    if (IS_TRACED_FL(p, F_TRACE_SCHED_PORTS)) {
-    	trace_sched_ports_where(p, am_in, am_call);
-    }
-    
-    if (erts_system_profile_flags.runnable_ports && !erts_port_is_scheduled(p)) {
-    	profile_runnable_port(p, am_active);
+	ERTS_BIF_EXITED(BIF_P);
     }
-    size = erts_encode_ext_size(arg3);
-    if (size > sizeof(port_input))
-	bytes = erts_alloc(ERTS_ALC_T_PORT_CALL_BUF, size);
 
-    endp = bytes;
-    erts_encode_ext(arg3, &endp);
+    BIF_RET(retval);
+}
 
-    real_size = endp - bytes;
-    if (real_size > size) {
-	erl_exit(1, "%s, line %d: buffer overflow: %d word(s)\n",
-		 __FILE__, __LINE__, endp - (bytes + size));
-    }
-    erts_smp_proc_unlock(c_p, ERTS_PROC_LOCK_MAIN);
-#ifdef USE_VM_PROBES
-    if (DTRACE_ENABLED(driver_call)) {
-        DTRACE_CHARBUF(process_str, DTRACE_TERM_BUF_SIZE);
-        DTRACE_CHARBUF(port_str, DTRACE_TERM_BUF_SIZE);
+/*
+ * erts_internal:port_close/1 is used by the
+ * erlang:port_close/1 BIF.
+ */
+BIF_RETTYPE erts_internal_port_close_1(BIF_ALIST_1)
+{
+    Eterm ref;
+    Port *prt;
 
-        dtrace_pid_str(p->connected, process_str);
-        dtrace_port_str(p, port_str);
-        DTRACE5(driver_call, process_str, port_str, p->name, op, real_size);
-    }
-#endif
-    prc  = (char *) port_resp;
-    fpe_was_unmasked = erts_block_fpe();
-    ret = drv->call((ErlDrvData)p->drv_data, 
-		    (unsigned) op,
-		    (char *) bytes, 
-		    (int) real_size,
-		    &prc, 
-		    (int) sizeof(port_result),
-		    &ret_flags);
-    erts_unblock_fpe(fpe_was_unmasked);
-    if (IS_TRACED_FL(p, F_TRACE_SCHED_PORTS)) {
-    	trace_sched_ports_where(p, am_out, am_call);
-    }
-    
-    if (erts_system_profile_flags.runnable_ports && !erts_port_is_scheduled(p)) {
-    	profile_runnable_port(p, am_inactive);
-    }
-   
-    port_resp = (byte *) prc;
-    p->caller = NIL;
-    erts_smp_proc_lock(c_p, ERTS_PROC_LOCK_MAIN);
-#ifdef HARDDEBUG
-    { 
-	ErlDrvSizeT z;
-	printf("real_size = %ld,%d, ret = %ld,%d\r\n", (unsigned long) real_size,
-	       (int) real_size, (unsigned long)ret, (int) ret);
-	printf("[");
-	for(z = 0; z < real_size; ++z) {
-	    printf("%d, ",(int) bytes[z]);
-	}
-	printf("]\r\n");
-	printf("[");
-	for(z = 0; z < ret; ++z) {
-	    printf("%d, ",(int) port_resp[z]);
-	}
-	printf("]\r\n");
-    }
-#endif
-    if (ret <= 0 || port_resp[0] != VERSION_MAGIC) { 
-	/* Error or a binary without magic/ with wrong magic */
-	goto error;
-    }
-    result_size = erts_decode_ext_size(port_resp, ret);
-    if (result_size < 0) {
-	goto error;
-    }
-    hp = HAlloc(c_p, result_size);
-    hp_end = hp + result_size;
-    endp = port_resp;
-    res = erts_decode_ext(&hp, &MSO(c_p), &endp);
-    if (res == THE_NON_VALUE) {
-	goto error;
-    }
-    HRelease(c_p, hp_end, hp);
-    if (port_resp != port_result && !(ret_flags & DRIVER_CALL_KEEP_BUFFER)) {
-	driver_free(port_resp);
-    }
-    if (bytes != &port_input[0])
-	erts_free(ERTS_ALC_T_PORT_CALL_BUF, bytes);
-    if (p)
-	erts_port_release(p);
-#ifdef ERTS_SMP
-    ERTS_SMP_BIF_CHK_PENDING_EXIT(c_p, ERTS_PROC_LOCK_MAIN);
-#else
-    ERTS_BIF_CHK_EXITED(c_p);
+#ifdef DEBUG
+    ref = NIL;
 #endif
-    if (IS_TRACED_FL(c_p, F_TRACE_SCHED_PROCS)) {
-	trace_virtual_sched(c_p, am_in);
-    }
 
-    if (erts_system_profile_flags.runnable_procs && erts_system_profile_flags.exclusive) {
-	profile_runnable_proc(c_p, am_active);
+    prt = lookup_port(BIF_P, BIF_ARG_1);
+    if (!prt)
+	BIF_RET(am_badarg);
+
+
+    switch (erts_port_exit(BIF_P, 0, prt, prt->common.id, am_normal, &ref)) {
+    case ERTS_PORT_OP_CALLER_EXIT:
+    case ERTS_PORT_OP_BADARG:
+    case ERTS_PORT_OP_DROPPED:
+	BIF_RET(am_badarg);
+    case ERTS_PORT_OP_SCHEDULED:
+	ASSERT(is_internal_ref(ref));
+	BIF_RET(ref);
+    case ERTS_PORT_OP_DONE:
+	BIF_RET(am_true);
+    default:
+	ERTS_INTERNAL_ERROR("Unexpected erts_port_exit() result");
+	BIF_RET(am_internal_error);
     }
-  
-    return res;
 }
-    
-BIF_RETTYPE port_control_3(BIF_ALIST_3)
-{
-    Port* p;
-    Uint op;
-    Eterm res = THE_NON_VALUE;
-    
-    /* Virtual schedule out calling process before lock wait */
-    if (IS_TRACED_FL(BIF_P, F_TRACE_SCHED_PROCS)) {
-	trace_virtual_sched(BIF_P, am_out);
-    }
 
-    if (erts_system_profile_flags.runnable_procs && erts_system_profile_flags.exclusive) {
-    	profile_runnable_proc(BIF_P, am_inactive);
-    }
+/*
+ * erts_internal:port_connect/2 is used by the
+ * erlang:port_connect/2 BIF.
+ */
+BIF_RETTYPE erts_internal_port_connect_2(BIF_ALIST_2)
+{
+    Eterm ref;
+    Port* prt;
 
-    p = id_or_name2port(BIF_P, BIF_ARG_1);
-    if (!p) {
-    	/* Schedule the process before exiting */
-    	if (IS_TRACED_FL(BIF_P, F_TRACE_SCHED_PROCS)) {
-	    trace_virtual_sched(BIF_P, am_in);
-    	}
-	
-	if (erts_system_profile_flags.runnable_procs && erts_system_profile_flags.exclusive) {
-    	    profile_runnable_proc(BIF_P, am_active);
-	}
-	
-	BIF_ERROR(BIF_P, BADARG);
-    }
+    prt = lookup_port(BIF_P, BIF_ARG_1);
+    if (!prt)
+	BIF_RET(am_badarg);
 
-    /* Trace the port for scheduling in */
-    if (IS_TRACED_FL(p, F_TRACE_SCHED_PORTS)) {
-    	trace_sched_ports_where(p, am_in, am_control);
-    }
-    
-    if (erts_system_profile_flags.runnable_ports && !erts_port_is_scheduled(p)) {
-    	profile_runnable_port(p, am_active);
-    }
+#ifdef DEBUG
+    ref = NIL;
+#endif
 
-    if (term_to_Uint(BIF_ARG_2, &op))
-	res = erts_port_control(BIF_P, p, op, BIF_ARG_3);
-    
-    /* Trace the port for scheduling out */
-    if (IS_TRACED_FL(p, F_TRACE_SCHED_PORTS)) {
-    	trace_sched_ports_where(p, am_out, am_control);
+    switch (erts_port_connect(BIF_P, 0, prt, prt->common.id, BIF_ARG_2, &ref)) {
+    case ERTS_PORT_OP_CALLER_EXIT:
+    case ERTS_PORT_OP_BADARG:
+    case ERTS_PORT_OP_DROPPED:
+	BIF_RET(am_badarg);
+    case ERTS_PORT_OP_SCHEDULED:
+	ASSERT(is_internal_ref(ref));
+	BIF_RET(ref);
+	break;
+    case ERTS_PORT_OP_DONE:
+	BIF_RET(am_true);
+	break;
+    default:
+	ERTS_INTERNAL_ERROR("Unexpected erts_port_connect() result");
+	BIF_RET(am_internal_error);
     }
+}
 
-    if (erts_system_profile_flags.runnable_ports && !erts_port_is_scheduled(p)) {
-    	profile_runnable_port(p, am_inactive);
-    }
+BIF_RETTYPE erts_internal_port_info_1(BIF_ALIST_1)
+{
+    Eterm retval;
+    Port* prt;
 
-    erts_port_release(p);
-#ifdef ERTS_SMP
-    ERTS_SMP_BIF_CHK_PENDING_EXIT(BIF_P, ERTS_PROC_LOCK_MAIN);
-#else
-    ERTS_BIF_CHK_EXITED(BIF_P);
-#endif
-    
-    if (IS_TRACED_FL(BIF_P, F_TRACE_SCHED_PROCS)) {
-	trace_virtual_sched(BIF_P, am_in);
+    if (is_internal_port(BIF_ARG_1) || is_atom(BIF_ARG_1)) {
+	prt = lookup_port(BIF_P, BIF_ARG_1);
+	if (!prt)
+	    BIF_RET(am_undefined);
     }
-    
-    if (erts_system_profile_flags.runnable_procs && erts_system_profile_flags.exclusive) {
-    	profile_runnable_proc(BIF_P, am_active);
+    else if (is_external_port(BIF_ARG_1)) {
+	if (external_port_dist_entry(BIF_ARG_1) == erts_this_dist_entry)
+	    BIF_RET(am_undefined);
+	else
+	    BIF_RET(am_badarg);
     }
-    
-    if (is_non_value(res)) {
-	BIF_ERROR(BIF_P, BADARG);
+    else {
+	BIF_RET(am_badarg);
+    }
+
+    switch (erts_port_info(BIF_P, prt, THE_NON_VALUE, &retval)) {
+    case ERTS_PORT_OP_CALLER_EXIT:
+    case ERTS_PORT_OP_BADARG:
+	BIF_RET(am_badarg);
+    case ERTS_PORT_OP_DROPPED:
+	BIF_RET(am_undefined);
+    case ERTS_PORT_OP_SCHEDULED:
+	ASSERT(is_internal_ref(retval));
+	BIF_RET(retval);
+    case ERTS_PORT_OP_DONE:
+	ASSERT(is_not_internal_ref(retval));
+	BIF_RET(retval);
+    default:
+	ERTS_INTERNAL_ERROR("Unexpected erts_port_info() result");
+	BIF_RET(am_internal_error);
     }
-    BIF_RET(res);
 }
 
-BIF_RETTYPE port_close_1(BIF_ALIST_1)
-{
-    Port* p;
-    erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_MAIN);
-    p = id_or_name2port(NULL, BIF_ARG_1);
-    if (!p) {
-	erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_MAIN);
-	BIF_ERROR(BIF_P, BADARG);
-    }
-    erts_do_exit_port(p, p->connected, am_normal);
-    /* if !ERTS_SMP: since we terminate port with reason normal 
-       we SHOULD never get an exit signal ourselves
-       */
-    erts_port_release(p);
-    erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_MAIN);
-    BIF_RET(am_true);
-}
 
-BIF_RETTYPE port_connect_2(BIF_ALIST_2)
+BIF_RETTYPE erts_internal_port_info_2(BIF_ALIST_2)
 {
+    Eterm retval;
     Port* prt;
-    Process* rp;
-    Eterm pid = BIF_ARG_2;
 
-    if (is_not_internal_pid(pid)) {
-    error:
-	BIF_ERROR(BIF_P, BADARG);
+    if (is_internal_port(BIF_ARG_1) || is_atom(BIF_ARG_1)) {
+	prt = lookup_port(BIF_P, BIF_ARG_1);
+	if (!prt)
+	    BIF_RET(am_undefined);
     }
-    prt = id_or_name2port(BIF_P, BIF_ARG_1);
-    if (!prt) {
-	goto error;
+    else if (is_external_port(BIF_ARG_1)) {
+	if (external_port_dist_entry(BIF_ARG_1) == erts_this_dist_entry)
+	    BIF_RET(am_undefined);
+	else
+	    BIF_RET(am_badarg);
     }
-
-    rp = erts_pid2proc(BIF_P, ERTS_PROC_LOCK_MAIN,
-		       pid, ERTS_PROC_LOCK_LINK);
-    if (!rp) {
-	erts_smp_port_unlock(prt);
-	ERTS_SMP_ASSERT_IS_NOT_EXITING(BIF_P);
-	goto error;
-    }
-
-    erts_add_link(&(rp->nlinks), LINK_PID, prt->id);
-    erts_add_link(&(prt->nlinks), LINK_PID, pid);
-
-    erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_LINK);
-
-    prt->connected = pid; /* internal pid */
-    erts_smp_port_unlock(prt);
-#ifdef USE_VM_PROBES
-    if (DTRACE_ENABLED(port_connect)) {
-        DTRACE_CHARBUF(process_str, DTRACE_TERM_BUF_SIZE);
-        DTRACE_CHARBUF(port_str, DTRACE_TERM_BUF_SIZE);
-        DTRACE_CHARBUF(newprocess_str, DTRACE_TERM_BUF_SIZE);
-
-        dtrace_pid_str(prt->connected, process_str);
-        erts_snprintf(port_str, sizeof(port_str), "%T", prt->id);
-        dtrace_proc_str(rp, newprocess_str);
-        DTRACE4(port_connect, process_str, port_str, prt->name, newprocess_str);
+    else {
+	BIF_RET(am_badarg);
+    }
+
+    switch (erts_port_info(BIF_P, prt, BIF_ARG_2, &retval)) {
+    case ERTS_PORT_OP_CALLER_EXIT:
+    case ERTS_PORT_OP_BADARG:
+	BIF_RET(am_badarg);
+    case ERTS_PORT_OP_DROPPED:
+	BIF_RET(am_undefined);
+    case ERTS_PORT_OP_SCHEDULED:
+	ASSERT(is_internal_ref(retval));
+	BIF_RET(retval);
+    case ERTS_PORT_OP_DONE:
+	ASSERT(is_not_internal_ref(retval));
+	BIF_RET(retval);
+    default:
+	ERTS_INTERNAL_ERROR("Unexpected erts_port_info() result");
+	BIF_RET(am_internal_error);
     }
-#endif
-    BIF_RET(am_true);
 }
 
-BIF_RETTYPE port_set_data_2(BIF_ALIST_2)
+
+BIF_RETTYPE erts_internal_port_set_data_2(BIF_ALIST_2)
 {
+    Eterm ref;
     Port* prt;
-    Eterm portid = BIF_ARG_1;
-    Eterm data   = BIF_ARG_2;
 
-    prt = id_or_name2port(BIF_P, portid);
-    if (!prt) {
-	BIF_ERROR(BIF_P, BADARG);
-    }
-    if (prt->bp != NULL) {
-	free_message_buffer(prt->bp);
-	prt->bp = NULL;
-    }
-    if (IS_CONST(data)) {
-	prt->data = data;
-    } else {
-	Uint size;
-	ErlHeapFragment* bp;
-	Eterm* hp;
-
-	size = size_object(data);
-	prt->bp = bp = new_message_buffer(size);
-	hp = bp->mem;
-	prt->data = copy_struct(data, size, &hp, &bp->off_heap);
+    prt = lookup_port(BIF_P, BIF_ARG_1);
+    if (!prt)
+	BIF_RET(am_badarg);
+
+    switch (erts_port_set_data(BIF_P, prt, BIF_ARG_2, &ref)) {
+    case ERTS_PORT_OP_CALLER_EXIT:
+    case ERTS_PORT_OP_BADARG:
+    case ERTS_PORT_OP_DROPPED:
+	BIF_RET(am_badarg);
+    case ERTS_PORT_OP_SCHEDULED:
+	ASSERT(is_internal_ref(ref));
+	BIF_RET(ref);
+    case ERTS_PORT_OP_DONE:
+	BIF_RET(am_true);
+    default:
+	ERTS_INTERNAL_ERROR("Unexpected erts_port_set_data() result");
+	BIF_RET(am_internal_error);
     }
-    erts_smp_port_unlock(prt);
-    BIF_RET(am_true);
 }
 
 
-BIF_RETTYPE port_get_data_1(BIF_ALIST_1)
+BIF_RETTYPE erts_internal_port_get_data_1(BIF_ALIST_1)
 {
-    BIF_RETTYPE res;
+    Eterm retval;
     Port* prt;
-    Eterm portid = BIF_ARG_1;
 
-    prt = id_or_name2port(BIF_P, portid);
-    if (!prt) {
-	BIF_ERROR(BIF_P, BADARG);
-    }
-    if (prt->bp == NULL) {	/* MUST be CONST! */
-	res = prt->data;
-    } else {
-	Eterm* hp = HAlloc(BIF_P, prt->bp->used_size);
-	res = copy_struct(prt->data, prt->bp->used_size, &hp, &MSO(BIF_P));
+    prt = lookup_port(BIF_P, BIF_ARG_1);
+    if (!prt)
+	BIF_RET(am_badarg);
+
+    switch (erts_port_get_data(BIF_P, prt, &retval)) {
+    case ERTS_PORT_OP_CALLER_EXIT:
+    case ERTS_PORT_OP_BADARG:
+    case ERTS_PORT_OP_DROPPED:
+	BIF_RET(am_badarg);
+    case ERTS_PORT_OP_SCHEDULED:
+	ASSERT(is_internal_ref(retval));
+	BIF_RET(retval);
+    case ERTS_PORT_OP_DONE:
+	ASSERT(is_not_internal_ref(retval));
+	BIF_RET(retval);
+    default:
+	ERTS_INTERNAL_ERROR("Unexpected erts_port_get_data() result");
+	BIF_RET(am_internal_error);
     }
-    erts_smp_port_unlock(prt);
-    BIF_RET(res);
 }
 
 /* 
@@ -625,11 +485,10 @@ BIF_RETTYPE port_get_data_1(BIF_ALIST_1)
  * either BADARG or SYSTEM_LIMIT).
  */
 
-static int
-open_port(Process* p, Eterm name, Eterm settings, int *err_nump)
+static Port *
+open_port(Process* p, Eterm name, Eterm settings, int *err_typep, int *err_nump)
 {
-#define OPEN_PORT_ERROR(VAL) do { port_num = (VAL); goto do_return; } while (0)
-    int i, port_num;
+    int i;
     Eterm option;
     Uint arity;
     Eterm* tp;
@@ -637,11 +496,11 @@ open_port(Process* p, Eterm name, Eterm settings, int *err_nump)
     erts_driver_t* driver;
     char* name_buf = NULL;
     SysDriverOpts opts;
-    int binary_io;
-    int soft_eof;
     Sint linebuf;
     Eterm edir = NIL;
     byte dir[MAXPATHLEN];
+    erts_aint32_t sflgs = 0;
+    Port *port;
 
     /* These are the defaults */
     opts.packet_bytes = 0;
@@ -655,8 +514,7 @@ open_port(Process* p, Eterm name, Eterm settings, int *err_nump)
     opts.overlapped_io = 0; 
     opts.spawn_type = ERTS_SPAWN_ANY; 
     opts.argv = NULL;
-    binary_io = 0;
-    soft_eof = 0;
+    opts.parallelism = erts_port_parallelism;
     linebuf = 0;
 
     *err_nump = 0;
@@ -734,6 +592,13 @@ open_port(Process* p, Eterm name, Eterm settings, int *err_nump)
 		    }
 		} else if (option == am_cd) {
 		    edir = *tp;
+		} else if (option == am_parallelism) {
+		    if (*tp == am_true)
+			opts.parallelism = 1;
+		    else if (*tp == am_false)
+			opts.parallelism = 0;
+		    else
+			goto badarg;
 		} else {
 		    goto badarg;
 		}
@@ -748,13 +613,13 @@ open_port(Process* p, Eterm name, Eterm settings, int *err_nump)
 	    } else if (*nargs == am_nouse_stdio) {
 		opts.use_stdio = 0;
 	    } else if (*nargs == am_binary) {
-		binary_io = 1;
+		sflgs |= ERTS_PORT_SFLG_BINARY_IO;
 	    } else if (*nargs == am_in) {
 		opts.read_write |= DO_READ;
 	    } else if (*nargs == am_out) {
 		opts.read_write |= DO_WRITE;
 	    } else if (*nargs == am_eof) {
-		soft_eof = 1;
+		sflgs |= ERTS_PORT_SFLG_SOFT_EOF;
 	    } else if (*nargs == am_hide) {
 		opts.hide_window = 1;
 	    } else if (*nargs == am_exit_status) {
@@ -902,9 +767,9 @@ open_port(Process* p, Eterm name, Eterm settings, int *err_nump)
 	    heap[2] = make_small(0);
 	    heap[3] = NIL;
 	    iolist = make_list(heap);
-	    r = io_list_to_buf(iolist, (char*) dir, MAXPATHLEN);
+	    r = erts_iolist_to_buf(iolist, (char*) dir, MAXPATHLEN);
 	    UnUseTmpHeap(4,p);
-	    if (r < 0) {
+	    if (ERTS_IOLIST_TO_BUF_FAILED(r)) {
 		goto badarg;
 	    }
 	    opts.wd = (char *) dir;
@@ -926,44 +791,40 @@ open_port(Process* p, Eterm name, Eterm settings, int *err_nump)
 
     erts_smp_proc_unlock(p, ERTS_PROC_LOCK_MAIN);
 
-    port_num = erts_open_driver(driver, p->id, name_buf, &opts, err_nump);
+    port = erts_open_driver(driver, p->common.id, name_buf, &opts, err_typep, err_nump);
 #ifdef USE_VM_PROBES
-    if (port_num >= 0 && DTRACE_ENABLED(port_open)) {
+    if (port && DTRACE_ENABLED(port_open)) {
         DTRACE_CHARBUF(process_str, DTRACE_TERM_BUF_SIZE);
         DTRACE_CHARBUF(port_str, DTRACE_TERM_BUF_SIZE);
 
         dtrace_proc_str(p, process_str);
-        erts_snprintf(port_str, sizeof(port_str), "%T", erts_port[port_num].id);
+        erts_snprintf(port_str, sizeof(port_str), "%T", port->common.id);
         DTRACE3(port_open, process_str, name_buf, port_str);
     }
 #endif
     erts_smp_proc_lock(p, ERTS_PROC_LOCK_MAIN);
 
-    if (port_num < 0) {
-	DEBUGF(("open_driver returned %d(%d)\n", port_num, *err_nump));
+    if (!port) {
+	DEBUGF(("open_driver returned (%d:%d)\n",
+		err_typep ? *err_typep : 4711,
+		err_nump ? *err_nump : 4711));
     	if (IS_TRACED_FL(p, F_TRACE_SCHED_PROCS)) {
             trace_virtual_sched(p, am_in);
     	}
-	OPEN_PORT_ERROR(port_num);
+	goto do_return;
     }
     
     if (IS_TRACED_FL(p, F_TRACE_SCHED_PROCS)) {
         trace_virtual_sched(p, am_in);
     }
 
-    if (binary_io) {
-	erts_port_status_bor_set(&erts_port[port_num],
-				 ERTS_PORT_SFLG_BINARY_IO);
-    }
-    if (soft_eof) {
-	erts_port_status_bor_set(&erts_port[port_num],
-				 ERTS_PORT_SFLG_SOFT_EOF);
-    }
-    if (linebuf && erts_port[port_num].linebuf == NULL){
-	erts_port[port_num].linebuf = allocate_linebuf(linebuf); 
-	erts_port_status_bor_set(&erts_port[port_num],
-				 ERTS_PORT_SFLG_LINEBUF_IO);
+    if (linebuf && port->linebuf == NULL){
+	port->linebuf = allocate_linebuf(linebuf);
+	sflgs |= ERTS_PORT_SFLG_LINEBUF_IO;
     }
+
+    if (sflgs)
+	erts_atomic32_read_bor_relb(&port->state, sflgs);
  
  do_return:
     if (name_buf)
@@ -974,13 +835,15 @@ open_port(Process* p, Eterm name, Eterm settings, int *err_nump)
     if (opts.wd && opts.wd != ((char *)dir)) {
 	erts_free(ERTS_ALC_T_TMP, (void *) opts.wd);
     }
-    return port_num;
+    return port;
     
  badarg:
-    *err_nump = BADARG;
-    OPEN_PORT_ERROR(-3);
+    if (err_typep)
+	*err_typep = -3;
+    if (err_nump)
+	*err_nump = BADARG;
+    port = NULL;
     goto do_return;
-#undef OPEN_PORT_ERROR
 }
 
 /* Arguments can be given i unicode and as raw binaries, convert filename is used to convert */
diff --git a/erts/emulator/beam/erl_bif_re.c b/erts/emulator/beam/erl_bif_re.c
index b036c5ef5c..88f980d19f 100644
--- a/erts/emulator/beam/erl_bif_re.c
+++ b/erts/emulator/beam/erl_bif_re.c
@@ -413,7 +413,7 @@ build_compile_result(Process *p, Eterm error_tag, pcre *result, int errcode, con
 static BIF_RETTYPE
 re_compile(Process* p, Eterm arg1, Eterm arg2)
 {
-    Uint slen;
+    ErlDrvSizeT slen;
     char *expr;
     pcre *result;
     int errcode = 0;
@@ -444,7 +444,7 @@ re_compile(Process* p, Eterm arg1, Eterm arg2)
         BIF_ERROR(p,BADARG);
     }
     expr = erts_alloc(ERTS_ALC_T_RE_TMP_BUF, slen + 1);
-    if (io_list_to_buf(arg1, expr, slen) != 0) {
+    if (erts_iolist_to_buf(arg1, expr, slen) != 0) {
 	erts_free(ERTS_ALC_T_RE_TMP_BUF, expr);
 	BIF_ERROR(p,BADARG);
     }
@@ -797,7 +797,7 @@ build_capture(Eterm capture_spec[CAPSPEC_SIZE], const pcre *code)
 			memcpy(tmpb,ap->name,ap->len);
 			tmpb[ap->len] = '\0';
 		    } else {
-			Uint slen;
+			ErlDrvSizeT slen;
 			if (erts_iolist_size(val, &slen)) {
 			    goto error;
 			}
@@ -809,7 +809,7 @@ build_capture(Eterm capture_spec[CAPSPEC_SIZE], const pcre *code)
 						    (tmpbsiz = slen + 1));
 			    }
 			}
-			if (io_list_to_buf(val, tmpb, slen) != 0) {
+			if (erts_iolist_to_buf(val, tmpb, slen) != 0) {
 			    goto error;
 			}
 			tmpb[slen] = '\0';
@@ -853,7 +853,7 @@ re_run(Process *p, Eterm arg1, Eterm arg2, Eterm arg3)
     const pcre *code_tmp;
     RestartContext restart;
     byte *temp_alloc = NULL;
-    Uint slength;
+    ErlDrvSizeT slength;
     int startoffset = 0;
     int options = 0, comp_options = 0;
     int ovsize;
@@ -877,7 +877,7 @@ re_run(Process *p, Eterm arg1, Eterm arg2, Eterm arg3)
     if (is_not_tuple(arg2) || (arityval(*tuple_val(arg2)) != 4)) {
 	if (is_binary(arg2) || is_list(arg2) || is_nil(arg2)) {
 	    /* Compile from textual RE */
-	    Uint slen;
+	    ErlDrvSizeT slen;
 	    char *expr;
 	    pcre *result;
 	    int errcode = 0;
@@ -896,7 +896,7 @@ re_run(Process *p, Eterm arg1, Eterm arg2, Eterm arg3)
 	    }
 	    
 	    expr = erts_alloc(ERTS_ALC_T_RE_TMP_BUF, slen + 1);
-	    if (io_list_to_buf(arg2, expr, slen) != 0) {
+	    if (erts_iolist_to_buf(arg2, expr, slen) != 0) {
 		erts_free(ERTS_ALC_T_RE_TMP_BUF, expr);
 		BIF_ERROR(p,BADARG);
 	    }
@@ -1039,7 +1039,7 @@ handle_iolist:
 	}
 	restart.subject = erts_alloc(ERTS_ALC_T_RE_SUBJECT, slength);
 
-	if (io_list_to_buf(arg1, restart.subject, slength) != 0) {
+	if (erts_iolist_to_buf(arg1, restart.subject, slength) != 0) {
 	    erts_free(ERTS_ALC_T_RE_SUBJECT, restart.ovector);
 	    erts_free(ERTS_ALC_T_RE_SUBJECT, restart.code);
 	    erts_free(ERTS_ALC_T_RE_SUBJECT, restart.subject);
diff --git a/erts/emulator/beam/erl_bif_timer.c b/erts/emulator/beam/erl_bif_timer.c
index 525b11f61c..d67695e533 100644
--- a/erts/emulator/beam/erl_bif_timer.c
+++ b/erts/emulator/beam/erl_bif_timer.c
@@ -265,10 +265,10 @@ link_proc(Process *p, ErtsBifTimer* btm)
 {
     btm->receiver.proc.ess = p;
     btm->receiver.proc.prev = NULL;
-    btm->receiver.proc.next = p->bif_timers;
-    if (p->bif_timers)	
-	p->bif_timers->receiver.proc.prev = btm;
-    p->bif_timers = btm;
+    btm->receiver.proc.next = p->u.bif_timers;
+    if (p->u.bif_timers)	
+	p->u.bif_timers->receiver.proc.prev = btm;
+    p->u.bif_timers = btm;
 }
 
 static ERTS_INLINE void
@@ -277,7 +277,7 @@ unlink_proc(ErtsBifTimer* btm)
     if (btm->receiver.proc.prev)
 	btm->receiver.proc.prev->receiver.proc.next = btm->receiver.proc.next;
     else
-	btm->receiver.proc.ess->bif_timers = btm->receiver.proc.next;
+	btm->receiver.proc.ess->u.bif_timers = btm->receiver.proc.next;
     if (btm->receiver.proc.next)
 	btm->receiver.proc.next->receiver.proc.prev = btm->receiver.proc.prev;
 }
@@ -613,7 +613,7 @@ erts_print_bif_timer_info(int to, void *to_arg)
 	for (btm = bif_timer_tab[i]; btm; btm = btm->tab.next) {
 	    Eterm receiver = (btm->flags & BTM_FLG_BYNAME
 			      ? btm->receiver.name
-			      : btm->receiver.proc.ess->id);
+			      : btm->receiver.proc.ess->common.id);
 	    erts_print(to, to_arg, "=timer:%T\n", receiver);
 	    erts_print(to, to_arg, "Message: %T\n", btm->message);
 	    erts_print(to, to_arg, "Time left: %u ms\n",
@@ -637,7 +637,7 @@ erts_cancel_bif_timers(Process *p, ErtsProcLocks plocks)
 	erts_smp_proc_lock(p, plocks);
     }
 
-    btm = p->bif_timers;
+    btm = p->u.bif_timers;
     while (btm) {
 	ErtsBifTimer *tmp_btm;
 	ASSERT(!(btm->flags & BTM_FLG_CANCELED));
@@ -647,7 +647,7 @@ erts_cancel_bif_timers(Process *p, ErtsProcLocks plocks)
 	erts_cancel_timer(&tmp_btm->tm);
     }
 
-    p->bif_timers = NULL;
+    p->u.bif_timers = NULL;
 
     erts_smp_btm_rwunlock();
 }
@@ -696,7 +696,7 @@ erts_bif_timer_foreach(void (*func)(Eterm, Eterm, ErlHeapFragment *, void *),
 	for (btm = bif_timer_tab[i]; btm; btm = btm->tab.next) {
 	    (*func)((btm->flags & BTM_FLG_BYNAME
 		     ? btm->receiver.name
-		     : btm->receiver.proc.ess->id),
+		     : btm->receiver.proc.ess->common.id),
 		    btm->message,
 		    btm->bp,
 		    arg);
diff --git a/erts/emulator/beam/erl_bif_trace.c b/erts/emulator/beam/erl_bif_trace.c
index 805d788177..99a4394666 100644
--- a/erts/emulator/beam/erl_bif_trace.c
+++ b/erts/emulator/beam/erl_bif_trace.c
@@ -124,7 +124,7 @@ trace_pattern(Process* p, Eterm MFA, Eterm Pattern, Eterm flaglist)
     struct trace_pattern_flags flags = erts_trace_pattern_flags_off;
     int is_global;
     Process *meta_tracer_proc = p;
-    Eterm meta_tracer_pid = p->id;
+    Eterm meta_tracer_pid = p->common.id;
 
     if (!erts_try_seize_code_write_permission(p)) {
 	ERTS_BIF_YIELD3(bif_export[BIF_trace_pattern_3], p, MFA, Pattern, flaglist);
@@ -171,14 +171,12 @@ trace_pattern(Process* p, Eterm MFA, Eterm Pattern, Eterm flaglist)
 		}
 	    } else if (is_internal_port(meta_tracer_pid)) {
 		Port *meta_tracer_port;
-		meta_tracer_proc = NULL;		
-		if (internal_port_index(meta_tracer_pid) >= erts_max_ports)
+		meta_tracer_proc = NULL;
+		meta_tracer_port = (erts_port_lookup(
+					meta_tracer_pid,
+					ERTS_PORT_SFLGS_INVALID_TRACER_LOOKUP));
+		if (!meta_tracer_port)
 		    goto error;
-		meta_tracer_port = 
-		    &erts_port[internal_port_index(meta_tracer_pid)];
-		if (INVALID_TRACER_PORT(meta_tracer_port, meta_tracer_pid)) {
-		    goto error;
-		}
 	    } else {
 		goto error;
 	    }
@@ -254,7 +252,7 @@ trace_pattern(Process* p, Eterm MFA, Eterm Pattern, Eterm flaglist)
 	    MatchSetRef(erts_default_meta_match_spec);
 	    erts_default_meta_tracer_pid = meta_tracer_pid;
 	    if (meta_tracer_proc) {
-		meta_tracer_proc->trace_flags |= F_TRACER;
+		ERTS_TRACE_FLAGS(meta_tracer_proc) |= F_TRACER;
 	    }
 	} else if (! flags.breakpoint) {
 	    MatchSetUnref(erts_default_meta_match_spec);
@@ -342,7 +340,7 @@ trace_pattern(Process* p, Eterm MFA, Eterm Pattern, Eterm flaglist)
 	}
     
 	if (meta_tracer_proc) {
-	    meta_tracer_proc->trace_flags |= F_TRACER;
+	    ERTS_TRACE_FLAGS(meta_tracer_proc) |= F_TRACER;
 	}
 
 	matches = erts_set_trace_pattern(p, mfa, specified,
@@ -526,24 +524,24 @@ Eterm trace_3(BIF_ALIST_3)
     if (is_nil(tracer) || is_internal_pid(tracer)) {
 	Process *tracer_proc = erts_pid2proc(p,
 					     ERTS_PROC_LOCK_MAIN,
-					     is_nil(tracer) ? p->id : tracer,
+					     is_nil(tracer) ? p->common.id : tracer,
 					     ERTS_PROC_LOCKS_ALL);
 	if (!tracer_proc)
 	    goto error;
-	tracer_proc->trace_flags |= F_TRACER;
+	ERTS_TRACE_FLAGS(tracer_proc) |= F_TRACER;
 	erts_smp_proc_unlock(tracer_proc,
 			     (tracer_proc == p
 			      ? ERTS_PROC_LOCKS_ALL_MINOR
 			      : ERTS_PROC_LOCKS_ALL));
     } else if (is_internal_port(tracer)) {
-	Port *tracer_port = erts_id2port(tracer, p, ERTS_PROC_LOCK_MAIN);
-	if (!erts_is_valid_tracer_port(tracer)) {
-	    if (tracer_port)
-		erts_smp_port_unlock(tracer_port);
+	Port *tracer_port = erts_id2port_sflgs(tracer,
+					       p,
+					       ERTS_PROC_LOCK_MAIN,
+					       ERTS_PORT_SFLGS_INVALID_TRACER_LOOKUP);
+	if (!tracer_port)
 	    goto error;
-	}
-	tracer_port->trace_flags |= F_TRACER;
-	erts_smp_port_unlock(tracer_port);
+	ERTS_TRACE_FLAGS(tracer_port) |= F_TRACER;
+	erts_port_release(tracer_port);
     } else
 	goto error;
 
@@ -554,7 +552,7 @@ Eterm trace_3(BIF_ALIST_3)
     case am_true: 
 	on = 1;
 	if (is_nil(tracer))
-	    tracer = p->id;
+	    tracer = p->common.id;
 	break;
     default: 
 	goto error;
@@ -576,26 +574,29 @@ Eterm trace_3(BIF_ALIST_3)
 	if (pid_spec == tracer)
 	    goto error;
 
-	tracee_port = erts_id2port(pid_spec, p, ERTS_PROC_LOCK_MAIN);
+	tracee_port = erts_id2port_sflgs(pid_spec,
+					 p,
+					 ERTS_PROC_LOCK_MAIN,
+					 ERTS_PORT_SFLGS_INVALID_LOOKUP);
 	if (!tracee_port)
 	    goto error;
 	
 	if (tracer != NIL && port_already_traced(p, tracee_port, tracer)) {
-	    erts_smp_port_unlock(tracee_port);
+	    erts_port_release(tracee_port);
 	    goto already_traced;
 	}
 
 	if (on)
-	    tracee_port->trace_flags |= mask;
+	    ERTS_TRACE_FLAGS(tracee_port) |= mask;
 	else
-	    tracee_port->trace_flags &= ~mask;
+	    ERTS_TRACE_FLAGS(tracee_port) &= ~mask;
 	
-	if (!tracee_port->trace_flags)
-	    tracee_port->tracer_proc = NIL;
+	if (!ERTS_TRACE_FLAGS(tracee_port))
+	    ERTS_TRACER_PROC(tracee_port) = NIL;
 	else if (tracer != NIL)
-	    tracee_port->tracer_proc = tracer;
+	    ERTS_TRACER_PROC(tracee_port) = tracer;
 
-	erts_smp_port_unlock(tracee_port);
+	erts_port_release(tracee_port);
 
 	matches = 1;
     } else if (is_pid(pid_spec)) {
@@ -627,14 +628,14 @@ Eterm trace_3(BIF_ALIST_3)
 	}
 
 	if (on)
-	    tracee_p->trace_flags |= mask;
+	    ERTS_TRACE_FLAGS(tracee_p) |= mask;
 	else
-	    tracee_p->trace_flags &= ~mask;
+	    ERTS_TRACE_FLAGS(tracee_p) &= ~mask;
 
-	if ((tracee_p->trace_flags & TRACEE_FLAGS) == 0)
-	    tracee_p->tracer_proc = NIL;
+	if ((ERTS_TRACE_FLAGS(tracee_p) & TRACEE_FLAGS) == 0)
+	    ERTS_TRACER_PROC(tracee_p) = NIL;
 	else if (tracer != NIL)
-	    tracee_p->tracer_proc = tracer;
+	    ERTS_TRACER_PROC(tracee_p) = tracer;
 
 	erts_smp_proc_unlock(tracee_p,
 			     (tracee_p == p
@@ -708,47 +709,56 @@ Eterm trace_3(BIF_ALIST_3)
 
 	    ok = 1;
 	    if (procs || mods) {
+		int max = erts_ptab_max(&erts_proc);
 		/* tracing of processes */
-		for (i = 0; i < erts_max_processes; i++) {
+		for (i = 0; i < max; i++) {
 		    Process* tracee_p = erts_pix2proc(i);
 		    if (! tracee_p) 
 			continue;
 		    if (tracer != NIL) {
-			if (tracee_p->id == tracer)
+			if (tracee_p->common.id == tracer)
 			    continue;
 			if (already_traced(NULL, tracee_p, tracer))
 			    continue;
 		    }
 		    if (on) {
-			tracee_p->trace_flags |= mask;
+			ERTS_TRACE_FLAGS(tracee_p) |= mask;
 		    } else {
-			tracee_p->trace_flags &= ~mask;
+			ERTS_TRACE_FLAGS(tracee_p) &= ~mask;
 		    }
-		    if(!(tracee_p->trace_flags & TRACEE_FLAGS)) {
-			tracee_p->tracer_proc = NIL;
+		    if(!(ERTS_TRACE_FLAGS(tracee_p) & TRACEE_FLAGS)) {
+			ERTS_TRACER_PROC(tracee_p) = NIL;
 		    } else if (tracer != NIL) {
-			tracee_p->tracer_proc = tracer;
+			ERTS_TRACER_PROC(tracee_p) = tracer;
 		    }
 		    matches++;
 		}
 	    }
 	    if (ports || mods) {
+		int max = erts_ptab_max(&erts_port);
 		/* tracing of ports */
-		for (i = 0; i < erts_max_ports; i++) {
-		    Port *tracee_port = &erts_port[i];
-		    if (tracee_port->status & ERTS_PORT_SFLGS_DEAD) continue;
+		for (i = 0; i < max; i++) {
+		    erts_aint32_t state;
+		    Port *tracee_port = erts_pix2port(i);
+		    if (!tracee_port)
+			continue;
+		    state = erts_atomic32_read_nob(&tracee_port->state);
+		    if (state & ERTS_PORT_SFLGS_DEAD)
+			continue;
 		    if (tracer != NIL) {
-			if (tracee_port->id == tracer) continue;
-			if (port_already_traced(NULL, tracee_port, tracer)) continue;
+			if (tracee_port->common.id == tracer)
+			    continue;
+			if (port_already_traced(NULL, tracee_port, tracer))
+			    continue;
 		    }
 
-		    if (on) tracee_port->trace_flags |= mask;
-		    else tracee_port->trace_flags &= ~mask;
+		    if (on) ERTS_TRACE_FLAGS(tracee_port) |= mask;
+		    else ERTS_TRACE_FLAGS(tracee_port) &= ~mask;
 		
-		    if (!(tracee_port->trace_flags & TRACEE_FLAGS)) {
-			tracee_port->tracer_proc = NIL;
+		    if (!(ERTS_TRACE_FLAGS(tracee_port) & TRACEE_FLAGS)) {
+			ERTS_TRACER_PROC(tracee_port) = NIL;
 		    } else if (tracer != NIL) {
-			tracee_port->tracer_proc = tracer;
+			ERTS_TRACER_PROC(tracee_port) = tracer;
 		    }
 		    /* matches are not counted for ports since it would violate compatibility */
 		    /* This could be a reason to modify this function or make a new one. */
@@ -817,20 +827,20 @@ static int port_already_traced(Process *c_p, Port *tracee_port, Eterm tracer)
      * * main lock is held on c_p
      * * all locks are held on port tracee_p
      */
-    if ((tracee_port->trace_flags & TRACEE_FLAGS)
-	&& tracee_port->tracer_proc != tracer) {
+    if ((ERTS_TRACE_FLAGS(tracee_port) & TRACEE_FLAGS)
+	&& ERTS_TRACER_PROC(tracee_port) != tracer) {
 	/* This tracee is already being traced, and not by the 
 	 * tracer to be */
-	if (is_internal_port(tracee_port->tracer_proc)) {
-	    if (!erts_is_valid_tracer_port(tracee_port->tracer_proc)) {
+	if (is_internal_port(ERTS_TRACER_PROC(tracee_port))) {
+	    if (!erts_is_valid_tracer_port(ERTS_TRACER_PROC(tracee_port))) {
 		/* Current trace port now invalid 
 		 * - discard it and approve the new. */
 		goto remove_tracer;
 	    } else
 		return 1;
 	}
-	else if(is_internal_pid(tracee_port->tracer_proc)) {
-	    Process *tracer_p = erts_proc_lookup(tracee_port->tracer_proc);
+	else if(is_internal_pid(ERTS_TRACER_PROC(tracee_port))) {
+	    Process *tracer_p = erts_proc_lookup(ERTS_TRACER_PROC(tracee_port));
 	    if (!tracer_p) {
 		/* Current trace process now invalid
 		 * - discard it and approve the new. */
@@ -840,8 +850,8 @@ static int port_already_traced(Process *c_p, Port *tracee_port, Eterm tracer)
 	}
 	else {
 	remove_tracer:
-	    tracee_port->trace_flags &= ~TRACEE_FLAGS;
-	    tracee_port->tracer_proc = NIL;
+	    ERTS_TRACE_FLAGS(tracee_port) &= ~TRACEE_FLAGS;
+	    ERTS_TRACER_PROC(tracee_port) = NIL;
 	}
     }
     return 0;
@@ -857,20 +867,22 @@ static int already_traced(Process *c_p, Process *tracee_p, Eterm tracer)
      * * main lock is held on c_p
      * * all locks multiple are held on tracee_p
      */
-    if ((tracee_p->trace_flags & TRACEE_FLAGS)
-	&& tracee_p->tracer_proc != tracer) {
+    if ((ERTS_TRACE_FLAGS(tracee_p) & TRACEE_FLAGS)
+	&& ERTS_TRACER_PROC(tracee_p) != tracer) {
 	/* This tracee is already being traced, and not by the 
 	 * tracer to be */
-	if (is_internal_port(tracee_p->tracer_proc)) {
-	    if (!erts_is_valid_tracer_port(tracee_p->tracer_proc)) {
+	if (is_internal_port(ERTS_TRACER_PROC(tracee_p))) {
+	    if (!erts_is_valid_tracer_port(ERTS_TRACER_PROC(tracee_p))) {
 		/* Current trace port now invalid 
 		 * - discard it and approve the new. */
 		goto remove_tracer;
 	    } else
 		return 1;
 	}
-	else if(is_internal_pid(tracee_p->tracer_proc)) {
-	    Process *tracer_p = erts_proc_lookup(tracee_p->tracer_proc);
+	else if(is_internal_pid(ERTS_TRACER_PROC(tracee_p))) {
+	    Process *tracer_p;
+
+	    tracer_p = erts_proc_lookup(ERTS_TRACER_PROC(tracee_p));
 	    if (!tracer_p) {
 		/* Current trace process now invalid
 		 * - discard it and approve the new. */
@@ -880,8 +892,8 @@ static int already_traced(Process *c_p, Process *tracee_p, Eterm tracer)
 	}
 	else {
 	remove_tracer:
-	    tracee_p->trace_flags &= ~TRACEE_FLAGS;
-	    tracee_p->tracer_proc = NIL;
+	    ERTS_TRACE_FLAGS(tracee_p) &= ~TRACEE_FLAGS;
+	    ERTS_TRACER_PROC(tracee_p) = NIL;
 	}
     }
     return 0;
@@ -925,8 +937,7 @@ trace_info_pid(Process* p, Eterm pid_spec, Eterm key)
 
     if (pid_spec == am_new) {
 	erts_get_default_tracing(&trace_flags, &tracer);
-    } else if (is_internal_pid(pid_spec)
-	       && internal_pid_index(pid_spec) < erts_max_processes) {
+    } else if (is_internal_pid(pid_spec)) {
 	Process *tracee;
 	tracee = erts_pid2proc(p, ERTS_PROC_LOCK_MAIN,
 			       pid_spec, ERTS_PROC_LOCKS_ALL);
@@ -934,16 +945,16 @@ trace_info_pid(Process* p, Eterm pid_spec, Eterm key)
 	if (!tracee) {
 	    return am_undefined;
 	} else {
-	    tracer = tracee->tracer_proc;
-	    trace_flags = tracee->trace_flags;
+	    tracer = ERTS_TRACER_PROC(tracee);
+	    trace_flags = ERTS_TRACE_FLAGS(tracee);
 	}
 
 	if (is_internal_pid(tracer)) {
 	    if (!erts_proc_lookup(tracer)) {
 	    reset_tracer:
-		tracee->trace_flags &= ~TRACEE_FLAGS;
-		trace_flags = tracee->trace_flags;
-		tracer = tracee->tracer_proc = NIL;
+		ERTS_TRACE_FLAGS(tracee) &= ~TRACEE_FLAGS;
+		trace_flags = ERTS_TRACE_FLAGS(tracee);
+		tracer = ERTS_TRACER_PROC(tracee) = NIL;
 	    }
 	}
 	else if (is_internal_port(tracer)) {
@@ -1877,7 +1888,7 @@ new_seq_trace_token(Process* p)
 	SEQ_TRACE_TOKEN(p) = TUPLE5(hp, make_small(0),		/* Flags  */ 
 				    make_small(0),		/* Label  */
 				    make_small(0),		/* Serial */
-				    p->id, /* Internal pid */	/* From   */
+				    p->common.id, /* Internal pid */	/* From   */
 				    make_small(p->seq_trace_lastcnt));
     }
 }
@@ -2247,9 +2258,11 @@ BIF_RETTYPE system_profile_2(BIF_ALIST_2)
 	    if (!profiler_p)
 		goto error;
 	} else if (is_internal_port(profiler)) {
-	    if (internal_port_index(profiler) >= erts_max_ports) goto error;
-	    profiler_port = &erts_port[internal_port_index(profiler)];
-	    if (INVALID_TRACER_PORT(profiler_port, profiler)) goto error;
+	    profiler_port = (erts_port_lookup(
+				 profiler,
+				 ERTS_PORT_SFLGS_INVALID_TRACER_LOOKUP));
+	    if (!profiler_port)
+		goto error;
 	} else {
 	    goto error;
 	}
@@ -2313,8 +2326,7 @@ trace_delivered_1(BIF_ALIST_1)
 	p = NULL;
     } else if (! (p = erts_pid2proc(BIF_P, ERTS_PROC_LOCK_MAIN,
 				    BIF_ARG_1, ERTS_PROC_LOCKS_ALL))) {
-	if (is_not_internal_pid(BIF_ARG_1)
-	    || internal_pid_index(BIF_ARG_1) >= erts_max_processes) {
+	if (is_not_internal_pid(BIF_ARG_1)) {
 	    BIF_ERROR(BIF_P, BADARG);
 	}
     }
@@ -2333,7 +2345,7 @@ trace_delivered_1(BIF_ALIST_1)
     msg = TUPLE3(hp, AM_trace_delivered, BIF_ARG_1, msg_ref);
 
 #ifdef ERTS_SMP
-    erts_send_sys_msg_proc(BIF_P->id, BIF_P->id, msg, bp);
+    erts_send_sys_msg_proc(BIF_P->common.id, BIF_P->common.id, msg, bp);
     if (p)
 	erts_smp_proc_unlock(p,
 			     (BIF_P == p
diff --git a/erts/emulator/beam/erl_db.c b/erts/emulator/beam/erl_db.c
index 1ba1048afa..48a95cdf32 100644
--- a/erts/emulator/beam/erl_db.c
+++ b/erts/emulator/beam/erl_db.c
@@ -425,7 +425,8 @@ DbTable* db_get_table_aux(Process *p,
     if (tb) {
 	db_lock(tb, kind);
 	if (tb->common.id != id
-	    || ((tb->common.status & what) == 0 && p->id != tb->common.owner)) {
+	    || ((tb->common.status & what) == 0
+		&& p->common.id != tb->common.owner)) {
 	    db_unlock(tb, kind);
 	    tb = NULL;
 	}
@@ -615,7 +616,7 @@ BIF_RETTYPE ets_safe_fixtable_2(BIF_ALIST_2)
 #ifdef HARDDEBUG
     erts_fprintf(stderr,
 		"ets:safe_fixtable(%T,%T); Process: %T, initial: %T:%T/%bpu\n",
-		BIF_ARG_1, BIF_ARG_2, BIF_P->id,
+		BIF_ARG_1, BIF_ARG_2, BIF_P->common.id,
 		BIF_P->initial[0], BIF_P->initial[1], BIF_P->initial[2]);
 #endif
     kind = (BIF_ARG_2 == am_true) ? LCK_READ : LCK_WRITE_REC; 
@@ -1194,7 +1195,7 @@ BIF_RETTYPE ets_rename_2(BIF_ALIST_2)
 #ifdef HARDDEBUG
     erts_fprintf(stderr,
 		"ets:rename(%T,%T); Process: %T, initial: %T:%T/%bpu\n",
-		BIF_ARG_1, BIF_ARG_2, BIF_P->id,
+		BIF_ARG_1, BIF_ARG_2, BIF_P->common.id,
 		BIF_P->initial[0], BIF_P->initial[1], BIF_P->initial[2]);
 #endif
 
@@ -1437,7 +1438,7 @@ BIF_RETTYPE ets_new_2(BIF_ALIST_2)
     db_init_lock(tb, status & (DB_FINE_LOCKED|DB_FREQ_READ),
 		 "db_tab", "db_tab_fix");
     tb->common.keypos = keypos;
-    tb->common.owner = BIF_P->id;
+    tb->common.owner = BIF_P->common.id;
     set_heir(BIF_P, tb, heir, heir_data);
 
     erts_smp_atomic_init_nob(&tb->common.nitems, 0);
@@ -1506,7 +1507,7 @@ BIF_RETTYPE ets_new_2(BIF_ALIST_2)
 #ifdef HARDDEBUG
     erts_fprintf(stderr,
 		"ets:new(%T,%T)=%T; Process: %T, initial: %T:%T/%bpu\n",
-		 BIF_ARG_1, BIF_ARG_2, ret, BIF_P->id,
+		 BIF_ARG_1, BIF_ARG_2, ret, BIF_P->common.id,
 		 BIF_P->initial[0], BIF_P->initial[1], BIF_P->initial[2]);
 	erts_fprintf(stderr, "ets: new: meta_pid_to_tab common.memory_size = %ld\n",
 		     erts_smp_atomic_read_nob(&meta_pid_to_tab->common.memory_size));
@@ -1518,7 +1519,9 @@ BIF_RETTYPE ets_new_2(BIF_ALIST_2)
 
     db_meta_lock(meta_pid_to_tab, LCK_WRITE_REC);
     if (db_put_hash(meta_pid_to_tab,
-		    TUPLE2(meta_tuple, BIF_P->id, make_small(slot)),
+		    TUPLE2(meta_tuple,
+			   BIF_P->common.id,
+			   make_small(slot)),
 		    0) != DB_ERROR_NONE) {
 	erl_exit(1,"Could not update ets metadata.");
     }
@@ -1637,7 +1640,7 @@ BIF_RETTYPE ets_delete_1(BIF_ALIST_1)
 #ifdef HARDDEBUG
     erts_fprintf(stderr,
 		"ets:delete(%T); Process: %T, initial: %T:%T/%bpu\n",
-		BIF_ARG_1, BIF_P->id,
+		BIF_ARG_1, BIF_P->common.id,
 		BIF_P->initial[0], BIF_P->initial[1], BIF_P->initial[2]);
 #endif
 
@@ -1654,7 +1657,7 @@ BIF_RETTYPE ets_delete_1(BIF_ALIST_1)
     tb->common.status &= ~(DB_PROTECTED|DB_PUBLIC|DB_PRIVATE);
     tb->common.status |= DB_DELETE;
 
-    if (tb->common.owner != BIF_P->id) {
+    if (tb->common.owner != BIF_P->common.id) {
 	DeclareTmpHeap(meta_tuple,3,BIF_P);
 
 	/*
@@ -1669,10 +1672,12 @@ BIF_RETTYPE ets_delete_1(BIF_ALIST_1)
 			    make_small(tb->common.slot));
 
 	BIF_P->flags |= F_USING_DB;
-	tb->common.owner = BIF_P->id;
+	tb->common.owner = BIF_P->common.id;
 
 	db_put_hash(meta_pid_to_tab,
-		    TUPLE2(meta_tuple,BIF_P->id,make_small(tb->common.slot)),
+		    TUPLE2(meta_tuple,
+			   BIF_P->common.id,
+			   make_small(tb->common.slot)),
 		    0);
 	db_meta_unlock(meta_pid_to_tab, LCK_WRITE_REC);
 	UnUseTmpHeap(3,BIF_P);
@@ -1748,7 +1753,7 @@ BIF_RETTYPE ets_give_away_3(BIF_ALIST_3)
     }
 
     if ((tb = db_get_table(BIF_P, BIF_ARG_1, DB_WRITE, LCK_WRITE)) == NULL
-	|| tb->common.owner != BIF_P->id) {
+	|| tb->common.owner != BIF_P->common.id) {
 	goto badarg;
     }
     from_pid = tb->common.owner;
@@ -1771,7 +1776,10 @@ BIF_RETTYPE ets_give_away_3(BIF_ALIST_3)
 
     db_unlock(tb,LCK_WRITE);
     erts_send_message(BIF_P, to_proc, &to_locks,
-		      TUPLE4(buf, am_ETS_TRANSFER, tb->common.id, from_pid, BIF_ARG_3), 
+		      TUPLE4(buf, am_ETS_TRANSFER,
+			     tb->common.id,
+			     from_pid,
+			     BIF_ARG_3), 
 		      0);
     erts_smp_proc_unlock(to_proc, to_locks);
     UnUseTmpHeap(5,BIF_P);
@@ -1833,7 +1841,7 @@ BIF_RETTYPE ets_setopts_2(BIF_ALIST_2)
 
     if (tail != NIL
 	|| (tb = db_get_table(BIF_P, BIF_ARG_1, DB_WRITE, LCK_WRITE)) == NULL
-	|| tb->common.owner != BIF_P->id) {
+	|| tb->common.owner != BIF_P->common.id) {
 	goto badarg;
     }
 
@@ -2647,7 +2655,7 @@ BIF_RETTYPE ets_info_1(BIF_ALIST_1)
     */
 
     /* If/when we implement lockless private tables:
-    if ((tb->common.status & DB_PRIVATE) && owner != BIF_P->id) {
+    if ((tb->common.status & DB_PRIVATE) && owner != BIF_P->common.id) {
 	db_unlock(tb, LCK_READ);
 	rp = erts_pid2proc_not_running(BIF_P, ERTS_PROC_LOCK_MAIN,
 				       owner, ERTS_PROC_LOCK_MAIN);
@@ -3039,9 +3047,9 @@ static int give_away_to_heir(Process* p, DbTable* tb)
     Eterm to_pid;
     UWord heir_data;
 
-    ASSERT(tb->common.owner == p->id);
+    ASSERT(tb->common.owner == p->common.id);
     ASSERT(is_internal_pid(tb->common.heir));
-    ASSERT(tb->common.heir != p->id);
+    ASSERT(tb->common.heir != p->common.id);
 retry:
     to_pid = tb->common.heir;
     to_proc = erts_pid2proc_opt(p, ERTS_PROC_LOCK_MAIN,
@@ -3054,7 +3062,7 @@ retry:
 	db_lock(tb,LCK_WRITE);
 	ASSERT(tb != NULL);
     
-	if (tb->common.owner != p->id) {
+	if (tb->common.owner != p->common.id) {
 	    if (to_proc != NULL ) {
 		erts_smp_proc_unlock(to_proc, to_locks);
 	    }
@@ -3065,7 +3073,7 @@ retry:
 	    if (to_proc != NULL ) {
 		erts_smp_proc_unlock(to_proc, to_locks);
 	    }
-	    if (to_pid == p->id || to_pid == am_none) {
+	    if (to_pid == p->common.id || to_pid == am_none) {
 		return 0; /* no real heir, table still mine */
 	    }
 	    goto retry;
@@ -3074,7 +3082,8 @@ retry:
     if (to_proc == NULL) {
 	return 0; /* heir not alive, table still mine */
     }
-    if (to_proc->started_interval != tb->common.heir_started_interval) {
+    if (to_proc->common.u.alive.started_interval
+	!= tb->common.heir_started_interval) {
 	erts_smp_proc_unlock(to_proc, to_locks);
 	return 0; /* heir dead and pid reused, table still mine */
     }
@@ -3099,7 +3108,11 @@ retry:
 	heir_data = tpv[1];
     }
     erts_send_message(p, to_proc, &to_locks,
-		      TUPLE4(buf, am_ETS_TRANSFER, tb->common.id, p->id, heir_data), 
+		      TUPLE4(buf,
+			     am_ETS_TRANSFER,
+			     tb->common.id,
+			     p->common.id,
+			     heir_data), 
 		      0);
     erts_smp_proc_unlock(to_proc, to_locks);
     return !0;
@@ -3108,7 +3121,7 @@ retry:
 /*
  * erts_db_process_exiting() is called when a process terminates.
  * It returns 0 when completely done, and !0 when it wants to
- * yield. c_p->u.exit_data can hold a pointer to a state while
+ * yield. c_p->u.terminate can hold a pointer to a state while
  * yielding.
  */
 #define ERTS_DB_INTERNAL_ERROR(LSTR) \
@@ -3118,8 +3131,8 @@ retry:
 int
 erts_db_process_exiting(Process *c_p, ErtsProcLocks c_p_locks)
 {
-    ErtsDbProcCleanupState *state = (ErtsDbProcCleanupState *) c_p->u.exit_data;
-    Eterm pid = c_p->id;
+    ErtsDbProcCleanupState *state = (ErtsDbProcCleanupState *) c_p->u.terminate;
+    Eterm pid = c_p->common.id;
     ErtsDbProcCleanupState default_state;
     int ret;
 
@@ -3300,7 +3313,7 @@ erts_db_process_exiting(Process *c_p, ErtsProcLocks c_p_locks)
 
 	    if (state != &default_state)
 		erts_free(ERTS_ALC_T_DB_PROC_CLEANUP, state);
-	    c_p->u.exit_data = NULL;
+	    c_p->u.terminate = NULL;
 	    return 0;
 
 	default:
@@ -3321,13 +3334,13 @@ erts_db_process_exiting(Process *c_p, ErtsProcLocks c_p_locks)
 	break;
     }
 
-    ASSERT(c_p->u.exit_data == (void *) state
+    ASSERT(c_p->u.terminate == (void *) state
 	   || state == &default_state);
 
     if (state == &default_state) {
-	c_p->u.exit_data = erts_alloc(ERTS_ALC_T_DB_PROC_CLEANUP,
+	c_p->u.terminate = erts_alloc(ERTS_ALC_T_DB_PROC_CLEANUP,
 				      sizeof(ErtsDbProcCleanupState));
-	sys_memcpy(c_p->u.exit_data,
+	sys_memcpy(c_p->u.terminate,
 		   (void*) state,
 		   sizeof(ErtsDbProcCleanupState));
     }
@@ -3353,7 +3366,7 @@ static void fix_table_locked(Process* p, DbTable* tb)
     }
     else {
 	for (; fix != NULL; fix = fix->next) {
-	    if (fix->pid == p->id) {
+	    if (fix->pid == p->common.id) {
 		++(fix->counter);
 #ifdef ERTS_SMP
 		erts_smp_mtx_unlock(&tb->common.fixlock);
@@ -3365,7 +3378,7 @@ static void fix_table_locked(Process* p, DbTable* tb)
     fix = (DbFixation *) erts_db_alloc(ERTS_ALC_T_DB_FIXATION,
 				       tb, sizeof(DbFixation));
     ERTS_ETS_MISC_MEM_ADD(sizeof(DbFixation));
-    fix->pid = p->id;
+    fix->pid = p->common.id;
     fix->counter = 1;
     fix->next = tb->common.fixations;
     tb->common.fixations = fix;
@@ -3376,7 +3389,9 @@ static void fix_table_locked(Process* p, DbTable* tb)
     UseTmpHeap(3,p);
     db_meta_lock(meta_pid_to_fixed_tab, LCK_WRITE_REC);
     if (db_put_hash(meta_pid_to_fixed_tab,
-		    TUPLE2(meta_tuple, p->id, make_small(tb->common.slot)),
+		    TUPLE2(meta_tuple,
+			   p->common.id,
+			   make_small(tb->common.slot)),
 		    0) != DB_ERROR_NONE) {
 	UnUseTmpHeap(3,p);
 	erl_exit(1,"Could not insert ets metadata in safe_fixtable.");
@@ -3396,7 +3411,7 @@ static void unfix_table_locked(Process* p,  DbTable* tb,
     erts_smp_mtx_lock(&tb->common.fixlock);
 #endif
     for (pp = &tb->common.fixations; *pp != NULL; pp = &(*pp)->next) {
-	if ((*pp)->pid == p->id) {
+	if ((*pp)->pid == p->common.id) {
 	    DbFixation* fix = *pp;
 	    erts_refc_dec(&tb->common.ref,0);
 	    --(fix->counter);
@@ -3410,7 +3425,7 @@ static void unfix_table_locked(Process* p,  DbTable* tb,
 #endif
 	    db_meta_lock(meta_pid_to_fixed_tab, LCK_WRITE_REC);
 	    db_erase_bag_exact2(meta_pid_to_fixed_tab,
-				p->id, make_small(tb->common.slot));
+				p->common.id, make_small(tb->common.slot));
 	    db_meta_unlock(meta_pid_to_fixed_tab, LCK_WRITE_REC);
 	    erts_db_free(ERTS_ALC_T_DB_FIXATION,
 			 tb, (void *) fix, sizeof(DbFixation));
@@ -3469,15 +3484,15 @@ static void set_heir(Process* me, DbTable* tb, Eterm heir, UWord heir_data)
     if (heir == am_none) {
 	return;
     }
-    if (heir == me->id) {
-	erts_ensure_later_proc_interval(me->started_interval);
-	tb->common.heir_started_interval = me->started_interval;
+    if (heir == me->common.id) {
+	erts_ensure_later_proc_interval(me->common.u.alive.started_interval);
+	tb->common.heir_started_interval = me->common.u.alive.started_interval;
     }
     else {
 	Process* heir_proc= erts_proc_lookup(heir);
 	if (heir_proc != NULL) {
-	    erts_ensure_later_proc_interval(heir_proc->started_interval);
-	    tb->common.heir_started_interval = heir_proc->started_interval;
+	    erts_ensure_later_proc_interval(heir_proc->common.u.alive.started_interval);
+	    tb->common.heir_started_interval = heir_proc->common.u.alive.started_interval;
 	} else {
 	    tb->common.heir = am_none;
 	}
diff --git a/erts/emulator/beam/erl_db_util.c b/erts/emulator/beam/erl_db_util.c
index 0c9ca83ce4..bcdb630140 100644
--- a/erts/emulator/beam/erl_db_util.c
+++ b/erts/emulator/beam/erl_db_util.c
@@ -138,21 +138,23 @@ set_tracee_flags(Process *tracee_p, Eterm tracer, Uint d_flags, Uint e_flags) {
     Uint flags;
 
     if (tracer == NIL) {
-	flags = tracee_p->trace_flags & ~TRACEE_FLAGS;
+	flags = ERTS_TRACE_FLAGS(tracee_p) & ~TRACEE_FLAGS;
     }  else {
-	flags = ((tracee_p->trace_flags & ~d_flags) | e_flags);
+	flags = ((ERTS_TRACE_FLAGS(tracee_p) & ~d_flags) | e_flags);
 	if (! flags) tracer = NIL;
     }
-    ret = tracee_p->tracer_proc != tracer || tracee_p->trace_flags != flags
-	? am_true : am_false;
-    tracee_p->tracer_proc = tracer;
-    tracee_p->trace_flags = flags;
+    ret = ((ERTS_TRACER_PROC(tracee_p) != tracer
+	    || ERTS_TRACE_FLAGS(tracee_p) != flags)
+	   ? am_true
+	   : am_false);
+    ERTS_TRACER_PROC(tracee_p) = tracer;
+    ERTS_TRACE_FLAGS(tracee_p) = flags;
     return ret;
 }
 /*
 ** Assuming all locks on tracee_p on entry
 **
-** Changes tracee_p->trace_flags and tracee_p->tracer_proc
+** Changes ERTS_TRACE_FLAGS(tracee_p) and ERTS_TRACER_PROC(tracee_p)
 ** according to input disable/enable flags and tracer.
 **
 ** Returns am_true|am_false on success, am_true if value changed,
@@ -173,17 +175,20 @@ set_match_trace(Process *tracee_p, Eterm fail_term, Eterm tracer,
 			  tracer, ERTS_PROC_LOCKS_ALL))) {
 	if (tracee_p != tracer_p) {
 	    ret = set_tracee_flags(tracee_p, tracer, d_flags, e_flags);
-	    tracer_p->trace_flags |= tracee_p->trace_flags ? F_TRACER : 0;
+	    ERTS_TRACE_FLAGS(tracer_p) |= (ERTS_TRACE_FLAGS(tracee_p)
+					   ? F_TRACER
+					   : 0);
 	    erts_smp_proc_unlock(tracer_p, ERTS_PROC_LOCKS_ALL);
 	}
     } else if (is_internal_port(tracer)) {
 	Port *tracer_port = 
-	    erts_id2port(tracer, tracee_p, ERTS_PROC_LOCKS_ALL);
+	    erts_id2port_sflgs(tracer,
+			       tracee_p,
+			       ERTS_PROC_LOCKS_ALL,
+			       ERTS_PORT_SFLGS_INVALID_TRACER_LOOKUP);
 	if (tracer_port) {
-	    if (! INVALID_TRACER_PORT(tracer_port, tracer)) {
-		ret = set_tracee_flags(tracee_p, tracer, d_flags, e_flags);
-	    }
-	    erts_smp_port_unlock(tracer_port);
+	    ret = set_tracee_flags(tracee_p, tracer, d_flags, e_flags);
+	    erts_port_release(tracer_port);
 	}
     } else {
 	ASSERT(is_nil(tracer));
@@ -2174,7 +2179,7 @@ restart:
 	    pc += n;
 	    break;
 	case matchSelf:
-	    *esp++ = c_p->id;
+	    *esp++ = c_p->common.id;
 	    break;
 	case matchWaste:
 	    --esp;
@@ -2261,7 +2266,7 @@ restart:
 	case matchEnableTrace:
 	    if ( (n = erts_trace_flag2bit(esp[-1]))) {
 		BEGIN_ATOMIC_TRACE(c_p);
-		set_tracee_flags(c_p, c_p->tracer_proc, 0, n);
+		set_tracee_flags(c_p, ERTS_TRACER_PROC(c_p), 0, n);
 		esp[-1] = am_true;
 	    } else {
 		esp[-1] = FAIL_TERM;
@@ -2274,7 +2279,7 @@ restart:
 		BEGIN_ATOMIC_TRACE(c_p);
 		if ( (tmpp = get_proc(c_p, 0, esp[0], 0))) {
 		    /* Always take over the tracer of the current process */
-		    set_tracee_flags(tmpp, c_p->tracer_proc, 0, n);
+		    set_tracee_flags(tmpp, ERTS_TRACER_PROC(c_p), 0, n);
 		    esp[-1] = am_true;
 		}
 	    }
@@ -2282,7 +2287,7 @@ restart:
 	case matchDisableTrace:
 	    if ( (n = erts_trace_flag2bit(esp[-1]))) {
 		BEGIN_ATOMIC_TRACE(c_p);
-		set_tracee_flags(c_p, c_p->tracer_proc, n, 0);
+		set_tracee_flags(c_p, ERTS_TRACER_PROC(c_p), n, 0);
 		esp[-1] = am_true;
 	    } else {
 		esp[-1] = FAIL_TERM;
@@ -2295,7 +2300,7 @@ restart:
 		BEGIN_ATOMIC_TRACE(c_p);
 		if ( (tmpp = get_proc(c_p, 0, esp[0], 0))) {
 		    /* Always take over the tracer of the current process */
-		    set_tracee_flags(tmpp, c_p->tracer_proc, n, 0);
+		    set_tracee_flags(tmpp, ERTS_TRACER_PROC(c_p), n, 0);
 		    esp[-1] = am_true;
 		}
 	    }
@@ -2316,12 +2321,12 @@ restart:
 	    --esp;
 	    if (*esp == am_true) {
 		erts_smp_proc_lock(c_p, ERTS_PROC_LOCKS_ALL_MINOR);
-		c_p->trace_flags |= F_TRACE_SILENT;
+		ERTS_TRACE_FLAGS(c_p) |= F_TRACE_SILENT;
 		erts_smp_proc_unlock(c_p, ERTS_PROC_LOCKS_ALL_MINOR);
 	    }
 	    else if (*esp == am_false) {
 		erts_smp_proc_lock(c_p, ERTS_PROC_LOCKS_ALL_MINOR);
-		c_p->trace_flags &= ~F_TRACE_SILENT;
+		ERTS_TRACE_FLAGS(c_p) &= ~F_TRACE_SILENT;
 		erts_smp_proc_unlock(c_p, ERTS_PROC_LOCKS_ALL_MINOR);
 	    }
 	    break;
@@ -2329,11 +2334,11 @@ restart:
 	    {
 		/*    disable         enable                                */
 		Uint  d_flags  = 0,   e_flags  = 0;  /* process trace flags */
-		Eterm tracer = c_p->tracer_proc;
+		Eterm tracer = ERTS_TRACER_PROC(c_p);
 		/* XXX Atomicity note: Not fully atomic. Default tracer
 		 * is sampled from current process but applied to
 		 * tracee and tracer later after releasing main
-		 * locks on current process, so c_p->tracer_proc
+		 * locks on current process, so ERTS_TRACER_PROC(c_p)
 		 * may actually have changed when tracee and tracer
 		 * gets updated. I do not think nobody will notice.
 		 * It is just the default value that is not fully atomic.
@@ -2358,7 +2363,7 @@ restart:
 	    {
 		/*    disable         enable                                */
 		Uint  d_flags  = 0,   e_flags  = 0;  /* process trace flags */
-		Eterm tracer = c_p->tracer_proc;
+		Eterm tracer = ERTS_TRACER_PROC(c_p);
 		/* XXX Atomicity note. Not fully atomic. See above. 
 		 * Above it could possibly be solved, but not here.
 		 */
diff --git a/erts/emulator/beam/erl_db_util.h b/erts/emulator/beam/erl_db_util.h
index dcecc4251a..d8f6e40d2e 100644
--- a/erts/emulator/beam/erl_db_util.h
+++ b/erts/emulator/beam/erl_db_util.h
@@ -320,10 +320,10 @@ ERTS_GLB_INLINE int db_eq(DbTableCommon* tb, Eterm a, DbTerm* b)
 #define DB_INFO  (DB_PROTECTED|DB_PUBLIC|DB_PRIVATE)
 
 #define ONLY_WRITER(P,T) (((T)->common.status & (DB_PRIVATE|DB_PROTECTED)) \
-			  && (T)->common.owner == (P)->id)
+			  && (T)->common.owner == (P)->common.id)
 
 #define ONLY_READER(P,T) (((T)->common.status & DB_PRIVATE) && \
-(T)->common.owner == (P)->id)
+(T)->common.owner == (P)->common.id)
 
 /* Function prototypes */
 BIF_RETTYPE db_get_trace_control_word(Process* p);
diff --git a/erts/emulator/beam/erl_debug.c b/erts/emulator/beam/erl_debug.c
index 22e873afc6..b90d00f236 100644
--- a/erts/emulator/beam/erl_debug.c
+++ b/erts/emulator/beam/erl_debug.c
@@ -252,16 +252,16 @@ void erts_check_stack(Process *p)
     if (p->stop > stack_start)
 	erl_exit(1,
 		 "<%lu.%lu.%lu>: Stack underflow\n",
-		 internal_pid_channel_no(p->id),
-		 internal_pid_number(p->id),
-		 internal_pid_serial(p->id));
+		 internal_pid_channel_no(p->common.id),
+		 internal_pid_number(p->common.id),
+		 internal_pid_serial(p->common.id));
 
     if (p->stop < stack_end)
 	erl_exit(1,
 		 "<%lu.%lu.%lu>: Stack overflow\n",
-		 internal_pid_channel_no(p->id),
-		 internal_pid_number(p->id),
-		 internal_pid_serial(p->id));
+		 internal_pid_channel_no(p->common.id),
+		 internal_pid_number(p->common.id),
+		 internal_pid_serial(p->common.id));
 
     for (elemp = p->stop; elemp < stack_start; elemp++) {
 	int in_mbuf = 0;
@@ -284,9 +284,9 @@ void erts_check_stack(Process *p)
 
 	erl_exit(1,
 		 "<%lu.%lu.%lu>: Wild stack pointer\n",
-		 internal_pid_channel_no(p->id),
-		 internal_pid_number(p->id),
-		 internal_pid_serial(p->id));
+		 internal_pid_channel_no(p->common.id),
+		 internal_pid_number(p->common.id),
+		 internal_pid_serial(p->common.id));
     }
 
 }
@@ -387,16 +387,16 @@ void verify_process(Process *p)
 #define VERIFY_AREA(name,ptr,sz) {                                      \
     int n = (sz);							\
     while (n--) if(!verify_eterm(p,*(ptr+n)))				\
-        erl_exit(1,"Wild pointer found in " name " of %T!\n",p->id); }
+        erl_exit(1,"Wild pointer found in " name " of %T!\n",p->common.id); }
 
 #define VERIFY_ETERM(name,eterm) {                                      \
     if(!verify_eterm(p,eterm))                                          \
-        erl_exit(1,"Wild pointer found in " name " of %T!\n",p->id); }
+        erl_exit(1,"Wild pointer found in " name " of %T!\n",p->common.id); }
 
 
     ErlMessage* mp = p->msg.first;
 
-    VERBOSE(DEBUG_MEMORY,("Verify process: %T...\n",p->id));
+    VERBOSE(DEBUG_MEMORY,("Verify process: %T...\n",p->common.id));
 
     while (mp != NULL) {
         VERIFY_ETERM("message term",ERL_MESSAGE_TERM(mp));
@@ -516,7 +516,7 @@ static void print_process_memory(Process *p)
     ErlHeapFragment* bp = MBUF(p);
 
     erts_printf("==============================\n");
-    erts_printf("|| Memory info for %T ||\n",p->id);
+    erts_printf("|| Memory info for %T ||\n",p->common.id);
     erts_printf("==============================\n");
 
     erts_printf("-- %-*s ---%s-%s-%s-%s--\n",
@@ -601,7 +601,7 @@ void print_memory_info(Process *p)
 {
     if (p != NULL) {
         erts_printf("======================================\n");
-        erts_printf("|| Memory info for %-12T ||\n",p->id);
+        erts_printf("|| Memory info for %-12T ||\n",p->common.id);
         erts_printf("======================================\n");
         erts_printf("+- local heap ----%s-%s-%s-%s-+\n",
                     dashes,dashes,dashes,dashes);
diff --git a/erts/emulator/beam/erl_driver.h b/erts/emulator/beam/erl_driver.h
index 771ee46d2b..046b46513f 100644
--- a/erts/emulator/beam/erl_driver.h
+++ b/erts/emulator/beam/erl_driver.h
@@ -133,7 +133,7 @@ typedef struct {
 
 #define ERL_DRV_EXTENDED_MARKER		(0xfeeeeeed)
 #define ERL_DRV_EXTENDED_MAJOR_VERSION	2
-#define ERL_DRV_EXTENDED_MINOR_VERSION	0
+#define ERL_DRV_EXTENDED_MINOR_VERSION	1
 
 /*
  * The emulator will refuse to load a driver with different major
@@ -154,6 +154,7 @@ typedef struct {
 
 #define ERL_DRV_FLAG_USE_PORT_LOCKING	(1 << 0)
 #define ERL_DRV_FLAG_SOFT_BUSY		(1 << 1)
+#define ERL_DRV_FLAG_NO_BUSY_MSGQ	(1 << 2)
 
 /*
  * Integer types
@@ -207,8 +208,8 @@ typedef struct erl_drv_binary {
 typedef struct _erl_drv_data* ErlDrvData; /* Data to be used by the driver itself. */
 #ifndef ERL_SYS_DRV
 typedef struct _erl_drv_event* ErlDrvEvent; /* An event to be selected on. */
-typedef struct _erl_drv_port* ErlDrvPort; /* A port descriptor. */
 #endif
+typedef struct _erl_drv_port* ErlDrvPort; /* A port descriptor. */
 typedef struct _erl_drv_port* ErlDrvThreadData; /* Thread data. */
 
 #if !defined(__WIN32__) && !defined(_WIN32) && !defined(_WIN32_) && !defined(USE_SELECT)
@@ -377,9 +378,18 @@ typedef struct erl_drv_entry {
     ErlDrvEntry* driver_init(void)
 #endif
 
+#define ERL_DRV_BUSY_MSGQ_DISABLED	(~((ErlDrvSizeT) 0))
+#define ERL_DRV_BUSY_MSGQ_READ_ONLY	((ErlDrvSizeT) 0)
+#define ERL_DRV_BUSY_MSGQ_LIM_MAX	(ERL_DRV_BUSY_MSGQ_DISABLED - 1)
+#define ERL_DRV_BUSY_MSGQ_LIM_MIN	((ErlDrvSizeT) 1)
+
 /*
  * These are the functions available for driver writers.
  */
+EXTERN void erl_drv_busy_msgq_limits(ErlDrvPort port,
+				     ErlDrvSizeT *low,
+				     ErlDrvSizeT *high);
+
 EXTERN int driver_select(ErlDrvPort port, ErlDrvEvent event, int mode, int on);
 EXTERN int driver_event(ErlDrvPort port, ErlDrvEvent event, 
 			ErlDrvEventData event_data);
@@ -594,11 +604,33 @@ EXTERN ErlDrvPort driver_create_port(ErlDrvPort creator_port,
 				     ErlDrvData drv_data);
 					 
 
+/*
+ * driver_output_term() is deprecated, and scheduled for removal in
+ * OTP-R17. Use erl_drv_output_term() instead. For more information
+ * see the erl_driver(3) documentation.
+ */
+EXTERN int driver_output_term(ErlDrvPort ix,
+			      ErlDrvTermData* data,
+			      int len) ERL_DRV_DEPRECATED_FUNC;
+/*
+ * driver_send_term() is deprecated, and scheduled for removal in
+ * OTP-R17. Use erl_drv_send_term() instead. For more information
+ * see the erl_driver(3) documentation.
+ */
+EXTERN int driver_send_term(ErlDrvPort ix,
+			    ErlDrvTermData to,
+			    ErlDrvTermData* data,
+			    int len) ERL_DRV_DEPRECATED_FUNC;
+
 /* output term data to the port owner */
-EXTERN int driver_output_term(ErlDrvPort ix, ErlDrvTermData* data, int len);
+EXTERN int erl_drv_output_term(ErlDrvTermData port,
+			       ErlDrvTermData* data,
+			       int len);
 /* output term data to a specific process */
-EXTERN int driver_send_term(ErlDrvPort ix, ErlDrvTermData to,
-			    ErlDrvTermData* data, int len);
+EXTERN int erl_drv_send_term(ErlDrvTermData port,
+			     ErlDrvTermData to,
+			     ErlDrvTermData* data,
+			     int len);
 
 /* Async IO functions */
 EXTERN long driver_async(ErlDrvPort ix,
diff --git a/erts/emulator/beam/erl_gc.c b/erts/emulator/beam/erl_gc.c
index 5ae4b9254b..d377ba8f31 100644
--- a/erts/emulator/beam/erl_gc.c
+++ b/erts/emulator/beam/erl_gc.c
@@ -59,7 +59,7 @@ static Uint reclaimed;			/* no of words reclaimed in GCs */
         erts_fprintf(stderr, "htop=%p\n", (p)->htop); \
         erts_fprintf(stderr, "heap=%p\n", (p)->heap); \
         erl_exit(ERTS_ABORT_EXIT, "%s, line %d: %T: Overrun stack and heap\n", \
-		 __FILE__,__LINE__,(P)->id); \
+		 __FILE__,__LINE__,(P)->common.id); \
     }
 
 #ifdef DEBUG
@@ -1946,9 +1946,9 @@ setup_rootset(Process *p, Eterm *objv, int nobj, Rootset *rootset)
 	n++;
     }
 #endif
-    ASSERT(is_nil(p->tracer_proc) ||
-	   is_internal_pid(p->tracer_proc) ||
-	   is_internal_port(p->tracer_proc));
+    ASSERT(is_nil(ERTS_TRACER_PROC(p)) ||
+	   is_internal_pid(ERTS_TRACER_PROC(p)) ||
+	   is_internal_port(ERTS_TRACER_PROC(p)));
 
     ASSERT(is_pid(follow_moved(p->group_leader)));
     if (is_not_immed(p->group_leader)) {
diff --git a/erts/emulator/beam/erl_init.c b/erts/emulator/beam/erl_init.c
index 4b90e5394a..175f04b15b 100644
--- a/erts/emulator/beam/erl_init.c
+++ b/erts/emulator/beam/erl_init.c
@@ -44,6 +44,7 @@
 #include "erl_thr_progress.h"
 #include "erl_thr_queue.h"
 #include "erl_async.h"
+#include "erl_ptab.h"
 
 #ifdef HIPE
 #include "hipe_mode_switch.h"	/* for hipe_mode_switch_init() */
@@ -109,6 +110,11 @@ const int etp_lock_check = 1;
 #else
 const int etp_lock_check = 0;
 #endif
+#ifdef WORDS_BIGENDIAN
+const int etp_big_endian = 1;
+#else
+const int etp_big_endian = 0;
+#endif
 /*
  * Note about VxWorks: All variables must be initialized by executable code,
  * not by an initializer. Otherwise a new instance of the emulator will
@@ -121,9 +127,10 @@ extern void ConNormalExit(void);
 extern void ConWaitForExit(void);
 #endif
 
-static void erl_init(int ncpu);
-
-#define ERTS_MIN_COMPAT_REL 7
+static void erl_init(int ncpu,
+		     int proc_tab_sz,
+		     int port_tab_sz,
+		     int port_tab_sz_ignore_files);
 
 static erts_atomic_t exiting;
 
@@ -206,8 +213,6 @@ ErtsModifiedTimings erts_modified_timings[] = {
 
 Export *erts_delay_trap = NULL;
 
-int erts_use_r9_pids_ports;
-
 int ignore_break;
 int replace_intr;
 
@@ -271,12 +276,18 @@ void
 erts_short_init(void)
 {
     int ncpu = early_init(NULL, NULL);
-    erl_init(ncpu);
+    erl_init(ncpu,
+	     ERTS_DEFAULT_MAX_PROCESSES,
+	     ERTS_DEFAULT_MAX_PORTS,
+	     0);
     erts_initialized = 1;
 }
 
 static void
-erl_init(int ncpu)
+erl_init(int ncpu,
+	 int proc_tab_sz,
+	 int port_tab_sz,
+	 int port_tab_sz_ignore_files)
 {
     init_benchmarking();
 
@@ -284,7 +295,7 @@ erl_init(int ncpu)
     erts_init_gc();
     erts_init_time();
     erts_init_sys_common_misc();
-    erts_init_process(ncpu);
+    erts_init_process(ncpu, proc_tab_sz);
     erts_init_scheduling(no_schedulers,
 			 no_schedulers_online);
     erts_init_cpu_topology(); /* Must be after init_scheduling */
@@ -306,6 +317,7 @@ erl_init(int ncpu)
     erts_bif_info_init();
     erts_ddll_init();
     init_emulator();
+    erts_ptab_init(); /* Must be after init_emulator() */
     erts_bp_init();
     init_db(); /* Must be after init_emulator */
     erts_bif_timer_init();
@@ -313,7 +325,7 @@ erl_init(int ncpu)
     init_dist();
     erl_drv_thr_init();
     erts_init_async();
-    init_io();
+    erts_init_io(port_tab_sz, port_tab_sz_ignore_files);
     init_load();
     erts_init_bif();
     erts_init_bif_chksum();
@@ -457,6 +469,7 @@ load_preloaded(void)
 /* be helpful (or maybe downright rude:-) */
 void erts_usage(void)
 {
+    int this_rel = this_rel_num();
     erts_fprintf(stderr, "Usage: %s [flags] [ -- [init_args] ]\n", progname(program));
     erts_fprintf(stderr, "The flags are:\n\n");
 
@@ -490,16 +503,20 @@ void erts_usage(void)
     /*    erts_fprintf(stderr, "-i module  set the boot module (default init)\n"); */
 
     erts_fprintf(stderr, "-K boolean  enable or disable kernel poll\n");
-
+    erts_fprintf(stderr, "-n[s|a|d]   Control behavior of signals to ports\n");
+    erts_fprintf(stderr, "            Note that this flag is deprecated!\n");
     erts_fprintf(stderr, "-M<X> <Y>   memory allocator switches,\n");
     erts_fprintf(stderr, "            see the erts_alloc(3) documentation for more info.\n");
 
     erts_fprintf(stderr, "-P number   set maximum number of processes on this node,\n");
     erts_fprintf(stderr, "            valid range is [%d-%d]\n",
-	       ERTS_MIN_PROCESSES, ERTS_MAX_PROCESSES);
+		 ERTS_MIN_PROCESSES, ERTS_MAX_PROCESSES);
+    erts_fprintf(stderr, "-Q number   set maximum number of ports on this node,\n");
+    erts_fprintf(stderr, "            valid range is [%d-%d]\n",
+		 ERTS_MIN_PORTS, ERTS_MAX_PORTS);
     erts_fprintf(stderr, "-R number   set compatibility release number,\n");
     erts_fprintf(stderr, "            valid range [%d-%d]\n",
-	       ERTS_MIN_COMPAT_REL, this_rel_num());
+		 this_rel-2, this_rel);
 
     erts_fprintf(stderr, "-r          force ets memory block to be moved on realloc\n");
     erts_fprintf(stderr, "-rg amount  set reader groups limit\n");
@@ -519,6 +536,7 @@ void erts_usage(void)
     erts_fprintf(stderr, "            valid range is [%d-%d]\n",
 		 ERTS_SCHED_THREAD_MIN_STACK_SIZE,
 		 ERTS_SCHED_THREAD_MAX_STACK_SIZE);
+    erts_fprintf(stderr, "-spp Bool   set port parallelism scheduling hint\n");
     erts_fprintf(stderr, "-S n1:n2    set number of schedulers (n1), and number of\n");
     erts_fprintf(stderr, "            schedulers online (n2), valid range for both\n");
     erts_fprintf(stderr, "            numbers are [1-%d]\n",
@@ -612,7 +630,6 @@ early_init(int *argc, char **argv) /*
     erts_printf_eterm_func = erts_printf_term;
     erts_disable_tolerant_timeofday = 0;
     display_items = 200;
-    erts_proc.max = ERTS_DEFAULT_MAX_PROCESSES;
     erts_backtrace_depth = DEFAULT_BACKTRACE_SIZE;
     erts_async_max_threads = 0;
     erts_async_thread_suggested_stack_size = ERTS_ASYNC_THREAD_MIN_STACK_SIZE;
@@ -641,8 +658,6 @@ early_init(int *argc, char **argv) /*
 
     erts_compat_rel = this_rel_num();
 
-    erts_use_r9_pids_ports = 0;
-
     erts_sys_pre_init();
     erts_atomic_init_nob(&exiting, 0);
 #ifdef ERTS_SMP
@@ -897,11 +912,13 @@ erl_start(int argc, char **argv)
 {
     int i = 1;
     char* arg=NULL;
-    char* Parg = NULL;
     int have_break_handler = 1;
     char envbuf[21]; /* enough for any 64-bit integer */
     size_t envbufsz;
     int ncpu = early_init(&argc, argv);
+    int proc_tab_sz = ERTS_DEFAULT_MAX_PROCESSES;
+    int port_tab_sz = ERTS_DEFAULT_MAX_PORTS;
+    int port_tab_sz_ignore_files = 0;
 
     envbufsz = sizeof(envbuf);
     if (erts_sys_getenv_raw(ERL_MAX_ETS_TABLES_ENV, envbuf, &envbufsz) == 0)
@@ -1152,12 +1169,53 @@ erl_start(int argc, char **argv)
 		       arg);
 	    break;
 
-	case 'P':
-	    /* set maximum number of processes */
-	    Parg = get_arg(argv[i]+2, argv[i+1], &i);
-	    erts_proc.max = atoi(Parg);
-	    /* Check of result is delayed until later. This is because +R
-	       may be given after +P. */
+	case 'n':
+	    arg = get_arg(argv[i]+2, argv[i+1], &i);
+	    switch (arg[0]) {
+	    case 's': /* synchronous */
+		erts_port_synchronous_ops = 1;
+		erts_port_schedule_all_ops = 0;
+		break;
+	    case 'a': /* asynchronous */
+		erts_port_synchronous_ops = 0;
+		erts_port_schedule_all_ops = 1;
+		break;
+	    case 'd': /* Default - schedule on conflict (asynchronous) */
+		erts_port_synchronous_ops = 0;
+		erts_port_schedule_all_ops = 0;
+		break;
+	    default:
+	    bad_n_option:
+		erts_fprintf(stderr, "bad -n option %s\n", arg);
+		erts_usage();
+	    }
+	    if (arg[1] != '\0')
+		goto bad_n_option;
+	    break;
+
+	case 'P': /* set maximum number of processes */
+	    arg = get_arg(argv[i]+2, argv[i+1], &i);
+	    errno = 0;
+	    proc_tab_sz = strtol(arg, NULL, 10);
+	    if (errno != 0
+		|| proc_tab_sz < ERTS_MIN_PROCESSES
+		|| ERTS_MAX_PROCESSES < proc_tab_sz) {
+		erts_fprintf(stderr, "bad number of processes %s\n", arg);
+		erts_usage();
+	    }
+	    break;
+
+	case 'Q': /* set maximum number of ports */
+	    arg = get_arg(argv[i]+2, argv[i+1], &i);
+	    errno = 0;
+	    port_tab_sz = strtol(arg, NULL, 10);
+	    if (errno != 0
+		|| port_tab_sz < ERTS_MIN_PROCESSES
+		|| ERTS_MAX_PROCESSES < port_tab_sz) {
+		erts_fprintf(stderr, "bad number of ports %s\n", arg);
+		erts_usage();
+	    }
+	    port_tab_sz_ignore_files = 1;
 	    break;
 
 	case 'S' : /* Was handled in early_init() just read past it */
@@ -1259,6 +1317,19 @@ erl_start(int argc, char **argv)
 		    erts_usage();
 		}
 	    }
+	    else if (has_prefix("pp", sub_param)) {
+		arg = get_arg(sub_param+2, argv[i+1], &i);
+		if (sys_strcmp(arg, "true") == 0)
+		    erts_port_parallelism = 1;
+		else if (sys_strcmp(arg, "false") == 0)
+		    erts_port_parallelism = 0;
+		else {
+		    erts_fprintf(stderr,
+				 "bad port parallelism scheduling hint %s\n",
+				 arg);
+		    erts_usage();
+		}
+	    }
 	    else if (sys_strcmp("nsp", sub_param) == 0)
 		erts_use_sender_punish = 0;
 	    else if (sys_strcmp("wt", sub_param) == 0) {
@@ -1340,22 +1411,19 @@ erl_start(int argc, char **argv)
 
 	case 'R': {
 	    /* set compatibility release */
+	    int this_rel;
 
 	    arg = get_arg(argv[i]+2, argv[i+1], &i);
 	    erts_compat_rel = atoi(arg);
 
-	    if (erts_compat_rel < ERTS_MIN_COMPAT_REL
-		|| erts_compat_rel > this_rel_num()) {
+	    this_rel = this_rel_num();
+	    if (erts_compat_rel < this_rel - 2 || this_rel < erts_compat_rel) {
 		erts_fprintf(stderr, "bad compatibility release number %s\n", arg);
 		erts_usage();
 	    }
 
-	    ASSERT(ERTS_MIN_COMPAT_REL >= 7);
 	    switch (erts_compat_rel) {
-	    case 7:
-	    case 8:
-	    case 9:
-		erts_use_r9_pids_ports = 1;
+		/* Currently no compat features... */
 	    default:
 		break;
 	    }
@@ -1397,8 +1465,6 @@ erl_start(int argc, char **argv)
 	    }
 	    break;
 	}
-	case 'n':   /* XXX obsolete */
-	    break;
 	case 'c':
 	    if (argv[i][2] == 0) { /* -c: documented option */
 		erts_disable_tolerant_timeofday = 1;
@@ -1453,15 +1519,6 @@ erl_start(int argc, char **argv)
 	i++;
     }
 
-    /* Delayed check of +P flag */
-    if (erts_proc.max < ERTS_MIN_PROCESSES
-	|| erts_proc.max > ERTS_MAX_PROCESSES
-	|| (erts_use_r9_pids_ports
-	    && erts_proc.max > ERTS_MAX_R9_PROCESSES)) {
-	erts_fprintf(stderr, "bad number of processes %s\n", Parg);
-	erts_usage();
-    }
-
    /* Restart will not reinstall the break handler */
 #ifdef __WIN32__
     if (ignore_break)
@@ -1482,7 +1539,10 @@ erl_start(int argc, char **argv)
     boot_argc = argc - i;  /* Number of arguments to init */
     boot_argv = &argv[i];
 
-    erl_init(ncpu);
+    erl_init(ncpu,
+	     proc_tab_sz,
+	     port_tab_sz,
+	     port_tab_sz_ignore_files);
 
     load_preloaded();
     erts_end_staging_code_ix();
diff --git a/erts/emulator/beam/erl_lock_check.c b/erts/emulator/beam/erl_lock_check.c
index 314d2f6a9c..69bb4be717 100644
--- a/erts/emulator/beam/erl_lock_check.c
+++ b/erts/emulator/beam/erl_lock_check.c
@@ -95,7 +95,6 @@ static erts_lc_lock_order_t erts_lock_order[] = {
     {	"dist_entry_links",			"address"		},
     {   "code_write_permission",                NULL                    },
     {	"proc_status",				"pid"			},
-    {	"proc_tab",				NULL			},
     {   "ports_snapshot",                       NULL                    },
     {	"meta_name_tab",	         	"address"		},
     {	"meta_main_tab_slot",			"address"		},
@@ -115,9 +114,6 @@ static erts_lc_lock_order_t erts_lock_order[] = {
 #if defined(ENABLE_CHILD_WAITER_THREAD) || defined(ERTS_SMP)
     {	"child_status",				NULL			},
 #endif
-#ifdef __WIN32__
-    {	"sys_driver_data_lock",			NULL 			},
-#endif
     {	"drv_ev_state_grow",			NULL,   		},
     {	"drv_ev_state",				"address"		},
     {	"safe_hash",				"address"		},
@@ -127,6 +123,7 @@ static erts_lc_lock_order_t erts_lock_order[] = {
     {	"schdlr_sspnd",				NULL			},
     {	"migration_info_update",		NULL			},
     {	"run_queue",				"address"		},
+    {	"process_table",			NULL			},
     {	"cpu_info",				NULL			},
     {	"pollset",				"address"		},
 #ifdef __WIN32__
@@ -157,12 +154,10 @@ static erts_lc_lock_order_t erts_lock_order[] = {
     {	"pmmap",				NULL			},
 #endif
 #ifdef ERTS_SMP
+    {	"port_sched_lock",			"port_id"		},
     {	"port_task_pre_alloc_lock",		"address"		},
-    {	"port_taskq_pre_alloc_lock",		"address"		},
     {	"proclist_pre_alloc_lock",		"address"		},
-    {	"port_tasks_lock",			NULL			},
-    {   "get_free_port",                        NULL                    },
-    {	"port_state",			        "address"		},
+    {   "port_table",                           NULL                    },
     {	"xports_list_pre_alloc_lock",		"address"		},
     {	"inet_buffer_stack_lock",		NULL			},
     {	"gc_info",				NULL			},
@@ -247,6 +242,7 @@ typedef struct {
 typedef struct erts_lc_locked_locks_t_ erts_lc_locked_locks_t;
 struct erts_lc_locked_locks_t_ {
     char *thread_name;
+    int emu_thread;
     erts_tid_t tid;
     erts_lc_locked_locks_t *next;
     erts_lc_locked_locks_t *prev;
@@ -364,6 +360,7 @@ create_locked_locks(char *thread_name)
     if (!l_lcks->thread_name)
 	lc_abort();
 
+    l_lcks->emu_thread = 0;
     l_lcks->tid = erts_thr_self();
     l_lcks->required.first = NULL;
     l_lcks->required.last = NULL;
@@ -671,7 +668,7 @@ erts_lc_set_thread_name(char *thread_name)
 {
     erts_lc_locked_locks_t *l_lcks = get_my_locked_locks();
     if (!l_lcks)
-	(void) create_locked_locks(thread_name);
+	l_lcks = create_locked_locks(thread_name);
     else {
 	ASSERT(l_lcks->thread_name);
 	free((void *) l_lcks->thread_name);
@@ -679,6 +676,14 @@ erts_lc_set_thread_name(char *thread_name)
 	if (!l_lcks->thread_name)
 	    lc_abort();
     }
+    l_lcks->emu_thread = 1;
+}
+
+int
+erts_lc_is_emu_thr(void)
+{
+    erts_lc_locked_locks_t *l_lcks = get_my_locked_locks();
+    return l_lcks->emu_thread;
 }
 
 int
diff --git a/erts/emulator/beam/erl_lock_check.h b/erts/emulator/beam/erl_lock_check.h
index df7b3758e1..068340abe7 100644
--- a/erts/emulator/beam/erl_lock_check.h
+++ b/erts/emulator/beam/erl_lock_check.h
@@ -102,6 +102,7 @@ void erts_lc_unrequire_lock_flg(erts_lc_lock_t *lck, Uint16 op_flags);
 void erts_lc_require_lock(erts_lc_lock_t *lck);
 void erts_lc_unrequire_lock(erts_lc_lock_t *lck);
 
+int erts_lc_is_emu_thr(void);
 
 #define ERTS_LC_ASSERT(A) \
     ((void) (((A) || ERTS_SOMEONE_IS_CRASH_DUMPING) ? 1 : erts_lc_assert_failed(__FILE__, __LINE__, #A)))
diff --git a/erts/emulator/beam/erl_message.c b/erts/emulator/beam/erl_message.c
index d5b7d01048..325d77e911 100644
--- a/erts/emulator/beam/erl_message.c
+++ b/erts/emulator/beam/erl_message.c
@@ -495,7 +495,7 @@ queue_message(Process *c_p,
 #ifndef ERTS_SMP
     res = receiver->msg.len;
 #else
-    res = receiver->u.alive.msg_inq.len;
+    res = receiver->msg_inq.len;
     if (*receiver_locks & ERTS_PROC_LOCK_MAIN) {
 	/*
 	 * We move 'in queue' to 'private queue' and place
@@ -894,8 +894,8 @@ erts_send_message(Process* sender,
  #ifdef USE_VM_PROBES
     *sender_name = *receiver_name = '\0';
    if (DTRACE_ENABLED(message_send)) {
-        erts_snprintf(sender_name, sizeof(DTRACE_CHARBUF_NAME(sender_name)), "%T", sender->id);
-        erts_snprintf(receiver_name, sizeof(DTRACE_CHARBUF_NAME(receiver_name)), "%T", receiver->id);
+        erts_snprintf(sender_name, sizeof(DTRACE_CHARBUF_NAME(sender_name)), "%T", sender->common.id);
+        erts_snprintf(receiver_name, sizeof(DTRACE_CHARBUF_NAME(receiver_name)), "%T", receiver->common.id);
     }
 #endif
     if (SEQ_TRACE_TOKEN(sender) != NIL && !(flags & ERTS_SND_FLG_NO_SEQ_TRACE)) {
@@ -917,7 +917,7 @@ erts_send_message(Process* sender,
 
 	    seq_trace_update_send(sender);
 	    seq_trace_output(stoken, message, SEQ_TRACE_SEND, 
-			     receiver->id, sender);
+			     receiver->common.id, sender);
 	    seq_trace_size = 6; /* TUPLE5 */
 #ifdef USE_VM_PROBES
 	}
@@ -948,7 +948,7 @@ erts_send_message(Process* sender,
 #ifdef DTRACE_TAG_HARDDEBUG
 	    erts_fprintf(stderr,
 			 "Dtrace -> (%T) Spreading tag (%T) with "
-			 "message %T!\r\n",sender->id, utag, message);
+			 "message %T!\r\n",sender->common.id, utag, message);
 #endif
 	}
 #endif
@@ -1136,7 +1136,7 @@ erts_deliver_exit_message(Eterm from, Process *to, ErtsProcLocks *to_locksp,
 	save = TUPLE3(hp, am_EXIT, from_copy, mess);
 	hp += 4;
 	/* the trace token must in this case be updated by the caller */
-	seq_trace_output(token, save, SEQ_TRACE_SEND, to->id, NULL);
+	seq_trace_output(token, save, SEQ_TRACE_SEND, to->common.id, NULL);
 	temptoken = copy_struct(token, sz_token, &hp, &bp->off_heap);
 	erts_queue_message(to, to_locksp, bp, save, temptoken
 #ifdef USE_VM_PROBES
diff --git a/erts/emulator/beam/erl_message.h b/erts/emulator/beam/erl_message.h
index 2ae94965b1..771eba431f 100644
--- a/erts/emulator/beam/erl_message.h
+++ b/erts/emulator/beam/erl_message.h
@@ -127,21 +127,21 @@ typedef struct {
 /* Move in message queue to end of private message queue */
 #define ERTS_SMP_MSGQ_MV_INQ2PRIVQ(P)					\
 do {									\
-    if ((P)->u.alive.msg_inq.first) {					\
-	*(P)->msg.last = (P)->u.alive.msg_inq.first;			\
-	(P)->msg.last = (P)->u.alive.msg_inq.last;			\
-	(P)->msg.len += (P)->u.alive.msg_inq.len;			\
-	(P)->u.alive.msg_inq.first = NULL;				\
-	(P)->u.alive.msg_inq.last = &(P)->u.alive.msg_inq.first;	\
-	(P)->u.alive.msg_inq.len = 0;					\
+    if ((P)->msg_inq.first) {						\
+	*(P)->msg.last = (P)->msg_inq.first;				\
+	(P)->msg.last = (P)->msg_inq.last;				\
+	(P)->msg.len += (P)->msg_inq.len;				\
+	(P)->msg_inq.first = NULL;					\
+	(P)->msg_inq.last = &(P)->msg_inq.first;			\
+	(P)->msg_inq.len = 0;						\
     }									\
 } while (0)
 
 /* Add message last in message queue */
 #define LINK_MESSAGE(p, mp) do { \
-    *(p)->u.alive.msg_inq.last = (mp); \
-    (p)->u.alive.msg_inq.last = &(mp)->next; \
-    (p)->u.alive.msg_inq.len++; \
+    *(p)->msg_inq.last = (mp); \
+    (p)->msg_inq.last = &(mp)->next; \
+    (p)->msg_inq.len++; \
 } while(0)
 
 #else
@@ -245,6 +245,9 @@ void erts_move_msg_attached_data_to_heap(Eterm **, ErlOffHeap *, ErlMessage *);
 Eterm erts_msg_distext2heap(Process *, ErtsProcLocks *, ErlHeapFragment **,
 			    Eterm *, ErtsDistExternal *);
 
+void erts_cleanup_offheap(ErlOffHeap *offheap);
+
+
 ERTS_GLB_INLINE Uint erts_msg_used_frag_sz(const ErlMessage *msg);
 ERTS_GLB_INLINE Uint erts_msg_attached_data_size(ErlMessage *msg);
 
diff --git a/erts/emulator/beam/erl_monitors.c b/erts/emulator/beam/erl_monitors.c
index 1a84950120..63175c44d6 100644
--- a/erts/emulator/beam/erl_monitors.c
+++ b/erts/emulator/beam/erl_monitors.c
@@ -971,7 +971,7 @@ Eterm erts_debug_dump_monitors_1(BIF_ALIST_1)
 	}
     } else {
 	erts_printf("Dumping pid monitors--------------------\n");
-	erts_dump_monitors(rp->monitors,0);
+	erts_dump_monitors(ERTS_P_MONITORS(rp),0);
 	erts_printf("Monitors dumped-------------------------\n");
 	erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_LINK);
 	BIF_RET(am_true);
@@ -985,12 +985,15 @@ Eterm erts_debug_dump_links_1(BIF_ALIST_1)
     Process *rp;
     DistEntry *dep;
     if (is_internal_port(pid)) {
-	Port *rport = erts_id2port(pid, p, ERTS_PROC_LOCK_MAIN);
+	Port *rport = erts_id2port_sflgs(pid,
+					 p,
+					 ERTS_PROC_LOCK_MAIN,
+					 ERTS_PORT_SFLGS_INVALID_LOOKUP);
 	if (rport) {
 	    erts_printf("Dumping port links----------------------\n");
-	    erts_dump_links(rport->nlinks,0);
+	    erts_dump_links(ERTS_P_LINKS(rport), 0);
 	    erts_printf("Links dumped----------------------------\n");
-	    erts_smp_port_unlock(rport);
+	    erts_port_release(rport);
 	    BIF_RET(am_true);
 	} else {
 	    BIF_ERROR(p,BADARG);
@@ -1014,7 +1017,7 @@ Eterm erts_debug_dump_links_1(BIF_ALIST_1)
 
 	} else {
 	    erts_printf("Dumping pid links-----------------------\n");
-	    erts_dump_links(rp->nlinks,0);
+	    erts_dump_links(ERTS_P_LINKS(rp), 0);
 	    erts_printf("Links dumped----------------------------\n");
 	    erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_LINK);
 	    BIF_RET(am_true);
diff --git a/erts/emulator/beam/erl_monitors.h b/erts/emulator/beam/erl_monitors.h
index d3f6d410dd..a7fa4e0145 100644
--- a/erts/emulator/beam/erl_monitors.h
+++ b/erts/emulator/beam/erl_monitors.h
@@ -137,8 +137,6 @@ typedef struct erts_suspend_monitor {
 #define ERTS_LINK_ROOT(Linkp) ((Linkp)->shared.root)
 #define ERTS_LINK_REFC(Linkp) ((Linkp)->shared.refc) 
 
-#define ERTS_LINK_ROOT_AS_UINT(Linkp) (*((Uint *) &((Linkp)->root)))
-
 Uint erts_tot_link_lh_size(void);
 
 
diff --git a/erts/emulator/beam/erl_nif.c b/erts/emulator/beam/erl_nif.c
index 632d756481..1bd2d933b2 100644
--- a/erts/emulator/beam/erl_nif.c
+++ b/erts/emulator/beam/erl_nif.c
@@ -263,7 +263,7 @@ ErlNifEnv* enif_alloc_env(void)
     HEAP_LIMIT(&msg_env->phony_proc) = phony_heap;
     HEAP_END(&msg_env->phony_proc) = phony_heap;
     MBUF(&msg_env->phony_proc) = NULL;
-    msg_env->phony_proc.id = ERTS_INVALID_PID;
+    msg_env->phony_proc.common.id = ERTS_INVALID_PID;
 #ifdef FORCE_HEAP_FRAGS
     msg_env->phony_proc.space_verified = 0;
     msg_env->phony_proc.space_verified_from = NULL;
@@ -287,7 +287,7 @@ void enif_clear_env(ErlNifEnv* env)
     struct enif_msg_environment_t* menv = (struct enif_msg_environment_t*)env;
     Process* p = &menv->phony_proc;
     ASSERT(p == menv->env.proc);
-    ASSERT(p->id == ERTS_INVALID_PID);
+    ASSERT(p->common.id == ERTS_INVALID_PID);
     ASSERT(MBUF(p) == menv->env.heap_frag);
     if (MBUF(p) != NULL) {
 	erts_cleanup_offheap(&MSO(p));
@@ -319,7 +319,7 @@ int enif_send(ErlNifEnv* env, const ErlNifPid* to_pid,
 
     if (env != NULL) {
 	c_p = env->proc;
-	if (receiver == c_p->id) {
+	if (receiver == c_p->common.id) {
 	    rp_locks = ERTS_PROC_LOCK_MAIN;
 	    flush_me = 1;
 	}
@@ -341,7 +341,7 @@ int enif_send(ErlNifEnv* env, const ErlNifPid* to_pid,
 	  : erts_pid2proc_opt(c_p, ERTS_PROC_LOCK_MAIN,
 			      receiver, rp_locks, ERTS_P2P_FLG_SMP_INC_REFC));
     if (rp == NULL) {
-	ASSERT(env == NULL || receiver != c_p->id);
+	ASSERT(env == NULL || receiver != c_p->common.id);
 	return 0;
     }
     flush_env(msg_env);
@@ -397,7 +397,7 @@ static int is_offheap(const ErlOffHeap* oh)
 
 ErlNifPid* enif_self(ErlNifEnv* caller_env, ErlNifPid* pid)
 {
-    pid->pid = caller_env->proc->id;
+    pid->pid = caller_env->proc->common.id;
     return pid;
 }
 int enif_get_local_pid(ErlNifEnv* env, ERL_NIF_TERM term, ErlNifPid* pid)
@@ -505,7 +505,7 @@ int enif_inspect_iolist_as_binary(ErlNifEnv* env, Eterm term, ErlNifBinary* bin)
 {
     struct enif_tmp_obj_t* tobj;
     ErtsAlcType_t allocator;
-    Uint sz;
+    ErlDrvSizeT sz;
     if (is_binary(term)) {
 	return enif_inspect_binary(env,term,bin);
     }
@@ -531,7 +531,7 @@ int enif_inspect_iolist_as_binary(ErlNifEnv* env, Eterm term, ErlNifBinary* bin)
     bin->size = sz;
     bin->bin_term = THE_NON_VALUE;
     bin->ref_bin = NULL;
-    io_list_to_buf(term, (char*) bin->data, sz);
+    erts_iolist_to_buf(term, (char*) bin->data, sz);
     ADD_READONLY_CHECK(env, bin->data, bin->size); 
     return 1;
 }
@@ -1844,7 +1844,7 @@ void erl_nif_init()
 #ifdef USE_VM_PROBES
 void dtrace_nifenv_str(ErlNifEnv *env, char *process_buf)
 {
-    dtrace_pid_str(env->proc->id, process_buf);
+    dtrace_pid_str(env->proc->common.id, process_buf);
 }
 #endif
 
diff --git a/erts/emulator/beam/erl_node_container_utils.h b/erts/emulator/beam/erl_node_container_utils.h
index 7b4cb7b042..667bda255b 100644
--- a/erts/emulator/beam/erl_node_container_utils.h
+++ b/erts/emulator/beam/erl_node_container_utils.h
@@ -20,7 +20,7 @@
 #ifndef ERL_NODE_CONTAINER_UTILS_H__
 #define ERL_NODE_CONTAINER_UTILS_H__
 
-#include "erl_term.h"
+#include "erl_ptab.h"
 
 /*
  * Note regarding node containers:
@@ -29,9 +29,6 @@
  * the emulator) for the Erlang data types that contain a reference
  * to a node, i.e. pids, ports, and references.
  *
- * Observe! The layouts of the node container data types have been
- * changed in R9. 
- *
  * Node containers are divided into internal and external node containers.
  * An internal node container refer to the current incarnation of the
  * node which it reside on. An external node container refer to
@@ -52,13 +49,6 @@
  * reference is a boxed data type. An internal node container have an
  * implicit reference to the 'erts_this_node' element in the node table.
  *
- * Due to the R9 changes in layouts of node containers there are room to
- * store more data than previously. Today (R9) this extra space is unused,
- * but it is planned to be used in the future. For example only 18 bits
- * are used for data in a pid but there is room for 28 bits of data (on a
- * 32-bit machine). Some preparations have been made in the emulator for
- * usage of this extra space.
- *
  * OBSERVE! Pids doesn't use fixed size 'serial' and 'number' fields any
  * more. Previously the 15 bit 'number' field of a pid was used as index
  * into the process table, and the 3 bit 'serial' field was used as a
@@ -104,8 +94,6 @@
 #define internal_dist_entry(x)		(erts_this_node->dist_entry)
 #define external_dist_entry(x)		(external_node((x))->dist_entry)
 
-extern int erts_use_r9_pids_ports;
-
 /*
  * For this node (and previous incarnations of this node), 0 is used as
  * channel no. For other nodes, the atom index of the atom corresponding
@@ -128,47 +116,20 @@ extern int erts_use_r9_pids_ports;
  * Pids                                                                    *
 \*                                                                         */
 
-#define erts_max_processes erts_proc.max
-
-typedef struct {
-    erts_smp_atomic_t *tab;
-    int max;
-    int tab_cache_lines;
-    int pix_per_cache_line;
-    int pix_cl_mask;
-    int pix_cl_shift;
-    int pix_cli_mask;
-    int pix_cli_shift;
-} ErtsProcTab;
-
-extern ErtsProcTab erts_proc;
-
-ERTS_GLB_INLINE int erts_pid_data2ix(Eterm pid_data);
-
-#if ERTS_GLB_INLINE_INCL_FUNC_DEF
-
-ERTS_GLB_INLINE int erts_pid_data2ix(Eterm pid_data)
-{
-    int n, pix;
-
-    n = (int) pid_data;
-    if (erts_proc.pix_cl_mask) {
-	pix = ((n & erts_proc.pix_cl_mask) << erts_proc.pix_cl_shift);
-	pix += ((n >> erts_proc.pix_cli_shift) & erts_proc.pix_cli_mask);
-    }
-    else {
-	n %= erts_proc.max;
-	pix = n % erts_proc.tab_cache_lines;
-	pix *= erts_proc.pix_per_cache_line;
-	pix += n / erts_proc.tab_cache_lines;
-    }
-    ASSERT(0 <= pix && pix < erts_proc.max);
-    return pix;
-}
+extern ErtsPTab erts_proc;
 
-#endif
+#define make_internal_pid(D)		erts_ptab_make_id(&erts_proc, \
+							  (D), \
+							  _TAG_IMMED1_PID)
 
-#define internal_pid_index(x)		erts_pid_data2ix(internal_pid_data((x)))
+#define internal_pid_index(PID)		(ASSERT_EXPR(is_internal_pid((PID))), \
+					 erts_ptab_id2pix(&erts_proc, (PID)))
+
+#define internal_pid_data(PID)		(ASSERT_EXPR(is_internal_pid((PID))), \
+					 erts_ptab_id2data(&erts_proc, (PID)))
+
+#define internal_pid_number(x)		_GET_PID_NUM(internal_pid_data((x)))
+#define internal_pid_serial(x)		_GET_PID_SER(internal_pid_data((x)))
 
 #define internal_pid_node_name(x)	(internal_pid_node((x))->sysname)
 #define external_pid_node_name(x)	(external_pid_node((x))->sysname)
@@ -208,34 +169,37 @@ ERTS_GLB_INLINE int erts_pid_data2ix(Eterm pid_data)
 					 || is_external_pid((x)))
 #define is_not_pid(x)			(!is_pid(x))
 
-#define ERTS_MAX_R9_PROCESSES		(1 << ERTS_R9_PROC_BITS)
-
 /*
  * Maximum number of processes. We want the number to fit in a SMALL on
  * 32-bit CPU.
  */
 
-#define ERTS_MAX_PROCESSES ((SWORD_CONSTANT(1) << 27)-1)
-#if (ERTS_MAX_PROCESSES > MAX_SMALL)
-# error "The maximum number of processes must fit in a SMALL."
-#endif
-
+#define ERTS_MAX_PROCESSES		(ERTS_PTAB_MAX_SIZE-1)
 #define ERTS_MAX_PID_DATA		((1 << _PID_DATA_SIZE) - 1)
 #define ERTS_MAX_PID_NUMBER		((1 << _PID_NUM_SIZE) - 1)
 #define ERTS_MAX_PID_SERIAL		((1 << _PID_SER_SIZE) - 1)
-#define ERTS_MAX_PID_R9_SERIAL		((1 << _PID_R9_SER_SIZE) - 1)
 
-#define ERTS_R9_PROC_BITS		(_PID_R9_SER_SIZE + _PID_NUM_SIZE)
 #define ERTS_PROC_BITS			(_PID_SER_SIZE + _PID_NUM_SIZE)
 
-#define ERTS_INVALID_PID		make_internal_pid(ERTS_MAX_PID_DATA)
+#define ERTS_INVALID_PID		ERTS_PTAB_INVALID_ID(_TAG_IMMED1_PID)
 
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *\
  * Ports                                                                   *
 \*                                                                         */
 
-#define internal_port_index(x)		(internal_port_data((x))	\
-					 & erts_port_tab_index_mask)
+extern ErtsPTab erts_port;
+
+#define make_internal_port(D)		erts_ptab_make_id(&erts_port, \
+							  (D), \
+							  _TAG_IMMED1_PORT)
+
+#define internal_port_index(PRT)	(ASSERT_EXPR(is_internal_port((PRT))), \
+					 erts_ptab_id2pix(&erts_port, (PRT)))
+
+#define internal_port_data(PRT)		(ASSERT_EXPR(is_internal_port((PRT))), \
+					 erts_ptab_id2data(&erts_port, (PRT)))
+
+#define internal_port_number(x) _GET_PORT_NUM(internal_port_data((x)))
 
 #define internal_port_node_name(x)	(internal_port_node((x))->sysname)
 #define external_port_node_name(x)	(external_port_node((x))->sysname)
@@ -274,18 +238,18 @@ ERTS_GLB_INLINE int erts_pid_data2ix(Eterm pid_data)
 #define is_not_port(x)			(!is_port(x))
 
 /* Highest port-ID part in a term of type Port 
-   Not necessarily the same as the variable erts_max_ports
+   Not necessarily the same as current maximum port table size
    which defines the maximum number of simultaneous Ports
    in the Erlang node. ERTS_MAX_PORTS is a hard upper limit.
 */
-#define ERTS_MAX_R9_PORTS		(1 << ERTS_R9_PORTS_BITS)
-#define ERTS_MAX_PORTS			(1 << ERTS_PORTS_BITS)
-
+#define ERTS_MAX_PORTS			(ERTS_PTAB_MAX_SIZE-1)
 #define ERTS_MAX_PORT_DATA		((1 << _PORT_DATA_SIZE) - 1)
 #define ERTS_MAX_PORT_NUMBER		((1 << _PORT_NUM_SIZE) - 1)
 
-#define ERTS_R9_PORTS_BITS		(_PORT_R9_NUM_SIZE)
 #define ERTS_PORTS_BITS			(_PORT_NUM_SIZE)
+
+#define ERTS_INVALID_PORT		ERTS_PTAB_INVALID_ID(_TAG_IMMED1_PORT)
+
 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *\
  * Refs                                                                    *
 \*                                                                         */
diff --git a/erts/emulator/beam/erl_node_tables.c b/erts/emulator/beam/erl_node_tables.c
index 40837d3817..ebfba065d1 100644
--- a/erts/emulator/beam/erl_node_tables.c
+++ b/erts/emulator/beam/erl_node_tables.c
@@ -116,8 +116,7 @@ dist_table_alloc(void *dep_tmpl)
     dep->qsize				= 0;
     dep->out_queue.first		= NULL;
     dep->out_queue.last			= NULL;
-    dep->suspended.first		= NULL;
-    dep->suspended.last			= NULL;
+    dep->suspended			= NULL;
 
     dep->finalized_out_queue.first	= NULL;
     dep->finalized_out_queue.last	= NULL;
@@ -769,8 +768,7 @@ void erts_init_node_tables(void)
     erts_this_dist_entry->qsize				= 0;
     erts_this_dist_entry->out_queue.first		= NULL;
     erts_this_dist_entry->out_queue.last		= NULL;
-    erts_this_dist_entry->suspended.first		= NULL;
-    erts_this_dist_entry->suspended.last		= NULL;
+    erts_this_dist_entry->suspended			= NULL;
 
     erts_this_dist_entry->finalized_out_queue.first	= NULL;
     erts_this_dist_entry->finalized_out_queue.last	= NULL;
@@ -1268,7 +1266,7 @@ setup_reference_table(void)
     ErlHeapFragment *hfp;
     DistEntry *dep;
     HashInfo hi;
-    int i;
+    int i, max;
     DeclareTmpHeapNoproc(heap,3);
 
     inserted_bins = NULL;
@@ -1297,8 +1295,9 @@ setup_reference_table(void)
 
     UnUseTmpHeapNoproc(3);
 
+    max = erts_ptab_max(&erts_proc);
     /* Insert all processes */
-    for (i = 0; i < erts_max_processes; i++) {
+    for (i = 0; i < max; i++) {
 	Process *proc = erts_pix2proc(i);
 	if (proc) {
 	    ErlMessage *msg;
@@ -1306,12 +1305,12 @@ setup_reference_table(void)
 	    /* Insert Heap */
 	    insert_offheap(&(proc->off_heap),
 			   HEAP_REF,
-			   proc->id);
+			   proc->common.id);
 	    /* Insert message buffers */
 	    for(hfp = proc->mbuf; hfp; hfp = hfp->next)
 		insert_offheap(&(hfp->off_heap),
 			       HEAP_REF,
-			       proc->id);
+			       proc->common.id);
 	    /* Insert msg msg buffers */
 	    for (msg = proc->msg.first; msg; msg = msg->next) {
 		ErlHeapFragment *heap_frag = NULL;
@@ -1321,7 +1320,7 @@ setup_reference_table(void)
 		    else {
 			if (msg->data.dist_ext->dep)
 			    insert_dist_entry(msg->data.dist_ext->dep,
-					      HEAP_REF, proc->id, 0);
+					      HEAP_REF, proc->common.id, 0);
 			if (is_not_nil(ERL_MESSAGE_TOKEN(msg)))
 			    heap_frag = erts_dist_ext_trailer(msg->data.dist_ext);
 		    }
@@ -1329,10 +1328,10 @@ setup_reference_table(void)
 		if (heap_frag)
 		    insert_offheap(&(heap_frag->off_heap),
 				   HEAP_REF,
-				   proc->id);
+				   proc->common.id);
 	    }
 #ifdef ERTS_SMP
-	    for (msg = proc->u.alive.msg_inq.first; msg; msg = msg->next) {
+	    for (msg = proc->msg_inq.first; msg; msg = msg->next) {
 		ErlHeapFragment *heap_frag = NULL;
 		if (msg->data.attached) {
 		    if (is_value(ERL_MESSAGE_TERM(msg)))
@@ -1340,7 +1339,7 @@ setup_reference_table(void)
 		    else {
 			if (msg->data.dist_ext->dep)
 			    insert_dist_entry(msg->data.dist_ext->dep,
-					      HEAP_REF, proc->id, 0);
+					      HEAP_REF, proc->common.id, 0);
 			if (is_not_nil(ERL_MESSAGE_TOKEN(msg)))
 			    heap_frag = erts_dist_ext_trailer(msg->data.dist_ext);
 		    }
@@ -1348,19 +1347,19 @@ setup_reference_table(void)
 		if (heap_frag)
 		    insert_offheap(&(heap_frag->off_heap),
 				   HEAP_REF,
-				   proc->id);
+				   proc->common.id);
 	    }
 #endif
 	    /* Insert links */
-	    if(proc->nlinks)
-		insert_links(proc->nlinks, proc->id);
-	    if(proc->monitors)
-		insert_monitors(proc->monitors, proc->id);
+	    if (ERTS_P_LINKS(proc))
+		insert_links(ERTS_P_LINKS(proc), proc->common.id);
+	    if (ERTS_P_MONITORS(proc))
+		insert_monitors(ERTS_P_MONITORS(proc), proc->common.id);
 	    /* Insert controller */
 	    {
 		DistEntry *dep = ERTS_PROC_GET_DIST_ENTRY(proc);
 		if (dep)
-		    insert_dist_entry(dep, CTRL_REF, proc->id, 0);
+		    insert_dist_entry(dep, CTRL_REF, proc->common.id, 0);
 	    }
 	}
     }
@@ -1370,21 +1369,33 @@ setup_reference_table(void)
 #endif
 
     /* Insert all ports */
-    for (i = 0; i < erts_max_ports; i++) {
-	if (erts_port[i].status & ERTS_PORT_SFLGS_DEAD)
+    max = erts_ptab_max(&erts_port);
+    for (i = 0; i < max; i++) {
+	erts_aint32_t state;
+	Port *prt;
+
+	prt = erts_pix2port(i);
+	if (!prt)
+	    continue;
+
+	state = erts_atomic32_read_nob(&prt->state);
+	if (state & ERTS_PORT_SFLGS_DEAD)
 	    continue;
 
 	/* Insert links */
-	if(erts_port[i].nlinks)
-	    insert_links(erts_port[i].nlinks, erts_port[i].id);
+	if (ERTS_P_LINKS(prt))
+	    insert_links(ERTS_P_LINKS(prt), prt->common.id);
+	/* Insert monitors */
+	if (ERTS_P_MONITORS(prt))
+	    insert_monitors(ERTS_P_MONITORS(prt), prt->common.id);
 	/* Insert port data */
-	for(hfp = erts_port[i].bp; hfp; hfp = hfp->next)
-	    insert_offheap(&(hfp->off_heap), HEAP_REF, erts_port[i].id);
+	for(hfp = prt->bp; hfp; hfp = hfp->next)
+	    insert_offheap(&(hfp->off_heap), HEAP_REF, prt->common.id);
 	/* Insert controller */
-	if (erts_port[i].dist_entry)
-	    insert_dist_entry(erts_port[i].dist_entry,
+	if (prt->dist_entry)
+	    insert_dist_entry(prt->dist_entry,
 			      CTRL_REF,
-			      erts_port[i].id,
+			      prt->common.id,
 			      0);
     }
 
diff --git a/erts/emulator/beam/erl_node_tables.h b/erts/emulator/beam/erl_node_tables.h
index 4a015bdef9..af60071ea5 100644
--- a/erts/emulator/beam/erl_node_tables.h
+++ b/erts/emulator/beam/erl_node_tables.h
@@ -84,10 +84,6 @@ typedef struct {
 } ErtsDistOutputQueue;
 
 struct ErtsProcList_;
-typedef struct {
-    struct ErtsProcList_ *first;
-    struct ErtsProcList_ *last;
-} ErtsDistSuspended;
 
 /*
  * Lock order:
@@ -100,7 +96,6 @@ typedef struct {
  */
 
 struct erl_link;
-struct port;
 
 typedef struct dist_entry_ {
     HashBucket hash_bucket;     /* Hash bucket */
@@ -135,13 +130,13 @@ typedef struct dist_entry_ {
     Uint32 qflgs;
     Sint qsize;
     ErtsDistOutputQueue out_queue;
-    ErtsDistSuspended suspended;
+    struct ErtsProcList_ *suspended;
 
     ErtsDistOutputQueue finalized_out_queue;
     erts_smp_atomic_t dist_cmd_scheduled;
     ErtsPortTaskHandle dist_cmd;
 
-    Uint (*send)(struct port *prt, ErtsDistOutputBuf *obuf);
+    Uint (*send)(Port *prt, ErtsDistOutputBuf *obuf);
 
     struct cache* cache;	/* The atom cache */
 } DistEntry;
diff --git a/erts/emulator/beam/erl_port.h b/erts/emulator/beam/erl_port.h
new file mode 100644
index 0000000000..f4d73e716a
--- /dev/null
+++ b/erts/emulator/beam/erl_port.h
@@ -0,0 +1,942 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2012. All Rights Reserved.
+ *
+ * The contents of this file are subject to the Erlang Public License,
+ * Version 1.1, (the "License"); you may not use this file except in
+ * compliance with the License. You should have received a copy of the
+ * Erlang Public License along with this software. If not, it can be
+ * retrieved online at http://www.erlang.org/.
+ *
+ * Software distributed under the License is distributed on an "AS IS"
+ * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+ * the License for the specific language governing rights and limitations
+ * under the License.
+ *
+ * %CopyrightEnd%
+ */
+
+#ifndef ERL_PORT_TYPE__
+#define ERL_PORT_TYPE__
+typedef struct _erl_drv_port Port;
+typedef struct ErtsProc2PortSigData_ ErtsProc2PortSigData;
+#endif
+
+#if !defined(ERL_PORT_H__) && !defined(ERL_PORT_GET_PORT_TYPE_ONLY__)
+#define ERL_PORT_H__
+
+#include "erl_port_task.h"
+#include "erl_ptab.h"
+#include "erl_thr_progress.h"
+#include "erl_trace.h"
+
+#define ERTS_DEFAULT_MAX_PORTS (1 << 16)
+#define ERTS_MIN_PORTS 1024
+
+extern int erts_port_synchronous_ops;
+extern int erts_port_schedule_all_ops;
+extern int erts_port_parallelism;
+
+typedef struct erts_driver_t_ erts_driver_t;
+
+#define ERTS_INVALID_ERL_DRV_PORT ((ErlDrvPort) (SWord) -1)
+#define SMALL_IO_QUEUE 5   /* Number of fixed elements */
+
+typedef struct {
+    ErlDrvSizeT size;       /* total size in bytes */
+
+    SysIOVec* v_start;
+    SysIOVec* v_end;
+    SysIOVec* v_head;
+    SysIOVec* v_tail;
+    SysIOVec  v_small[SMALL_IO_QUEUE];
+
+    ErlDrvBinary** b_start;
+    ErlDrvBinary** b_end;
+    ErlDrvBinary** b_head;
+    ErlDrvBinary** b_tail;
+    ErlDrvBinary*  b_small[SMALL_IO_QUEUE];
+} ErlIOQueue;
+
+typedef struct line_buf {  /* Buffer used in line oriented I/O */
+    ErlDrvSizeT bufsiz;      /* Size of character buffer */
+    ErlDrvSizeT ovlen;       /* Length of overflow data */
+    ErlDrvSizeT ovsiz;       /* Actual size of overflow buffer */
+    char data[1];            /* Starting point of buffer data,
+			      data[0] is a flag indicating an unprocess CR,
+			      The rest is the overflow buffer. */
+} LineBuf;
+
+/*
+ * Items part of erlang:port_info/1 result. Note am_registered_name
+ * *need* to be first.
+ */
+
+#define ERTS_PORT_INFO_1_ITEMS				\
+    {	am_registered_name,	/* Needs to be first */	\
+	am_name,					\
+	am_links,					\
+	am_id,						\
+	am_connected,					\
+	am_input,					\
+	am_output,					\
+	am_os_pid }
+
+/*
+ * Port Specific Data.
+ *
+ * Only use PrtSD for very rarely used data.
+ */
+
+#define ERTS_PRTSD_SCHED_ID 0
+
+#define ERTS_PRTSD_SIZE 1
+
+typedef struct {
+    void *data[ERTS_PRTSD_SIZE];
+} ErtsPrtSD;
+
+#ifdef ERTS_SMP
+typedef struct ErtsXPortsList_ ErtsXPortsList;
+#endif
+
+/*
+ * Port locking:
+ *
+ * Locking is done either driver specific or port specific. When
+ * driver specific locking is used, all instances of the driver,
+ * i.e. ports running the driver, share the same lock. When port
+ * specific locking is used each instance have its own lock.
+ *
+ * Most fields in the Port structure are protected by the lock
+ * referred to by the 'lock' field. This lock is shared between
+ * all ports running the same driver when driver specific locking
+ * is used.
+ *
+ * The 'sched' field is protected by the run queue lock that the
+ * port currently is assigned to.
+ *
+ */
+
+struct _erl_drv_port {
+    ErtsPTabElementCommon common; /* *Need* to be first in struct */
+
+    ErtsPortTaskSched sched;
+    ErtsPortTaskHandle timeout_task;
+#ifdef ERTS_SMP
+    erts_mtx_t *lock;
+    ErtsXPortsList *xports;
+    erts_smp_atomic_t run_queue;
+#else
+    erts_atomic32_t refc;
+    int cleanup;
+#endif
+    erts_atomic_t connected;	/* A connected process */
+    Eterm caller;		/* Current caller. */
+    Eterm data;			/* Data associated with port. */
+    ErlHeapFragment* bp;	/* Heap fragment holding data (NULL if imm data). */
+    Uint bytes_in;		/* Number of bytes read */
+    Uint bytes_out;		/* Number of bytes written */
+
+    ErlIOQueue ioq;              /* driver accessible i/o queue */
+    DistEntry *dist_entry;       /* Dist entry used in DISTRIBUTION */
+    char *name;		         /* String used in the open */
+    erts_driver_t* drv_ptr;
+    UWord drv_data;
+    SWord os_pid;                /* Child process ID */
+    ErtsProcList *suspended;	 /* List of suspended processes. */
+    LineBuf *linebuf;            /* Buffer to hold data not ready for
+				    process to get (line oriented I/O)*/
+    erts_atomic32_t state;	 /* Status and type flags */
+    int control_flags;		 /* Flags for port_control()  */
+    ErlDrvPDL port_data_lock;
+
+    ErtsPrtSD *psd;		 /* Port specific data */
+};
+
+#define ERTS_PORT_GET_CONNECTED(PRT) \
+    ((Eterm) erts_atomic_read_nob(&(PRT)->connected))
+#define ERTS_PORT_SET_CONNECTED(PRT, PID) \
+    erts_atomic_set_relb(&(PRT)->connected, (erts_aint_t) (PID))
+#define ERTS_PORT_INIT_CONNECTED(PRT, PID) \
+    erts_atomic_init_nob(&(PRT)->connected, (erts_aint_t) (PID))
+
+
+struct erl_drv_port_data_lock {
+    erts_mtx_t mtx;
+    erts_atomic_t refc;
+    Port *prt;
+};
+
+ERTS_GLB_INLINE ErtsRunQueue *erts_port_runq(Port *prt);
+
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+
+ERTS_GLB_INLINE ErtsRunQueue *
+erts_port_runq(Port *prt)
+{
+#ifdef ERTS_SMP
+    ErtsRunQueue *rq1, *rq2;
+    rq1 = (ErtsRunQueue *) erts_smp_atomic_read_nob(&prt->run_queue);
+    if (!rq1)
+	return NULL;
+    while (1) {
+	erts_smp_runq_lock(rq1);
+	rq2 = (ErtsRunQueue *) erts_smp_atomic_read_nob(&prt->run_queue);
+	if (rq1 == rq2)
+	    return rq1;
+	erts_smp_runq_unlock(rq1);
+	rq1 = rq2;
+	if (!rq1)
+	    return NULL;
+    }
+#else
+    return ERTS_RUNQ_IX(0);
+#endif
+}
+
+#endif
+
+
+ERTS_GLB_INLINE void *erts_prtsd_get(Port *p, int ix);
+ERTS_GLB_INLINE void *erts_prtsd_set(Port *p, int ix, void *new);
+
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+
+ERTS_GLB_INLINE void *
+erts_prtsd_get(Port *prt, int ix)
+{
+    return prt->psd ? prt->psd->data[ix] : NULL;
+}
+
+ERTS_GLB_INLINE void *
+erts_prtsd_set(Port *prt, int ix, void *data)
+{
+    if (prt->psd) {
+	void *old = prt->psd->data[ix];
+	prt->psd->data[ix] = data;
+	return old;
+    }
+    else {
+	prt->psd = erts_alloc(ERTS_ALC_T_PRTSD, sizeof(ErtsPrtSD));
+	prt->psd->data[ix] = data;
+	return NULL;
+    }
+}
+
+#endif
+
+extern erts_smp_atomic_t erts_bytes_out;	/* no bytes written out */
+extern erts_smp_atomic_t erts_bytes_in;		/* no bytes sent into the system */
+
+
+/* port status flags */
+
+#define ERTS_PORT_SFLG_CONNECTED	((Uint32) (1 <<  0))
+/* Port have begun exiting */
+#define ERTS_PORT_SFLG_EXITING		((Uint32) (1 <<  1))
+/* Distribution port */
+#define ERTS_PORT_SFLG_DISTRIBUTION	((Uint32) (1 <<  2))
+#define ERTS_PORT_SFLG_BINARY_IO	((Uint32) (1 <<  3))
+#define ERTS_PORT_SFLG_SOFT_EOF		((Uint32) (1 <<  4))
+/* Flow control */
+/* Port is closing (no i/o accepted) */
+#define ERTS_PORT_SFLG_CLOSING		((Uint32) (1 <<  5))
+/* Send a closed message when terminating */
+#define ERTS_PORT_SFLG_SEND_CLOSED	((Uint32) (1 <<  6))
+/* Line orinted io on port */  
+#define ERTS_PORT_SFLG_LINEBUF_IO	((Uint32) (1 <<  7))
+/* Immortal port (only certain system ports) */
+#define ERTS_PORT_SFLG_FREE		((Uint32) (1 <<  8))
+#define ERTS_PORT_SFLG_INITIALIZING	((Uint32) (1 <<  9))
+/* Port uses port specific locking (opposed to driver specific locking) */
+#define ERTS_PORT_SFLG_PORT_SPECIFIC_LOCK ((Uint32) (1 << 10))
+#define ERTS_PORT_SFLG_INVALID		((Uint32) (1 << 11))
+/* Last port to terminate halts the emulator */
+#define ERTS_PORT_SFLG_HALT		((Uint32) (1 << 12))
+#ifdef DEBUG
+/* Only debug: make sure all flags aren't cleared unintentionally */
+#define ERTS_PORT_SFLG_PORT_DEBUG	((Uint32) (1 << 31))
+#endif
+
+/* Combinations of port status flags */ 
+#define ERTS_PORT_SFLGS_DEAD						\
+  (ERTS_PORT_SFLG_FREE | ERTS_PORT_SFLG_INITIALIZING)
+#define ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP				\
+  (ERTS_PORT_SFLGS_DEAD | ERTS_PORT_SFLG_INVALID)
+#define ERTS_PORT_SFLGS_INVALID_LOOKUP					\
+  (ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP				\
+   | ERTS_PORT_SFLG_EXITING						\
+   | ERTS_PORT_SFLG_CLOSING)
+#define ERTS_PORT_SFLGS_INVALID_TRACER_LOOKUP				\
+  (ERTS_PORT_SFLGS_INVALID_LOOKUP					\
+   | ERTS_PORT_SFLG_DISTRIBUTION)
+
+
+/*
+ * Costs in reductions for some port operations.
+ */
+#define ERTS_PORT_REDS_EXECUTE		10
+#define ERTS_PORT_REDS_FREE		100
+#define ERTS_PORT_REDS_TIMEOUT		400
+#define ERTS_PORT_REDS_INPUT		400
+#define ERTS_PORT_REDS_OUTPUT		400
+#define ERTS_PORT_REDS_EVENT		400
+#define ERTS_PORT_REDS_CMD_OUTPUTV	400
+#define ERTS_PORT_REDS_CMD_OUTPUT	400
+#define ERTS_PORT_REDS_EXIT		300
+#define ERTS_PORT_REDS_CONNECT		40
+#define ERTS_PORT_REDS_UNLINK		40
+#define ERTS_PORT_REDS_LINK		40
+#define ERTS_PORT_REDS_BADSIG		40
+#define ERTS_PORT_REDS_CONTROL		400
+#define ERTS_PORT_REDS_CALL		400
+#define ERTS_PORT_REDS_INFO		100
+#define ERTS_PORT_REDS_SET_DATA		40
+#define ERTS_PORT_REDS_GET_DATA		40
+#define ERTS_PORT_REDS_TERMINATE	200
+
+void print_port_info(Port *, int, void *);
+void erts_port_free(Port *);
+#ifndef ERTS_SMP
+void erts_port_cleanup(Port *);
+#endif
+void erts_fire_port_monitor(Port *prt, Eterm ref);
+#ifdef ERTS_SMP
+int erts_port_handle_xports(Port *);
+#endif
+
+#if defined(ERTS_SMP) && defined(ERTS_ENABLE_LOCK_CHECK)
+int erts_lc_is_port_locked(Port *);
+#endif
+
+ERTS_GLB_INLINE void erts_port_inc_refc(Port *prt);
+ERTS_GLB_INLINE void erts_port_dec_refc(Port *prt);
+ERTS_GLB_INLINE void erts_port_add_refc(Port *prt, Sint32 add_refc);
+
+ERTS_GLB_INLINE int erts_smp_port_trylock(Port *prt);
+ERTS_GLB_INLINE void erts_smp_port_lock(Port *prt);
+ERTS_GLB_INLINE void erts_smp_port_unlock(Port *prt);
+
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+
+ERTS_GLB_INLINE void erts_port_inc_refc(Port *prt)
+{
+#ifdef ERTS_SMP
+    erts_ptab_inc_refc(&prt->common);
+#else
+    erts_atomic32_inc_nob(&prt->refc);
+#endif
+}
+
+ERTS_GLB_INLINE void erts_port_dec_refc(Port *prt)
+{
+#ifdef ERTS_SMP
+    int referred = erts_ptab_dec_test_refc(&prt->common);
+    if (!referred)
+	erts_port_free(prt);
+#else
+    int refc = erts_atomic32_dec_read_nob(&prt->refc);
+    if (refc == 0)
+	erts_port_free(prt);	
+#endif
+}
+
+ERTS_GLB_INLINE void erts_port_add_refc(Port *prt, Sint32 add_refc)
+{
+#ifdef ERTS_SMP
+    int referred = erts_ptab_add_test_refc(&prt->common, add_refc);
+    if (!referred)
+	erts_port_free(prt);
+#else
+    int refc = erts_atomic32_add_read_nob(&prt->refc, add_refc);
+    if (refc == 0)
+	erts_port_free(prt);	
+#endif
+}
+
+ERTS_GLB_INLINE int
+erts_smp_port_trylock(Port *prt)
+{
+#ifdef ERTS_SMP
+    /* *Need* to be a managed thread */
+    ERTS_SMP_LC_ASSERT(erts_thr_progress_is_managed_thread());
+    return erts_mtx_trylock(prt->lock);
+#else
+    return 0;
+#endif
+}
+
+ERTS_GLB_INLINE void
+erts_smp_port_lock(Port *prt)
+{
+#ifdef ERTS_SMP
+    /* *Need* to be a managed thread */
+    ERTS_SMP_LC_ASSERT(erts_thr_progress_is_managed_thread());
+    erts_mtx_lock(prt->lock);
+#endif
+}
+
+ERTS_GLB_INLINE void
+erts_smp_port_unlock(Port *prt)
+{
+#ifdef ERTS_SMP
+    /* *Need* to be a managed thread */
+    ERTS_SMP_LC_ASSERT(erts_thr_progress_is_managed_thread());
+    erts_mtx_unlock(prt->lock);
+#endif
+}
+
+#endif /* #if ERTS_GLB_INLINE_INCL_FUNC_DEF */
+
+
+#define ERTS_INVALID_PORT_OPT(PP, ID, FLGS)			\
+    (!(PP)							\
+     || (erts_atomic32_read_nob(&(PP)->state) & (FLGS))	\
+     || (PP)->common.id != (ID))
+
+/* port lookup */
+
+#define INVALID_PORT(PP, ID) \
+  ERTS_INVALID_PORT_OPT((PP), (ID), ERTS_PORT_SFLGS_INVALID_LOOKUP)
+
+/* Invalidate trace port if anything suspicious, for instance
+ * that the port is a distribution port or it is busy.
+ */
+#define INVALID_TRACER_PORT(PP, ID)					\
+  ERTS_INVALID_PORT_OPT((PP), (ID), ERTS_PORT_SFLGS_INVALID_TRACER_LOOKUP)
+
+#define ERTS_PORT_SCHED_ID(P, ID) \
+  ((Uint) (UWord) erts_prtsd_set((P), ERTS_PSD_SCHED_ID, (void *) (UWord) (ID)))
+
+extern const Port erts_invalid_port;
+#define ERTS_PORT_LOCK_BUSY ((Port *) &erts_invalid_port)
+
+int erts_is_port_ioq_empty(Port *);
+void erts_terminate_port(Port *);
+
+#ifdef ERTS_SMP
+Port *erts_de2port(DistEntry *, Process *, ErtsProcLocks);
+#endif
+
+ERTS_GLB_INLINE Port *erts_pix2port(int);
+ERTS_GLB_INLINE Port *erts_port_lookup_raw(Eterm);
+ERTS_GLB_INLINE Port *erts_port_lookup(Eterm, Uint32);
+ERTS_GLB_INLINE Port*erts_id2port(Eterm id);
+ERTS_GLB_INLINE Port *erts_id2port_sflgs(Eterm, Process *, ErtsProcLocks, Uint32);
+ERTS_GLB_INLINE void erts_port_release(Port *);
+#ifdef ERTS_SMP
+ERTS_GLB_INLINE Port *erts_thr_id2port_sflgs(Eterm id, Uint32 invalid_sflgs);
+ERTS_GLB_INLINE void erts_thr_port_release(Port *prt);
+#endif
+ERTS_GLB_INLINE Port *erts_thr_drvport2port_raw(ErlDrvPort);
+ERTS_GLB_INLINE Port *erts_drvport2port_raw(ErlDrvPort drvport);
+ERTS_GLB_INLINE Port *erts_drvport2port(ErlDrvPort, erts_aint32_t *);
+ERTS_GLB_INLINE Port *erts_drvportid2port(Eterm);
+ERTS_GLB_INLINE Eterm erts_drvport2id(ErlDrvPort);
+ERTS_GLB_INLINE Uint32 erts_portid2status(Eterm);
+ERTS_GLB_INLINE int erts_is_port_alive(Eterm);
+ERTS_GLB_INLINE int erts_is_valid_tracer_port(Eterm);
+ERTS_GLB_INLINE int erts_port_driver_callback_epilogue(Port *, erts_aint32_t *);
+
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+
+ERTS_GLB_INLINE Port *erts_pix2port(int ix)
+{
+    Port *prt;
+    ASSERT(0 <= ix && ix < erts_ptab_max(&erts_port));
+    prt = (Port *) erts_ptab_pix2intptr_nob(&erts_port, ix);
+    return prt == ERTS_PORT_LOCK_BUSY ? NULL : prt;
+}
+
+ERTS_GLB_INLINE Port *
+erts_port_lookup_raw(Eterm id)
+{
+    Port *prt;
+
+    ERTS_SMP_LC_ASSERT(erts_thr_progress_lc_is_delaying());
+
+    if (is_not_internal_port(id))
+	return NULL;
+
+    prt = (Port *) erts_ptab_pix2intptr_ddrb(&erts_port,
+					     internal_port_index(id));
+    return prt && prt->common.id == id ? prt : NULL;
+}
+
+ERTS_GLB_INLINE Port *
+erts_port_lookup(Eterm id, Uint32 invalid_sflgs)
+{
+    Port *prt = erts_port_lookup_raw(id);
+    return (!prt
+	    ? NULL
+	    : ((invalid_sflgs & erts_atomic32_read_nob(&prt->state))
+	       ? NULL
+	       : prt));
+}
+
+
+ERTS_GLB_INLINE Port*
+erts_id2port(Eterm id)
+{
+    erts_aint32_t state;
+    Port *prt;
+
+    /* Only allowed to be called from managed threads */
+    ERTS_SMP_LC_ASSERT(erts_thr_progress_is_managed_thread());
+
+    if (is_not_internal_port(id))
+	return NULL;
+
+    prt = (Port *) erts_ptab_pix2intptr_ddrb(&erts_port,
+					     internal_port_index(id));
+
+    if (!prt || prt->common.id != id)
+	return NULL;
+
+    erts_smp_port_lock(prt);
+    state = erts_atomic32_read_nob(&prt->state);
+    if (state & ERTS_PORT_SFLGS_INVALID_LOOKUP) {
+	erts_smp_port_unlock(prt);
+	return NULL;
+    }
+
+    return prt;
+}
+
+
+ERTS_GLB_INLINE Port*
+erts_id2port_sflgs(Eterm id,
+		   Process *c_p, ErtsProcLocks c_p_locks,
+		   Uint32 invalid_sflgs)
+{
+#ifdef ERTS_SMP
+    int no_proc_locks = !c_p || !c_p_locks;
+#endif
+    erts_aint32_t state;
+    Port *prt;
+
+    /* Only allowed to be called from managed threads */
+    ERTS_SMP_LC_ASSERT(erts_thr_progress_is_managed_thread());
+
+    if (is_not_internal_port(id))
+	return NULL;
+
+    prt = (Port *) erts_ptab_pix2intptr_ddrb(&erts_port,
+					     internal_port_index(id));
+
+    if (!prt || prt->common.id != id)
+	return NULL;
+
+#ifdef ERTS_SMP
+    if (no_proc_locks)
+	erts_smp_port_lock(prt);
+    else if (erts_smp_port_trylock(prt) == EBUSY) {
+	/* Unlock process locks, and acquire locks in lock order... */
+	erts_smp_proc_unlock(c_p, c_p_locks);
+	erts_smp_port_lock(prt);
+	erts_smp_proc_lock(c_p, c_p_locks);
+    }
+#endif
+    state = erts_atomic32_read_nob(&prt->state);
+    if (state & invalid_sflgs) {
+#ifdef ERTS_SMP
+	erts_smp_port_unlock(prt);
+#endif
+	return NULL;
+    }
+
+    return prt;
+}
+
+ERTS_GLB_INLINE void
+erts_port_release(Port *prt)
+{
+    /* Only allowed to be called from managed threads */
+    ERTS_SMP_LC_ASSERT(erts_thr_progress_is_managed_thread());
+#ifdef ERTS_SMP
+    erts_smp_port_unlock(prt);
+#else
+    if (prt->cleanup) {
+	prt->cleanup = 0;
+	erts_port_cleanup(prt);
+    }
+#endif
+}
+
+#ifdef ERTS_SMP
+
+/*
+ * erts_thr_id2port_sflgs() and erts_thr_port_release() can
+ * be used by unmanaged threads in the SMP case.
+ */
+ERTS_GLB_INLINE Port *
+erts_thr_id2port_sflgs(Eterm id, Uint32 invalid_sflgs)
+{
+    Port *prt;
+    ErtsThrPrgrDelayHandle dhndl;
+
+    if (is_not_internal_port(id))
+	return NULL;
+
+    dhndl = erts_thr_progress_unmanaged_delay();
+
+    prt = (Port *) erts_ptab_pix2intptr_ddrb(&erts_port,
+					     internal_port_index(id));
+
+    if (!prt || prt->common.id != id) {
+	erts_thr_progress_unmanaged_continue(dhndl);
+	prt = NULL;
+    }
+    else {
+	erts_aint32_t state;
+	if (dhndl != ERTS_THR_PRGR_DHANDLE_MANAGED) {
+	    erts_port_inc_refc(prt);
+	    erts_thr_progress_unmanaged_continue(dhndl);
+	}
+
+	erts_mtx_lock(prt->lock);
+	state = erts_atomic32_read_nob(&prt->state);
+	if (state & invalid_sflgs) {
+	    erts_mtx_unlock(prt->lock);
+	    if (dhndl != ERTS_THR_PRGR_DHANDLE_MANAGED)
+		erts_port_dec_refc(prt);
+	    prt = NULL;
+	}
+    }
+
+    return prt;
+}
+
+ERTS_GLB_INLINE void
+erts_thr_port_release(Port *prt)
+{
+    erts_mtx_unlock(prt->lock);
+#ifdef ERTS_SMP
+    if (!erts_thr_progress_is_managed_thread())
+	erts_port_dec_refc(prt);
+#endif
+}
+
+#endif
+
+ERTS_GLB_INLINE Port*
+erts_thr_drvport2port_raw(ErlDrvPort drvport)
+{
+#if ERTS_ENABLE_LOCK_CHECK
+    int emu_thread = erts_lc_is_emu_thr();
+#endif
+    if (drvport == ERTS_INVALID_ERL_DRV_PORT)
+	return NULL;
+    else {
+	Port *prt = (Port *) drvport;
+#if ERTS_ENABLE_LOCK_CHECK
+	if (!ERTS_IS_CRASH_DUMPING) {
+	    if (emu_thread) {
+		ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
+		ERTS_LC_ASSERT(!prt->port_data_lock
+			       || erts_lc_mtx_is_locked(&prt->port_data_lock->mtx));
+	    }
+	    else {
+		ERTS_LC_ASSERT(prt->port_data_lock);
+		ERTS_LC_ASSERT(erts_lc_mtx_is_locked(&prt->port_data_lock->mtx));
+	    }
+	}
+#endif
+	return prt;
+    }
+}
+
+ERTS_GLB_INLINE Port*
+erts_drvport2port_raw(ErlDrvPort drvport)
+{
+    ERTS_LC_ASSERT(erts_lc_is_emu_thr());
+    if (drvport == ERTS_INVALID_ERL_DRV_PORT)
+	return NULL;
+    else {
+	Port *prt = (Port *) drvport;
+	ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt)
+			   || ERTS_IS_CRASH_DUMPING);
+	return prt;
+    }
+}
+
+ERTS_GLB_INLINE Port*
+erts_drvport2port(ErlDrvPort drvport, erts_aint32_t *statep)
+{
+    Port *prt = erts_drvport2port_raw(drvport);
+    erts_aint32_t state;
+    if (!prt)
+	return NULL;
+    state = erts_atomic32_read_nob(&prt->state);
+    if (state & ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP)
+	return NULL;
+    if (statep)
+	*statep = state;
+    return prt;
+}
+
+ERTS_GLB_INLINE Port*
+erts_drvportid2port(Eterm id)
+{
+    Port *prt;
+    erts_aint32_t state;
+    if (is_not_internal_port(id))
+	return NULL;
+    prt = (Port *) erts_ptab_pix2intptr_nob(&erts_port,
+					    internal_port_index(id));
+    if (!prt)
+	return NULL;
+    ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt)
+		       || ERTS_IS_CRASH_DUMPING);
+    if (prt->common.id != id)
+	return NULL;
+    state = erts_atomic32_read_nob(&prt->state);
+    if (state & ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP)
+	return NULL;
+    return prt;
+}
+
+ERTS_GLB_INLINE Eterm
+erts_drvport2id(ErlDrvPort drvport)
+{
+    Port *prt = erts_drvport2port_raw(drvport);
+    if (!prt)
+	return am_undefined;
+    else
+	return prt->common.id;
+}
+
+ERTS_GLB_INLINE Uint32
+erts_portid2status(Eterm id)
+{
+    Port *prt = erts_port_lookup_raw(id);
+    if (prt)
+	return (Uint32) erts_atomic32_read_acqb(&prt->state);
+    else
+	return ERTS_PORT_SFLG_INVALID;
+}
+
+ERTS_GLB_INLINE int
+erts_is_port_alive(Eterm id)
+{
+    return !(erts_portid2status(id) & (ERTS_PORT_SFLG_INVALID
+				       | ERTS_PORT_SFLGS_DEAD));
+}
+
+ERTS_GLB_INLINE int
+erts_is_valid_tracer_port(Eterm id)
+{
+    return !(erts_portid2status(id) & ERTS_PORT_SFLGS_INVALID_TRACER_LOOKUP);
+}
+
+ERTS_GLB_INLINE int
+erts_port_driver_callback_epilogue(Port *prt, erts_aint32_t *statep)
+{
+    int reds = 0;
+    erts_aint32_t state;
+
+    ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
+
+    state = erts_atomic32_read_nob(&prt->state);
+    if ((state & ERTS_PORT_SFLG_CLOSING) && erts_is_port_ioq_empty(prt)) {
+	reds += ERTS_PORT_REDS_TERMINATE;
+	erts_terminate_port(prt);
+	state = erts_atomic32_read_nob(&prt->state);
+	ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
+    }
+
+#ifdef ERTS_SMP
+    if (prt->xports) {
+	reds += erts_port_handle_xports(prt);
+	ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
+	ASSERT(!prt->xports);
+    }
+#endif
+
+    if (statep)
+	*statep = state;
+
+    return reds;
+}
+
+#endif /* #if ERTS_GLB_INLINE_INCL_FUNC_DEF */
+
+void erts_port_resume_procs(Port *);
+
+struct binary;
+
+#define ERTS_P2P_SIG_TYPE_BAD			0
+#define ERTS_P2P_SIG_TYPE_OUTPUT		1
+#define ERTS_P2P_SIG_TYPE_OUTPUTV		2
+#define ERTS_P2P_SIG_TYPE_CONNECT		3
+#define ERTS_P2P_SIG_TYPE_EXIT			4
+#define ERTS_P2P_SIG_TYPE_CONTROL		5
+#define ERTS_P2P_SIG_TYPE_CALL			6
+#define ERTS_P2P_SIG_TYPE_INFO			7
+#define ERTS_P2P_SIG_TYPE_LINK			8
+#define ERTS_P2P_SIG_TYPE_UNLINK		9
+#define ERTS_P2P_SIG_TYPE_SET_DATA		10
+#define ERTS_P2P_SIG_TYPE_GET_DATA		11
+
+#define ERTS_P2P_SIG_TYPE_BITS			4
+#define ERTS_P2P_SIG_TYPE_MASK \
+    ((1 << ERTS_P2P_SIG_TYPE_BITS) - 1)
+
+#define ERTS_P2P_SIG_DATA_FLG(N) \
+    (1 << (ERTS_P2P_SIG_TYPE_BITS + (N)))
+#define ERTS_P2P_SIG_DATA_FLG_BANG_OP		ERTS_P2P_SIG_DATA_FLG(0)
+#define ERTS_P2P_SIG_DATA_FLG_REPLY		ERTS_P2P_SIG_DATA_FLG(1)
+#define ERTS_P2P_SIG_DATA_FLG_NOSUSPEND		ERTS_P2P_SIG_DATA_FLG(2)
+#define ERTS_P2P_SIG_DATA_FLG_FORCE		ERTS_P2P_SIG_DATA_FLG(3)
+#define ERTS_P2P_SIG_DATA_FLG_BAD_OUTPUT	ERTS_P2P_SIG_DATA_FLG(4)
+#define ERTS_P2P_SIG_DATA_FLG_BROKEN_LINK	ERTS_P2P_SIG_DATA_FLG(5)
+#define ERTS_P2P_SIG_DATA_FLG_SCHED		ERTS_P2P_SIG_DATA_FLG(6)
+
+struct ErtsProc2PortSigData_ {
+    int flags;
+    Eterm caller;
+    Uint32 ref[ERTS_MAX_REF_NUMBERS];
+    union {
+	struct {
+	    Eterm from;
+	    ErlIOVec *evp;
+	    ErlDrvBinary *cbinp;
+	} outputv;
+	struct {
+	    Eterm from;
+	    char *bufp;
+	    ErlDrvSizeT size;
+	} output;
+	struct {
+	    Eterm from;
+	    Eterm connected;
+	} connect;
+	struct {
+	    Eterm from;
+	    Eterm reason;
+	    ErlHeapFragment *bp;
+	} exit;
+	struct {
+	    struct binary *binp;
+	    unsigned int command;
+	    char *bufp;
+	    ErlDrvSizeT size;
+	} control;
+	struct {
+	    unsigned int command;
+	    char *bufp;
+	    ErlDrvSizeT size;
+	} call;
+	struct {
+	    Eterm item;
+	} info;
+	struct {
+	    Eterm port;
+	    Eterm to;
+	} link;
+	struct {
+	    Eterm from;
+	} unlink;
+	struct {
+	    ErlHeapFragment *bp;
+	    Eterm data;
+	} set_data;
+    } u;
+} ;
+
+ERTS_GLB_INLINE int
+erts_proc2port_sig_is_command_op(ErtsProc2PortSigData *sigdp);
+ERTS_GLB_INLINE ErlDrvSizeT
+erts_proc2port_sig_command_data_size(ErtsProc2PortSigData *sigdp);
+
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+
+ERTS_GLB_INLINE int
+erts_proc2port_sig_is_command_op(ErtsProc2PortSigData *sigdp)
+{
+    switch (sigdp->flags & ERTS_P2P_SIG_TYPE_MASK) {
+    case ERTS_P2P_SIG_TYPE_OUTPUT:	return !0;
+    case ERTS_P2P_SIG_TYPE_OUTPUTV:	return !0;
+    default:				return 0;
+    }
+}
+
+ERTS_GLB_INLINE ErlDrvSizeT
+erts_proc2port_sig_command_data_size(ErtsProc2PortSigData *sigdp)
+{
+    switch (sigdp->flags & ERTS_P2P_SIG_TYPE_MASK) {
+    case ERTS_P2P_SIG_TYPE_OUTPUT:	return sigdp->u.output.size;
+    case ERTS_P2P_SIG_TYPE_OUTPUTV:	return sigdp->u.outputv.evp->size;
+    default:				return (ErlDrvSizeT) 0;
+    }
+}
+
+#endif
+
+#define ERTS_PROC2PORT_SIG_EXEC			0
+#define ERTS_PROC2PORT_SIG_ABORT		1
+#define ERTS_PROC2PORT_SIG_ABORT_NOSUSPEND	2
+#define ERTS_PROC2PORT_SIG_ABORT_CLOSED		3
+
+typedef int (*ErtsProc2PortSigCallback)(Port *,
+					erts_aint32_t,
+					int,
+					ErtsProc2PortSigData *);
+
+typedef enum {
+    ERTS_PORT_OP_BADARG,
+    ERTS_PORT_OP_CALLER_EXIT,
+    ERTS_PORT_OP_BUSY,
+    ERTS_PORT_OP_BUSY_SCHEDULED,
+    ERTS_PORT_OP_SCHEDULED,
+    ERTS_PORT_OP_DROPPED,
+    ERTS_PORT_OP_DONE
+} ErtsPortOpResult;
+
+ErtsPortOpResult
+erts_schedule_proc2port_signal(Process *,
+			       Port *,
+			       Eterm,
+			       Eterm *,
+			       ErtsProc2PortSigData *,
+			       int,
+			       ErtsProc2PortSigCallback);
+
+int erts_deliver_port_exit(Port *, Eterm, Eterm, int);
+
+/*
+ * Port signal flags
+ */
+#define ERTS_PORT_SIG_FLG_BANG_OP		ERTS_P2P_SIG_DATA_FLG_BANG_OP
+#define ERTS_PORT_SIG_FLG_NOSUSPEND		ERTS_P2P_SIG_DATA_FLG_NOSUSPEND
+#define ERTS_PORT_SIG_FLG_FORCE			ERTS_P2P_SIG_DATA_FLG_FORCE
+#define ERTS_PORT_SIG_FLG_BROKEN_LINK		ERTS_P2P_SIG_DATA_FLG_BROKEN_LINK
+#define ERTS_PORT_SIG_FLG_BAD_OUTPUT		ERTS_P2P_SIG_DATA_FLG_BAD_OUTPUT
+#define ERTS_PORT_SIG_FLG_FORCE_SCHED		ERTS_P2P_SIG_DATA_FLG_SCHED
+/* ERTS_PORT_SIG_FLG_FORCE_IMM_CALL only when crash dumping... */
+#define ERTS_PORT_SIG_FLG_FORCE_IMM_CALL	ERTS_P2P_SIG_DATA_FLG_BAD_OUTPUT
+
+/*
+ * Port ! {Owner, {command, Data}}
+ * Port ! {Owner, {connect, NewOwner}}
+ * Port ! {Owner, close}
+ */
+ErtsPortOpResult erts_port_command(Process *, int, Port *, Eterm, Eterm *);
+
+/*
+ * Signals from processes to ports.
+ */
+ErtsPortOpResult erts_port_output(Process *, int, Port *, Eterm, Eterm, Eterm *);
+ErtsPortOpResult erts_port_exit(Process *, int, Port *, Eterm, Eterm, Eterm *);
+ErtsPortOpResult erts_port_connect(Process *, int, Port *, Eterm, Eterm, Eterm *);
+ErtsPortOpResult erts_port_link(Process *, Port *, Eterm, Eterm *);
+ErtsPortOpResult erts_port_unlink(Process *, Port *, Eterm, Eterm *);
+ErtsPortOpResult erts_port_control(Process *, Port *, unsigned int, Eterm, Eterm *);
+ErtsPortOpResult erts_port_call(Process *, Port *, unsigned int, Eterm, Eterm *);
+ErtsPortOpResult erts_port_info(Process *, Port *, Eterm, Eterm *);
+ErtsPortOpResult erts_port_set_data(Process *, Port *, Eterm, Eterm *);
+ErtsPortOpResult erts_port_get_data(Process *, Port *, Eterm *);
+
+#endif
diff --git a/erts/emulator/beam/erl_port_task.c b/erts/emulator/beam/erl_port_task.c
index b6bc59a1c3..b661c26036 100644
--- a/erts/emulator/beam/erl_port_task.c
+++ b/erts/emulator/beam/erl_port_task.c
@@ -33,36 +33,29 @@
 #include "erl_port_task.h"
 #include "dist.h"
 #include "dtrace-wrapper.h"
+#include <stdarg.h>
 
 #if defined(DEBUG) && 0
-#define HARD_DEBUG
+#define ERTS_HARD_DEBUG_TASK_QUEUES
+#else
+#undef ERTS_HARD_DEBUG_TASK_QUEUES
 #endif
 
-/*
- * Costs in reductions for some port operations.
- */
-#define ERTS_PORT_REDS_EXECUTE		0
-#define ERTS_PORT_REDS_FREE		50
-#define ERTS_PORT_REDS_TIMEOUT		200
-#define ERTS_PORT_REDS_INPUT		200
-#define ERTS_PORT_REDS_OUTPUT		200
-#define ERTS_PORT_REDS_EVENT		200
-#define ERTS_PORT_REDS_TERMINATE	100
-
-
-#define ERTS_PORT_TASK_INVALID_PORT(P, ID) \
-  ((erts_port_status_get((P)) & ERTS_PORT_SFLGS_DEAD) || (P)->id != (ID))
-
-#define ERTS_PORT_IS_IN_RUNQ(RQ, P) \
-  ((P)->sched.next || (P)->sched.prev || (RQ)->ports.start == (P))
+#ifdef ERTS_HARD_DEBUG_TASK_QUEUES
+static void chk_task_queues(Port *pp, ErtsPortTask *execq, int processing_busy_queue);
+#define ERTS_PT_DBG_CHK_TASK_QS(PP, EQ, PBQ) \
+    chk_task_queues((PP), (EQ), (PBQ))
+#else
+#define ERTS_PT_DBG_CHK_TASK_QS(PP, EQ, PBQ)
+#endif
 
 #ifdef USE_VM_PROBES
 #define DTRACE_DRIVER(PROBE_NAME, PP)                              \
-    if (DTRACE_ENABLED(driver_ready_input)) {                      \
+    if (DTRACE_ENABLED(PROBE_NAME)) {                              \
         DTRACE_CHARBUF(process_str, DTRACE_TERM_BUF_SIZE);         \
         DTRACE_CHARBUF(port_str, DTRACE_TERM_BUF_SIZE);            \
                                                                    \
-        dtrace_pid_str(PP->connected, process_str);                \
+        dtrace_pid_str(ERTS_PORT_GET_CONNECTED(PP), process_str);  \
         dtrace_port_str(PP, port_str);                             \
         DTRACE3(PROBE_NAME, process_str, port_str, PP->name);      \
     }
@@ -72,83 +65,766 @@
 
 erts_smp_atomic_t erts_port_task_outstanding_io_tasks;
 
-struct ErtsPortTaskQueue_ {
-    ErtsPortTask *first;
-    ErtsPortTask *last;
-    Port *port;
-};
+#define ERTS_PT_STATE_SCHEDULED		0
+#define ERTS_PT_STATE_ABORTED		1
+#define ERTS_PT_STATE_EXECUTING		2
+
+typedef union {
+    struct { /* I/O tasks */
+	ErlDrvEvent event;
+	ErlDrvEventData event_data;
+    } io;
+    struct {
+	ErtsProc2PortSigCallback callback;
+	ErtsProc2PortSigData data;
+    } psig;
+} ErtsPortTaskTypeData;
 
 struct ErtsPortTask_ {
-    ErtsPortTask *prev;
-    ErtsPortTask *next;
-    ErtsPortTaskQueue *queue;
-    ErtsPortTaskHandle *handle;
+    erts_smp_atomic32_t state;
     ErtsPortTaskType type;
-    ErlDrvEvent event;
-    ErlDrvEventData event_data;
+    union {
+	struct {
+	    ErtsPortTask *next;
+	    ErtsPortTaskHandle *handle;
+	    int flags;
+	    Uint32 ref[ERTS_MAX_REF_NUMBERS];
+	    ErtsPortTaskTypeData td;
+	} alive;
+	ErtsThrPrgrLaterOp release;
+    } u;
 };
 
-#ifdef HARD_DEBUG
-#define ERTS_PT_CHK_PORTQ(RQ) check_port_queue((RQ), NULL, 0)
-#define ERTS_PT_CHK_PRES_PORTQ(RQ, PP) check_port_queue((RQ), (PP), -1)
-#define ERTS_PT_CHK_IN_PORTQ(RQ, PP) check_port_queue((RQ), (PP), 1)
-#define ERTS_PT_CHK_NOT_IN_PORTQ(RQ, PP) check_port_queue((RQ), (PP), 0)
-#define ERTS_PT_CHK_TASKQ(Q) check_task_queue((Q), NULL, 0)
-#define ERTS_PT_CHK_IN_TASKQ(Q, T) check_task_queue((Q), (T), 1)
-#define ERTS_PT_CHK_NOT_IN_TASKQ(Q, T) check_task_queue((Q), (T), 0)
-static void
-check_port_queue(Port *chk_pp, int inq);
-static void
-check_task_queue(ErtsPortTaskQueue *ptqp,
-		 ErtsPortTask *chk_ptp,
-		 int inq);
-#else
-#define ERTS_PT_CHK_PORTQ(RQ)
-#define ERTS_PT_CHK_PRES_PORTQ(RQ, PP)
-#define ERTS_PT_CHK_IN_PORTQ(RQ, PP)
-#define ERTS_PT_CHK_NOT_IN_PORTQ(RQ, PP)
-#define ERTS_PT_CHK_TASKQ(Q)
-#define ERTS_PT_CHK_IN_TASKQ(Q, T)
-#define ERTS_PT_CHK_NOT_IN_TASKQ(Q, T)
+struct ErtsPortTaskHandleList_ {
+    ErtsPortTaskHandle handle;
+    union {
+	ErtsPortTaskHandleList *next;
+#ifdef ERTS_SMP
+	ErtsThrPrgrLaterOp release;
 #endif
+    } u;
+};
+
+typedef struct ErtsPortTaskBusyCaller_ ErtsPortTaskBusyCaller;
+struct ErtsPortTaskBusyCaller_ {
+    ErtsPortTaskBusyCaller *next;
+    Eterm caller;
+    SWord count;
+    ErtsPortTask *last;
+};
+
+#define ERTS_PORT_TASK_BUSY_CALLER_TABLE_BUCKETS 17
+struct ErtsPortTaskBusyCallerTable_ {
+    ErtsPortTaskBusyCaller *bucket[ERTS_PORT_TASK_BUSY_CALLER_TABLE_BUCKETS];
+    ErtsPortTaskBusyCaller pre_alloc_busy_caller;
+};
+
 
-static void handle_remaining_tasks(ErtsRunQueue *runq, Port *pp);
+static void begin_port_cleanup(Port *pp, ErtsPortTask **execq);
 
 ERTS_SCHED_PREF_QUICK_ALLOC_IMPL(port_task,
 				 ErtsPortTask,
-				 200,
+				 1000,
 				 ERTS_ALC_T_PORT_TASK)
-ERTS_SCHED_PREF_QUICK_ALLOC_IMPL(port_taskq,
-				 ErtsPortTaskQueue,
+
+ERTS_SCHED_PREF_QUICK_ALLOC_IMPL(busy_caller_table,
+				 ErtsPortTaskBusyCallerTable,
 				 50,
-				 ERTS_ALC_T_PORT_TASKQ)
+				 ERTS_ALC_T_BUSY_CALLER_TAB)
+
+#ifdef ERTS_SMP
+static void
+call_port_task_free(void *vptp)
+{
+    port_task_free((ErtsPortTask *) vptp);
+}
+#endif
+
+static ERTS_INLINE void
+schedule_port_task_free(ErtsPortTask *ptp)
+{
+#ifdef ERTS_SMP
+    erts_schedule_thr_prgr_later_op(call_port_task_free,
+				    (void *) ptp,
+				    &ptp->u.release);
+#else
+    port_task_free(ptp);
+#endif
+}
+
+static ERTS_INLINE ErtsPortTask *
+p2p_sig_data_to_task(ErtsProc2PortSigData *sigdp)
+{
+    ErtsPortTask *ptp;
+    char *ptr = (char *) sigdp;
+    ptr -= offsetof(ErtsPortTask, u.alive.td.psig.data);
+    ptp = (ErtsPortTask *) ptr;
+    ASSERT(ptp->type == ERTS_PORT_TASK_PROC_SIG);
+    return ptp;
+}
+
+ErtsProc2PortSigData *
+erts_port_task_alloc_p2p_sig_data(void)
+{
+    ErtsPortTask *ptp = port_task_alloc();
+
+    ptp->type = ERTS_PORT_TASK_PROC_SIG;
+    ptp->u.alive.flags = ERTS_PT_FLG_SIG_DEP;
+    erts_smp_atomic32_init_nob(&ptp->state, ERTS_PT_STATE_SCHEDULED);
+
+    ASSERT(ptp == p2p_sig_data_to_task(&ptp->u.alive.td.psig.data));
+
+    return &ptp->u.alive.td.psig.data;
+}
+
+static ERTS_INLINE Eterm
+task_caller(ErtsPortTask *ptp)
+{
+    Eterm caller;
+
+    ASSERT(ptp->type == ERTS_PORT_TASK_PROC_SIG);
+
+    caller = ptp->u.alive.td.psig.data.caller;
+
+    ASSERT(is_internal_pid(caller) || is_internal_port(caller));
+
+    return caller;
+}
+
+/*
+ * Busy queue management
+ */
+
+static ERTS_INLINE int
+caller2bix(Eterm caller)
+{
+    ASSERT(is_internal_pid(caller) || is_internal_port(caller));
+    return (int) (_GET_PID_DATA(caller) % ERTS_PORT_TASK_BUSY_CALLER_TABLE_BUCKETS);
+}
+
+
+static void
+popped_from_busy_queue(Port *pp, ErtsPortTask *ptp, int last)
+{
+    ErtsPortTaskBusyCaller **prev_bcpp = NULL, *bcp;
+    ErtsPortTaskBusyCallerTable *tabp = pp->sched.taskq.local.busy.table;
+    Eterm caller = task_caller(ptp);
+    int bix = caller2bix(caller);
+
+    ASSERT(is_internal_pid(caller));
+
+    ASSERT(tabp);
+    bcp = tabp->bucket[bix];
+    prev_bcpp = &tabp->bucket[bix];
+    ASSERT(bcp);
+    while (bcp->caller != caller) {
+	prev_bcpp = &bcp->next;
+	bcp = bcp->next;
+	ASSERT(bcp);
+    }
+    ASSERT(bcp->count > 0);
+    if (--bcp->count != 0) {
+	ASSERT(!last);
+    }
+    else {
+	*prev_bcpp = bcp->next;
+	if (bcp == &tabp->pre_alloc_busy_caller)
+	    bcp->caller = am_undefined;
+	else
+	    erts_free(ERTS_ALC_T_BUSY_CALLER, bcp);
+	if (last) {
+#ifdef DEBUG
+	    erts_aint32_t flags =
+#endif
+		erts_smp_atomic32_read_band_nob(
+		    &pp->sched.flags,
+		    ~ERTS_PTS_FLG_HAVE_BUSY_TASKS);
+	    ASSERT(flags & ERTS_PTS_FLG_HAVE_BUSY_TASKS);
+#ifdef DEBUG
+	    for (bix = 0; bix < ERTS_PORT_TASK_BUSY_CALLER_TABLE_BUCKETS; bix++) {
+		ASSERT(!tabp->bucket[bix]);
+	    }
+#endif
+	    busy_caller_table_free(tabp);
+	    pp->sched.taskq.local.busy.first = NULL;
+	    pp->sched.taskq.local.busy.last = NULL;
+	    pp->sched.taskq.local.busy.table = NULL;
+	}
+    }
+}
+
+static void
+busy_wait_move_to_busy_queue(Port *pp, ErtsPortTask *ptp)
+{
+    ErtsPortTaskBusyCallerTable *tabp = pp->sched.taskq.local.busy.table;
+    Eterm caller = task_caller(ptp);
+    ErtsPortTaskBusyCaller *bcp;
+    int bix;
+
+    ASSERT(is_internal_pid(caller));
+    /*
+     * Port is busy and this task type needs to wait until not busy.
+     */
+
+    ASSERT(ptp->u.alive.flags & ERTS_PT_FLG_WAIT_BUSY);
+
+    ptp->u.alive.next = NULL;
+    if (pp->sched.taskq.local.busy.last) {
+	ASSERT(pp->sched.taskq.local.busy.first);
+	pp->sched.taskq.local.busy.last->u.alive.next = ptp;
+    }
+    else {
+	int i;
+	erts_aint32_t flags;
+
+	pp->sched.taskq.local.busy.first = ptp;
+	flags = erts_smp_atomic32_read_bor_nob(&pp->sched.flags,
+					       ERTS_PTS_FLG_HAVE_BUSY_TASKS);
+	ASSERT(!(flags & ERTS_PTS_FLG_HAVE_BUSY_TASKS));
+
+	ASSERT(!tabp);
+
+	tabp = busy_caller_table_alloc();
+	pp->sched.taskq.local.busy.table = tabp;
+	for (i = 0; i < ERTS_PORT_TASK_BUSY_CALLER_TABLE_BUCKETS; i++)
+	    tabp->bucket[i] = NULL;
+	tabp->pre_alloc_busy_caller.caller = am_undefined;
+    }
+    pp->sched.taskq.local.busy.last = ptp;
+
+    bix = caller2bix(caller);
+    ASSERT(tabp);
+    bcp = tabp->bucket[bix];
+
+    while (bcp && bcp->caller != caller)
+	bcp = bcp->next;
+
+    if (bcp)
+	bcp->count++;
+    else {
+	if (tabp->pre_alloc_busy_caller.caller == am_undefined)
+	    bcp = &tabp->pre_alloc_busy_caller;
+	else
+	    bcp = erts_alloc(ERTS_ALC_T_BUSY_CALLER,
+			     sizeof(ErtsPortTaskBusyCaller));
+	bcp->caller = caller;
+	bcp->count = 1;
+	bcp->next = tabp->bucket[bix];
+	tabp->bucket[bix] = bcp;
+    }
+
+    bcp->last = ptp;
+}
+
+static ERTS_INLINE int
+check_sig_dep_move_to_busy_queue(Port *pp, ErtsPortTask *ptp)
+{
+    ErtsPortTaskBusyCallerTable *tabp = pp->sched.taskq.local.busy.table;
+    ErtsPortTask *last_ptp;
+    ErtsPortTaskBusyCaller *bcp;
+    int bix;
+    Eterm caller;
+
+    ASSERT(ptp->u.alive.flags & ERTS_PT_FLG_SIG_DEP);
+    ASSERT(pp->sched.taskq.local.busy.last);
+    ASSERT(tabp);
+
+
+    /*
+     * We are either not busy, or the task does not imply wait on busy port.
+     * However, due to the signaling order requirements the task might depend
+     * on other tasks in the busy queue.
+     */
+
+    caller = task_caller(ptp);
+    bix = caller2bix(caller);
+    bcp = tabp->bucket[bix];
+    while (bcp && bcp->caller != caller)
+	bcp = bcp->next;
+
+    if (!bcp)
+	return 0;
+
+    /*
+     * There are other tasks that we depend on in the busy queue;
+     * move into busy queue.
+     */
+
+    bcp->count++;
+    last_ptp = bcp->last;
+    ptp->u.alive.next = last_ptp->u.alive.next;
+    if (!ptp->u.alive.next) {
+	ASSERT(pp->sched.taskq.local.busy.last == last_ptp);
+	pp->sched.taskq.local.busy.last = ptp;
+    }
+    last_ptp->u.alive.next = ptp;
+    bcp->last = ptp;
+
+    return 1;
+}
+
+static void
+no_sig_dep_move_from_busyq(Port *pp)
+{
+    ErtsPortTaskBusyCallerTable *tabp = pp->sched.taskq.local.busy.table;
+    ErtsPortTask *first_ptp, *last_ptp, *ptp;
+    ErtsPortTaskBusyCaller **prev_bcpp = NULL, *bcp = NULL;
+
+    /*
+     * Move tasks at the head of the busy queue that no longer
+     * have any dependencies to busy wait tasks into the ordinary
+     * queue.
+     */
+
+    first_ptp = ptp = pp->sched.taskq.local.busy.first;
+
+    ASSERT(ptp && !(ptp->u.alive.flags & ERTS_PT_FLG_WAIT_BUSY));
+    ASSERT(tabp);
+
+    do {
+	Eterm caller = task_caller(ptp);
+
+	if (!bcp || bcp->caller != caller) {
+	    int bix = caller2bix(caller);
+
+	    prev_bcpp = &tabp->bucket[bix];
+	    bcp = tabp->bucket[bix];
+	    ASSERT(bcp);
+	    while (bcp->caller != caller) {
+		ASSERT(bcp);
+		prev_bcpp = &bcp->next;
+		bcp = bcp->next;
+	    }
+	}
+
+	ASSERT(bcp->caller == caller);
+	ASSERT(bcp->count > 0);
+
+	if (--bcp->count == 0) {
+	    *prev_bcpp = bcp->next;
+	    if (bcp == &tabp->pre_alloc_busy_caller)
+		bcp->caller = am_undefined;
+	    else
+		erts_free(ERTS_ALC_T_BUSY_CALLER, bcp);
+	}
+
+	last_ptp = ptp;
+	ptp = ptp->u.alive.next;
+    } while (ptp && !(ptp->u.alive.flags & ERTS_PT_FLG_WAIT_BUSY));
+
+    pp->sched.taskq.local.busy.first = last_ptp->u.alive.next;
+    if (!pp->sched.taskq.local.busy.first) {
+#ifdef DEBUG
+	int bix;
+	erts_aint32_t flags =
+#endif
+	    erts_smp_atomic32_read_band_nob(
+		&pp->sched.flags,
+		~ERTS_PTS_FLG_HAVE_BUSY_TASKS);
+	ASSERT(flags & ERTS_PTS_FLG_HAVE_BUSY_TASKS);
+#ifdef DEBUG
+	for (bix = 0; bix < ERTS_PORT_TASK_BUSY_CALLER_TABLE_BUCKETS; bix++) {
+	    ASSERT(!tabp->bucket[bix]);
+	}
+#endif
+	busy_caller_table_free(tabp);
+	pp->sched.taskq.local.busy.last = NULL;
+	pp->sched.taskq.local.busy.table = NULL;
+    }
+    last_ptp->u.alive.next = pp->sched.taskq.local.first;
+    pp->sched.taskq.local.first = first_ptp;
+}
+
+#ifdef ERTS_HARD_DEBUG_TASK_QUEUES
+
+static void
+chk_task_queues(Port *pp, ErtsPortTask *execq, int processing_busy_queue)
+{
+    Sint tot_count, tot_table_count;
+    int bix;
+    ErtsPortTask *ptp, *last;
+    ErtsPortTask *first = processing_busy_queue ? execq : pp->sched.taskq.local.busy.first;
+    ErtsPortTask *nb_task_queue = processing_busy_queue ? pp->sched.taskq.local.first : execq;
+    ErtsPortTaskBusyCallerTable *tabp = pp->sched.taskq.local.busy.table;
+    ErtsPortTaskBusyCaller *bcp;
+
+    if (!first) {
+	ASSERT(!tabp);
+	ASSERT(!pp->sched.taskq.local.busy.last);
+	ASSERT(!(erts_smp_atomic32_read_nob(&pp->sched.flags) & ERTS_PTS_FLG_HAVE_BUSY_TASKS));
+	return;
+    }
+
+    ASSERT(erts_smp_atomic32_read_nob(&pp->sched.flags) & ERTS_PTS_FLG_HAVE_BUSY_TASKS);
+    ASSERT(tabp);
+
+    tot_count = 0;
+    ptp = first;
+    while (ptp) {
+	Sint count = 0;
+	Eterm caller = task_caller(ptp);
+	int bix = caller2bix(caller);
+	for (bcp = tabp->bucket[bix]; bcp; bcp = bcp->next)
+	    if (bcp->caller == caller)
+		break;
+	ASSERT(bcp && bcp->caller == caller);
+
+	ASSERT(bcp->last);
+	while (1) {
+	    ErtsPortTask *ptp2;
+
+	    ASSERT(caller == task_caller(ptp));
+	    count++;
+	    tot_count++;
+	    last = ptp;
+
+	    for (ptp2 = nb_task_queue; ptp2; ptp2 = ptp2->u.alive.next) {
+		ASSERT(ptp != ptp2);
+	    }
+
+	    if (ptp == bcp->last)
+		break;
+	    ptp = ptp->u.alive.next;
+	}
+
+	ASSERT(count == bcp->count);
+	ptp = ptp->u.alive.next;
+    }
+
+    tot_table_count = 0;
+    for (bix = 0; bix < ERTS_PORT_TASK_BUSY_CALLER_TABLE_BUCKETS; bix++) {
+	for (bcp = tabp->bucket[bix]; bcp; bcp = bcp->next)
+	    tot_table_count += bcp->count;
+    }
+
+    ASSERT(tot_count == tot_table_count);
+
+    ASSERT(last == pp->sched.taskq.local.busy.last);
+}
+
+#endif /* ERTS_HARD_DEBUG_TASK_QUEUES */
 
 /*
  * Task handle manipulation.
  */
 
+static ERTS_INLINE void
+reset_port_task_handle(ErtsPortTaskHandle *pthp)
+{
+    erts_smp_atomic_set_relb(pthp, (erts_aint_t) NULL);
+}
+
 static ERTS_INLINE ErtsPortTask *
 handle2task(ErtsPortTaskHandle *pthp)
 {
-    return (ErtsPortTask *) erts_smp_atomic_read_nob(pthp);
+    return (ErtsPortTask *) erts_smp_atomic_read_acqb(pthp);
 }
 
 static ERTS_INLINE void
 reset_handle(ErtsPortTask *ptp)
 {
-    if (ptp->handle) {
-	ASSERT(ptp == handle2task(ptp->handle));
-	erts_smp_atomic_set_nob(ptp->handle, (erts_aint_t) NULL);
+    if (ptp->u.alive.handle) {
+	ASSERT(ptp == handle2task(ptp->u.alive.handle));
+	reset_port_task_handle(ptp->u.alive.handle);
     }
 }
 
 static ERTS_INLINE void
 set_handle(ErtsPortTask *ptp, ErtsPortTaskHandle *pthp)
 {
-    ptp->handle = pthp;
+    ptp->u.alive.handle = pthp;
     if (pthp) {
-	erts_smp_atomic_set_nob(pthp, (erts_aint_t) ptp);
-	ASSERT(ptp == handle2task(ptp->handle));
+	erts_smp_atomic_set_relb(pthp, (erts_aint_t) ptp);
+	ASSERT(ptp == handle2task(ptp->u.alive.handle));
+    }
+}
+
+
+/*
+ * Busy port queue management
+ */
+
+static erts_aint32_t
+check_unset_busy_port_q(Port *pp,
+			erts_aint32_t flags,
+			ErtsPortTaskBusyPortQ *bpq)
+{
+    ErlDrvSizeT qsize, low;
+    int resume_procs = 0;
+
+    ASSERT(bpq);
+    ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(pp));
+
+    erts_port_task_sched_lock(&pp->sched);
+    qsize = (ErlDrvSizeT) erts_smp_atomic_read_nob(&bpq->size);
+    low = (ErlDrvSizeT) erts_smp_atomic_read_nob(&bpq->low);
+    if (qsize < low) {
+	erts_aint32_t mask = ~(ERTS_PTS_FLG_CHK_UNSET_BUSY_PORT_Q
+			       | ERTS_PTS_FLG_BUSY_PORT_Q);
+	flags = erts_smp_atomic32_read_band_relb(&pp->sched.flags, mask);
+	if ((flags & ERTS_PTS_FLGS_BUSY) == ERTS_PTS_FLG_BUSY_PORT_Q)
+	    resume_procs = 1;
+    }
+    else if (flags & ERTS_PTS_FLG_CHK_UNSET_BUSY_PORT_Q) {
+	flags = erts_smp_atomic32_read_band_relb(&pp->sched.flags,
+						 ~ERTS_PTS_FLG_CHK_UNSET_BUSY_PORT_Q);
+	flags &= ~ERTS_PTS_FLG_CHK_UNSET_BUSY_PORT_Q;
+    }
+    erts_port_task_sched_unlock(&pp->sched);
+    if (resume_procs)
+	erts_port_resume_procs(pp);
+
+    return flags;
+}
+
+static ERTS_INLINE void
+aborted_proc2port_data(Port *pp, ErlDrvSizeT size)
+{
+    ErtsPortTaskBusyPortQ *bpq;
+    erts_aint32_t flags;
+    ErlDrvSizeT qsz;
+
+    ASSERT(pp->sched.taskq.bpq);
+
+    if (size == 0)
+	return;
+
+    bpq = pp->sched.taskq.bpq;
+
+    qsz = (ErlDrvSizeT) erts_smp_atomic_add_read_acqb(&bpq->size,
+						      (erts_aint_t) -size);
+    ASSERT(qsz + size > qsz);
+    flags = erts_smp_atomic32_read_nob(&pp->sched.flags);
+    ASSERT(pp->sched.taskq.bpq);
+    if ((flags & (ERTS_PTS_FLG_CHK_UNSET_BUSY_PORT_Q
+		  | ERTS_PTS_FLG_BUSY_PORT_Q)) != ERTS_PTS_FLG_BUSY_PORT_Q)
+	return;
+    if (qsz < (ErlDrvSizeT) erts_smp_atomic_read_nob(&bpq->low))
+	erts_smp_atomic32_read_bor_nob(&pp->sched.flags,
+				       ERTS_PTS_FLG_CHK_UNSET_BUSY_PORT_Q);
+}
+
+static ERTS_INLINE void
+dequeued_proc2port_data(Port *pp, ErlDrvSizeT size)
+{
+    ErtsPortTaskBusyPortQ *bpq;
+    erts_aint32_t flags;
+    ErlDrvSizeT qsz;
+
+    ASSERT(pp->sched.taskq.bpq);
+
+    if (size == 0)
+	return;
+
+    bpq = pp->sched.taskq.bpq;
+
+    qsz = (ErlDrvSizeT) erts_smp_atomic_add_read_acqb(&bpq->size,
+						      (erts_aint_t) -size);
+    ASSERT(qsz + size > qsz);
+    flags = erts_smp_atomic32_read_nob(&pp->sched.flags);
+    if (!(flags & ERTS_PTS_FLG_BUSY_PORT_Q))
+	return;
+    if (qsz < (ErlDrvSizeT) erts_smp_atomic_read_acqb(&bpq->low))
+	check_unset_busy_port_q(pp, flags, bpq);
+}
+
+static ERTS_INLINE erts_aint32_t
+enqueue_proc2port_data(Port *pp,
+		       ErtsProc2PortSigData *sigdp,
+		       erts_aint32_t flags)
+{
+    ErtsPortTaskBusyPortQ *bpq = pp->sched.taskq.bpq;
+    if (sigdp && bpq) {
+	ErlDrvSizeT size = erts_proc2port_sig_command_data_size(sigdp);
+	if (size) {
+	    erts_aint_t asize = erts_smp_atomic_add_read_acqb(&bpq->size,
+							      (erts_aint_t) size);
+	    ErlDrvSizeT qsz = (ErlDrvSizeT) asize;
+
+	    ASSERT(qsz - size < qsz);
+
+	    if (!(flags & ERTS_PTS_FLG_BUSY_PORT_Q) && qsz > bpq->high) {
+		flags = erts_smp_atomic32_read_bor_acqb(&pp->sched.flags,
+							ERTS_PTS_FLG_BUSY_PORT_Q);
+		flags |= ERTS_PTS_FLG_BUSY_PORT_Q;
+		qsz = (ErlDrvSizeT) erts_smp_atomic_read_acqb(&bpq->size);
+		if (qsz < (ErlDrvSizeT) erts_smp_atomic_read_nob(&bpq->low)) {
+		    flags = (erts_smp_atomic32_read_bor_relb(
+				 &pp->sched.flags,
+				 ERTS_PTS_FLG_CHK_UNSET_BUSY_PORT_Q));
+		    flags |= ERTS_PTS_FLG_CHK_UNSET_BUSY_PORT_Q;
+		}
+	    }
+	    ASSERT(!(flags & ERTS_PTS_FLG_EXIT));
+	}
+    }
+    return flags;
+}
+
+/*
+ * erl_drv_busy_msgq_limits() is called by drivers either reading or
+ * writing the limits.
+ *
+ * A limit of zero is interpreted as a read only request (using a
+ * limit of zero would not be useful). Other values are interpreted
+ * as a write-read request.
+ */
+
+void
+erl_drv_busy_msgq_limits(ErlDrvPort dport, ErlDrvSizeT *lowp, ErlDrvSizeT *highp)
+{
+    Port *pp = erts_drvport2port(dport, NULL);
+    ErtsPortTaskBusyPortQ *bpq = pp->sched.taskq.bpq;
+    int written = 0, resume_procs = 0;
+    ErlDrvSizeT low, high;
+
+    if (!pp || !bpq) {
+	if (lowp)
+	    *lowp = ERL_DRV_BUSY_MSGQ_DISABLED;
+	if (highp)
+	    *highp = ERL_DRV_BUSY_MSGQ_DISABLED;
+	return;
+    }
+
+    low = lowp ? *lowp : 0;
+    high = highp ? *highp : 0;
+
+    erts_port_task_sched_lock(&pp->sched);
+
+    if (low == ERL_DRV_BUSY_MSGQ_DISABLED
+	|| high == ERL_DRV_BUSY_MSGQ_DISABLED) {
+	/* Disable busy msgq feature */
+	erts_aint32_t flags;
+	pp->sched.taskq.bpq = NULL;
+	flags = ~(ERTS_PTS_FLG_BUSY_PORT_Q|ERTS_PTS_FLG_CHK_UNSET_BUSY_PORT_Q);
+	flags = erts_smp_atomic32_read_band_acqb(&pp->sched.flags, flags);
+	if ((flags & ERTS_PTS_FLGS_BUSY) == ERTS_PTS_FLG_BUSY_PORT_Q)
+	    resume_procs = 1;
+    }
+    else {
+
+	if (!low)
+	    low = (ErlDrvSizeT) erts_smp_atomic_read_nob(&bpq->low);
+	else {
+	    if (bpq->high < low)
+		bpq->high = low;
+	    erts_smp_atomic_set_relb(&bpq->low, (erts_aint_t) low);
+	    written = 1;
+	}
+    
+	if (!high)
+	    high = bpq->high;
+	else {
+	    if (low > high) {
+		low = high;
+		erts_smp_atomic_set_relb(&bpq->low, (erts_aint_t) low);
+	    }
+	    bpq->high = high;
+	    written = 1;
+	}
+
+	if (written) {
+	    ErlDrvSizeT size = (ErlDrvSizeT) erts_smp_atomic_read_nob(&bpq->size);
+	    if (size > high)
+		erts_smp_atomic32_read_bor_relb(&pp->sched.flags,
+						ERTS_PTS_FLG_BUSY_PORT_Q);
+	    else if (size < low)
+		erts_smp_atomic32_read_bor_relb(&pp->sched.flags,
+						ERTS_PTS_FLG_CHK_UNSET_BUSY_PORT_Q);
+	}
+    }
+
+    erts_port_task_sched_unlock(&pp->sched);
+
+    if (resume_procs)
+	erts_port_resume_procs(pp);
+    if (lowp)
+	*lowp = low;
+    if (highp)
+	*highp = high;
+}
+
+/*
+ * No-suspend handles.
+ */
+
+#ifdef ERTS_SMP
+static void
+free_port_task_handle_list(void *vpthlp)
+{
+    erts_free(ERTS_ALC_T_PT_HNDL_LIST, vpthlp);
+}
+#endif
+
+static void
+schedule_port_task_handle_list_free(ErtsPortTaskHandleList *pthlp)
+{
+#ifdef ERTS_SMP
+    erts_schedule_thr_prgr_later_op(free_port_task_handle_list,
+				    (void *) pthlp,
+				    &pthlp->u.release);
+#else
+    erts_free(ERTS_ALC_T_PT_HNDL_LIST, pthlp);
+#endif
+}
+
+static ERTS_INLINE void
+abort_nosuspend_task(Port *pp,
+		     ErtsPortTaskType type,
+		     ErtsPortTaskTypeData *tdp)
+{
+
+    ASSERT(type == ERTS_PORT_TASK_PROC_SIG);
+
+    if (!pp->sched.taskq.bpq)
+	tdp->psig.callback(NULL,
+			   ERTS_PORT_SFLG_INVALID,
+			   ERTS_PROC2PORT_SIG_ABORT_NOSUSPEND,
+			   &tdp->psig.data);
+    else {
+	ErlDrvSizeT size = erts_proc2port_sig_command_data_size(&tdp->psig.data);
+	tdp->psig.callback(NULL,
+			   ERTS_PORT_SFLG_INVALID,
+			   ERTS_PROC2PORT_SIG_ABORT_NOSUSPEND,
+			   &tdp->psig.data);
+	aborted_proc2port_data(pp, size);
+    }
+}
+
+static ErtsPortTaskHandleList *
+get_free_nosuspend_handles(Port *pp)
+{
+    ErtsPortTaskHandleList *nshp, *last_nshp = NULL;
+
+    ERTS_SMP_LC_ASSERT(erts_port_task_sched_lock_is_locked(&pp->sched));
+
+    nshp = pp->sched.taskq.local.busy.nosuspend;
+
+    while (nshp && !erts_port_task_is_scheduled(&nshp->handle)) {
+	last_nshp = nshp;
+	nshp = nshp->u.next;
+    }
+
+    if (!last_nshp)
+	nshp = NULL;
+    else {
+	nshp = pp->sched.taskq.local.busy.nosuspend;
+	pp->sched.taskq.local.busy.nosuspend = last_nshp->u.next;
+	last_nshp->u.next = NULL;
+	if (!pp->sched.taskq.local.busy.nosuspend)
+	    erts_smp_atomic32_read_band_nob(&pp->sched.flags,
+					    ~ERTS_PTS_FLG_HAVE_NS_TASKS);
+    }
+    return nshp;
+}
+
+static void
+free_nosuspend_handles(ErtsPortTaskHandleList *free_nshp)
+{
+    while (free_nshp) {
+	ErtsPortTaskHandleList *nshp = free_nshp;
+	free_nshp = free_nshp->u.next;
+	schedule_port_task_handle_list_free(nshp);
     }
 }
 
@@ -161,7 +837,6 @@ enqueue_port(ErtsRunQueue *runq, Port *pp)
 {
     ERTS_SMP_LC_ASSERT(erts_smp_lc_runq_is_locked(runq));
     pp->sched.next = NULL;
-    pp->sched.in_runq = 1;
     if (runq->ports.end) {
 	ASSERT(runq->ports.start);
 	runq->ports.end->sched.next = pp;
@@ -199,285 +874,423 @@ pop_port(ErtsRunQueue *runq)
     return pp;
 }
 
+/*
+ * Task queue operations
+ */
 
-#ifdef HARD_DEBUG
+static ERTS_INLINE int
+enqueue_task(Port *pp,
+	     ErtsPortTask *ptp,
+	     ErtsProc2PortSigData *sigdp,
+	     ErtsPortTaskHandleList *ns_pthlp,
+	     erts_aint32_t *flagsp)
 
-static void
-check_port_queue(ErtsRunQueue *runq, Port *chk_pp, int inq)
 {
-    Port *pp;
-    Port *last_pp;
-    Port *first_pp = runq->ports.start;
-    int no_forward = 0, no_backward = 0;
-    int found_forward = 0, found_backward = 0;
-    if (!first_pp) {
-	ASSERT(!runq->ports.end);
-    }
+    int res;
+    erts_aint32_t fail_flags = ERTS_PTS_FLG_EXIT;
+    erts_aint32_t flags;
+    ptp->u.alive.next = NULL;
+    if (ns_pthlp)
+	fail_flags |= ERTS_PTS_FLG_BUSY_PORT;
+    erts_port_task_sched_lock(&pp->sched);
+    flags = erts_smp_atomic32_read_nob(&pp->sched.flags);
+    if (flags & fail_flags)
+	res = 0;
     else {
-	ASSERT(!first_pp->sched.prev);
-	for (pp = first_pp; pp; pp = pp->sched.next) {
-	    ASSERT(pp->sched.taskq);
-	    if (pp->sched.taskq->first)
-		no_forward++;
-	    if (chk_pp == pp)
-		found_forward = 1;
-	    if (!pp->sched.prev) {
-		ASSERT(first_pp == pp);
-	    }
-	    if (!pp->sched.next) {
-		ASSERT(runq->ports.end == pp);
-		last_pp = pp;
-	    }
-	}
-	for (pp = last_pp; pp; pp = pp->sched.prev) {
-	    ASSERT(pp->sched.taskq);
-	    if (pp->sched.taskq->last)
-		no_backward++;
-	    if (chk_pp == pp)
-		found_backward = 1;
-	    if (!pp->sched.prev) {
-		ASSERT(first_pp == pp);
-	    }
-	    if (!pp->sched.next) {
-		ASSERT(runq->ports.end == pp);
-	    }
-	    check_task_queue(pp->sched.taskq, NULL, 0);
+	if (ns_pthlp) {
+	    ns_pthlp->u.next = pp->sched.taskq.local.busy.nosuspend;
+	    pp->sched.taskq.local.busy.nosuspend = ns_pthlp;
 	}
-	ASSERT(no_forward == no_backward);
-    }
-    ASSERT(no_forward == RUNQ_READ_LEN(&runq->ports.info.len));
-    if (chk_pp) {
-	if (chk_pp->sched.taskq || chk_pp->sched.exe_taskq) {
-	    ASSERT(chk_pp->sched.taskq != chk_pp->sched.exe_taskq);
-	}
-	ASSERT(!chk_pp->sched.taskq || chk_pp->sched.taskq->first);
-	if (inq < 0)
-	    inq = chk_pp->sched.taskq && !chk_pp->sched.exe_taskq;
-	if (inq) {
-	    ASSERT(found_forward && found_backward);
+	if (pp->sched.taskq.in.last) {
+	    ASSERT(pp->sched.taskq.in.first);
+	    ASSERT(!pp->sched.taskq.in.last->u.alive.next);
+
+	    pp->sched.taskq.in.last->u.alive.next = ptp;
 	}
 	else {
-	    ASSERT(!found_forward && !found_backward);
-	}
-    }
-}
-
-#endif
+	    ASSERT(!pp->sched.taskq.in.first);
 
-/*
- * Task queue operations
- */
-
-static ERTS_INLINE ErtsPortTaskQueue *
-port_taskq_init(ErtsPortTaskQueue *ptqp, Port *pp)
-{
-    if (ptqp) {
-	ptqp->first = NULL;
-	ptqp->last = NULL;
-	ptqp->port = pp;
+	    pp->sched.taskq.in.first = ptp;
+	}
+	pp->sched.taskq.in.last = ptp;
+	flags = enqueue_proc2port_data(pp, sigdp, flags);
+	res = 1;
     }
-    return ptqp;
+    erts_port_task_sched_unlock(&pp->sched);
+    *flagsp = flags;
+    return res;
 }
 
 static ERTS_INLINE void
-enqueue_task(ErtsPortTaskQueue *ptqp, ErtsPortTask *ptp)
+prepare_exec(Port *pp, ErtsPortTask **execqp, int *processing_busy_q_p)
 {
-    ERTS_PT_CHK_NOT_IN_TASKQ(ptqp, ptp);
-    ptp->next = NULL;
-    ptp->prev = ptqp->last;
-    ptp->queue = ptqp;
-    if (ptqp->last) {
-	ASSERT(ptqp->first);
-	ptqp->last->next = ptp;
+    erts_aint32_t act = erts_smp_atomic32_read_nob(&pp->sched.flags);
+
+    if (!pp->sched.taskq.local.busy.first || (act & ERTS_PTS_FLG_BUSY_PORT)) {
+	*execqp = pp->sched.taskq.local.first;
+	*processing_busy_q_p = 0;
     }
     else {
-	ASSERT(!ptqp->first);
-	ptqp->first = ptp;
+	*execqp = pp->sched.taskq.local.busy.first;
+	*processing_busy_q_p = 1;
+    }
+
+    ERTS_PT_DBG_CHK_TASK_QS(pp, *execqp, *processing_busy_q_p);
+
+    while (1) {
+	erts_aint32_t new, exp;
+
+	new = exp = act;
+
+	new &= ~ERTS_PTS_FLG_IN_RUNQ;
+	new |= ERTS_PTS_FLG_EXEC;
+
+	act = erts_smp_atomic32_cmpxchg_nob(&pp->sched.flags, new, exp);
+
+	ASSERT(act & ERTS_PTS_FLG_IN_RUNQ);
+
+	if (exp == act)
+	    break;
     }
-    ptqp->last = ptp;
-    ERTS_PT_CHK_IN_TASKQ(ptqp, ptp);
 }
 
-static ERTS_INLINE void
-push_task(ErtsPortTaskQueue *ptqp, ErtsPortTask *ptp)
+/* finalize_exec() return value != 0 if port should remain active */
+static ERTS_INLINE int
+finalize_exec(Port *pp, ErtsPortTask **execq, int processing_busy_q)
 {
-    ERTS_PT_CHK_NOT_IN_TASKQ(ptqp, ptp);
-    ptp->next = ptqp->first;
-    ptp->prev = NULL;
-    ptp->queue = ptqp;
-    if (ptqp->first) {
-	ASSERT(ptqp->last);
-	ptqp->first->prev = ptp;
-    }
+    erts_aint32_t act;
+
+    if (!processing_busy_q)
+	pp->sched.taskq.local.first = *execq;
     else {
-	ASSERT(!ptqp->last);
-	ptqp->last = ptp;
+	pp->sched.taskq.local.busy.first = *execq;
+	ASSERT(*execq);
+    }
+
+    ERTS_PT_DBG_CHK_TASK_QS(pp, *execq, processing_busy_q);
+
+    *execq = NULL;
+
+    act = erts_smp_atomic32_read_nob(&pp->sched.flags);
+    if (act & ERTS_PTS_FLG_CHK_UNSET_BUSY_PORT_Q)
+	act = check_unset_busy_port_q(pp, act, pp->sched.taskq.bpq);
+
+    while (1) {
+	erts_aint32_t new, exp;
+
+	new = exp = act;
+
+	new &= ~ERTS_PTS_FLG_EXEC;
+	if (act & ERTS_PTS_FLG_HAVE_TASKS)
+	    new |= ERTS_PTS_FLG_IN_RUNQ;
+
+	act = erts_smp_atomic32_cmpxchg_relb(&pp->sched.flags, new, exp);
+
+	ASSERT(!(act & ERTS_PTS_FLG_IN_RUNQ));
+
+	if (exp == act)
+	    break;
     }
-    ptqp->first = ptp;
-    ERTS_PT_CHK_IN_TASKQ(ptqp, ptp);
+
+    return (act & ERTS_PTS_FLG_HAVE_TASKS) != 0;
 }
 
-static ERTS_INLINE void
-dequeue_task(ErtsPortTask *ptp)
+static ERTS_INLINE erts_aint32_t
+select_queue_for_exec(Port *pp, ErtsPortTask **execqp, int *processing_busy_q_p)
 {
-    ASSERT(ptp);
-    ASSERT(ptp->queue);
-    ERTS_PT_CHK_IN_TASKQ(ptp->queue, ptp);
-    if (ptp->next)
-	ptp->next->prev = ptp->prev;
-    else {
-	ASSERT(ptp->queue->last == ptp);
-	ptp->queue->last = ptp->prev;
+    erts_aint32_t flags = erts_smp_atomic32_read_nob(&pp->sched.flags);
+
+    if (flags & ERTS_PTS_FLG_CHK_UNSET_BUSY_PORT_Q)
+	flags = check_unset_busy_port_q(pp, flags, pp->sched.taskq.bpq);
+
+    ERTS_PT_DBG_CHK_TASK_QS(pp, *execqp, *processing_busy_q_p);
+
+    if (flags & ERTS_PTS_FLG_BUSY_PORT) {
+	if (*processing_busy_q_p) {
+	    ErtsPortTask *ptp;
+
+	    ptp = pp->sched.taskq.local.busy.first = *execqp;
+	    if (!ptp)
+		pp->sched.taskq.local.busy.last = NULL;
+	    else if (!(ptp->u.alive.flags & ERTS_PT_FLG_WAIT_BUSY))
+		no_sig_dep_move_from_busyq(pp);
+
+	    *execqp = pp->sched.taskq.local.first;
+	    *processing_busy_q_p = 0;
+
+	    ERTS_PT_DBG_CHK_TASK_QS(pp, *execqp, *processing_busy_q_p);
+	}
+
+	return flags;
     }
-    if (ptp->prev)
-	ptp->prev->next = ptp->next;
-    else {
-	ASSERT(ptp->queue->first == ptp);
-	ptp->queue->first = ptp->next;
+
+    /* Not busy */
+
+    if (!*processing_busy_q_p && pp->sched.taskq.local.busy.first) {
+	pp->sched.taskq.local.first = *execqp;
+	*execqp = pp->sched.taskq.local.busy.first;
+	*processing_busy_q_p = 1;
+
+	ERTS_PT_DBG_CHK_TASK_QS(pp, *execqp, *processing_busy_q_p);
     }
 
-    ASSERT(ptp->queue->first || !ptp->queue->last);
-    ASSERT(ptp->queue->last || !ptp->queue->first);
-    ERTS_PT_CHK_NOT_IN_TASKQ(ptp->queue, ptp);
+    return flags;
 }
 
-static ERTS_INLINE ErtsPortTask *
-pop_task(ErtsPortTaskQueue *ptqp)
+/*
+ * check_task_for_exec() returns a value !0 if the task
+ * is ok to execute; otherwise 0.
+ */
+static ERTS_INLINE int
+check_task_for_exec(Port *pp,
+		    erts_aint32_t flags,
+		    ErtsPortTask **execqp,
+		    int *processing_busy_q_p,
+		    ErtsPortTask *ptp)
 {
-    ErtsPortTask *ptp = ptqp->first;
-    if (!ptp) {
-	ASSERT(!ptqp->last);
+
+    if (!*processing_busy_q_p) {
+	/* Processing normal queue */
+
+	ERTS_PT_DBG_CHK_TASK_QS(pp, ptp, *processing_busy_q_p);
+
+	if ((flags & ERTS_PTS_FLG_BUSY_PORT)
+	    && (ptp->u.alive.flags & ERTS_PT_FLG_WAIT_BUSY)) {
+
+	    busy_wait_move_to_busy_queue(pp, ptp);
+	    ERTS_PT_DBG_CHK_TASK_QS(pp, *execqp, *processing_busy_q_p);
+
+	    return 0;
+	}
+
+	if (pp->sched.taskq.local.busy.last
+	    && (ptp->u.alive.flags & ERTS_PT_FLG_SIG_DEP)) {
+
+	    int res = !check_sig_dep_move_to_busy_queue(pp, ptp);
+	    ERTS_PT_DBG_CHK_TASK_QS(pp, *execqp, *processing_busy_q_p);
+
+	    return res;
+	}
+
     }
     else {
-	ERTS_PT_CHK_IN_TASKQ(ptqp, ptp);
-	ASSERT(!ptp->prev);
-	ptqp->first = ptp->next;
-	if (ptqp->first)
-	    ptqp->first->prev = NULL;
-	else {
-	    ASSERT(ptqp->last == ptp);
-	    ptqp->last = NULL;
+	/* Processing busy queue */
+
+	ASSERT(!(flags & ERTS_PTS_FLG_BUSY_PORT));
+
+	ERTS_PT_DBG_CHK_TASK_QS(pp, ptp, *processing_busy_q_p);
+
+	popped_from_busy_queue(pp, ptp, !*execqp);
+
+	if (!*execqp) {
+	    *execqp = pp->sched.taskq.local.first;
+	    *processing_busy_q_p = 0;
 	}
-	ASSERT(ptp->queue->first || !ptp->queue->last);
-	ASSERT(ptp->queue->last || !ptp->queue->first);
+
+	ERTS_PT_DBG_CHK_TASK_QS(pp, *execqp, *processing_busy_q_p);
+
     }
-    ERTS_PT_CHK_NOT_IN_TASKQ(ptqp, ptp);
-    return ptp;
+
+    return 1;
 }
 
-#ifdef HARD_DEBUG
+static ErtsPortTask *
+fetch_in_queue(Port *pp, ErtsPortTask **execqp)
+{
+    ErtsPortTask *ptp;
+    ErtsPortTaskHandleList *free_nshp = NULL;
 
-static void
-check_task_queue(ErtsPortTaskQueue *ptqp,
-		 ErtsPortTask *chk_ptp,
-		 int inq)
+    erts_port_task_sched_lock(&pp->sched);
+
+    ptp = pp->sched.taskq.in.first;
+    pp->sched.taskq.in.first = NULL;
+    pp->sched.taskq.in.last = NULL;
+    if (ptp)
+	*execqp = ptp->u.alive.next;
+    else
+	erts_smp_atomic32_read_band_nob(&pp->sched.flags,
+					~ERTS_PTS_FLG_HAVE_TASKS);
+
+    
+    if (pp->sched.taskq.local.busy.nosuspend)
+	free_nshp = get_free_nosuspend_handles(pp);
+
+    erts_port_task_sched_unlock(&pp->sched);
+
+    if (free_nshp)
+	free_nosuspend_handles(free_nshp);
+
+    return ptp;
+}
+
+static ERTS_INLINE ErtsPortTask *
+select_task_for_exec(Port *pp,
+		     ErtsPortTask **execqp,
+		     int *processing_busy_q_p)
 {
     ErtsPortTask *ptp;
-    ErtsPortTask *last_ptp;
-    ErtsPortTask *first_ptp = ptqp->first;
-    int found_forward = 0, found_backward = 0;
-    if (!first_ptp) {
-	ASSERT(!ptqp->last);
-    }
-    else {
-	ASSERT(!first_ptp->prev);
-	for (ptp = first_ptp; ptp; ptp = ptp->next) {
-	    ASSERT(ptp->queue == ptqp);
-	    if (chk_ptp == ptp)
-		found_forward = 1;
-	    if (!ptp->prev) {
-		ASSERT(first_ptp == ptp);
-	    }
-	    if (!ptp->next) {
-		ASSERT(ptqp->last == ptp);
-		last_ptp = ptp;
-	    }
-	}
-	for (ptp = last_ptp; ptp; ptp = ptp->prev) {
-	    ASSERT(ptp->queue == ptqp);
-	    if (chk_ptp == ptp)
-		found_backward = 1;
-	    if (!ptp->prev) {
-		ASSERT(first_ptp == ptp);
-	    }
-	    if (!ptp->next) {
-		ASSERT(ptqp->last == ptp);
-	    }
-	}
-    }
-    if (chk_ptp) {
-	if (inq) {
-	    ASSERT(found_forward && found_backward);
-	}
+    erts_aint32_t flags;
+
+    flags = select_queue_for_exec(pp, execqp, processing_busy_q_p);
+
+    while (1) {
+	ptp = *execqp;
+	if (ptp)
+	    *execqp = ptp->u.alive.next;
 	else {
-	    ASSERT(!found_forward && !found_backward);
+	    ptp = fetch_in_queue(pp, execqp);
+	    if (!ptp)
+		return NULL;
 	}
+	if (check_task_for_exec(pp, flags, execqp, processing_busy_q_p, ptp))
+	    return ptp;
     }
 }
-#endif
 
 /*
  * Abort a scheduled task.
  */
 
 int
-erts_port_task_abort(Eterm id, ErtsPortTaskHandle *pthp)
+erts_port_task_abort(ErtsPortTaskHandle *pthp)
 {
-    ErtsRunQueue *runq;
-    ErtsPortTaskQueue *ptqp;
+    int res;
     ErtsPortTask *ptp;
-    Port *pp;
-
-    pp = &erts_port[internal_port_index(id)];
-    runq = erts_port_runq(pp);
-    if (!runq)
-	return 1;
+#ifdef ERTS_SMP
+    ErtsThrPrgrDelayHandle dhndl = erts_thr_progress_unmanaged_delay();
+#endif
 
     ptp = handle2task(pthp);
+    if (!ptp)
+	res = -1;
+    else {
+	erts_aint32_t old_state;
+
+#ifdef DEBUG
+	ErtsPortTaskHandle *saved_pthp = ptp->u.alive.handle;
+	ERTS_SMP_READ_MEMORY_BARRIER;
+	old_state = erts_smp_atomic32_read_nob(&ptp->state);
+	if (old_state == ERTS_PT_STATE_SCHEDULED) {
+	    ASSERT(saved_pthp == pthp);
+	}
+#endif
 
-    if (!ptp) {
-	erts_smp_runq_unlock(runq);
-	return 1;
+	old_state = erts_smp_atomic32_cmpxchg_nob(&ptp->state,
+						  ERTS_PT_STATE_ABORTED,
+						  ERTS_PT_STATE_SCHEDULED);
+	if (old_state != ERTS_PT_STATE_SCHEDULED)
+	    res = - 1; /* Task already aborted, executing, or executed */
+	else {
+
+	    reset_port_task_handle(pthp);
+
+	    switch (ptp->type) {
+	    case ERTS_PORT_TASK_INPUT:
+	    case ERTS_PORT_TASK_OUTPUT:
+	    case ERTS_PORT_TASK_EVENT:
+		ASSERT(erts_smp_atomic_read_nob(
+			   &erts_port_task_outstanding_io_tasks) > 0);
+		erts_smp_atomic_dec_relb(&erts_port_task_outstanding_io_tasks);
+		break;
+	    case ERTS_PORT_TASK_PROC_SIG:
+		ERTS_INTERNAL_ERROR("Aborted process to port signal");
+		break;
+	    default:
+		break;
+	    }
+
+	    res = 0;
+	}
     }
 
-    ASSERT(ptp->handle == pthp);
-    ptqp = ptp->queue;
-    ASSERT(pp == ptqp->port);
+#ifdef ERTS_SMP
+    erts_thr_progress_unmanaged_continue(dhndl);
+#endif
 
-    ERTS_PT_CHK_PRES_PORTQ(runq, pp);
-    ASSERT(ptqp);
-    ASSERT(ptqp->first);
+    return res;
+}
 
-    dequeue_task(ptp);
-    reset_handle(ptp);
+void
+erts_port_task_abort_nosuspend_tasks(Port *pp)
+{
+    erts_aint32_t flags;
+    ErtsPortTaskHandleList *abort_list;
+#ifdef ERTS_SMP
+    ErtsThrPrgrDelayHandle dhndl = ERTS_THR_PRGR_DHANDLE_INVALID;
+#endif
 
-    switch (ptp->type) {
-    case ERTS_PORT_TASK_INPUT:
-    case ERTS_PORT_TASK_OUTPUT:
-    case ERTS_PORT_TASK_EVENT:
-	ASSERT(erts_smp_atomic_read_nob(&erts_port_task_outstanding_io_tasks) > 0);
-	erts_smp_atomic_dec_relb(&erts_port_task_outstanding_io_tasks);
-	break;
-    default:
-	break;
-    }
+    erts_port_task_sched_lock(&pp->sched);
+    flags = erts_smp_atomic32_read_band_nob(&pp->sched.flags,
+					    ~ERTS_PTS_FLG_HAVE_NS_TASKS);
+    abort_list = pp->sched.taskq.local.busy.nosuspend;
+    pp->sched.taskq.local.busy.nosuspend = NULL;
+    erts_port_task_sched_unlock(&pp->sched);
 
-    ASSERT(ptqp == pp->sched.taskq || ptqp == pp->sched.exe_taskq);
+    while (abort_list) {
+#ifdef DEBUG
+	ErtsPortTaskHandle *saved_pthp;
+#endif
+	ErtsPortTaskType type;
+	ErtsPortTaskTypeData td;
+	ErtsPortTaskHandle *pthp;
+	ErtsPortTask *ptp;
+	ErtsPortTaskHandleList *pthlp;
+	erts_aint32_t old_state;
 
-    if (ptqp->first || pp->sched.taskq != ptqp)
-	ptqp = NULL;
-    else
-	pp->sched.taskq = NULL;
+	pthlp = abort_list;
+	abort_list = pthlp->u.next;
 
-    ERTS_PT_CHK_PRES_PORTQ(runq, pp);
+#ifdef ERTS_SMP
+	if (dhndl != ERTS_THR_PRGR_DHANDLE_MANAGED)
+	    dhndl = erts_thr_progress_unmanaged_delay();
+#endif
 
-    erts_smp_runq_unlock(runq);
+	pthp = &pthlp->handle;
+	ptp = handle2task(pthp);
+	if (!ptp) {
+#ifdef ERTS_SMP
+	    if (dhndl != ERTS_THR_PRGR_DHANDLE_MANAGED)
+		erts_thr_progress_unmanaged_continue(dhndl);
+#endif
+	    schedule_port_task_handle_list_free(pthlp);
+	    continue;
+	}
 
-    port_task_free(ptp);
-    if (ptqp)
-	port_taskq_free(ptqp);
+#ifdef DEBUG
+	saved_pthp = ptp->u.alive.handle;
+	ERTS_SMP_READ_MEMORY_BARRIER;
+	old_state = erts_smp_atomic32_read_nob(&ptp->state);
+	if (old_state == ERTS_PT_STATE_SCHEDULED) {
+	    ASSERT(saved_pthp == pthp);
+	}
+#endif
 
-    return 0;
+	old_state = erts_smp_atomic32_cmpxchg_nob(&ptp->state,
+						  ERTS_PT_STATE_ABORTED,
+						  ERTS_PT_STATE_SCHEDULED);
+	if (old_state != ERTS_PT_STATE_SCHEDULED) {
+	    /* Task already aborted, executing, or executed */
+#ifdef ERTS_SMP
+	    if (dhndl != ERTS_THR_PRGR_DHANDLE_MANAGED)
+		erts_thr_progress_unmanaged_continue(dhndl);
+#endif
+	    schedule_port_task_handle_list_free(pthlp);
+	    continue;
+	}
+
+	reset_port_task_handle(pthp);
+
+	type = ptp->type;
+	td = ptp->u.alive.td;
+
+#ifdef ERTS_SMP
+	if (dhndl != ERTS_THR_PRGR_DHANDLE_MANAGED)
+	    erts_thr_progress_unmanaged_continue(dhndl);
+#endif
+	schedule_port_task_handle_list_free(pthlp);
+
+	abort_nosuspend_task(pp, type, &td);
+    }
 }
 
 /*
@@ -488,243 +1301,264 @@ int
 erts_port_task_schedule(Eterm id,
 			ErtsPortTaskHandle *pthp,
 			ErtsPortTaskType type,
-			ErlDrvEvent event,
-			ErlDrvEventData event_data)
+			...)
 {
+    ErtsProc2PortSigData *sigdp = NULL;
+    ErtsPortTaskHandleList *ns_pthlp = NULL;
+#ifdef ERTS_SMP
+    ErtsRunQueue *xrunq;
+    ErtsThrPrgrDelayHandle dhndl;
+#endif
     ErtsRunQueue *runq;
     Port *pp;
-    ErtsPortTask *ptp;
-    int enq_port = 0;
-
-    /*
-     * NOTE:	We might not have the port lock here. We are only
-     *		allowed to access the 'sched', 'tab_status',
-     *          and 'id' fields of the port struct while
-     *          tasks_lock is held.
-     */
+    ErtsPortTask *ptp = NULL;
+    erts_aint32_t act, add_flags;
 
     if (pthp && erts_port_task_is_scheduled(pthp)) {
 	ASSERT(0);
-	erts_port_task_abort(id, pthp);
+	erts_port_task_abort(pthp);
     }
 
-    ptp = port_task_alloc();
-
     ASSERT(is_internal_port(id));
-    pp = &erts_port[internal_port_index(id)];
-    runq = erts_port_runq(pp);
 
-    if (!runq || ERTS_PORT_TASK_INVALID_PORT(pp, id)) {
-	if (runq)
-	    erts_smp_runq_unlock(runq);
-	return -1;
-    }
-
-    ASSERT(!erts_port_task_is_scheduled(pthp));
+#ifdef ERTS_SMP
+    dhndl = erts_thr_progress_unmanaged_delay();
+#endif
 
-    ERTS_PT_CHK_PRES_PORTQ(runq, pp);
+    pp = erts_port_lookup_raw(id);
 
-    if (!pp->sched.taskq && !pp->sched.in_runq && !pp->sched.exe_taskq) {
 #ifdef ERTS_SMP
-	ErtsRunQueue *xrunq = erts_check_emigration_need(runq, ERTS_PORT_PRIO_LEVEL);
-	if (xrunq) {
-	    /* Port emigrated ... */
-	    erts_smp_atomic_set_nob(&pp->run_queue, (erts_aint_t) xrunq);
-	    erts_smp_runq_unlock(runq);
-	    runq = erts_port_runq(pp);
-	    if (!runq)
-		return -1;
-	}
-	enq_port = !pp->sched.taskq && !pp->sched.in_runq && !pp->sched.exe_taskq;
-#else
-	enq_port = 1;
-#endif
+    if (dhndl != ERTS_THR_PRGR_DHANDLE_MANAGED) {
+	if (pp)
+	    erts_port_inc_refc(pp);
+	erts_thr_progress_unmanaged_continue(dhndl);
     }
+#endif
 
-    ASSERT(!enq_port
-	   || !(ERTS_RUNQ_FLGS_GET_NOB(runq) & ERTS_RUNQ_FLG_SUSPENDED));
+    if (!pp)
+	goto fail;
 
-    if (!pp->sched.taskq)
-	pp->sched.taskq = port_taskq_init(port_taskq_alloc(), pp);
+    if (type != ERTS_PORT_TASK_PROC_SIG) {
+	ptp = port_task_alloc();
 
-    ASSERT(ptp);
+	ptp->type = type;
+	ptp->u.alive.flags = 0;
 
-    ptp->type = type;
-    ptp->event = event;
-    ptp->event_data = event_data;
+	erts_smp_atomic32_init_nob(&ptp->state, ERTS_PT_STATE_SCHEDULED);
 
-    set_handle(ptp, pthp);
+	set_handle(ptp, pthp);
+    }
 
     switch (type) {
-    case ERTS_PORT_TASK_FREE:
-	erl_exit(ERTS_ABORT_EXIT,
-		 "erts_port_task_schedule(): Cannot schedule free task\n");
-	break;
     case ERTS_PORT_TASK_INPUT:
-    case ERTS_PORT_TASK_OUTPUT:
-    case ERTS_PORT_TASK_EVENT:
+    case ERTS_PORT_TASK_OUTPUT: {
+	va_list argp;
+	va_start(argp, type);
+	ptp->u.alive.td.io.event = va_arg(argp, ErlDrvEvent);
+	va_end(argp);
 	erts_smp_atomic_inc_relb(&erts_port_task_outstanding_io_tasks);
-	/* Fall through... */
+	break;
+    }
+    case ERTS_PORT_TASK_EVENT: {
+	va_list argp;
+	va_start(argp, type);
+	ptp->u.alive.td.io.event = va_arg(argp, ErlDrvEvent);
+	ptp->u.alive.td.io.event_data = va_arg(argp, ErlDrvEventData);
+	va_end(argp);
+	erts_smp_atomic_inc_relb(&erts_port_task_outstanding_io_tasks);
+	break;
+    }
+    case ERTS_PORT_TASK_PROC_SIG: {
+	va_list argp;
+	ASSERT(!pthp);
+	va_start(argp, type);
+	sigdp = va_arg(argp, ErtsProc2PortSigData *);
+	ptp = p2p_sig_data_to_task(sigdp);
+	ptp->u.alive.td.psig.callback = va_arg(argp, ErtsProc2PortSigCallback);
+ 	ptp->u.alive.flags |= va_arg(argp, int);
+	va_end(argp);
+	if (!(ptp->u.alive.flags & ERTS_PT_FLG_NOSUSPEND))
+	    set_handle(ptp, pthp);
+	else {
+	    ns_pthlp = erts_alloc(ERTS_ALC_T_PT_HNDL_LIST,
+				  sizeof(ErtsPortTaskHandleList));
+	    set_handle(ptp, &ns_pthlp->handle);
+	}
+	break;
+    }
     default:
-	enqueue_task(pp->sched.taskq, ptp);
 	break;
     }
 
-#ifndef ERTS_SMP
-    /*
-     * When (!enq_port && !pp->sched.exe_taskq) is true in the smp case,
-     * the port might not be in the run queue. If this is the case, another
-     * thread is in the process of enqueueing the port. This very seldom
-     * occur, but do occur and is a valid scenario. Debug info showing this
-     * enqueue in progress must be introduced before we can enable (modified
-     * versions of these) assertions in the smp case again.
-     */
-#if defined(HARD_DEBUG)
-    if (pp->sched.exe_taskq || enq_port)
-	ERTS_PT_CHK_NOT_IN_PORTQ(runq, pp);
-    else
-	ERTS_PT_CHK_IN_PORTQ(runq, pp);
-#elif defined(DEBUG)
-    if (!enq_port && !pp->sched.exe_taskq) {
-	/* We should be in port run q */
-	ASSERT(pp->sched.in_runq);
+    if (!enqueue_task(pp, ptp, sigdp, ns_pthlp, &act)) {
+	reset_handle(ptp);
+	if (ns_pthlp && !(act & ERTS_PTS_FLG_EXIT))
+	    goto abort_nosuspend;
+	else
+	    goto fail;
     }
-#endif
-#endif
 
-    if (!enq_port) {
-	ERTS_PT_CHK_PRES_PORTQ(runq, pp);
-	erts_smp_runq_unlock(runq);
-    }
-    else {
-	enqueue_port(runq, pp);
-	ERTS_PT_CHK_PRES_PORTQ(runq, pp);
-	    
-	if (erts_system_profile_flags.runnable_ports) {
-	    profile_runnable_port(pp, am_active);
+    add_flags = ERTS_PTS_FLG_HAVE_TASKS;
+    if (ns_pthlp)
+	add_flags |= ERTS_PTS_FLG_HAVE_NS_TASKS;
+
+    while (1) {
+	erts_aint32_t new, exp;
+
+	if ((act & add_flags) == add_flags
+	    && (act & (ERTS_PTS_FLG_IN_RUNQ|ERTS_PTS_FLG_EXEC)))
+	    goto done; /* Done */
+
+	new = exp = act;
+	new |= add_flags;
+	if (!(act & (ERTS_PTS_FLG_IN_RUNQ|ERTS_PTS_FLG_EXEC)))
+	    new |= ERTS_PTS_FLG_IN_RUNQ;
+
+	act = erts_smp_atomic32_cmpxchg_relb(&pp->sched.flags, new, exp);
+
+	if (exp == act) {
+	    if (!(act & (ERTS_PTS_FLG_IN_RUNQ|ERTS_PTS_FLG_EXEC)))
+		break; /* Need to enqueue port */
+	    goto done; /* Done */
 	}
 
+	if (act & ERTS_PTS_FLG_EXIT)
+	    goto done; /* Died after our task insert... */
+    }
+
+    /* Enqueue port on run-queue */
+
+    runq = erts_port_runq(pp);
+    if (!runq)
+	ERTS_INTERNAL_ERROR("Missing run-queue");
+
+#ifdef ERTS_SMP
+    xrunq = erts_check_emigration_need(runq, ERTS_PORT_PRIO_LEVEL);
+    if (xrunq) {
+	/* Port emigrated ... */
+	erts_smp_atomic_set_nob(&pp->run_queue, (erts_aint_t) xrunq);
 	erts_smp_runq_unlock(runq);
+	runq = erts_port_runq(pp);
+	if (!runq)
+	    ERTS_INTERNAL_ERROR("Missing run-queue");
+    }
+#endif
 
-	erts_smp_notify_inc_runq(runq);
+    enqueue_port(runq, pp);
+	    
+    if (erts_system_profile_flags.runnable_ports) {
+	profile_runnable_port(pp, am_active);
     }
+
+    erts_smp_runq_unlock(runq);
+
+    erts_smp_notify_inc_runq(runq);
+
+done:
+
+#ifdef ERTS_SMP
+    if (dhndl != ERTS_THR_PRGR_DHANDLE_MANAGED)
+	erts_port_dec_refc(pp);
+#endif
+
+    return 0;
+
+abort_nosuspend:
+
+#ifdef ERTS_SMP
+    if (dhndl != ERTS_THR_PRGR_DHANDLE_MANAGED)
+	erts_port_dec_refc(pp);
+#endif
+
+    abort_nosuspend_task(pp, ptp->type, &ptp->u.alive.td);
+
+    ASSERT(ns_pthlp);
+    erts_free(ERTS_ALC_T_PT_HNDL_LIST, ns_pthlp);
+    if (ptp)
+	port_task_free(ptp);
+
     return 0;
+
+fail:
+
+#ifdef ERTS_SMP
+    if (dhndl != ERTS_THR_PRGR_DHANDLE_MANAGED)
+	erts_port_dec_refc(pp);
+#endif
+
+    if (ns_pthlp)
+	erts_free(ERTS_ALC_T_PT_HNDL_LIST, ns_pthlp);
+
+    if (ptp)
+	port_task_free(ptp);
+
+    return -1;
 }
 
 void
 erts_port_task_free_port(Port *pp)
 {
+    ErtsProcList *suspended;
+    erts_aint32_t flags;
     ErtsRunQueue *runq;
-    ErtsPortTaskQueue *ptqp;
 
     ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(pp));
-    ASSERT(!(pp->status & ERTS_PORT_SFLGS_DEAD));
+    ASSERT(!(erts_atomic32_read_nob(&pp->state) & ERTS_PORT_SFLGS_DEAD));
+
     runq = erts_port_runq(pp);
-    ASSERT(runq);
-    ERTS_PT_CHK_PRES_PORTQ(runq, pp);
-    ptqp = pp->sched.exe_taskq;
-    if (ptqp) {
-	/* I (this thread) am currently executing this port, free it
-	   when scheduled out... */
-	ErtsPortTask *ptp;
-    enqueue_free:
-	ptp = port_task_alloc();
-	erts_smp_port_state_lock(pp);
-	pp->status &= ~ERTS_PORT_SFLG_CLOSING;
-	pp->status |= ERTS_PORT_SFLG_FREE_SCHEDULED;
-	erts_may_save_closed_port(pp);
-	erts_smp_port_state_unlock(pp);
-	ERTS_LC_ASSERT(erts_smp_atomic_read_nob(&pp->refc) > 1);
-	ptp->type = ERTS_PORT_TASK_FREE;
-	ptp->event = (ErlDrvEvent) -1;
-	ptp->event_data = NULL;
-	set_handle(ptp, NULL);
-	push_task(ptqp, ptp);
-	ERTS_PT_CHK_PRES_PORTQ(runq, pp);
-	erts_smp_runq_unlock(runq);
-    }
-    else {
-	if (pp->sched.in_runq) {
-	    ptqp = pp->sched.taskq;
-	    if (!ptqp)
-		pp->sched.taskq = ptqp = port_taskq_init(port_taskq_alloc(), pp);
-	    goto enqueue_free;
-	}
-	ASSERT(!pp->sched.taskq);
-	erts_smp_port_state_lock(pp);
-	pp->status &= ~ERTS_PORT_SFLG_CLOSING;
-	pp->status |= ERTS_PORT_SFLG_FREE_SCHEDULED;
-	erts_may_save_closed_port(pp);
-	erts_smp_port_state_unlock(pp);
-	erts_smp_atomic_dec_nob(&pp->refc); /* Not alive */
-	ERTS_LC_ASSERT(erts_smp_atomic_read_nob(&pp->refc) > 0); /* Lock */
-	handle_remaining_tasks(runq, pp); /* May release runq lock */
-	ASSERT(!pp->sched.exe_taskq && (!ptqp || !ptqp->first));
-	pp->sched.taskq = NULL;
-	ERTS_PT_CHK_PRES_PORTQ(runq, pp);
-	erts_smp_runq_unlock(runq);
-    }
-}
+    if (!runq)
+	ERTS_INTERNAL_ERROR("Missing run-queue");
+    erts_port_task_sched_lock(&pp->sched);
+    flags = erts_smp_atomic32_read_bor_relb(&pp->sched.flags,
+					    ERTS_PTS_FLG_EXIT);
+    suspended = pp->suspended;
+    pp->suspended = NULL;
+    erts_port_task_sched_unlock(&pp->sched);
+    erts_atomic32_read_bset_relb(&pp->state,
+				 (ERTS_PORT_SFLG_CLOSING
+				  | ERTS_PORT_SFLG_FREE),
+				 ERTS_PORT_SFLG_FREE);
 
-typedef struct {
-    ErtsRunQueue *runq;
-    int *resp;
-} ErtsPortTaskExeBlockData;
+    erts_smp_runq_unlock(runq);
+
+    if (erts_proclist_fetch(&suspended, NULL))
+	erts_resume_processes(suspended);
+
+    if (!(flags & (ERTS_PTS_FLG_IN_RUNQ|ERTS_PTS_FLG_EXEC)))
+	begin_port_cleanup(pp, NULL);
+}
 
 /*
- * Run all scheduled tasks for the first port in run queue. If
- * new tasks appear while running reschedule port (free task is
- * an exception; it is always handled instantly).
+ * Execute scheduled tasks of a port.
  *
  * erts_port_task_execute() is called by scheduler threads between
- * scheduleing of processes. Sched lock should be held by caller.
+ * scheduling of processes. Run-queue lock should be held by caller.
  */
 
 int
 erts_port_task_execute(ErtsRunQueue *runq, Port **curr_port_pp)
 {
     Port *pp;
-    ErtsPortTaskQueue *ptqp;
-    ErtsPortTask *ptp;
+    ErtsPortTask *execq;
+    int processing_busy_q;
     int res = 0;
     int reds = ERTS_PORT_REDS_EXECUTE;
     erts_aint_t io_tasks_executed = 0;
     int fpe_was_unmasked;
+    erts_aint32_t state;
+    int active;
 
     ERTS_SMP_LC_ASSERT(erts_smp_lc_runq_is_locked(runq));
 
-    ERTS_PT_CHK_PORTQ(runq);
-
     pp = pop_port(runq);
     if (!pp) {
 	res = 0;
 	goto done;
     }
 
-    ASSERT(pp->sched.in_runq);
-    pp->sched.in_runq = 0;
-    if (!pp->sched.taskq) {
-	if (erts_system_profile_flags.runnable_ports)
-	    profile_runnable_port(pp, am_inactive);
-	res = (erts_smp_atomic_read_nob(&erts_port_task_outstanding_io_tasks)
-	       != (erts_aint_t) 0);
-	goto done;
-    }
+    erts_smp_runq_unlock(runq);
 
     *curr_port_pp = pp;
-
-    ASSERT(pp->sched.taskq->first);
-    ptqp = pp->sched.taskq;
-    pp->sched.taskq = NULL;
-
-    ASSERT(!pp->sched.exe_taskq);
-    pp->sched.exe_taskq = ptqp;
-
-    if (erts_smp_port_trylock(pp) == EBUSY) {
-	erts_smp_runq_unlock(runq);
-	erts_smp_port_lock(pp);
-	erts_smp_runq_lock(runq);
-    }
     
     if (erts_sched_stat.enabled) {
 	ErtsSchedulerData *esdp = erts_get_scheduler_data();
@@ -741,77 +1575,94 @@ erts_port_task_execute(ErtsRunQueue *runq, Port **curr_port_pp)
 	erts_smp_spin_unlock(&erts_sched_stat.lock);
     }
 
+    prepare_exec(pp, &execq, &processing_busy_q);
+
+    erts_smp_port_lock(pp);
+
     /* trace port scheduling, in */
     if (IS_TRACED_FL(pp, F_TRACE_SCHED_PORTS)) {
 	trace_sched_ports(pp, am_in);
     }
 
-    ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(pp));
+    fpe_was_unmasked = erts_block_fpe();
 
-    ERTS_PT_CHK_PRES_PORTQ(runq, pp);
-    ptp = pop_task(ptqp);
+    state = erts_atomic32_read_nob(&pp->state);
+    goto begin_handle_tasks;
 
-    fpe_was_unmasked = erts_block_fpe();
+    while (1) {
+	erts_aint32_t task_state;
+	ErtsPortTask *ptp;
 
-    while (ptp) {
-	ASSERT(pp->sched.taskq != pp->sched.exe_taskq);
+	ptp = select_task_for_exec(pp, &execq, &processing_busy_q);
+	if (!ptp)
+	    break;
+
+	task_state = erts_smp_atomic32_cmpxchg_nob(&ptp->state,
+						   ERTS_PT_STATE_EXECUTING,
+						   ERTS_PT_STATE_SCHEDULED);
+	if (task_state != ERTS_PT_STATE_SCHEDULED) {
+	    ASSERT(task_state == ERTS_PT_STATE_ABORTED);
+	    goto aborted_port_task;
+	}
 
 	reset_handle(ptp);
-	erts_smp_runq_unlock(runq);
 
 	ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(pp));
 	ERTS_SMP_CHK_NO_PROC_LOCKS;
 	ASSERT(pp->drv_ptr);
 
 	switch (ptp->type) {
-	case ERTS_PORT_TASK_FREE: /* May be pushed in q at any time */
-	    reds += ERTS_PORT_REDS_FREE;
-	    erts_smp_runq_lock(runq);
-
-	    erts_unblock_fpe(fpe_was_unmasked);
-	    ASSERT(pp->status & ERTS_PORT_SFLG_FREE_SCHEDULED);
-	    if (ptqp->first || (pp->sched.taskq && pp->sched.taskq->first))
-		handle_remaining_tasks(runq, pp);
-	    ASSERT(!ptqp->first
-		   && (!pp->sched.taskq || !pp->sched.taskq->first));
-	    erts_smp_atomic_dec_nob(&pp->refc); /* Not alive */
-	    ERTS_LC_ASSERT(erts_smp_atomic_read_nob(&pp->refc) > 0); /* Lock */
-
-	    port_task_free(ptp);
-	    if (pp->sched.taskq)
-		port_taskq_free(pp->sched.taskq);
-	    pp->sched.taskq = NULL;
-
-	    goto tasks_done;
 	case ERTS_PORT_TASK_TIMEOUT:
 	    reds += ERTS_PORT_REDS_TIMEOUT;
-	    if (!(pp->status & ERTS_PORT_SFLGS_DEAD)) {
+	    if (!(state & ERTS_PORT_SFLGS_DEAD)) {
                 DTRACE_DRIVER(driver_timeout, pp);
 		(*pp->drv_ptr->timeout)((ErlDrvData) pp->drv_data);
             }
 	    break;
 	case ERTS_PORT_TASK_INPUT:
 	    reds += ERTS_PORT_REDS_INPUT;
-	    ASSERT((pp->status & ERTS_PORT_SFLGS_DEAD) == 0);
+	    ASSERT((state & ERTS_PORT_SFLGS_DEAD) == 0);
             DTRACE_DRIVER(driver_ready_input, pp);
 	    /* NOTE some windows drivers use ->ready_input for input and output */
-	    (*pp->drv_ptr->ready_input)((ErlDrvData) pp->drv_data, ptp->event);
+	    (*pp->drv_ptr->ready_input)((ErlDrvData) pp->drv_data,
+					ptp->u.alive.td.io.event);
 	    io_tasks_executed++;
 	    break;
 	case ERTS_PORT_TASK_OUTPUT:
 	    reds += ERTS_PORT_REDS_OUTPUT;
-	    ASSERT((pp->status & ERTS_PORT_SFLGS_DEAD) == 0);
+	    ASSERT((state & ERTS_PORT_SFLGS_DEAD) == 0);
             DTRACE_DRIVER(driver_ready_output, pp);
-	    (*pp->drv_ptr->ready_output)((ErlDrvData) pp->drv_data, ptp->event);
+	    (*pp->drv_ptr->ready_output)((ErlDrvData) pp->drv_data,
+					 ptp->u.alive.td.io.event);
 	    io_tasks_executed++;
 	    break;
 	case ERTS_PORT_TASK_EVENT:
 	    reds += ERTS_PORT_REDS_EVENT;
-	    ASSERT((pp->status & ERTS_PORT_SFLGS_DEAD) == 0);
+	    ASSERT((state & ERTS_PORT_SFLGS_DEAD) == 0);
             DTRACE_DRIVER(driver_event, pp);
-	    (*pp->drv_ptr->event)((ErlDrvData) pp->drv_data, ptp->event, ptp->event_data);
+	    (*pp->drv_ptr->event)((ErlDrvData) pp->drv_data,
+				  ptp->u.alive.td.io.event,
+				  ptp->u.alive.td.io.event_data);
 	    io_tasks_executed++;
 	    break;
+	case ERTS_PORT_TASK_PROC_SIG: {
+	    ErtsProc2PortSigData *sigdp = &ptp->u.alive.td.psig.data;
+	    ASSERT((state & ERTS_PORT_SFLGS_DEAD) == 0);
+	    if (!pp->sched.taskq.bpq)
+		reds += ptp->u.alive.td.psig.callback(pp,
+						      state,
+						      ERTS_PROC2PORT_SIG_EXEC,
+						      sigdp);
+	    else {
+		ErlDrvSizeT size = erts_proc2port_sig_command_data_size(sigdp);
+		reds += ptp->u.alive.td.psig.callback(pp,
+						      state,
+						      ERTS_PROC2PORT_SIG_EXEC,
+						      sigdp);
+		dequeued_proc2port_data(pp, size);
+	    }
+	    break;
+	}
 	case ERTS_PORT_TASK_DIST_CMD:
 	    reds += erts_dist_command(pp, CONTEXT_REDS-reds);
 	    break;
@@ -822,33 +1673,31 @@ erts_port_task_execute(ErtsRunQueue *runq, Port **curr_port_pp)
 	    break;
 	}
 
-	if ((pp->status & ERTS_PORT_SFLG_CLOSING)
-	    && erts_is_port_ioq_empty(pp)) {
-	    reds += ERTS_PORT_REDS_TERMINATE;
-	    erts_terminate_port(pp);
-	}
+	reds += erts_port_driver_callback_epilogue(pp, &state);
 
-	ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(pp));
+    aborted_port_task:
+	schedule_port_task_free(ptp);
 
-#ifdef ERTS_SMP
-	if (pp->xports)
-	    erts_smp_xports_unlock(pp);
-	ASSERT(!pp->xports);
-#endif
-
-	ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(pp));
+    begin_handle_tasks:
+	if (state & ERTS_PORT_SFLG_FREE) {
+	    reds += ERTS_PORT_REDS_FREE;
 
-	port_task_free(ptp);
+	    begin_port_cleanup(pp, &execq);
 
-	erts_smp_runq_lock(runq);
+	    break;
+	}
 
-	ptp = pop_task(ptqp);
+	if (reds >= CONTEXT_REDS)
+	    break;
     }
 
- tasks_done:
-
     erts_unblock_fpe(fpe_was_unmasked);
 
+    /* trace port scheduling, out */
+    if (IS_TRACED_FL(pp, F_TRACE_SCHED_PORTS)) {
+    	trace_sched_ports(pp, am_out);
+    }
+
     if (io_tasks_executed) {
 	ASSERT(erts_smp_atomic_read_nob(&erts_port_task_outstanding_io_tasks)
 	       >= io_tasks_executed);
@@ -856,15 +1705,19 @@ erts_port_task_execute(ErtsRunQueue *runq, Port **curr_port_pp)
 				 -1*io_tasks_executed);
     }
 
-    *curr_port_pp = NULL;
-
 #ifdef ERTS_SMP
     ASSERT(runq == (ErtsRunQueue *) erts_smp_atomic_read_nob(&pp->run_queue));
 #endif
 
-    if (!pp->sched.taskq) {
-	ASSERT(pp->sched.exe_taskq);
-	pp->sched.exe_taskq = NULL;
+    active = finalize_exec(pp, &execq, processing_busy_q);
+
+    erts_port_release(pp);
+
+    *curr_port_pp = NULL;
+
+    erts_smp_runq_lock(runq);
+ 
+    if (!active) {
 	if (erts_system_profile_flags.runnable_ports)
 	    profile_runnable_port(pp, am_inactive);
     }
@@ -873,16 +1726,13 @@ erts_port_task_execute(ErtsRunQueue *runq, Port **curr_port_pp)
 	ErtsRunQueue *xrunq;
 #endif
 
-	ASSERT(!(pp->status & ERTS_PORT_SFLGS_DEAD));
-	ASSERT(pp->sched.taskq->first);
+	ASSERT(!(erts_atomic32_read_nob(&pp->state) & ERTS_PORT_SFLGS_DEAD));
 
 #ifdef ERTS_SMP
 	xrunq = erts_check_emigration_need(runq, ERTS_PORT_PRIO_LEVEL);
 	if (!xrunq) {
 #endif
 	    enqueue_port(runq, pp);
-	    ASSERT(pp->sched.exe_taskq);
-	    pp->sched.exe_taskq = NULL;
 	    /* No need to notify ourselves about inc in runq. */
 #ifdef ERTS_SMP
 	}
@@ -892,49 +1742,20 @@ erts_port_task_execute(ErtsRunQueue *runq, Port **curr_port_pp)
 	    erts_smp_runq_unlock(runq);
 
 	    xrunq = erts_port_runq(pp);
-	    if (xrunq) {
-		enqueue_port(xrunq, pp);
-		ASSERT(pp->sched.exe_taskq);
-		pp->sched.exe_taskq = NULL;
-		erts_smp_runq_unlock(xrunq);
-		erts_smp_notify_inc_runq(xrunq);
-	    }
+	    ASSERT(xrunq);
+	    enqueue_port(xrunq, pp);
+	    erts_smp_runq_unlock(xrunq);
+	    erts_smp_notify_inc_runq(xrunq);
 
 	    erts_smp_runq_lock(runq);
 	}
 #endif
     }
 
+ done:
     res = (erts_smp_atomic_read_nob(&erts_port_task_outstanding_io_tasks)
 	   != (erts_aint_t) 0);
 
-    ERTS_PT_CHK_PRES_PORTQ(runq, pp);
-
-    port_taskq_free(ptqp);
-
-    /* trace port scheduling, out */
-    if (IS_TRACED_FL(pp, F_TRACE_SCHED_PORTS)) {
-    	trace_sched_ports(pp, am_out);
-    }
-#ifndef ERTS_SMP
-    erts_port_release(pp);
-#else
-    {
-	erts_aint_t refc;
-	erts_smp_mtx_unlock(pp->lock);
-	refc = erts_smp_atomic_dec_read_nob(&pp->refc);
-	ASSERT(refc >= 0);
-	if (refc == 0) {
-	    erts_smp_runq_unlock(runq);
-	    erts_port_cleanup(pp); /* Might aquire runq lock */
-	    erts_smp_runq_lock(runq);
-	    res = (erts_smp_atomic_read_nob(&erts_port_task_outstanding_io_tasks)
-		   != (erts_aint_t) 0);
-	}
-    }
-#endif
-
- done:
     runq->scheduler->reductions += reds;
 
     ERTS_SMP_LC_ASSERT(erts_smp_lc_runq_is_locked(runq));
@@ -943,78 +1764,146 @@ erts_port_task_execute(ErtsRunQueue *runq, Port **curr_port_pp)
     return res;
 }
 
-/*
- * Handle remaining tasks after a free task.
- */
+#ifdef ERTS_SMP
+static void
+release_port(void *vport)
+{
+    erts_port_dec_refc((Port *) vport);
+}
+#endif
 
 static void
-handle_remaining_tasks(ErtsRunQueue *runq, Port *pp)
+begin_port_cleanup(Port *pp, ErtsPortTask **execqp)
 {
-    int i;
-    ErtsPortTask *ptp;
-    ErtsPortTaskQueue *ptqps[] = {pp->sched.exe_taskq, pp->sched.taskq};
+    int i, max;
+    ErtsPortTask *qs[2];
 
     ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(pp));
 
-    for (i = 0; i < sizeof(ptqps)/sizeof(ErtsPortTaskQueue *); i++) {
-	if (!ptqps[i])
-	    continue;
 
-	ptp = pop_task(ptqps[i]);
-	while (ptp) {
+    /*
+     * Handle remaining tasks...
+     */
+
+    max = 0;
+    if (execqp && *execqp) {
+	qs[max++] = *execqp;
+	*execqp = NULL;
+    }
+
+    erts_port_task_sched_lock(&pp->sched);
+    qs[max] = pp->sched.taskq.in.first;
+    pp->sched.taskq.in.first = NULL;
+    pp->sched.taskq.in.last = NULL;
+    erts_port_task_sched_unlock(&pp->sched);
+    if (qs[max])
+	max++;
+
+    for (i = 0; i < max; i++) {
+	while (1) {
+	    erts_aint32_t state;
+	    ErtsPortTask *ptp = qs[i];
+	    if (!ptp)
+		break;
+
+	    qs[i] = ptp->u.alive.next;
+
+	    /* Normal case here is aborted tasks... */
+	    state = erts_smp_atomic32_read_nob(&ptp->state);
+	    if (state == ERTS_PT_STATE_ABORTED)
+		goto aborted_port_task;
+
+	    state = erts_smp_atomic32_cmpxchg_nob(&ptp->state,
+						  ERTS_PT_STATE_EXECUTING,
+						  ERTS_PT_STATE_SCHEDULED);
+	    if (state != ERTS_PT_STATE_SCHEDULED) {
+		ASSERT(state == ERTS_PT_STATE_ABORTED);
+		goto aborted_port_task;
+	    }
+
 	    reset_handle(ptp);
-	    erts_smp_runq_unlock(runq);
 
 	    switch (ptp->type) {
-	    case ERTS_PORT_TASK_FREE:
 	    case ERTS_PORT_TASK_TIMEOUT:
 		break;
 	    case ERTS_PORT_TASK_INPUT:
-		erts_stale_drv_select(pp->id, ptp->event, DO_READ, 1);
+		erts_stale_drv_select(pp->common.id,
+				      ptp->u.alive.td.io.event,
+				      DO_READ,
+				      1);
 		break;
 	    case ERTS_PORT_TASK_OUTPUT:
-		erts_stale_drv_select(pp->id, ptp->event, DO_WRITE, 1);
+		erts_stale_drv_select(pp->common.id,
+				      ptp->u.alive.td.io.event,
+				      DO_WRITE,
+				      1);
 		break;
 	    case ERTS_PORT_TASK_EVENT:
-		erts_stale_drv_select(pp->id, ptp->event, 0, 1);
+		erts_stale_drv_select(pp->common.id,
+				      ptp->u.alive.td.io.event,
+				      0,
+				      1);
 		break;
 	    case ERTS_PORT_TASK_DIST_CMD:
 		break;
+	    case ERTS_PORT_TASK_PROC_SIG: {
+		ErtsProc2PortSigData *sigdp = &ptp->u.alive.td.psig.data;
+		if (!pp->sched.taskq.bpq)
+		    ptp->u.alive.td.psig.callback(NULL,
+						  ERTS_PORT_SFLG_INVALID,
+						  ERTS_PROC2PORT_SIG_ABORT_CLOSED,
+						  sigdp);
+		else {
+		    ErlDrvSizeT size = erts_proc2port_sig_command_data_size(sigdp);
+		    ptp->u.alive.td.psig.callback(NULL,
+						  ERTS_PORT_SFLG_INVALID,
+						  ERTS_PROC2PORT_SIG_ABORT_CLOSED,
+						  sigdp);
+		    aborted_proc2port_data(pp, size);
+		}
+		break;
+	    }
 	    default:
 		erl_exit(ERTS_ABORT_EXIT,
 			 "Invalid port task type: %d\n",
 			 (int) ptp->type);
 	    }
 
-	    port_task_free(ptp);
-
-	    erts_smp_runq_lock(runq);
-	    ptp = pop_task(ptqps[i]);
+	aborted_port_task:
+	    schedule_port_task_free(ptp);
 	}
     }
 
-    ASSERT(!pp->sched.taskq || !pp->sched.taskq->first);
+    erts_smp_atomic32_read_band_nob(&pp->sched.flags,
+				    ~ERTS_PTS_FLG_HAVE_TASKS);
+
+    /*
+     * Schedule cleanup of port structure...
+     */
+#ifdef ERTS_SMP
+    erts_schedule_thr_prgr_later_op(release_port,
+				    (void *) pp,
+				    &pp->common.u.release);
+#else
+    pp->cleanup = 1;
+#endif
 }
 
 int
 erts_port_is_scheduled(Port *pp)
 {
-    int res;
-    ErtsRunQueue *runq = erts_port_runq(pp);
-    if (!runq)
-	return 0;
-    res = pp->sched.taskq || pp->sched.exe_taskq;
-    erts_smp_runq_unlock(runq);
-    return res;
+    erts_aint32_t flags = erts_smp_atomic32_read_acqb(&pp->sched.flags);
+    return (flags & (ERTS_PTS_FLG_IN_RUNQ|ERTS_PTS_FLG_EXEC)) != 0;
 }
 
 #ifdef ERTS_SMP
+
 void
 erts_enqueue_port(ErtsRunQueue *rq, Port *pp)
 {
     ERTS_SMP_LC_ASSERT(erts_smp_lc_runq_is_locked(rq));
     ASSERT(rq == (ErtsRunQueue *) erts_smp_atomic_read_nob(&pp->run_queue));
-    ASSERT(pp->sched.in_runq);
+    ASSERT(erts_smp_atomic32_read_nob(&pp->sched.flags) & ERTS_PTS_FLG_IN_RUNQ);
     enqueue_port(rq, pp);
 }
 
@@ -1026,7 +1915,8 @@ erts_dequeue_port(ErtsRunQueue *rq)
     pp = pop_port(rq);
     ASSERT(!pp
 	   || rq == (ErtsRunQueue *) erts_smp_atomic_read_nob(&pp->run_queue));
-    ASSERT(!pp || pp->sched.in_runq);
+    ASSERT(!pp || (erts_smp_atomic32_read_nob(&pp->sched.flags)
+		   & ERTS_PTS_FLG_IN_RUNQ));
     return pp;
 }
 
@@ -1041,5 +1931,5 @@ erts_port_task_init(void)
     erts_smp_atomic_init_nob(&erts_port_task_outstanding_io_tasks,
 			     (erts_aint_t) 0);
     init_port_task_alloc();
-    init_port_taskq_alloc();
+    init_busy_caller_table_alloc();
 }
diff --git a/erts/emulator/beam/erl_port_task.h b/erts/emulator/beam/erl_port_task.h
index fd88b1c1ff..ae6cd69ae2 100644
--- a/erts/emulator/beam/erl_port_task.h
+++ b/erts/emulator/beam/erl_port_task.h
@@ -1,7 +1,7 @@
 /*
  * %CopyrightBegin%
  * 
- * Copyright Ericsson AB 2006-2011. All Rights Reserved.
+ * Copyright Ericsson AB 2006-2012. All Rights Reserved.
  * 
  * The contents of this file are subject to the Erlang Public License,
  * Version 1.1, (the "License"); you may not use this file except in
@@ -27,6 +27,9 @@
 #define ERTS_PORT_TASK_H_BASIC_TYPES__
 #include "erl_sys_driver.h"
 #include "erl_smp.h"
+#define ERL_PORT_GET_PORT_TYPE_ONLY__
+#include "erl_port.h"
+#undef ERL_PORT_GET_PORT_TYPE_ONLY__
 typedef erts_smp_atomic_t ErtsPortTaskHandle;
 #endif
 
@@ -43,13 +46,19 @@ typedef erts_smp_atomic_t ErtsPortTaskHandle;
 #define ERTS_INCLUDE_SCHEDULER_INTERNALS
 #endif
 
+#define ERTS_PT_FLG_WAIT_BUSY		(1 << 0)
+#define ERTS_PT_FLG_SIG_DEP		(1 << 1)
+#define ERTS_PT_FLG_NOSUSPEND		(1 << 2)
+#define ERTS_PT_FLG_REF			(1 << 3)
+#define ERTS_PT_FLG_BAD_OUTPUT		(1 << 4)
+
 typedef enum {
-    ERTS_PORT_TASK_FREE,
     ERTS_PORT_TASK_INPUT,
     ERTS_PORT_TASK_OUTPUT,
     ERTS_PORT_TASK_EVENT,
     ERTS_PORT_TASK_TIMEOUT,
-    ERTS_PORT_TASK_DIST_CMD
+    ERTS_PORT_TASK_DIST_CMD,
+    ERTS_PORT_TASK_PROC_SIG
 } ErtsPortTaskType;
 
 #ifdef ERTS_INCLUDE_SCHEDULER_INTERNALS
@@ -57,19 +66,76 @@ typedef enum {
 extern erts_smp_atomic_t erts_port_task_outstanding_io_tasks;
 #endif
 
+#define ERTS_PTS_FLG_IN_RUNQ			(((erts_aint32_t) 1) <<  0)
+#define ERTS_PTS_FLG_EXEC			(((erts_aint32_t) 1) <<  1)
+#define ERTS_PTS_FLG_HAVE_TASKS			(((erts_aint32_t) 1) <<  2)
+#define ERTS_PTS_FLG_EXIT			(((erts_aint32_t) 1) <<  3)
+#define ERTS_PTS_FLG_BUSY_PORT			(((erts_aint32_t) 1) <<  4)
+#define ERTS_PTS_FLG_BUSY_PORT_Q		(((erts_aint32_t) 1) <<  5)
+#define ERTS_PTS_FLG_CHK_UNSET_BUSY_PORT_Q	(((erts_aint32_t) 1) <<  6)
+#define ERTS_PTS_FLG_HAVE_BUSY_TASKS		(((erts_aint32_t) 1) <<  7)
+#define ERTS_PTS_FLG_HAVE_NS_TASKS		(((erts_aint32_t) 1) <<  8)
+#define ERTS_PTS_FLG_PARALLELISM		(((erts_aint32_t) 1) <<  9)
+#define ERTS_PTS_FLG_FORCE_SCHED		(((erts_aint32_t) 1) << 10)
+
+#define ERTS_PTS_FLGS_BUSY \
+    (ERTS_PTS_FLG_BUSY_PORT | ERTS_PTS_FLG_BUSY_PORT_Q)
+
+#define ERTS_PTS_FLGS_FORCE_SCHEDULE_OP		\
+    (ERTS_PTS_FLG_EXIT				\
+     | ERTS_PTS_FLG_HAVE_BUSY_TASKS		\
+     | ERTS_PTS_FLG_HAVE_TASKS			\
+     | ERTS_PTS_FLG_EXEC			\
+     | ERTS_PTS_FLG_FORCE_SCHED)
+
+#define ERTS_PORT_TASK_DEFAULT_BUSY_PORT_Q_HIGH			8192
+#define ERTS_PORT_TASK_DEFAULT_BUSY_PORT_Q_LOW			4096
+
+typedef struct {
+    ErlDrvSizeT high;
+    erts_smp_atomic_t low;
+    erts_smp_atomic_t size;
+}  ErtsPortTaskBusyPortQ;
+
 typedef struct ErtsPortTask_ ErtsPortTask;
-typedef struct ErtsPortTaskQueue_ ErtsPortTaskQueue;
+typedef struct ErtsPortTaskBusyCallerTable_ ErtsPortTaskBusyCallerTable;
+typedef struct ErtsPortTaskHandleList_ ErtsPortTaskHandleList;
 
 typedef struct {
     Port *next;
-    int in_runq;
-    ErtsPortTaskQueue *taskq;
-    ErtsPortTaskQueue *exe_taskq;
+    struct {
+	struct {
+	    struct {
+		ErtsPortTask *first;
+		ErtsPortTask *last;
+		ErtsPortTaskBusyCallerTable *table;
+		ErtsPortTaskHandleList *nosuspend;
+	    } busy;
+	    ErtsPortTask *first;
+	} local;
+	struct {
+	    ErtsPortTask *first;
+	    ErtsPortTask *last;
+	} in;
+	ErtsPortTaskBusyPortQ *bpq;
+    } taskq;
+    erts_smp_atomic32_t flags;
+#ifdef ERTS_SMP
+    erts_mtx_t mtx;
+#endif
 } ErtsPortTaskSched;
 
 ERTS_GLB_INLINE void erts_port_task_handle_init(ErtsPortTaskHandle *pthp);
 ERTS_GLB_INLINE int erts_port_task_is_scheduled(ErtsPortTaskHandle *pthp);
-ERTS_GLB_INLINE void erts_port_task_init_sched(ErtsPortTaskSched *ptsp);
+ERTS_GLB_INLINE void erts_port_task_pre_init_sched(ErtsPortTaskSched *ptsp,
+						   ErtsPortTaskBusyPortQ *bpq);
+ERTS_GLB_INLINE void erts_port_task_init_sched(ErtsPortTaskSched *ptsp,
+					       Eterm id);
+ERTS_GLB_INLINE void erts_port_task_fini_sched(ErtsPortTaskSched *ptsp);
+ERTS_GLB_INLINE void erts_port_task_sched_lock(ErtsPortTaskSched *ptsp);
+ERTS_GLB_INLINE void erts_port_task_sched_unlock(ErtsPortTaskSched *ptsp);
+ERTS_GLB_INLINE int erts_port_task_sched_lock_is_locked(ErtsPortTaskSched *ptsp);
+
 #ifdef ERTS_INCLUDE_SCHEDULER_INTERNALS
 ERTS_GLB_INLINE int erts_port_task_have_outstanding_io_tasks(void);
 #endif
@@ -88,13 +154,75 @@ erts_port_task_is_scheduled(ErtsPortTaskHandle *pthp)
     return ((void *) erts_smp_atomic_read_nob(pthp)) != NULL;
 }
 
+ERTS_GLB_INLINE void erts_port_task_pre_init_sched(ErtsPortTaskSched *ptsp,
+						   ErtsPortTaskBusyPortQ *bpq)
+{
+    if (bpq) {
+	erts_aint_t low = (erts_aint_t) ERTS_PORT_TASK_DEFAULT_BUSY_PORT_Q_LOW;
+	erts_smp_atomic_init_nob(&bpq->low, low);
+ 	bpq->high = (ErlDrvSizeT) ERTS_PORT_TASK_DEFAULT_BUSY_PORT_Q_HIGH;
+	erts_smp_atomic_init_nob(&bpq->size, (erts_aint_t) 0);
+    }
+    ptsp->taskq.bpq = bpq;
+}
+
 ERTS_GLB_INLINE void
-erts_port_task_init_sched(ErtsPortTaskSched *ptsp)
+erts_port_task_init_sched(ErtsPortTaskSched *ptsp, Eterm instr_id)
 {
+#ifdef ERTS_SMP
+    char *lock_str = "port_sched_lock";
+#endif
     ptsp->next = NULL;
-    ptsp->in_runq = 0;
-    ptsp->taskq = NULL;
-    ptsp->exe_taskq = NULL;
+    ptsp->taskq.local.busy.first = NULL;
+    ptsp->taskq.local.busy.last = NULL;
+    ptsp->taskq.local.busy.table = NULL;
+    ptsp->taskq.local.busy.nosuspend = NULL;
+    ptsp->taskq.local.first = NULL;
+    ptsp->taskq.in.first = NULL;
+    ptsp->taskq.in.last = NULL;
+    erts_smp_atomic32_init_nob(&ptsp->flags, 0);
+#ifdef ERTS_SMP
+#ifdef ERTS_ENABLE_LOCK_COUNT
+    if (!(erts_lcnt_rt_options & ERTS_LCNT_OPT_PORTLOCK))
+	lock_str = NULL;
+#endif
+    erts_mtx_init_x(&ptsp->mtx, lock_str, instr_id);
+#endif
+}
+
+ERTS_GLB_INLINE void
+erts_port_task_sched_lock(ErtsPortTaskSched *ptsp)
+{
+#ifdef ERTS_SMP
+    erts_mtx_lock(&ptsp->mtx);
+#endif
+}
+
+ERTS_GLB_INLINE void
+erts_port_task_sched_unlock(ErtsPortTaskSched *ptsp)
+{
+#ifdef ERTS_SMP
+    erts_mtx_unlock(&ptsp->mtx);
+#endif
+}
+
+ERTS_GLB_INLINE int
+erts_port_task_sched_lock_is_locked(ErtsPortTaskSched *ptsp)
+{
+#if defined(ERTS_SMP) && defined(ERTS_ENABLE_LOCK_CHECK)
+    return erts_lc_mtx_is_locked(&ptsp->mtx);
+#else
+    return 0;
+#endif
+}
+
+
+ERTS_GLB_INLINE void
+erts_port_task_fini_sched(ErtsPortTaskSched *ptsp)
+{
+#ifdef ERTS_SMP
+    erts_mtx_destroy(&ptsp->mtx);
+#endif
 }
 
 #ifdef ERTS_INCLUDE_SCHEDULER_INTERNALS
@@ -115,14 +243,16 @@ int erts_port_task_execute(ErtsRunQueue *, Port **);
 void erts_port_task_init(void);
 #endif
 
-int erts_port_task_abort(Eterm id, ErtsPortTaskHandle *);
+int erts_port_task_abort(ErtsPortTaskHandle *);
+void erts_port_task_abort_nosuspend_tasks(Port *);
+
 int erts_port_task_schedule(Eterm,
 			    ErtsPortTaskHandle *,
 			    ErtsPortTaskType,
-			    ErlDrvEvent,
-			    ErlDrvEventData);
+			    ...);
 void erts_port_task_free_port(Port *);
 int erts_port_is_scheduled(Port *);
+ErtsProc2PortSigData *erts_port_task_alloc_p2p_sig_data(void);
 
 #ifdef ERTS_SMP
 void erts_enqueue_port(ErtsRunQueue *rq, Port *pp);
diff --git a/erts/emulator/beam/erl_process.c b/erts/emulator/beam/erl_process.c
index 61554780c4..aaca4b5f59 100644
--- a/erts/emulator/beam/erl_process.c
+++ b/erts/emulator/beam/erl_process.c
@@ -42,6 +42,7 @@
 #include "erl_thr_queue.h"
 #include "erl_async.h"
 #include "dtrace-wrapper.h"
+#include "erl_ptab.h"
 
 #define ERTS_DELAYED_WAKEUP_INFINITY (~(Uint64) 0)
 #define ERTS_DELAYED_WAKEUP_REDUCTIONS ((Uint64) CONTEXT_REDS/2)
@@ -136,155 +137,16 @@ do { \
 #define ERTS_EMPTY_RUNQ_PORTS(RQ) \
     (RUNQ_READ_LEN(&(RQ)->ports.info.len) == 0 && (RQ)->misc.start == NULL)
 
+const Process erts_invalid_process = {{ERTS_INVALID_PID}};
+
 extern BeamInstr beam_apply[];
 extern BeamInstr beam_exit[];
 extern BeamInstr beam_continue_exit[];
 
-#ifdef ARCH_32
-
-union {
-    erts_smp_dw_atomic_t pid_data;
-    char align[ERTS_CACHE_LINE_SIZE];
-} last erts_align_attribute(ERTS_CACHE_LINE_SIZE);
-
-
-static ERTS_INLINE Uint64
-dw_aint_to_uint64(erts_dw_aint_t *dw)
-{
-#ifdef ETHR_SU_DW_NAINT_T__
-    return (Uint64) dw->dw_sint;
-#else
-    Uint64 res;
-    res = (Uint64) ((Uint32) dw->sint[ERTS_DW_AINT_HIGH_WORD]);
-    res <<= 32;
-    res |= (Uint64) ((Uint32) dw->sint[ERTS_DW_AINT_LOW_WORD]);
-    return res;
-#endif
-}
-
-static void
-unint64_to_dw_aint(erts_dw_aint_t *dw, Uint64 val)
-{
-#ifdef ETHR_SU_DW_NAINT_T__
-    dw->dw_sint = (ETHR_SU_DW_NAINT_T__) val;
-#else
-    dw->sint[ERTS_DW_AINT_LOW_WORD] = (erts_aint_t) (val & 0xffffffff);
-    dw->sint[ERTS_DW_AINT_HIGH_WORD] = (erts_aint_t) ((val >> 32) & 0xffffffff);
-#endif
-}
-
-static ERTS_INLINE void
-last_pid_data_init_nob(Uint64 val)
-{
-    erts_dw_aint_t dw;
-    unint64_to_dw_aint(&dw, val);
-    erts_smp_dw_atomic_init_nob(&last.pid_data, &dw);
-}
-
-static ERTS_INLINE void
-last_pid_data_set_relb(Uint64 val)
-{
-    erts_dw_aint_t dw;
-    unint64_to_dw_aint(&dw, val);
-    erts_smp_dw_atomic_set_relb(&last.pid_data, &dw);
-}
-
-static ERTS_INLINE Uint64
-last_pid_data_read_nob(void)
-{
-    erts_dw_aint_t dw;
-    erts_smp_dw_atomic_read_nob(&last.pid_data, &dw);
-    return dw_aint_to_uint64(&dw);
-}
-
-static ERTS_INLINE Uint64
-last_pid_data_read_acqb(void)
-{
-    erts_dw_aint_t dw;
-    erts_smp_dw_atomic_read_acqb(&last.pid_data, &dw);
-    return dw_aint_to_uint64(&dw);
-}
-
-static ERTS_INLINE Uint64
-last_pid_data_cmpxchg_relb(Uint64 new, Uint64 exp)
-{
-    erts_dw_aint_t dw_new, dw_xchg;
-
-    unint64_to_dw_aint(&dw_new, new);
-    unint64_to_dw_aint(&dw_xchg, exp);
-
-    if (erts_smp_dw_atomic_cmpxchg_relb(&last.pid_data, &dw_new, &dw_xchg))
-	return exp;
-    else
-	return dw_aint_to_uint64(&dw_xchg);
-}
-
-#elif defined(ARCH_64)
-
-union {
-    erts_smp_atomic_t pid_data;
-    char align[ERTS_CACHE_LINE_SIZE];
-} last erts_align_attribute(ERTS_CACHE_LINE_SIZE);
-
-static ERTS_INLINE void
-last_pid_data_init_nob(Uint64 val)
-{
-    erts_smp_atomic_init_nob(&last.pid_data, (erts_aint_t) val);
-}
-
-static ERTS_INLINE void
-last_pid_data_set_relb(Uint64 val)
-{
-    erts_smp_atomic_set_relb(&last.pid_data, (erts_aint_t) val);
-}
-
-static ERTS_INLINE Uint64
-last_pid_data_read_nob(void)
-{
-    return (Uint64) erts_smp_atomic_read_nob(&last.pid_data);
-}
-
-static ERTS_INLINE Uint64
-last_pid_data_read_acqb(void)
-{
-    return (Uint64) erts_smp_atomic_read_acqb(&last.pid_data);
-}
-
-static ERTS_INLINE Uint64
-last_pid_data_cmpxchg_relb(Uint64 new, Uint64 exp)
-{
-    return (Uint64) erts_smp_atomic_cmpxchg_relb(&last.pid_data,
-						 (erts_aint_t) new,
-						 (erts_aint_t) exp);
-}
-
-#else
-#  error "Not 64-bit, nor 32-bit architecture..."
-#endif
-
-static ERTS_INLINE int
-last_pid_data_cmp(Uint64 lpd1, Uint64 lpd2)
-{
-    Uint64 lpd1_wrap;
-
-    if (lpd1 == lpd2)
-	return 0;
-
-    lpd1_wrap = lpd1 + (((Uint64) 1) << 63);
-
-    if (lpd1 < lpd1_wrap)
-	return (lpd1 < lpd2 && lpd2 < lpd1_wrap) ? -1 : 1;
-    else
-	return (lpd1_wrap <= lpd2 && lpd2 < lpd1) ? 1 : -1;
-}
-
-
-#define ERTS_PID_DATA_MASK__ ((1 << _PID_DATA_SIZE) - 1)
-
 int erts_sched_compact_load;
 Uint erts_no_schedulers;
 
-ErtsProcTab erts_proc erts_align_attribute(ERTS_CACHE_LINE_SIZE);
+ErtsPTab erts_proc erts_align_attribute(ERTS_CACHE_LINE_SIZE);
 
 int erts_sched_thread_suggested_stack_size = -1;
 
@@ -371,8 +233,6 @@ erts_sched_stat_t erts_sched_stat;
 static erts_tsd_key_t sched_data_key;
 #endif
 
-erts_smp_rwmtx_t erts_proc_tab_rwmtx;
-
 static erts_smp_atomic32_t function_calls;
 
 #ifdef ERTS_SMP
@@ -409,29 +269,6 @@ struct erts_system_profile_flags_t erts_system_profile_flags;
 #if ERTS_MAX_PROCESSES > 0x7fffffff
 #error "Need to store process_count in another type"
 #endif
-static erts_smp_atomic32_t process_count;
-
-typedef struct ErtsTermProcElement_ ErtsTermProcElement;
-struct ErtsTermProcElement_ {
-    ErtsTermProcElement *next;
-    ErtsTermProcElement *prev;
-    int ix;
-    union {
-	struct {
-	    Eterm pid;
-	    Uint64 spawned;
-	    Uint64 exited;
-	} process;
-	struct {
-	    Uint64 interval;
-	} bif_invocation;
-    } u;
-};
-
-static struct {
-    ErtsTermProcElement *start;
-    ErtsTermProcElement *end;
-} saved_term_procs;
 
 ERTS_SCHED_PREF_QUICK_ALLOC_IMPL(misc_op_list,
 				 ErtsMiscOpList,
@@ -493,8 +330,6 @@ do {									\
  * Local functions.
  */
 
-static void init_processes_bif(void);
-static void save_terminating_process(Process *p);
 static void exec_misc_ops(ErtsRunQueue *);
 static void print_function_from_pc(int to, void *to_arg, BeamInstr* x);
 static int stack_element_dump(int to, void *to_arg, Process* p, Eterm* sp,
@@ -562,39 +397,17 @@ erts_smp_lc_runq_is_locked(ErtsRunQueue *runq)
 }
 #endif
 
-static erts_interval_t *proc_interval;
-
-static void
-proc_interval_init(void)
-{
-    proc_interval = erts_alloc_permanent_cache_aligned(
-	ERTS_ALC_T_PROC_INTERVAL,
-	sizeof(erts_interval_t));
-    erts_smp_interval_init(proc_interval);
-}
-
-static ERTS_INLINE Uint64
-get_proc_interval(void)
-{
-    return erts_smp_current_interval_nob(proc_interval);
-}
 
 static ERTS_INLINE Uint64
 ensure_later_proc_interval(Uint64 interval)
 {
-    return erts_smp_ensure_later_interval_nob(proc_interval, interval);
-}
-
-static ERTS_INLINE Uint64
-step_proc_interval(void)
-{
-    return erts_smp_step_interval_nob(proc_interval);
+    return erts_smp_ensure_later_interval_nob(erts_ptab_interval(&erts_proc), interval);
 }
 
 Uint64
 erts_get_proc_interval(void)
 {
-    return get_proc_interval();
+    return erts_smp_current_interval_nob(erts_ptab_interval(&erts_proc));
 }
 
 Uint64
@@ -606,7 +419,7 @@ erts_ensure_later_proc_interval(Uint64 interval)
 Uint64
 erts_step_proc_interval(void)
 {
-    return step_proc_interval();
+    return erts_smp_step_interval_nob(erts_ptab_interval(&erts_proc));
 }
 
 void
@@ -654,20 +467,18 @@ erts_pre_init_process(void)
 #endif
 }
 
+#ifdef ERTS_SMP
+static void
+release_process(void *vproc)
+{
+    erts_smp_proc_dec_refc((Process *) vproc);
+}
+#endif
+
 /* initialize the scheduler */
 void
-erts_init_process(int ncpu)
+erts_init_process(int ncpu, int proc_tab_size)
 {
-    int proc_tab_sz;
-    int max_proc_bits;
-    int proc_bits = ERTS_PROC_BITS;
-    erts_smp_atomic_t *proc_entry;
-    char *proc_tab_end;
-    erts_smp_rwmtx_opt_t proc_tab_rwmtx_opts = ERTS_SMP_RWMTX_OPT_DEFAULT_INITER;
-    proc_tab_rwmtx_opts.type = ERTS_SMP_RWMTX_TYPE_EXTREMELY_FREQUENT_READ;
-    proc_tab_rwmtx_opts.lived = ERTS_SMP_RWMTX_LONG_LIVED;
-
-    proc_interval_init();
 
 #ifdef ERTS_SMP
     erts_disable_proc_not_running_opt = 0;
@@ -676,52 +487,16 @@ erts_init_process(int ncpu)
 
     init_proclist_alloc();
 
-    erts_smp_atomic32_init_nob(&process_count, 0);
-
-    if (erts_use_r9_pids_ports)
-	proc_bits = ERTS_R9_PROC_BITS;
-
-    if (erts_proc.max > (1 << proc_bits))
-	erts_proc.max = 1 << proc_bits;
-
-    proc_tab_sz = ERTS_ALC_CACHE_LINE_ALIGN_SIZE(erts_proc.max
-						 * sizeof(erts_smp_atomic_t));
-    erts_proc.tab = erts_alloc(ERTS_ALC_T_PROC_TABLE, proc_tab_sz);
-    proc_tab_end = ((char *) erts_proc.tab) + proc_tab_sz;
-    proc_entry = erts_proc.tab;
-    while (proc_tab_end > ((char *) proc_entry)) {
-	erts_smp_atomic_init_nob(proc_entry, ERTS_AINT_NULL);
-	proc_entry++;
-    }
-
-    erts_smp_rwmtx_init_opt(&erts_proc_tab_rwmtx,
-			    &proc_tab_rwmtx_opts,
-			    "proc_tab");
-    last_pid_data_init_nob(~((Uint64) 0));
-
-    max_proc_bits = erts_fit_in_bits_int32((Sint32) erts_proc.max - 1);
-
-    erts_proc.tab_cache_lines = proc_tab_sz/ERTS_CACHE_LINE_SIZE;
-    erts_proc.pix_per_cache_line = ERTS_CACHE_LINE_SIZE/sizeof(erts_smp_atomic_t);
-    if ((erts_proc.max & (erts_proc.max - 1))
-	| (erts_proc.pix_per_cache_line & (erts_proc.pix_per_cache_line - 1))) {
-	/*
-	 * erts_proc.max or erts_proc.pix_per_cache_line
-	 * not a power of 2 :(
-	 */
-	erts_proc.pix_cl_mask = 0;
-	erts_proc.pix_cl_shift = 0;
-	erts_proc.pix_cli_mask = 0;
-	erts_proc.pix_cli_shift = 0;
-    }
-    else {
-	ASSERT((erts_proc.tab_cache_lines
-		& (erts_proc.tab_cache_lines - 1)) == 0);
-	erts_proc.pix_cl_mask = erts_proc.tab_cache_lines-1;
-	erts_proc.pix_cl_shift = erts_fit_in_bits_int32(erts_proc.pix_per_cache_line-1);
-	erts_proc.pix_cli_shift = erts_fit_in_bits_int32(erts_proc.pix_cl_mask);
-	erts_proc.pix_cli_mask = (1 << (max_proc_bits - erts_proc.pix_cli_shift)) - 1;
-    }
+    erts_ptab_init_table(&erts_proc,
+			 ERTS_ALC_T_PROC_TABLE,
+#ifdef ERTS_SMP
+			 release_process,
+#else
+			 NULL,
+#endif
+			 (ErtsPTabElementCommon *) &erts_invalid_process.common,
+			 proc_tab_size,
+			 "process_table");
 
     last_reductions = 0;
     last_exact_reductions = 0;
@@ -732,7 +507,6 @@ void
 erts_late_init_process(void)
 {
     int ix;
-    init_processes_bif();
 
     erts_smp_spinlock_init(&erts_sched_stat.lock, "sched_stat");
     for (ix = 0; ix < ERTS_NO_PRIO_LEVELS; ix++) {
@@ -980,9 +754,9 @@ static ERTS_INLINE ErtsProcList *
 proclist_create(Process *p)
 {
     ErtsProcList *plp = proclist_alloc();
-    ensure_later_proc_interval(p->started_interval);
-    plp->pid = p->id;
-    plp->started_interval = p->started_interval;
+    ensure_later_proc_interval(p->common.u.alive.started_interval);
+    plp->pid = p->common.id;
+    plp->started_interval = p->common.u.alive.started_interval;
     return plp;
 }
 
@@ -992,12 +766,6 @@ proclist_destroy(ErtsProcList *plp)
     proclist_free(plp);
 }
 
-static ERTS_INLINE int
-proclist_same(ErtsProcList *plp, Process *p)
-{
-    return plp->pid == p->id && plp->started_interval == p->started_interval;
-}
-
 ErtsProcList *
 erts_proclist_create(Process *p)
 {
@@ -1010,12 +778,6 @@ erts_proclist_destroy(ErtsProcList *plp)
     proclist_destroy(plp);
 }
 
-int
-erts_proclist_same(ErtsProcList *plp, Process *p)
-{
-    return proclist_same(plp, p);
-}
-
 void *
 erts_psd_set_init(Process *p, ErtsProcLocks plocks, int ix, void *data)
 {
@@ -1776,37 +1538,32 @@ handle_reap_ports(ErtsAuxWorkData *awdp, erts_aint32_t aux_work, int waiting)
     unset_aux_work_flags(awdp->ssi, ERTS_SSI_AUX_WORK_REAP_PORTS);
     awdp->esdp->run_queue->halt_in_progress = 1;
     if (erts_smp_atomic32_dec_read_acqb(&erts_halt_progress) == 0) {
-	int i;
+	int i, max = erts_ptab_max(&erts_port);
 	erts_smp_atomic32_set_nob(&erts_halt_progress, 1);
-	for (i = 0; i < erts_max_ports; i++) {
-	    Port *prt = &erts_port[i];
-	    erts_smp_port_state_lock(prt);
-	    if ((prt->status & (ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP
-				| ERTS_PORT_SFLG_HALT))) {
-		erts_smp_port_state_unlock(prt);
-		continue;
-	    }
-	    /* We need to set the halt flag - get the port lock */
-#ifdef ERTS_SMP
-	    erts_smp_atomic_inc_nob(&prt->refc);
-#endif
-	    erts_smp_port_state_unlock(prt);
-#ifdef ERTS_SMP
-	    erts_smp_mtx_lock(prt->lock);
-#endif
-	    if ((prt->status & (ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP
-				| ERTS_PORT_SFLG_HALT))) {
-		erts_port_release(prt);
+	for (i = 0; i < max; i++) {
+	    erts_aint32_t state;
+	    Port *prt = erts_pix2port(i);
+	    if (!prt)
 		continue;
-	    }
-	    erts_port_status_bor_set(prt, ERTS_PORT_SFLG_HALT);
-	    erts_smp_atomic32_inc_nob(&erts_halt_progress);
-	    if (prt->status & (ERTS_PORT_SFLG_EXITING
-			       | ERTS_PORT_SFLG_CLOSING)) {
-		erts_port_release(prt);
+	    state = erts_atomic32_read_acqb(&prt->state);
+	    if (state & (ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP
+			 | ERTS_PORT_SFLG_HALT))
 		continue;
+
+	    /* We need to set the halt flag - get the port lock */
+
+	    erts_smp_port_lock(prt);
+
+	    state = erts_atomic32_read_nob(&prt->state);
+	    if (!(state & (ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP
+			   | ERTS_PORT_SFLG_HALT))) {
+		state = erts_atomic32_read_bor_relb(&prt->state,
+						    ERTS_PORT_SFLG_HALT);
+		erts_smp_atomic32_inc_nob(&erts_halt_progress);
+		if (!(state & (ERTS_PORT_SFLG_EXITING|ERTS_PORT_SFLG_CLOSING)))
+		    erts_deliver_port_exit(prt, prt->common.id, am_killed, 0);
 	    }
-	    erts_do_exit_port(prt, prt->id, am_killed);
+
 	    erts_port_release(prt);
 	}
 	if (erts_smp_atomic32_dec_read_nob(&erts_halt_progress) == 0) {
@@ -3183,12 +2940,12 @@ resume_run_queue(ErtsRunQueue *rq)
 
     erts_smp_runq_lock(rq);
 
-    (void) ERTS_RUNQ_FLGS_MASK_SET(rq,
-				   (ERTS_RUNQ_FLG_OUT_OF_WORK
-				    | ERTS_RUNQ_FLG_HALFTIME_OUT_OF_WORK
-				    | ERTS_RUNQ_FLG_SUSPENDED),
-				   (ERTS_RUNQ_FLG_OUT_OF_WORK
-				    | ERTS_RUNQ_FLG_HALFTIME_OUT_OF_WORK));
+    (void) ERTS_RUNQ_FLGS_READ_BSET(rq,
+				    (ERTS_RUNQ_FLG_OUT_OF_WORK
+				     | ERTS_RUNQ_FLG_HALFTIME_OUT_OF_WORK
+				     | ERTS_RUNQ_FLG_SUSPENDED),
+				    (ERTS_RUNQ_FLG_OUT_OF_WORK
+				     | ERTS_RUNQ_FLG_HALFTIME_OUT_OF_WORK));
 
     rq->check_balance_reds = ERTS_RUNQ_CALL_CHECK_BALANCE_REDS;
     for (pix = 0; pix < ERTS_NO_PROC_PRIO_LEVELS; pix++) {
@@ -4210,7 +3967,7 @@ erts_fprintf(stderr, "--------------------------------\n");
 	ERTS_DBG_CHK_FULL_REDS_HISTORY(rq);
 
 	rq->out_of_work_count = 0;
-	(void) ERTS_RUNQ_FLGS_MASK_SET(rq, ERTS_RUNQ_FLGS_MIGRATION_INFO, flags);
+	(void) ERTS_RUNQ_FLGS_READ_BSET(rq, ERTS_RUNQ_FLGS_MIGRATION_INFO, flags);
 
 	rq->max_len = rq->len;
 	for (pix = 0; pix < ERTS_NO_PRIO_LEVELS; pix++) {
@@ -4896,6 +4653,11 @@ erts_init_scheduling(int no_schedulers, int no_schedulers_online)
 
     erts_smp_atomic32_init_relb(&erts_halt_progress, -1);
     erts_halt_code = 0;
+
+#if !defined(ERTS_SMP) && defined(ERTS_ENABLE_LOCK_CHECK)
+    erts_lc_set_thread_name("scheduler 1");
+#endif
+
 }
 
 ErtsRunQueue *
@@ -5573,8 +5335,7 @@ erts_block_multi_scheduling(Process *p, ErtsProcLocks plocks, int on, int all)
     else if (on) { /* ------ BLOCK ------ */
 	if (schdlr_sspnd.msb.procs) {
 	    plp = proclist_create(p);
-	    plp->next = schdlr_sspnd.msb.procs;
-	    schdlr_sspnd.msb.procs = plp;
+	    erts_proclist_store_last(&schdlr_sspnd.msb.procs, plp);
 	    p->flags |= F_HAVE_BLCKD_MSCHED;
 	    ASSERT(erts_smp_atomic32_read_nob(&schdlr_sspnd.active) == 1);
 	    ASSERT(p->scheduler_data->no == 1);
@@ -5659,8 +5420,7 @@ erts_block_multi_scheduling(Process *p, ErtsProcLocks plocks, int on, int all)
 						~ERTS_SCHDLR_SSPND_CHNG_WAITER);
 	    }
 	    plp = proclist_create(p);
-	    plp->next = schdlr_sspnd.msb.procs;
-	    schdlr_sspnd.msb.procs = plp;
+	    erts_proclist_store_last(&schdlr_sspnd.msb.procs, plp);
 	    ASSERT(p->scheduler_data);
 	}
     }
@@ -5671,20 +5431,16 @@ erts_block_multi_scheduling(Process *p, ErtsProcLocks plocks, int on, int all)
     }
     else {  /* ------ UNBLOCK ------ */
 	if (p->flags & F_HAVE_BLCKD_MSCHED) {
-	    ErtsProcList **plpp = &schdlr_sspnd.msb.procs;
-	    plp = schdlr_sspnd.msb.procs;
+	    ErtsProcList *plp = erts_proclist_peek_first(schdlr_sspnd.msb.procs);
 
 	    while (plp) {
-		if (!proclist_same(plp, p)){
-		    plpp = &plp->next;
-		    plp = plp->next;
-		}
-		else {
-		    *plpp = plp->next;
-		    proclist_destroy(plp);
+		ErtsProcList *tmp_plp = plp;
+		plp = erts_proclist_peek_next(schdlr_sspnd.msb.procs, plp);
+		if (erts_proclist_same(tmp_plp, p)) {
+		    erts_proclist_remove(&schdlr_sspnd.msb.procs, tmp_plp);
+		    proclist_destroy(tmp_plp);
 		    if (!all)
 			break;
-		    plp = *plpp;
 		}
 	    }
 	}
@@ -5753,23 +5509,25 @@ erts_multi_scheduling_blockers(Process *p)
     Eterm res = NIL;
 
     erts_smp_mtx_lock(&schdlr_sspnd.mtx);
-    if (schdlr_sspnd.msb.procs) {
+    if (!erts_proclist_is_empty(schdlr_sspnd.msb.procs)) {
 	Eterm *hp, *hp_end;
 	ErtsProcList *plp1, *plp2;
-	Uint max_size;
-	ASSERT(schdlr_sspnd.msb.procs);
-	for (max_size = 0, plp1 = schdlr_sspnd.msb.procs;
+	Uint max_size = 0;
+
+	for (plp1 = erts_proclist_peek_first(schdlr_sspnd.msb.procs);
 	     plp1;
-	     plp1 = plp1->next) {
+	     plp1 = erts_proclist_peek_next(schdlr_sspnd.msb.procs, plp1)) {
 	    max_size += 2;
 	}
 	ASSERT(max_size);
 	hp = HAlloc(p, max_size);
 	hp_end = hp + max_size;
-	for (plp1 = schdlr_sspnd.msb.procs; plp1; plp1 = plp1->next) {
-	    for (plp2 = schdlr_sspnd.msb.procs;
+	for (plp1 = erts_proclist_peek_first(schdlr_sspnd.msb.procs);
+	     plp1;
+	     plp1 = erts_proclist_peek_next(schdlr_sspnd.msb.procs, plp1)) {
+	    for (plp2 = erts_proclist_peek_first(schdlr_sspnd.msb.procs);
 		 plp2->pid != plp1->pid;
-		 plp2 = plp2->next);
+		 plp2 = erts_proclist_peek_next(schdlr_sspnd.msb.procs, plp2));
 	    if (plp2 == plp1) {
 		res = CONS(hp, plp1->pid, res);
 		hp += 2;
@@ -6021,7 +5779,7 @@ handle_pend_sync_suspend(Process *suspendee,
 	ASSERT(is_nil(suspender->suspendee));
 	if (suspendee_alive) {
 	    erts_suspend(suspendee, suspendee_locks, NULL);
-	    suspender->suspendee = suspendee->id;
+	    suspender->suspendee = suspendee->common.id;
 	}
 	/* suspender is suspended waiting for suspendee to suspend;
 	   resume suspender */
@@ -6042,7 +5800,7 @@ pid2proc_not_running(Process *c_p, ErtsProcLocks c_p_locks,
     ERTS_SMP_LC_ASSERT(c_p_locks & ERTS_PROC_LOCK_MAIN);
     ERTS_SMP_LC_ASSERT(pid_locks & (ERTS_PROC_LOCK_MAIN|ERTS_PROC_LOCK_STATUS));
 
-    if (c_p->id == pid)
+    if (c_p->common.id == pid)
 	return erts_pid2proc(c_p, c_p_locks, pid, pid_locks);
 
     if (c_p_locks & ERTS_PROC_LOCK_STATUS)
@@ -6094,7 +5852,7 @@ pid2proc_not_running(Process *c_p, ErtsProcLocks c_p_locks,
 	 */
 	if (!c_p->pending_suspenders) {
 	    /* Mark rp pending for suspend by c_p */
-	    add_pend_suspend(rp, c_p->id, handle_pend_sync_suspend);
+	    add_pend_suspend(rp, c_p->common.id, handle_pend_sync_suspend);
 	    ASSERT(is_nil(c_p->suspendee));
 
 	    /* Suspend c_p; when rp is suspended c_p will be resumed. */
@@ -6200,20 +5958,20 @@ handle_pend_bif_sync_suspend(Process *suspendee,
 	ASSERT(is_nil(suspender->suspendee));
 	if (!suspendee_alive)
 	    erts_delete_suspend_monitor(&suspender->suspend_monitors,
-					suspendee->id);
+					suspendee->common.id);
 	else {
 #ifdef DEBUG
 	    int res;
 #endif
 	    ErtsSuspendMonitor *smon;
 	    smon = erts_lookup_suspend_monitor(suspender->suspend_monitors,
-					       suspendee->id);
+					       suspendee->common.id);
 #ifdef DEBUG
 	    res =
 #endif
 		do_bif_suspend_process(suspendee, smon, suspendee);
 	    ASSERT(!smon || res != 0);
-	    suspender->suspendee = suspendee->id;
+	    suspender->suspendee = suspendee->common.id;
 	}
 	/* suspender is suspended waiting for suspendee to suspend;
 	   resume suspender */
@@ -6242,14 +6000,14 @@ handle_pend_bif_async_suspend(Process *suspendee,
 	ASSERT(is_nil(suspender->suspendee));
 	if (!suspendee_alive)
 	    erts_delete_suspend_monitor(&suspender->suspend_monitors,
-					suspendee->id);
+					suspendee->common.id);
 	else {
 #ifdef DEBUG
 	    int res;
 #endif
 	    ErtsSuspendMonitor *smon;
 	    smon = erts_lookup_suspend_monitor(suspender->suspend_monitors,
-					       suspendee->id);
+					       suspendee->common.id);
 #ifdef DEBUG
 	    res =
 #endif
@@ -6294,7 +6052,7 @@ suspend_process_2(BIF_ALIST_2)
     int unless_suspending = 0;
 
 
-    if (BIF_P->id == BIF_ARG_1)
+    if (BIF_P->common.id == BIF_ARG_1)
 	goto badarg; /* We are not allowed to suspend ourselves */
 
     if (is_not_nil(BIF_ARG_2)) {
@@ -6390,7 +6148,7 @@ suspend_process_2(BIF_ALIST_2)
 
 		if (!do_bif_suspend_process(BIF_P, smon, suspendee))
 		    add_pend_suspend(suspendee,
-				     BIF_P->id,
+				     BIF_P->common.id,
 				     handle_pend_bif_async_suspend);
 
 		res = am_true;
@@ -6453,7 +6211,7 @@ suspend_process_2(BIF_ALIST_2)
 	    else {
 		/* Mark suspendee pending for suspend by BIF_P */
 		add_pend_suspend(suspendee,
-				 BIF_P->id,
+				 BIF_P->common.id,
 				 handle_pend_bif_sync_suspend);
 
 		ASSERT(is_nil(BIF_P->suspendee));
@@ -6527,7 +6285,7 @@ resume_process_1(BIF_ALIST_1)
     Process *suspendee;
     int is_active;
  
-    if (BIF_P->id == BIF_ARG_1)
+    if (BIF_P->common.id == BIF_ARG_1)
 	BIF_ERROR(BIF_P, BADARG);
 
     erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_LINK);
@@ -6652,7 +6410,8 @@ erts_process_status(Process *c_p, ErtsProcLocks c_p_locks,
 	for (i = 0; i < erts_no_schedulers; i++) {
 	    esdp = ERTS_SCHEDULER_IX(i);
 	    erts_smp_runq_lock(esdp->run_queue);
-	    if (esdp->free_process && esdp->free_process->id == rpid) {
+	    if (esdp->free_process
+		&& esdp->free_process->common.id == rpid) {
 		res = am_free;
 		erts_smp_runq_unlock(esdp->run_queue);
 		break;
@@ -6673,27 +6432,31 @@ erts_process_status(Process *c_p, ErtsProcLocks c_p_locks,
 void
 erts_suspend(Process* c_p, ErtsProcLocks c_p_locks, Port *busy_port)
 {
-#ifdef DEBUG
-    int res;
-#endif
+    int suspend;
+
     ASSERT(c_p == erts_get_current_process());
     ERTS_SMP_LC_ASSERT(c_p_locks == erts_proc_lc_my_proc_locks(c_p));
     if (!(c_p_locks & ERTS_PROC_LOCK_STATUS))
 	erts_smp_proc_lock(c_p, ERTS_PROC_LOCK_STATUS);
 
+    if (busy_port)
+	suspend = erts_save_suspend_process_on_port(busy_port, c_p);
+    else
+	suspend = 1;
+
+    if (suspend) {
 #ifdef DEBUG
-    res =
+	int res =
 #endif
-	suspend_process(c_p, c_p);
-
-    ASSERT(res);
-
-    if (busy_port)
-	erts_wake_process_later(busy_port, c_p);
+	    suspend_process(c_p, c_p);
+	ASSERT(res);
+    }
 
     if (!(c_p_locks & ERTS_PROC_LOCK_STATUS))
 	erts_smp_proc_unlock(c_p, ERTS_PROC_LOCK_STATUS);
 
+    if (suspend && busy_port && erts_system_monitor_flags.busy_port)
+	monitor_generic(c_p, am_busy_port, busy_port->common.id);
 }
 
 void
@@ -6708,16 +6471,19 @@ erts_resume(Process* process, ErtsProcLocks process_locks)
 }
 
 int
-erts_resume_processes(ErtsProcList *plp)
+erts_resume_processes(ErtsProcList *list)
 {
+    /* 'list' is expected to have been fetched (i.e. not a ring anymore) */
     int nresumed = 0;
+    ErtsProcList *plp = list;
+
     while (plp) {
 	Process *proc;
 	ErtsProcList *fplp;
 	ASSERT(is_internal_pid(plp->pid));
 	proc = erts_pid2proc(NULL, 0, plp->pid, ERTS_PROC_LOCK_STATUS);
 	if (proc) {
-	    if (proclist_same(plp, proc)) {
+	    if (erts_proclist_same(plp, proc)) {
 		resume_process(proc);
 		nresumed++;
 	    }
@@ -6870,9 +6636,8 @@ Process *schedule(Process *p, int calls)
 	state = erts_smp_atomic32_read_acqb(&p->state);
 
 	if (IS_TRACED(p)) {
-	    if (IS_TRACED_FL(p, F_TRACE_CALLS) && !(state & ERTS_PSFLG_FREE)) {
+	    if (IS_TRACED_FL(p, F_TRACE_CALLS) && !(state & ERTS_PSFLG_FREE))
 		erts_schedule_time_break(p, ERTS_BP_CALL_TIME_SCHEDULE_OUT);
-	    }
 	    if (state & (ERTS_PSFLG_FREE|ERTS_PSFLG_EXITING)) {
 		if (ARE_TRACE_FLAGS_ON(p, F_TRACE_SCHED_EXIT))
 		    trace_sched(p, ((state & ERTS_PSFLG_FREE)
@@ -6885,7 +6650,7 @@ Process *schedule(Process *p, int calls)
 		else if (ARE_TRACE_FLAGS_ON(p, F_TRACE_SCHED_PROCS))
 		    trace_virtual_sched(p, am_out);
 	    }
-	}	
+	}
 
 #ifdef ERTS_SMP
 	if (state & ERTS_PSFLG_PENDING_EXIT)
@@ -6949,9 +6714,8 @@ Process *schedule(Process *p, int calls)
 #ifdef ERTS_SMP
 	{
 	    ErtsProcList *pnd_xtrs = rq->procs.pending_exiters;
-	    rq->procs.pending_exiters = NULL;
-
-	    if (pnd_xtrs) {
+	    if (erts_proclist_fetch(&pnd_xtrs, NULL)) {
+		rq->procs.pending_exiters = NULL;
 		erts_smp_runq_unlock(rq);
 		handle_pending_exiters(pnd_xtrs);
 		erts_smp_runq_lock(rq);
@@ -7247,7 +7011,7 @@ Process *schedule(Process *p, int calls)
 	erts_smp_proc_unlock(p, ERTS_PROC_LOCK_STATUS);
 
 #ifdef ERTS_SMP
-	if (is_not_nil(p->tracer_proc))
+	if (is_not_nil(ERTS_TRACER_PROC(p)))
 	    erts_check_my_tracer_proc(p);
 #endif
 
@@ -7450,70 +7214,6 @@ erts_get_exact_total_reductions(Process *c_p, Uint *redsp, Uint *diffp)
     erts_smp_proc_lock(c_p, ERTS_PROC_LOCK_MAIN);
 }
 
-/*
- * erts_test_next_pid() is only used for testing.
- */
-Sint
-erts_test_next_pid(int set, Uint next)
-{
-    Uint64 lpd;
-    Sint res;
-    Eterm pid_data;
-    int first_pix = -1;
-
-    erts_smp_rwmtx_rwlock(&erts_proc_tab_rwmtx);
-
-    if (!set)
-	lpd = last_pid_data_read_nob();
-    else {
-
-	lpd = (Uint64) next;
-	pid_data = (Eterm) (lpd & ERTS_PID_DATA_MASK__);
-	if (ERTS_INVALID_PID == make_internal_pid(pid_data)) {
-	    lpd += erts_proc.max;
-	    ASSERT(erts_pid_data2ix(pid_data)
-		   == erts_pid_data2ix(lpd & ERTS_PID_DATA_MASK__));
-	}
-	last_pid_data_set_relb(lpd);
-    }
-
-    while (1) {
-	int pix;
-	lpd++;
-	pix = (int) (lpd % erts_proc.max);
-	if (first_pix < 0)
-	    first_pix = pix;
-	else if (pix == first_pix) {
-	    res = -1;
-	    break;
-	}
-	if (ERTS_AINT_NULL == erts_smp_atomic_read_nob(&erts_proc.tab[pix])) {
-	    pid_data = (Eterm) (lpd & ERTS_PID_DATA_MASK__);
-	    if (ERTS_INVALID_PID == make_internal_pid(pid_data)) {
-		lpd += erts_proc.max;
-		ASSERT(erts_pid_data2ix(pid_data)
-		       == erts_pid_data2ix(lpd & ERTS_PID_DATA_MASK__));
-	    }
-	    res = lpd & ERTS_PID_DATA_MASK__;
-	    break;
-	}
-    }
-
-    erts_smp_rwmtx_rwunlock(&erts_proc_tab_rwmtx);
-
-    return res;
-
-}
-
-Uint erts_process_count(void)
-{
-    erts_aint32_t res = erts_smp_atomic32_read_nob(&process_count);
-    if (res > erts_proc.max)
-	return erts_proc.max;
-    ASSERT(res >= 0);
-    return (Uint) res;
-}
-
 void
 erts_free_proc(Process *p)
 {
@@ -7523,132 +7223,66 @@ erts_free_proc(Process *p)
     erts_free(ERTS_ALC_T_PROC, (void *) p);
 }
 
+typedef struct {
+    Process *proc;
+    erts_aint32_t state;
+    ErtsRunQueue *run_queue;
+} ErtsEarlyProcInit;
+
+static void early_init_process_struct(void *varg, Eterm data)
+{
+    ErtsEarlyProcInit *arg = (ErtsEarlyProcInit *) varg;
+    Process *proc = arg->proc;
+
+    proc->common.id = make_internal_pid(data);
+    erts_smp_atomic32_init_relb(&proc->state, arg->state);
+
+#ifdef ERTS_SMP
+    RUNQ_SET_RQ(&proc->run_queue, arg->run_queue);
+
+    erts_proc_lock_init(proc); /* All locks locked */
+#endif
+
+}
+
 /*
 ** Allocate process and find out where to place next process.
 */
 static Process*
 alloc_process(ErtsRunQueue *rq, erts_aint32_t state)
 {
-    int pix;
-    Process* p;
-    Uint64 lpd, exp_lpd;
-    Eterm pid_data;
-    erts_aint32_t proc_count;
-#ifdef DEBUG
-    Eterm pid;
-#endif
-
-    erts_smp_rwmtx_rlock(&erts_proc_tab_rwmtx);
-
-    proc_count = erts_smp_atomic32_inc_read_acqb(&process_count);
-    if (proc_count > erts_proc.max) {
-	while (1) {
-	    erts_aint32_t act_proc_count;
-
-	    act_proc_count = erts_smp_atomic32_cmpxchg_relb(&process_count,
-							    proc_count-1,
-							    proc_count);
-	    if (act_proc_count == proc_count)
-		goto system_limit;
-	    proc_count = act_proc_count;
-	    if (proc_count <= erts_proc.max)
-		break;
-	}
-    }
+    ErtsEarlyProcInit init_arg;
+    Process *p;
 
-    p = (Process*) erts_alloc_fnf(ERTS_ALC_T_PROC, sizeof(Process));
+    p = erts_alloc_fnf(ERTS_ALC_T_PROC, sizeof(Process));
     if (!p)
-	goto enomem;
-
-    p->approx_started = erts_get_approx_time();
-    p->started_interval = get_proc_interval();
-
-    lpd = last_pid_data_read_acqb();
-
-    /* Reserve slot */
-    while (1) {
-	lpd++;
-	pix = erts_pid_data2ix((Eterm) (lpd & ERTS_PID_DATA_MASK__));
-	if (erts_smp_atomic_read_nob(&erts_proc.tab[pix]) == ERTS_AINT_NULL) {
-	    erts_aint_t val;
-	    val = erts_smp_atomic_cmpxchg_relb(&erts_proc.tab[pix],
-					       ((erts_aint_t)
-						ERTS_PROC_LOCK_BUSY),	
-					       ERTS_AINT_NULL);
-
-	    if (ERTS_AINT_NULL == val)
-		break;
-	}
-    }
-
-    pid_data = (Eterm) lpd & ERTS_PID_DATA_MASK__;
+	return NULL;
 
-    p->id = make_internal_pid(pid_data);
-    if (p->id == ERTS_INVALID_PID) {
-	/* Do not use the invalid pid; change serial */
-	lpd += erts_proc.max;
-	ASSERT(pix == erts_pid_data2ix((Eterm) (lpd & ERTS_PID_DATA_MASK__)));
-	pid_data = (Eterm) lpd & ERTS_PID_DATA_MASK__;
-	p->id = make_internal_pid(pid_data);
-	ASSERT(p->id != ERTS_INVALID_PID);
-    }
+    init_arg.proc = (Process *) p;
+    init_arg.run_queue = rq;
+    init_arg.state = state;
 
-    exp_lpd = last_pid_data_read_nob();
+    ASSERT(((char *) p) == ((char *) &p->common));
 
-    /* Move last pid data forward */
-    while (1) {
-	Uint64 act_lpd;
-	if (last_pid_data_cmp(lpd, exp_lpd) < 0)
-	    break;
-	act_lpd = last_pid_data_cmpxchg_relb(lpd, exp_lpd);
-	if (act_lpd == exp_lpd)
-	    break;
-	exp_lpd = act_lpd;
+    if (!erts_ptab_new_element(&erts_proc,
+			       &p->common,
+			       (void *) &init_arg,
+			       early_init_process_struct)) {
+	erts_free(ERTS_ALC_T_PROC, p);
+	return NULL;
     }
 
-#ifdef ERTS_SMP
-    RUNQ_SET_RQ(&p->run_queue, rq);
-#endif
-
-    erts_smp_atomic32_init_relb(&p->state, state);
-
-#ifdef DEBUG
-    pid = p->id;
-#endif
-
-#ifdef ERTS_SMP
-    erts_proc_lock_init(p); /* All locks locked */
-#endif
-
-    /* Move into slot reserved */
-#ifdef DEBUG
-    ASSERT(ERTS_PROC_LOCK_BUSY
-	   == (Process *) erts_smp_atomic_xchg_relb(&erts_proc.tab[pix],
-						    (erts_aint_t) p));
-#else
-    erts_smp_atomic_set_relb(&erts_proc.tab[pix], (erts_aint_t) p);
-#endif
-
-    ASSERT(internal_pid_serial(p->id) <= (erts_use_r9_pids_ports
-					  ? ERTS_MAX_PID_R9_SERIAL
-					  : ERTS_MAX_PID_SERIAL));
-
-    erts_smp_rwmtx_runlock(&erts_proc_tab_rwmtx);
-
+    ASSERT(internal_pid_serial(p->common.id) <= ERTS_MAX_PID_SERIAL);
+    
+    p->approx_started = erts_get_approx_time();
     p->rcount = 0;
 
-    ASSERT(p == (Process *)
-	   erts_smp_atomic_read_nob(
-	       &erts_proc.tab[internal_pid_index(pid)]));
-
-    return p;
 
-enomem:
-system_limit:
-
-    erts_smp_rwmtx_runlock(&erts_proc_tab_rwmtx);
-    return NULL;
+    ASSERT(p == (Process *) (erts_ptab_pix2intptr_nob(
+				 &erts_proc,
+				 internal_pid_index(p->common.id))));
 
+    return p;
 }
 
 Eterm
@@ -7795,21 +7429,21 @@ erl_create_process(Process* parent, /* Parent of process (default group leader).
     p->reds = 0;
 
 #ifdef ERTS_SMP
-    p->u.alive.ptimer = NULL;
+    p->common.u.alive.ptimer = NULL;
 #else
-    sys_memset(&p->u.alive.tm, 0, sizeof(ErlTimer));
+    sys_memset(&p->common.u.alive.tm, 0, sizeof(ErlTimer));
 #endif
 
-    p->reg = NULL;
-    p->nlinks = NULL;
-    p->monitors = NULL;
+    p->common.u.alive.reg = NULL;
+    ERTS_P_LINKS(p) = NULL;
+    ERTS_P_MONITORS(p) = NULL;
     p->nodes_monitors = NULL;
     p->suspend_monitors = NULL;
 
     ASSERT(is_pid(parent->group_leader));
 
     if (parent->group_leader == ERTS_INVALID_PID)
-	p->group_leader = p->id;
+	p->group_leader = p->common.id;
     else {
 	/* Needs to be done after the heap has been set up */
 	p->group_leader =
@@ -7818,18 +7452,18 @@ erl_create_process(Process* parent, /* Parent of process (default group leader).
 	    : STORE_NC(&p->htop, &p->off_heap, parent->group_leader);
     }
 
-    erts_get_default_tracing(&p->trace_flags, &p->tracer_proc);
+    erts_get_default_tracing(&ERTS_TRACE_FLAGS(p), &ERTS_TRACER_PROC(p));
 
     p->msg.first = NULL;
     p->msg.last = &p->msg.first;
     p->msg.save = &p->msg.first;
     p->msg.len = 0;
 #ifdef ERTS_SMP
-    p->u.alive.msg_inq.first = NULL;
-    p->u.alive.msg_inq.last = &p->u.alive.msg_inq.first;
-    p->u.alive.msg_inq.len = 0;
+    p->msg_inq.first = NULL;
+    p->msg_inq.last = &p->msg_inq.first;
+    p->msg_inq.len = 0;
 #endif
-    p->bif_timers = NULL;
+    p->u.bif_timers = NULL;
     p->mbuf = NULL;
     p->mbuf_sz = 0;
     p->psd = NULL;
@@ -7841,7 +7475,9 @@ erl_create_process(Process* parent, /* Parent of process (default group leader).
     DT_UTAG(p) = NIL;
     DT_UTAG_FLAGS(p) = 0;
 #endif
-    p->parent = parent->id == ERTS_INVALID_PID ? NIL : parent->id;
+    p->parent = (parent->common.id == ERTS_INVALID_PID
+		 ? NIL
+		 : parent->common.id);
 
     INIT_HOLE_CHECK(p);
 #ifdef DEBUG
@@ -7849,18 +7485,19 @@ erl_create_process(Process* parent, /* Parent of process (default group leader).
 #endif
 
     if (IS_TRACED(parent)) {
-	if (parent->trace_flags & F_TRACE_SOS) {
-	    p->trace_flags |= (parent->trace_flags & TRACEE_FLAGS);
-	    p->tracer_proc = parent->tracer_proc;
+	if (ERTS_TRACE_FLAGS(parent) & F_TRACE_SOS) {
+	    ERTS_TRACE_FLAGS(p) |= (ERTS_TRACE_FLAGS(parent) & TRACEE_FLAGS);
+	    ERTS_TRACER_PROC(p) = ERTS_TRACER_PROC(parent);
 	}
 	if (ARE_TRACE_FLAGS_ON(parent, F_TRACE_PROCS)) {
-	    trace_proc_spawn(parent, p->id, mod, func, args);
+	    trace_proc_spawn(parent, p->common.id, mod, func, args);
 	}
-	if (parent->trace_flags & F_TRACE_SOS1) { /* Overrides TRACE_CHILDREN */
-	    p->trace_flags |= (parent->trace_flags & TRACEE_FLAGS);
-	    p->tracer_proc = parent->tracer_proc;
-	    p->trace_flags &= ~(F_TRACE_SOS1 | F_TRACE_SOS);
-	    parent->trace_flags &= ~(F_TRACE_SOS1 | F_TRACE_SOS);
+	if (ERTS_TRACE_FLAGS(parent) & F_TRACE_SOS1) {
+	    /* Overrides TRACE_CHILDREN */
+	    ERTS_TRACE_FLAGS(p) |= (ERTS_TRACE_FLAGS(parent) & TRACEE_FLAGS);
+	    ERTS_TRACER_PROC(p) = ERTS_TRACER_PROC(parent);
+	    ERTS_TRACE_FLAGS(p) &= ~(F_TRACE_SOS1 | F_TRACE_SOS);
+	    ERTS_TRACE_FLAGS(parent) &= ~(F_TRACE_SOS1 | F_TRACE_SOS);
 	}
     }
 
@@ -7873,27 +7510,27 @@ erl_create_process(Process* parent, /* Parent of process (default group leader).
 	int ret;
 #endif
 	if (IS_TRACED_FL(parent, F_TRACE_PROCS)) {
-	    trace_proc(parent, parent, am_link, p->id);
+	    trace_proc(parent, parent, am_link, p->common.id);
 	}
 
 #ifdef DEBUG
-	ret = erts_add_link(&(parent->nlinks),  LINK_PID, p->id);
+	ret = erts_add_link(&ERTS_P_LINKS(parent),  LINK_PID, p->common.id);
 	ASSERT(ret == 0);
-	ret = erts_add_link(&(p->nlinks), LINK_PID, parent->id);
+	ret = erts_add_link(&ERTS_P_LINKS(p), LINK_PID, parent->common.id);
 	ASSERT(ret == 0);
 #else	
-	erts_add_link(&(parent->nlinks), LINK_PID, p->id);
-	erts_add_link(&(p->nlinks), LINK_PID, parent->id);
+	erts_add_link(&ERTS_P_LINKS(parent), LINK_PID, p->common.id);
+	erts_add_link(&ERTS_P_LINKS(p), LINK_PID, parent->common.id);
 #endif
 
 	if (IS_TRACED(parent)) {
-	    if (parent->trace_flags & (F_TRACE_SOL|F_TRACE_SOL1))  {
-		p->trace_flags |= (parent->trace_flags & TRACEE_FLAGS);
-		p->tracer_proc = parent->tracer_proc;    /* maybe steal */
+	    if (ERTS_TRACE_FLAGS(parent) & (F_TRACE_SOL|F_TRACE_SOL1)) {
+		ERTS_TRACE_FLAGS(p) |= (ERTS_TRACE_FLAGS(parent)&TRACEE_FLAGS);
+		ERTS_TRACER_PROC(p) = ERTS_TRACER_PROC(parent); /*maybe steal*/
 
-		if (parent->trace_flags & F_TRACE_SOL1)  { /* maybe override */
-		    p ->trace_flags &= ~(F_TRACE_SOL1 | F_TRACE_SOL);
-		    parent->trace_flags &= ~(F_TRACE_SOL1 | F_TRACE_SOL);
+		if (ERTS_TRACE_FLAGS(parent) & F_TRACE_SOL1) {/*maybe override*/
+		    ERTS_TRACE_FLAGS(p) &= ~(F_TRACE_SOL1 | F_TRACE_SOL);
+		    ERTS_TRACE_FLAGS(parent) &= ~(F_TRACE_SOL1 | F_TRACE_SOL);
 		}
 	    }
 	}
@@ -7906,8 +7543,8 @@ erl_create_process(Process* parent, /* Parent of process (default group leader).
 	Eterm mref;
 
 	mref = erts_make_ref(parent);
-	erts_add_monitor(&(parent->monitors), MON_ORIGIN, mref, p->id, NIL);
-	erts_add_monitor(&(p->monitors), MON_TARGET, mref, parent->id, NIL);
+	erts_add_monitor(&ERTS_P_MONITORS(parent), MON_ORIGIN, mref, p->common.id, NIL);
+	erts_add_monitor(&ERTS_P_MONITORS(p), MON_TARGET, mref, parent->common.id, NIL);
 	so->mref = mref;
     }
 
@@ -7915,8 +7552,8 @@ erl_create_process(Process* parent, /* Parent of process (default group leader).
     p->scheduler_data = NULL;
     p->suspendee = NIL;
     p->pending_suspenders = NULL;
-    p->u.alive.pending_exit.reason = THE_NON_VALUE;
-    p->u.alive.pending_exit.bp = NULL;
+    p->pending_exit.reason = THE_NON_VALUE;
+    p->pending_exit.bp = NULL;
 #endif
 
 #if !defined(NO_FPE_SIGNALS) || defined(HIPE)
@@ -7925,7 +7562,7 @@ erl_create_process(Process* parent, /* Parent of process (default group leader).
 
     erts_smp_proc_unlock(p, ERTS_PROC_LOCKS_ALL);
 
-    res = p->id;
+    res = p->common.id;
 
     /*
      * Schedule process for execution.
@@ -7933,7 +7570,7 @@ erl_create_process(Process* parent, /* Parent of process (default group leader).
 
     schedule_process(p, state, 0);
 
-    VERBOSE(DEBUG_PROCESSES, ("Created a new process: %T\n",p->id));
+    VERBOSE(DEBUG_PROCESSES, ("Created a new process: %T\n",p->common.id));
 
 #ifdef USE_VM_PROBES
     if (DTRACE_ENABLED(process_spawn)) {
@@ -7968,10 +7605,10 @@ void erts_init_empty_process(Process *p)
     p->min_heap_size = 0;
     p->min_vheap_size = 0;
     p->rcount = 0;
-    p->id = ERTS_INVALID_PID;
+    p->common.id = ERTS_INVALID_PID;
     p->reds = 0;
-    p->tracer_proc = NIL;
-    p->trace_flags = F_INITIAL_TRACE_FLAGS;
+    ERTS_TRACER_PROC(p) = NIL;
+    ERTS_TRACE_FLAGS(p) = F_INITIAL_TRACE_FLAGS;
     p->group_leader = ERTS_INVALID_PID;
     p->flags = 0;
     p->fvalue = NIL;
@@ -7984,14 +7621,14 @@ void erts_init_empty_process(Process *p)
     p->bin_old_vheap = 0;
     p->bin_vheap_mature = 0;
 #ifdef ERTS_SMP
-    p->u.alive.ptimer = NULL;
+    p->common.u.alive.ptimer = NULL;
 #else
-    memset(&(p->u.alive.tm), 0, sizeof(ErlTimer));
+    memset(&(p->common.u.alive.tm), 0, sizeof(ErlTimer));
 #endif
     p->next = NULL;
     p->off_heap.first = NULL;
     p->off_heap.overhead = 0;
-    p->reg = NULL;
+    p->common.u.alive.reg = NULL;
     p->heap_sz = 0;
     p->high_water = NULL;
     p->old_hend = NULL;
@@ -8000,15 +7637,15 @@ void erts_init_empty_process(Process *p)
     p->mbuf = NULL;
     p->mbuf_sz = 0;
     p->psd = NULL;
-    p->monitors = NULL;
-    p->nlinks = NULL;         /* List of links */
+    ERTS_P_MONITORS(p) = NULL;
+    ERTS_P_LINKS(p) = NULL;         /* List of links */
     p->nodes_monitors = NULL;
     p->suspend_monitors = NULL;
     p->msg.first = NULL;
     p->msg.last = &p->msg.first;
     p->msg.save = &p->msg.first;
     p->msg.len = 0;
-    p->bif_timers = NULL;
+    p->u.bif_timers = NULL;
     p->dictionary = NULL;
     p->seq_trace_clock = 0;
     p->seq_trace_lastcnt = 0;
@@ -8036,7 +7673,7 @@ void erts_init_empty_process(Process *p)
 
     p->parent = NIL;
     p->approx_started = 0;
-    p->started_interval = 0;
+    p->common.u.alive.started_interval = 0;
 
 #ifdef HIPE
     hipe_init_process(&p->hipe);
@@ -8054,13 +7691,13 @@ void erts_init_empty_process(Process *p)
 
 #ifdef ERTS_SMP
     p->scheduler_data = NULL;
-    p->u.alive.msg_inq.first = NULL;
-    p->u.alive.msg_inq.last = &p->u.alive.msg_inq.first;
-    p->u.alive.msg_inq.len = 0;
+    p->msg_inq.first = NULL;
+    p->msg_inq.last = &p->msg_inq.first;
+    p->msg_inq.len = 0;
     p->suspendee = NIL;
     p->pending_suspenders = NULL;
-    p->u.alive.pending_exit.reason = THE_NON_VALUE;
-    p->u.alive.pending_exit.bp = NULL;
+    p->pending_exit.reason = THE_NON_VALUE;
+    p->pending_exit.bp = NULL;
     erts_proc_lock_init(p);
     erts_smp_proc_unlock(p, ERTS_PROC_LOCKS_ALL);
     RUNQ_SET_RQ(&p->run_queue, ERTS_RUNQ_IX(0));
@@ -8082,25 +7719,25 @@ erts_debug_verify_clean_empty_process(Process* p)
     ASSERT(p->stop == NULL);
     ASSERT(p->hend == NULL);
     ASSERT(p->heap == NULL);
-    ASSERT(p->id == ERTS_INVALID_PID);
-    ASSERT(p->tracer_proc == NIL);
-    ASSERT(p->trace_flags == F_INITIAL_TRACE_FLAGS);
+    ASSERT(p->common.id == ERTS_INVALID_PID);
+    ASSERT(ERTS_TRACER_PROC(p) == NIL);
+    ASSERT(ERTS_TRACE_FLAGS(p) == F_INITIAL_TRACE_FLAGS);
     ASSERT(p->group_leader == ERTS_INVALID_PID);
     ASSERT(p->next == NULL);
-    ASSERT(p->reg == NULL);
+    ASSERT(p->common.u.alive.reg == NULL);
     ASSERT(p->heap_sz == 0);
     ASSERT(p->high_water == NULL);
     ASSERT(p->old_hend == NULL);
     ASSERT(p->old_htop == NULL);
     ASSERT(p->old_heap == NULL);
 
-    ASSERT(p->monitors == NULL);
-    ASSERT(p->nlinks == NULL);
+    ASSERT(ERTS_P_MONITORS(p) == NULL);
+    ASSERT(ERTS_P_LINKS(p) == NULL);
     ASSERT(p->nodes_monitors == NULL);
     ASSERT(p->suspend_monitors == NULL);
     ASSERT(p->msg.first == NULL);
     ASSERT(p->msg.len == 0);
-    ASSERT(p->bif_timers == NULL);
+    ASSERT(p->u.bif_timers == NULL);
     ASSERT(p->dictionary == NULL);
     ASSERT(p->catches == 0);
     ASSERT(p->cp == NULL);
@@ -8110,12 +7747,12 @@ erts_debug_verify_clean_empty_process(Process* p)
     ASSERT(p->parent == NIL);
 
 #ifdef ERTS_SMP
-    ASSERT(p->u.alive.msg_inq.first == NULL);
-    ASSERT(p->u.alive.msg_inq.len == 0);
+    ASSERT(p->msg_inq.first == NULL);
+    ASSERT(p->msg_inq.len == 0);
     ASSERT(p->suspendee == NIL);
     ASSERT(p->pending_suspenders == NULL);
-    ASSERT(p->u.alive.pending_exit.reason == THE_NON_VALUE);
-    ASSERT(p->u.alive.pending_exit.bp == NULL);
+    ASSERT(p->pending_exit.reason == THE_NON_VALUE);
+    ASSERT(p->pending_exit.bp == NULL);
 #endif
 
     /* Thing that erts_cleanup_empty_process() cleans up */
@@ -8157,7 +7794,7 @@ delete_process(Process* p)
 {
     ErlMessage* mp;
 
-    VERBOSE(DEBUG_PROCESSES, ("Removing process: %T\n",p->id));
+    VERBOSE(DEBUG_PROCESSES, ("Removing process: %T\n",p->common.id));
 
     /* Cleanup psd */
 
@@ -8231,8 +7868,6 @@ delete_process(Process* p)
 	mp = next_mp;
     }
 
-    ASSERT(!p->monitors);
-    ASSERT(!p->nlinks);
     ASSERT(!p->nodes_monitors);
     ASSERT(!p->suspend_monitors);
 
@@ -8296,7 +7931,7 @@ void
 erts_handle_pending_exit(Process *c_p, ErtsProcLocks locks)
 {
     ErtsProcLocks xlocks;
-    ASSERT(is_value(c_p->u.alive.pending_exit.reason));
+    ASSERT(is_value(c_p->pending_exit.reason));
     ERTS_SMP_LC_ASSERT(erts_proc_lc_my_proc_locks(c_p) == locks);
     ERTS_SMP_LC_ASSERT(locks & ERTS_PROC_LOCK_MAIN);
     ERTS_SMP_LC_ASSERT(!((ERTS_PSFLG_EXITING|ERTS_PSFLG_FREE)
@@ -8315,10 +7950,10 @@ erts_handle_pending_exit(Process *c_p, ErtsProcLocks locks)
 
     set_proc_exiting(c_p,
 		     erts_smp_atomic32_read_acqb(&c_p->state),
-		     c_p->u.alive.pending_exit.reason,
-		     c_p->u.alive.pending_exit.bp);
-    c_p->u.alive.pending_exit.reason = THE_NON_VALUE;
-    c_p->u.alive.pending_exit.bp = NULL;
+		     c_p->pending_exit.reason,
+		     c_p->pending_exit.bp);
+    c_p->pending_exit.reason = THE_NON_VALUE;
+    c_p->pending_exit.bp = NULL;
 
     if (xlocks)
 	erts_smp_proc_unlock(c_p, xlocks);
@@ -8327,12 +7962,14 @@ erts_handle_pending_exit(Process *c_p, ErtsProcLocks locks)
 static void
 handle_pending_exiters(ErtsProcList *pnd_xtrs)
 {
+    /* 'list' is expected to have been fetched (i.e. not a ring anymore) */
     ErtsProcList *plp = pnd_xtrs;
-    ErtsProcList *free_plp;
+
     while (plp) {
+	ErtsProcList *free_plp;
 	Process *p = erts_pid2proc(NULL, 0, plp->pid, ERTS_PROC_LOCKS_ALL);
 	if (p) {
-	    if (proclist_same(plp, p)) {
+	    if (erts_proclist_same(plp, p)) {
 		erts_aint32_t state = erts_smp_atomic32_read_acqb(&p->state);
 		if (!(state & ERTS_PSFLG_RUNNING)) {
 		    ASSERT(state & ERTS_PSFLG_PENDING_EXIT);
@@ -8361,8 +7998,7 @@ save_pending_exiter(Process *p)
 
     erts_smp_runq_lock(rq);
 
-    plp->next = rq->procs.pending_exiters;
-    rq->procs.pending_exiters = plp;
+    erts_proclist_store_last(&rq->procs.pending_exiters, plp);
 
     erts_smp_runq_unlock(rq);
     wake_scheduler(rq, 1);
@@ -8409,7 +8045,7 @@ send_exit_message(Process *to, ErtsProcLocks *to_locksp,
 	hp = bp->mem;
 	mess = copy_struct(exit_term, term_size, &hp, &bp->off_heap);
 	/* the trace token must in this case be updated by the caller */
-	seq_trace_output(token, mess, SEQ_TRACE_SEND, to->id, NULL);
+	seq_trace_output(token, mess, SEQ_TRACE_SEND, to->common.id, NULL);
 	temp_token = copy_struct(token, sz_token, &hp, &bp->off_heap);
 	erts_queue_message(to, to_locksp, bp, mess, temp_token
 #ifdef USE_VM_PROBES
@@ -8539,7 +8175,7 @@ send_exit_signal(Process *c_p,		/* current process if and only
     else if (reason != am_normal || (flags & ERTS_XSIG_FLG_NO_IGN_NORMAL)) {
 #ifdef ERTS_SMP
 	if (!(state & (ERTS_PSFLG_EXITING|ERTS_PSFLG_PENDING_EXIT))) {
-	    ASSERT(!rp->u.alive.pending_exit.bp);
+	    ASSERT(!rp->pending_exit.bp);
 
 	    if (rp == c_p && (*rp_locks & ERTS_PROC_LOCK_MAIN)) {
 		/* Ensure that all locks on c_p are locked before
@@ -8589,7 +8225,7 @@ send_exit_signal(Process *c_p,		/* current process if and only
 
 	    set_pending_exit:
 		if (is_immed(rsn)) {
-		    rp->u.alive.pending_exit.reason = rsn;
+		    rp->pending_exit.reason = rsn;
 		}
 		else {
 		    Eterm *hp;
@@ -8597,11 +8233,11 @@ send_exit_signal(Process *c_p,		/* current process if and only
 		    ErlHeapFragment *bp = new_message_buffer(sz);
 
 		    hp = &bp->mem[0];
-		    rp->u.alive.pending_exit.reason = copy_struct(rsn,
-								  sz,
-								  &hp,
-								  &bp->off_heap);
-		    rp->u.alive.pending_exit.bp = bp;
+		    rp->pending_exit.reason = copy_struct(rsn,
+							  sz,
+							  &hp,
+							  &bp->off_heap);
+		    rp->pending_exit.bp = bp;
 		}
 		erts_smp_atomic32_read_bor_relb(&rp->state,
 						ERTS_PSFLG_PENDING_EXIT);
@@ -8700,7 +8336,7 @@ static void doit_exit_monitor(ErtsMonitor *mon, void *vpcontext)
 		if (!rp) {
 		    goto done;
 		}
-		rmon = erts_remove_monitor(&(rp->monitors),mon->ref);
+		rmon = erts_remove_monitor(&ERTS_P_MONITORS(rp), mon->ref);
 		erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_LINK);
 		if (rmon == NULL) {
 		    goto done;
@@ -8735,7 +8371,7 @@ static void doit_exit_monitor(ErtsMonitor *mon, void *vpcontext)
 	ASSERT(mon->type == MON_TARGET);
 	ASSERT(is_pid(mon->pid) || is_internal_port(mon->pid));
 	if (is_internal_port(mon->pid)) {
-	    Port *prt = erts_id2port(mon->pid, NULL, 0);
+	    Port *prt = erts_id2port(mon->pid);
 	    if (prt == NULL) {
 		goto done;
 	    }
@@ -8751,13 +8387,13 @@ static void doit_exit_monitor(ErtsMonitor *mon, void *vpcontext)
 		goto done;
 	    }
 	    UseTmpHeapNoproc(3);
-	    rmon = erts_remove_monitor(&(rp->monitors),mon->ref);
+	    rmon = erts_remove_monitor(&ERTS_P_MONITORS(rp), mon->ref);
 	    if (rmon) {
 		erts_destroy_monitor(rmon);
 		watched = (is_atom(mon->name)
 			   ? TUPLE2(lhp, mon->name, 
 				    erts_this_dist_entry->sysname)
-			   : pcontext->p->id);
+			   : pcontext->p->common.id);
 		erts_queue_monitor_message(rp, &rp_locks, mon->ref, am_process, 
 					   watched, pcontext->reason);
 	    }
@@ -8822,21 +8458,22 @@ static void doit_exit_link(ErtsLink *lnk, void *vpcontext)
     switch(lnk->type) {
     case LINK_PID:
 	if(is_internal_port(item)) {
-	    Port *prt = erts_id2port(item, NULL, 0);
-	    if (prt) {
-		rlnk = erts_remove_link(&prt->nlinks, p->id);
-		if (rlnk)
-		    erts_destroy_link(rlnk);
-		erts_do_exit_port(prt, p->id, reason);
-		erts_port_release(prt);
-	    }
+	    Port *prt = erts_port_lookup(item, ERTS_PORT_SFLGS_INVALID_LOOKUP);
+	    if (prt)
+		erts_port_exit(NULL,
+			       (ERTS_PORT_SIG_FLG_FORCE_SCHED
+				| ERTS_PORT_SIG_FLG_BROKEN_LINK),
+			       prt,
+			       p->common.id,
+			       reason,
+			       NULL);
 	}
 	else if(is_external_port(item)) {
 	    erts_dsprintf_buf_t *dsbufp = erts_create_logger_dsbuf();
 	    erts_dsprintf(dsbufp,
 			  "Erroneous link between %T and external port %T "
 			  "found\n",
-			  p->id,
+			  p->common.id,
 			  item);
 	    erts_send_error_to_logger_nogl(dsbufp);
 	    ASSERT(0); /* It isn't possible to setup such a link... */
@@ -8846,14 +8483,14 @@ static void doit_exit_link(ErtsLink *lnk, void *vpcontext)
 				      | ERTS_PROC_LOCKS_XSIG_SEND);
 	    rp = erts_pid2proc(NULL, 0, item, rp_locks);
 	    if (rp) {
-		rlnk = erts_remove_link(&(rp->nlinks), p->id);
+		rlnk = erts_remove_link(&ERTS_P_LINKS(rp), p->common.id);
 		/* If rlnk == NULL, we got unlinked while exiting,
 		   i.e., do nothing... */
 		if (rlnk) {
 		    int xres;
 		    erts_destroy_link(rlnk);
 		    xres = send_exit_signal(NULL,
-					    p->id,
+					    p->common.id,
 					    rp,
 					    &rp_locks, 
 					    reason,
@@ -8865,7 +8502,7 @@ static void doit_exit_link(ErtsLink *lnk, void *vpcontext)
 		    if (xres >= 0 && IS_TRACED_FL(rp, F_TRACE_PROCS)) {
 			/* We didn't exit the process and it is traced */
 			if (IS_TRACED_FL(rp, F_TRACE_PROCS)) {
-			    trace_proc(p, rp, am_getting_unlinked, p->id);
+			    trace_proc(p, rp, am_getting_unlinked, p->common.id);
 			}
 		    }
 		}
@@ -8879,12 +8516,12 @@ static void doit_exit_link(ErtsLink *lnk, void *vpcontext)
 		ErtsDSigData dsd;
 		int code;
 		ErtsDistLinkData dld;
-		erts_remove_dist_link(&dld, p->id, item, dep);
+		erts_remove_dist_link(&dld, p->common.id, item, dep);
 		erts_smp_proc_lock(p, ERTS_PROC_LOCK_MAIN);
 		code = erts_dsig_prepare(&dsd, dep, p, ERTS_DSP_NO_LOCK, 0);
 		if (code == ERTS_DSIG_PREP_CONNECTED) {
-		    code = erts_dsig_send_exit_tt(&dsd, p->id, item, reason,
-						  SEQ_TRACE_TOKEN(p));
+		    code = erts_dsig_send_exit_tt(&dsd, p->common.id, item,
+						  reason, SEQ_TRACE_TOKEN(p));
 		    ASSERT(code == ERTS_DSIG_SEND_OK);
 		}
 		erts_smp_proc_unlock(p, ERTS_PROC_LOCK_MAIN);
@@ -8899,7 +8536,7 @@ static void doit_exit_link(ErtsLink *lnk, void *vpcontext)
 	    /* dist entries have node links in a separate structure to 
 	       avoid confusion */
 	    erts_smp_de_links_lock(dep);
-	    rlnk = erts_remove_link(&(dep->node_links), p->id);
+	    rlnk = erts_remove_link(&(dep->node_links), p->common.id);
 	    erts_smp_de_links_unlock(dep);
 	    if (rlnk)
 		erts_destroy_link(rlnk);
@@ -8927,15 +8564,6 @@ resume_suspend_monitor(ErtsSuspendMonitor *smon, void *vc_p)
     erts_destroy_suspend_monitor(smon);
 }
 
-#ifdef ERTS_SMP
-static void
-proc_dec_refc(void *vproc)
-{
-    erts_smp_proc_dec_refc((Process *) vproc);
-}
-#endif
-
-
 /* this function fishishes a process and propagates exit messages - called
    by process_main when a process dies */
 void 
@@ -8973,10 +8601,10 @@ erts_do_exit_process(Process* p, Eterm reason)
     state = set_proc_exiting_state(p, erts_smp_atomic32_read_nob(&p->state));
     if (state & ERTS_PSFLG_PENDING_EXIT) {
 	/* Process exited before pending exit was received... */
-	p->u.alive.pending_exit.reason = THE_NON_VALUE;
-	if (p->u.alive.pending_exit.bp) {
-	    free_message_buffer(p->u.alive.pending_exit.bp);
-	    p->u.alive.pending_exit.bp = NULL;
+	p->pending_exit.reason = THE_NON_VALUE;
+	if (p->pending_exit.bp) {
+	    free_message_buffer(p->pending_exit.bp);
+	    p->pending_exit.bp = NULL;
 	}
     }
 
@@ -8993,23 +8621,25 @@ erts_do_exit_process(Process* p, Eterm reason)
 	    trace_proc(p, p, am_exit, reason);
     }
 
-    erts_trace_check_exiting(p->id);
+    erts_trace_check_exiting(p->common.id);
 
-    ASSERT((p->trace_flags & F_INITIAL_TRACE_FLAGS) == F_INITIAL_TRACE_FLAGS);
+    ASSERT((ERTS_TRACE_FLAGS(p) & F_INITIAL_TRACE_FLAGS)
+	   == F_INITIAL_TRACE_FLAGS);
 
     cancel_timer(p);		/* Always cancel timer just in case */
 
-    /*
-     * The timer of this process can *not* be used anymore. The field used
-     * for the timer is now used for misc exiting data.
-     */
-    p->u.exit_data = NULL;
-
-    if (p->bif_timers)
+    if (p->u.bif_timers)
 	erts_cancel_bif_timers(p, ERTS_PROC_LOCKS_ALL);
 
     erts_smp_proc_unlock(p, ERTS_PROC_LOCKS_ALL_MINOR);
 
+    /*
+     * The p->u.bif_timers of this process can *not* be used anymore;
+     * will be overwritten by misc termination data.
+     */
+    p->u.terminate = NULL;
+
+
     erts_continue_exit_process(p);
 }
 
@@ -9081,9 +8711,9 @@ erts_continue_exit_process(Process *p)
      * The registered name *should* be the last "erlang resource" to
      * cleanup.
      */
-    if (p->reg) {
+    if (p->common.u.alive.reg) {
 	(void) erts_unregister_name(p, ERTS_PROC_LOCK_MAIN, NULL, THE_NON_VALUE);
-	ASSERT(!p->reg);
+	ASSERT(!p->common.u.alive.reg);
     }
 
     erts_smp_proc_lock(p, ERTS_PROC_LOCKS_ALL_MINOR);
@@ -9097,22 +8727,18 @@ erts_continue_exit_process(Process *p)
     yield_allowed = 0;
 #endif
 
+    /*
+     * Note! The monitor and link fields will be overwritten 
+     * by erts_ptab_delete_element() below.
+     */
+    mon = ERTS_P_MONITORS(p);
+    lnk = ERTS_P_LINKS(p);
+
     {
-	int maybe_save;
-	int pix;
 	/* Do *not* use erts_get_runq_proc() */
 	ErtsRunQueue *rq;
 	rq = erts_get_runq_current(ERTS_GET_SCHEDULER_DATA_FROM_PROC(p));
 
-	pix = internal_pid_index(p->id);
-
-	erts_smp_rwmtx_rlock(&erts_proc_tab_rwmtx);
-	maybe_save = saved_term_procs.end != NULL;
-	if (maybe_save) {
-	    erts_smp_rwmtx_runlock(&erts_proc_tab_rwmtx);
-	    erts_smp_rwmtx_rwlock(&erts_proc_tab_rwmtx);
-	}
-
 	erts_smp_runq_lock(rq);
 
 #ifdef ERTS_SMP
@@ -9123,22 +8749,11 @@ erts_continue_exit_process(Process *p)
 	p->scheduler_data->current_process = NULL;
 	p->scheduler_data->free_process = p;
 #endif
-	/* Time of death! */
-	erts_smp_atomic_set_relb(&erts_proc.tab[pix], ERTS_AINT_NULL);
 
-	ASSERT(erts_smp_atomic32_read_nob(&process_count) > 0);
-	erts_smp_atomic32_dec_relb(&process_count);
+	/* Time of death! */
+	erts_ptab_delete_element(&erts_proc, &p->common);
 
 	erts_smp_runq_unlock(rq);
-
-	if (!maybe_save)
-	    erts_smp_rwmtx_runlock(&erts_proc_tab_rwmtx);
-	else {
-	    if (saved_term_procs.end)
-		save_terminating_process(p);
-	    erts_smp_rwmtx_rwunlock(&erts_proc_tab_rwmtx);
-	}
-
     }
 
     /*
@@ -9148,12 +8763,6 @@ erts_continue_exit_process(Process *p)
      * when the monitors and/or links hit.
      */
 
-    mon = p->monitors;
-    p->monitors = NULL; /* to avoid recursive deletion during traversal */
-
-    lnk = p->nlinks;
-    p->nlinks = NULL;
-
     {
 	/* Inactivate and notify free */
 	erts_aint32_t n, e, a = erts_smp_atomic32_read_nob(&p->state);
@@ -9197,7 +8806,7 @@ erts_continue_exit_process(Process *p)
 	UseTmpHeap(4,p);
 	hp = &tmp_heap[0];
 
-	exit_tuple = TUPLE3(hp, am_EXIT, p->id, reason);
+	exit_tuple = TUPLE3(hp, am_EXIT, p->common.id, reason);
 
 	exit_tuple_sz = size_object(exit_tuple);
 
@@ -9223,9 +8832,6 @@ erts_continue_exit_process(Process *p)
     delete_process(p);
 
 #ifdef ERTS_SMP
-    erts_schedule_thr_prgr_later_op(proc_dec_refc,
-				    (void *) p,
-				    &p->u.release_data);
     erts_smp_proc_lock(p, ERTS_PROC_LOCK_MAIN);
     ERTS_SMP_CHK_HAVE_ONLY_MAIN_PROC_LOCK(p);
 #endif
@@ -9277,9 +8883,9 @@ cancel_timer(Process* p)
     ERTS_SMP_LC_ASSERT(ERTS_PROC_LOCK_MAIN & erts_proc_lc_my_proc_locks(p));
     p->flags &= ~(F_INSLPQUEUE|F_TIMO);
 #ifdef ERTS_SMP
-    erts_cancel_smp_ptimer(p->u.alive.ptimer);
+    erts_cancel_smp_ptimer(p->common.u.alive.ptimer);
 #else
-    erts_cancel_timer(&p->u.alive.tm);
+    erts_cancel_timer(&p->common.u.alive.tm);
 #endif
 }
 
@@ -9300,12 +8906,12 @@ set_timer(Process* p, Uint timeout)
     p->flags &= ~F_TIMO;
 
 #ifdef ERTS_SMP
-    erts_create_smp_ptimer(&p->u.alive.ptimer,
-			   p->id,
+    erts_create_smp_ptimer(&p->common.u.alive.ptimer,
+			   p->common.id,
 			   (ErlTimeoutProc) timeout_proc,
 			   timeout);
 #else
-    erts_set_timer(&p->u.alive.tm,
+    erts_set_timer(&p->common.u.alive.tm,
 		  (ErlTimeoutProc) timeout_proc,
 		  NULL,
 		  (void*) p,
@@ -9323,7 +8929,7 @@ erts_stack_dump(int to, void *to_arg, Process *p)
     Eterm* sp;
     int yreg = -1;
 
-    if (p->trace_flags & F_SENSITIVE) {
+    if (ERTS_TRACE_FLAGS(p) & F_SENSITIVE) {
 	return;
     }
     erts_program_counter_info(to, to_arg, p);
@@ -9411,1068 +9017,6 @@ stack_element_dump(int to, void *to_arg, Process* p, Eterm* sp, int yreg)
     return yreg;
 }
 
-/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *\
- * The processes/0 BIF implementation.                                       *
-\*                                                                           */
-
-
-#define ERTS_PROCESSES_BIF_TAB_INSPECT_INDICES_PER_RED 25
-#define ERTS_PROCESSES_BIF_TAB_CHUNK_SIZE 1000
-#define ERTS_PROCESSES_BIF_MIN_START_REDS		\
- (ERTS_PROCESSES_BIF_TAB_CHUNK_SIZE			\
-  / ERTS_PROCESSES_BIF_TAB_INSPECT_INDICES_PER_RED)
-
-#define ERTS_PROCESSES_BIF_TAB_FREE_TERM_PROC_REDS 1
-
-#define ERTS_PROCESSES_BIF_INSPECT_TERM_PROC_PER_RED 10
-
-#define ERTS_PROCESSES_INSPECT_TERM_PROC_MAX_REDS \
- (ERTS_PROCESSES_BIF_TAB_CHUNK_SIZE			\
-  / ERTS_PROCESSES_BIF_TAB_INSPECT_INDICES_PER_RED)
- 
-
-#define ERTS_PROCESSES_BIF_BUILD_RESULT_CONSES_PER_RED 75
-
-#define ERTS_PROCS_DBG_DO_TRACE 0
-
-#ifdef DEBUG
-#  define ERTS_PROCESSES_BIF_DEBUGLEVEL 100
-#else
-#  define ERTS_PROCESSES_BIF_DEBUGLEVEL 0
-#endif
-
-#define ERTS_PROCS_DBGLVL_CHK_HALLOC 1
-#define ERTS_PROCS_DBGLVL_CHK_FOUND_PIDS 5
-#define ERTS_PROCS_DBGLVL_CHK_PIDS 10
-#define ERTS_PROCS_DBGLVL_CHK_TERM_PROC_LIST 20
-#define ERTS_PROCS_DBGLVL_CHK_RESLIST 20
-
-#if ERTS_PROCESSES_BIF_DEBUGLEVEL == 0
-#  define ERTS_PROCS_ASSERT(EXP)
-#else
-#  define ERTS_PROCS_ASSERT(EXP) \
-    ((void) ((EXP) \
-	     ? 1 \
-	     : (debug_processes_assert_error(#EXP, __FILE__, __LINE__), 0)))
-#endif
-
-
-#if ERTS_PROCESSES_BIF_DEBUGLEVEL >=  ERTS_PROCS_DBGLVL_CHK_HALLOC
-#  define ERTS_PROCS_DBG_SAVE_HEAP_ALLOC(PBDP, HP, SZ)			\
-do {									\
-    ERTS_PROCS_ASSERT(!(PBDP)->debug.heap);				\
-    ERTS_PROCS_ASSERT(!(PBDP)->debug.heap_size);			\
-    (PBDP)->debug.heap = (HP);						\
-    (PBDP)->debug.heap_size = (SZ);					\
-} while (0)
-#  define ERTS_PROCS_DBG_VERIFY_HEAP_ALLOC_USED(PBDP, HP)		\
-do {									\
-    ERTS_PROCS_ASSERT((PBDP)->debug.heap);				\
-    ERTS_PROCS_ASSERT((PBDP)->debug.heap_size);				\
-    ERTS_PROCS_ASSERT((PBDP)->debug.heap + (PBDP)->debug.heap_size == (HP));\
-    (PBDP)->debug.heap = NULL;						\
-    (PBDP)->debug.heap_size = 0;					\
-} while (0)
-#  define ERTS_PROCS_DBG_HEAP_ALLOC_INIT(PBDP)				\
-do {									\
-    (PBDP)->debug.heap = NULL;						\
-    (PBDP)->debug.heap_size = 0;					\
-} while (0)
-#else
-#  define ERTS_PROCS_DBG_SAVE_HEAP_ALLOC(PBDP, HP, SZ)
-#  define ERTS_PROCS_DBG_VERIFY_HEAP_ALLOC_USED(PBDP, HP)
-#  define ERTS_PROCS_DBG_HEAP_ALLOC_INIT(PBDP)
-#endif
-
-#if ERTS_PROCESSES_BIF_DEBUGLEVEL >= ERTS_PROCS_DBGLVL_CHK_RESLIST
-#  define ERTS_PROCS_DBG_CHK_RESLIST(R) debug_processes_check_res_list((R))
-#else
-#  define ERTS_PROCS_DBG_CHK_RESLIST(R)
-#endif
-
-#if ERTS_PROCESSES_BIF_DEBUGLEVEL >= ERTS_PROCS_DBGLVL_CHK_PIDS
-#  define ERTS_PROCS_DBG_SAVE_PIDS(PBDP) debug_processes_save_all_pids((PBDP))
-#  define ERTS_PROCS_DBG_VERIFY_PIDS(PBDP)		\
-do {							\
-    if (!(PBDP)->debug.correct_pids_verified)		\
-	debug_processes_verify_all_pids((PBDP));	\
-} while (0)
-#  define ERTS_PROCS_DBG_CLEANUP_CHK_PIDS(PBDP)		\
-do {							\
-    if ((PBDP)->debug.correct_pids) {			\
-	erts_free(ERTS_ALC_T_PROCS_PIDS,		\
-		  (PBDP)->debug.correct_pids);		\
-	(PBDP)->debug.correct_pids = NULL;		\
-    }							\
-} while(0)
-#  define ERTS_PROCS_DBG_CHK_PIDS_INIT(PBDP)		\
-do {							\
-    (PBDP)->debug.correct_pids_verified = 0;		\
-    (PBDP)->debug.correct_pids = NULL;			\
-} while (0)
-#else
-#  define ERTS_PROCS_DBG_SAVE_PIDS(PBDP)
-#  define ERTS_PROCS_DBG_VERIFY_PIDS(PBDP)
-#  define ERTS_PROCS_DBG_CLEANUP_CHK_PIDS(PBDP)
-#  define ERTS_PROCS_DBG_CHK_PIDS_INIT(PBDP)
-#endif
-
-#if ERTS_PROCESSES_BIF_DEBUGLEVEL >= ERTS_PROCS_DBGLVL_CHK_FOUND_PIDS
-#  define ERTS_PROCS_DBG_CHK_PID_FOUND(PBDP, PID, IC) \
-  debug_processes_check_found_pid((PBDP), (PID), (IC), 1)
-#  define ERTS_PROCS_DBG_CHK_PID_NOT_FOUND(PBDP, PID, IC) \
-  debug_processes_check_found_pid((PBDP), (PID), (IC), 0)
-#else
-#  define ERTS_PROCS_DBG_CHK_PID_FOUND(PBDP, PID, IC)
-#  define ERTS_PROCS_DBG_CHK_PID_NOT_FOUND(PBDP, PID, IC)
-#endif
-
-#if ERTS_PROCESSES_BIF_DEBUGLEVEL >= ERTS_PROCS_DBGLVL_CHK_TERM_PROC_LIST
-#  define ERTS_PROCS_DBG_CHK_TPLIST() \
-  debug_processes_check_term_proc_list()
-#  define ERTS_PROCS_DBG_CHK_FREELIST(FL) \
-  debug_processes_check_term_proc_free_list(FL)
-#else
-#  define ERTS_PROCS_DBG_CHK_TPLIST()
-#  define ERTS_PROCS_DBG_CHK_FREELIST(FL)
-#endif
-
-#if ERTS_PROCESSES_BIF_DEBUGLEVEL == 0
-#if ERTS_PROCS_DBG_DO_TRACE
-#    define ERTS_PROCS_DBG_INIT(P, PBDP) (PBDP)->debug.caller = (P)->id
-#  else
-#    define ERTS_PROCS_DBG_INIT(P, PBDP)
-#  endif
-#  define ERTS_PROCS_DBG_CLEANUP(PBDP)
-#else
-#  define ERTS_PROCS_DBG_INIT(P, PBDP)			\
-do {							\
-    (PBDP)->debug.caller = (P)->id;			\
-    ERTS_PROCS_DBG_HEAP_ALLOC_INIT((PBDP));		\
-    ERTS_PROCS_DBG_CHK_PIDS_INIT((PBDP));		\
-} while (0)
-#  define ERTS_PROCS_DBG_CLEANUP(PBDP)			\
-do {							\
-    ERTS_PROCS_DBG_CLEANUP_CHK_PIDS((PBDP));		\
-} while (0)
-#endif
-
-#if ERTS_PROCS_DBG_DO_TRACE
-#  define ERTS_PROCS_DBG_TRACE(PID, FUNC, WHAT)			\
-     erts_fprintf(stderr, "%T %s:%d:%s(): %s\n",		\
-		  (PID), __FILE__, __LINE__, #FUNC, #WHAT)
-#else
-#  define ERTS_PROCS_DBG_TRACE(PID, FUNC, WHAT)
-#endif
-
-static Uint processes_bif_tab_chunks;
-static Export processes_trap_export;
-
-typedef struct {
-    Uint64 interval;
-} ErtsProcessesBifChunkInfo;
-
-typedef enum {
-    INITIALIZING,
-    INSPECTING_TABLE,
-    INSPECTING_TERMINATED_PROCESSES,
-    BUILDING_RESULT,
-    RETURN_RESULT
-} ErtsProcessesBifState;
-
-typedef struct {
-    ErtsProcessesBifState state;
-    Eterm caller;
-    ErtsProcessesBifChunkInfo *chunk;
-    int tix;
-    int pid_ix;
-    int pid_sz;
-    Eterm *pid;
-    ErtsTermProcElement *bif_invocation; /* Only used when > 1 chunk */
-
-#if ERTS_PROCESSES_BIF_DEBUGLEVEL != 0 || ERTS_PROCS_DBG_DO_TRACE
-    struct {
-	Eterm caller;
-#if ERTS_PROCESSES_BIF_DEBUGLEVEL >= ERTS_PROCS_DBGLVL_CHK_FOUND_PIDS
-	Uint64 *pid_started;
-#endif
-#if ERTS_PROCESSES_BIF_DEBUGLEVEL >= ERTS_PROCS_DBGLVL_CHK_HALLOC
-	Eterm *heap;
-	Uint heap_size;
-#endif
-#if ERTS_PROCESSES_BIF_DEBUGLEVEL >= ERTS_PROCS_DBGLVL_CHK_PIDS
-	int correct_pids_verified;
-	Eterm *correct_pids;
-#endif
-    } debug;
-#endif
-
-} ErtsProcessesBifData;
-
-
-#if ERTS_PROCESSES_BIF_DEBUGLEVEL != 0
-static void debug_processes_assert_error(char* expr, char* file, int line);
-#endif
-#if ERTS_PROCESSES_BIF_DEBUGLEVEL >= ERTS_PROCS_DBGLVL_CHK_RESLIST
-static void debug_processes_check_res_list(Eterm list);
-#endif
-#if ERTS_PROCESSES_BIF_DEBUGLEVEL >= ERTS_PROCS_DBGLVL_CHK_PIDS
-static void debug_processes_save_all_pids(ErtsProcessesBifData *pbdp);
-static void debug_processes_verify_all_pids(ErtsProcessesBifData *pbdp);
-#endif
-#if ERTS_PROCESSES_BIF_DEBUGLEVEL >= ERTS_PROCS_DBGLVL_CHK_FOUND_PIDS
-static void debug_processes_check_found_pid(ErtsProcessesBifData *pbdp,
-					    Eterm pid,
-					    Uint64 ic,
-					    int pid_should_be_found);
-#endif
-#if ERTS_PROCESSES_BIF_DEBUGLEVEL >= ERTS_PROCS_DBGLVL_CHK_TERM_PROC_LIST
-static void debug_processes_check_term_proc_list(void);
-static void debug_processes_check_term_proc_free_list(ErtsTermProcElement *tpep);
-#endif
-
-static void
-save_terminating_process(Process *p)
-{
-    ErtsTermProcElement *tpep = erts_alloc(ERTS_ALC_T_PROCS_TPROC_EL,
-					   sizeof(ErtsTermProcElement));
-    ERTS_PROCS_ASSERT(saved_term_procs.start && saved_term_procs.end);
-    ERTS_SMP_LC_ASSERT(erts_lc_rwmtx_is_rwlocked(&erts_proc_tab_rwmtx));
-
-    ERTS_PROCS_DBG_CHK_TPLIST();
-
-    tpep->prev = saved_term_procs.end;
-    tpep->next = NULL;
-    tpep->ix = internal_pid_index(p->id);
-    tpep->u.process.pid = p->id;
-    tpep->u.process.spawned = p->started_interval;
-    tpep->u.process.exited = get_proc_interval();
-
-    saved_term_procs.end->next = tpep;
-    saved_term_procs.end = tpep;
-
-    ERTS_PROCS_DBG_CHK_TPLIST();
-
-    ERTS_PROCS_ASSERT(tpep->prev->ix >= 0
-		      ? (tpep->u.process.exited
-			 >= tpep->prev->u.process.exited)
-		      : (tpep->u.process.exited
-			 >= tpep->prev->u.bif_invocation.interval));
-}
-
-static void
-cleanup_processes_bif_data(Binary *bp)
-{
-    ErtsProcessesBifData *pbdp = ERTS_MAGIC_BIN_DATA(bp);
-
-    ERTS_PROCS_DBG_TRACE(pbdp->debug.caller, cleanup_processes_bif_data, call);
-
-    if (pbdp->state != INITIALIZING) {
-
-	if (pbdp->chunk) {
-	    erts_free(ERTS_ALC_T_PROCS_CNKINF, pbdp->chunk);
-	    pbdp->chunk = NULL;
-	}
-	if (pbdp->pid) {
-	    erts_free(ERTS_ALC_T_PROCS_PIDS, pbdp->pid);
-	    pbdp->pid = NULL;
-	}
-
-#if ERTS_PROCESSES_BIF_DEBUGLEVEL >= ERTS_PROCS_DBGLVL_CHK_FOUND_PIDS
-	if (pbdp->debug.pid_started) {
-	    erts_free(ERTS_ALC_T_PROCS_PIDS, pbdp->debug.pid_started);
-	    pbdp->debug.pid_started = NULL;
-	}
-#endif
-
-	if (pbdp->bif_invocation) {
-	    ErtsTermProcElement *tpep;
-
-	    erts_smp_rwmtx_rwlock(&erts_proc_tab_rwmtx);
-
-	    ERTS_PROCS_DBG_TRACE(pbdp->debug.caller,
-				 cleanup_processes_bif_data,
-				 term_proc_cleanup);
-
-	    tpep = pbdp->bif_invocation;
-	    pbdp->bif_invocation = NULL;
-
-	    ERTS_PROCS_DBG_CHK_TPLIST();
-
-	    if (tpep->prev) {
-		/*
-		 * Only remove this bif invokation when we
-		 * have preceding invokations.
-		 */
-		tpep->prev->next = tpep->next;
-		if (tpep->next)
-		    tpep->next->prev = tpep->prev;
-		else {
-		    /*
-		     * At the time of writing this branch cannot be
-		     * reached. I don't want to remove this code though
-		     * since it may be possible to reach this line
-		     * in the future if the cleanup order in
-		     * erts_do_exit_process() is changed. The ASSERT(0)
-		     * is only here to make us aware that the reorder
-		     * has happened. /rickard
-		     */
-		    ASSERT(0);
-		    saved_term_procs.end = tpep->prev;
-		}
-		erts_free(ERTS_ALC_T_PROCS_TPROC_EL, tpep);
-	    }
-	    else {
-		/*
-		 * Free all elements until next bif invokation
-		 * is found.
-		 */
-		ERTS_PROCS_ASSERT(saved_term_procs.start == tpep);
-		do {
-		    ErtsTermProcElement *ftpep = tpep;
-		    tpep = tpep->next;
-		    erts_free(ERTS_ALC_T_PROCS_TPROC_EL, ftpep);
-		} while (tpep && tpep->ix >= 0);
-		saved_term_procs.start = tpep;
-		if (tpep)
-		    tpep->prev = NULL;
-		else
-		    saved_term_procs.end = NULL;
-	    }
-
-	    ERTS_PROCS_DBG_CHK_TPLIST();
-
-	    erts_smp_rwmtx_rwunlock(&erts_proc_tab_rwmtx);
-
-	}
-    }
-
-    ERTS_PROCS_DBG_TRACE(pbdp->debug.caller,
-			 cleanup_processes_bif_data,
-			 return);
-    ERTS_PROCS_DBG_CLEANUP(pbdp);
-}
-
-static int
-processes_bif_engine(Process *p, Eterm *res_accp, Binary *mbp)
-{
-    ErtsProcessesBifData *pbdp = ERTS_MAGIC_BIN_DATA(mbp);
-    int have_reds;
-    int reds;
-    int locked = 0;
-
-    do {
-	switch (pbdp->state) {
-	case INITIALIZING:
-	    pbdp->chunk = erts_alloc(ERTS_ALC_T_PROCS_CNKINF,
-				     (sizeof(ErtsProcessesBifChunkInfo)
-				      * processes_bif_tab_chunks));
-	    pbdp->tix = 0;
-	    pbdp->pid_ix = 0;
-
-	    erts_smp_rwmtx_rwlock(&erts_proc_tab_rwmtx);
-	    locked = 1;
-
-	    ERTS_PROCS_DBG_TRACE(p->id, processes_bif_engine, init);
-
-	    pbdp->pid_sz = erts_process_count();
-	    pbdp->pid = erts_alloc(ERTS_ALC_T_PROCS_PIDS,
-				   sizeof(Eterm)*pbdp->pid_sz);
-
-#if ERTS_PROCESSES_BIF_DEBUGLEVEL >= ERTS_PROCS_DBGLVL_CHK_FOUND_PIDS
-	    pbdp->debug.pid_started = erts_alloc(ERTS_ALC_T_PROCS_PIDS,
-						 sizeof(Uint64)*pbdp->pid_sz);
-#endif
-
-	    ERTS_PROCS_DBG_SAVE_PIDS(pbdp);
-
-	    if (processes_bif_tab_chunks == 1)
-		pbdp->bif_invocation = NULL;
-	    else {
-		/*
-		 * We will have to access the table multiple times
-		 * releasing the table lock in between chunks.
-		 */
-		pbdp->bif_invocation = erts_alloc(ERTS_ALC_T_PROCS_TPROC_EL,
-						  sizeof(ErtsTermProcElement));
-		pbdp->bif_invocation->ix = -1;
-		pbdp->bif_invocation->u.bif_invocation.interval
-		    = step_proc_interval();
-		ERTS_PROCS_DBG_CHK_TPLIST();
-
-		pbdp->bif_invocation->next = NULL;
-		if (saved_term_procs.end) {
-		    pbdp->bif_invocation->prev = saved_term_procs.end;
-		    saved_term_procs.end->next = pbdp->bif_invocation;
-		    ERTS_PROCS_ASSERT(saved_term_procs.start);
-		}
-		else {
-		    pbdp->bif_invocation->prev = NULL;
-		    saved_term_procs.start = pbdp->bif_invocation;
-		}
-		saved_term_procs.end = pbdp->bif_invocation;
-
-		ERTS_PROCS_DBG_CHK_TPLIST();
-
-	    }
-
-	    pbdp->state = INSPECTING_TABLE;
-	    /* Fall through */
-
-	case INSPECTING_TABLE: {
-	    int ix = pbdp->tix;
-	    int indices = ERTS_PROCESSES_BIF_TAB_CHUNK_SIZE;
-	    int cix = ix / ERTS_PROCESSES_BIF_TAB_CHUNK_SIZE;
-	    int end_ix = ix + indices;
-	    Uint64 *invocation_interval_p;
-
-	    invocation_interval_p
-		= (pbdp->bif_invocation
-		   ? &pbdp->bif_invocation->u.bif_invocation.interval
-		   : NULL);
-
-	    ERTS_PROCS_ASSERT(is_nil(*res_accp));
-	    if (!locked) {
-		erts_smp_rwmtx_rwlock(&erts_proc_tab_rwmtx);
-		locked = 1;
-	    }
-
-	    ERTS_SMP_LC_ASSERT(erts_lc_rwmtx_is_rwlocked(&erts_proc_tab_rwmtx));
-	    ERTS_PROCS_DBG_TRACE(p->id, processes_bif_engine, insp_table);
-
-	    if (cix != 0)
-		pbdp->chunk[cix].interval = step_proc_interval();
-	    else if (pbdp->bif_invocation)
-		pbdp->chunk[0].interval = *invocation_interval_p;
-	    /* else: interval is irrelevant */
-
-	    if (end_ix >= erts_proc.max) {
-		ERTS_PROCS_ASSERT(cix+1 == processes_bif_tab_chunks);
-		end_ix = erts_proc.max;
-		indices = end_ix - ix;
-		/* What to do when done with this chunk */
-		pbdp->state = (processes_bif_tab_chunks == 1
-			       ? BUILDING_RESULT
-			       : INSPECTING_TERMINATED_PROCESSES);
-	    }
-    
-	    for (; ix < end_ix; ix++) {
-		Process *rp = erts_pix2proc(ix);
-		if (rp
-		    && (!invocation_interval_p
-			|| rp->started_interval < *invocation_interval_p)) {
-		    ERTS_PROCS_ASSERT(is_internal_pid(rp->id));
-		    pbdp->pid[pbdp->pid_ix] = rp->id;
-
-#if ERTS_PROCESSES_BIF_DEBUGLEVEL >= ERTS_PROCS_DBGLVL_CHK_FOUND_PIDS
-		    pbdp->debug.pid_started[pbdp->pid_ix] = rp->started_interval;
-#endif
-
-		    pbdp->pid_ix++;
-		    ERTS_PROCS_ASSERT(pbdp->pid_ix <= pbdp->pid_sz);
-		}
-	    }
-
-	    pbdp->tix = end_ix;
-	    
-	    erts_smp_rwmtx_rwunlock(&erts_proc_tab_rwmtx);
-	    locked = 0;
-
-	    reds = indices/ERTS_PROCESSES_BIF_TAB_INSPECT_INDICES_PER_RED;
-	    BUMP_REDS(p, reds);
-
-	    have_reds = ERTS_BIF_REDS_LEFT(p);
-
-	    if (have_reds && pbdp->state == INSPECTING_TABLE) {
-		ix = pbdp->tix;
-		indices = ERTS_PROCESSES_BIF_TAB_CHUNK_SIZE;
-		end_ix = ix + indices;
-		if (end_ix > erts_proc.max) {
-		    end_ix = erts_proc.max;
-		    indices = end_ix - ix;
-		}
-		
-		reds = indices/ERTS_PROCESSES_BIF_TAB_INSPECT_INDICES_PER_RED;
-
-		/* Pretend we have no reds left if we haven't got enough
-		   reductions to complete next chunk */
-		if (reds > have_reds)
-		    have_reds = 0;
-	    }
-
-	    break;
-	}
-
-	case INSPECTING_TERMINATED_PROCESSES: {
-	    int i;
-	    int max_reds;
-	    int free_term_procs = 0;
-	    Uint64 invocation_interval;
-	    ErtsTermProcElement *tpep;
-	    ErtsTermProcElement *free_list = NULL;
-
-	    tpep = pbdp->bif_invocation;
-	    ERTS_PROCS_ASSERT(tpep);
-	    invocation_interval = tpep->u.bif_invocation.interval;
-
-	    max_reds = have_reds = ERTS_BIF_REDS_LEFT(p);
-	    if (max_reds > ERTS_PROCESSES_INSPECT_TERM_PROC_MAX_REDS)
-		max_reds = ERTS_PROCESSES_INSPECT_TERM_PROC_MAX_REDS;
-
-	    reds = 0;
-	    erts_smp_rwmtx_rwlock(&erts_proc_tab_rwmtx);
-	    ERTS_PROCS_DBG_TRACE(p->id, processes_bif_engine, insp_term_procs);
-
-	    ERTS_PROCS_DBG_CHK_TPLIST();
-
-	    if (tpep->prev)
-		tpep->prev->next = tpep->next;
-	    else {
-		ERTS_PROCS_ASSERT(saved_term_procs.start == tpep);
-		saved_term_procs.start = tpep->next;
-
-		if (saved_term_procs.start && saved_term_procs.start->ix >= 0) {
-		    free_list = saved_term_procs.start;
-		    free_term_procs = 1;
-		}
-	    }
-
-	    if (tpep->next)
-		tpep->next->prev = tpep->prev;
-	    else
-		saved_term_procs.end = tpep->prev;
-
-	    tpep = tpep->next;
-
-	    i = 0;
-	    while (reds < max_reds && tpep) {
-		if (tpep->ix < 0) {
-		    if (free_term_procs) {
-			ERTS_PROCS_ASSERT(free_list);
-			ERTS_PROCS_ASSERT(tpep->prev);
-
-			tpep->prev->next = NULL; /* end of free_list */
-			saved_term_procs.start = tpep;
-			tpep->prev = NULL;
-			free_term_procs = 0;
-		    }
-		}
-		else {
-		    int cix = tpep->ix/ERTS_PROCESSES_BIF_TAB_CHUNK_SIZE;
-		    Uint64 chunk_interval = pbdp->chunk[cix].interval;
-		    Eterm pid = tpep->u.process.pid;
-		    ERTS_PROCS_ASSERT(is_internal_pid(pid));
-
-		    if (tpep->u.process.spawned < invocation_interval) {
-			if (tpep->u.process.exited < chunk_interval) {
-			    ERTS_PROCS_DBG_CHK_PID_NOT_FOUND(pbdp,
-							     pid,
-							     tpep->u.process.spawned);
-			    pbdp->pid[pbdp->pid_ix] = pid;
-#if ERTS_PROCESSES_BIF_DEBUGLEVEL >= ERTS_PROCS_DBGLVL_CHK_FOUND_PIDS
-			    pbdp->debug.pid_started[pbdp->pid_ix]
-				= tpep->u.process.spawned;
-#endif
-			    pbdp->pid_ix++;
-			    ERTS_PROCS_ASSERT(pbdp->pid_ix <= pbdp->pid_sz);
-			}
-			else {
-			    ERTS_PROCS_DBG_CHK_PID_FOUND(pbdp,
-							 pid,
-							 tpep->u.process.spawned);
-			}
-		    }
-		    else {
-			ERTS_PROCS_DBG_CHK_PID_NOT_FOUND(pbdp,
-							 pid,
-							 tpep->u.process.spawned);
-		    }
-
-		    i++;
-		    if (i == ERTS_PROCESSES_BIF_INSPECT_TERM_PROC_PER_RED) {
-			reds++;
-			i = 0;
-		    }
-		    if (free_term_procs)
-			reds += ERTS_PROCESSES_BIF_TAB_FREE_TERM_PROC_REDS;
-		}
-		tpep = tpep->next;
-	    }
-
-	    if (free_term_procs) {
- 		ERTS_PROCS_ASSERT(free_list);
-		saved_term_procs.start = tpep;
-		if (!tpep)
-		    saved_term_procs.end = NULL;
-		else {
-		    ERTS_PROCS_ASSERT(tpep->prev);
-		    tpep->prev->next = NULL; /* end of free_list */
-		    tpep->prev = NULL;
-		}
-	    }
-
-	    if (!tpep) {
-		/* Done */
-		ERTS_PROCS_ASSERT(pbdp->pid_ix == pbdp->pid_sz);
-		pbdp->state = BUILDING_RESULT;
-		pbdp->bif_invocation->next = free_list;
-		free_list = pbdp->bif_invocation;
-		pbdp->bif_invocation = NULL;
-	    }
-	    else {
-		/* Link in bif_invocation again where we left off */
-		pbdp->bif_invocation->prev = tpep->prev;
-		pbdp->bif_invocation->next = tpep;
-		tpep->prev = pbdp->bif_invocation;
-		if (pbdp->bif_invocation->prev)
-		    pbdp->bif_invocation->prev->next = pbdp->bif_invocation;
-		else {
-		    ERTS_PROCS_ASSERT(saved_term_procs.start == tpep);
-		    saved_term_procs.start = pbdp->bif_invocation;
-		}
-	    }
-
-	    ERTS_PROCS_DBG_CHK_TPLIST();
-	    ERTS_PROCS_DBG_CHK_FREELIST(free_list);
-	    erts_smp_rwmtx_rwunlock(&erts_proc_tab_rwmtx);
-
-	    /*
-	     * We do the actual free of term proc structures now when we
-	     * have released the table lock instead of when we encountered
-	     * them. This since free() isn't for free and we don't want to
-	     * unnecessarily block other schedulers.
-	     */
-	    while (free_list) {
-		tpep = free_list;
-		free_list = tpep->next;
-		erts_free(ERTS_ALC_T_PROCS_TPROC_EL, tpep);
-	    }
-
-	    have_reds -= reds;
-	    if (have_reds < 0)	
-		have_reds = 0;
-	    BUMP_REDS(p, reds);
-	    break;
-	}
-
-	case BUILDING_RESULT: {
-	    int conses, ix, min_ix;
-	    Eterm *hp;
-	    Eterm res = *res_accp;
-
-	    ERTS_PROCS_DBG_VERIFY_PIDS(pbdp);
-	    ERTS_PROCS_DBG_CHK_RESLIST(res);
-
-	    ERTS_PROCS_DBG_TRACE(p->id, processes_bif_engine, begin_build_res);
-
-	    have_reds = ERTS_BIF_REDS_LEFT(p);
-	    conses = ERTS_PROCESSES_BIF_BUILD_RESULT_CONSES_PER_RED*have_reds;
-	    min_ix = pbdp->pid_ix - conses;
-	    if (min_ix < 0) {
-		min_ix = 0;
-		conses = pbdp->pid_ix;
-	    }
-
-	    hp = HAlloc(p, conses*2);
-	    ERTS_PROCS_DBG_SAVE_HEAP_ALLOC(pbdp, hp, conses*2);
-
-	    for (ix = pbdp->pid_ix - 1; ix >= min_ix; ix--) {
-		ERTS_PROCS_ASSERT(is_internal_pid(pbdp->pid[ix]));
-		res = CONS(hp, pbdp->pid[ix], res);
-		hp += 2;
-	    }
-
-	    ERTS_PROCS_DBG_VERIFY_HEAP_ALLOC_USED(pbdp, hp);
-
-	    pbdp->pid_ix = min_ix;
-	    if (min_ix == 0)
-		pbdp->state = RETURN_RESULT;
-	    else {
-		pbdp->pid_sz = min_ix;
-		pbdp->pid = erts_realloc(ERTS_ALC_T_PROCS_PIDS,
-					 pbdp->pid,
-					 sizeof(Eterm)*pbdp->pid_sz);
-#if ERTS_PROCESSES_BIF_DEBUGLEVEL >= ERTS_PROCS_DBGLVL_CHK_FOUND_PIDS
-		pbdp->debug.pid_started = erts_realloc(ERTS_ALC_T_PROCS_PIDS,
-						       pbdp->debug.pid_started,
-						       (sizeof(Uint64)
-							* pbdp->pid_sz));
-#endif
-	    }
-	    reds = conses/ERTS_PROCESSES_BIF_BUILD_RESULT_CONSES_PER_RED;
-	    BUMP_REDS(p, reds);
-	    have_reds -= reds;
-
-	    ERTS_PROCS_DBG_CHK_RESLIST(res);
-	    ERTS_PROCS_DBG_TRACE(p->id, processes_bif_engine, end_build_res);
-	    *res_accp = res;
-	    break;
-	}
-	case RETURN_RESULT:
-	    cleanup_processes_bif_data(mbp);
-	    return 1;
-
-	default:
-	    erl_exit(ERTS_ABORT_EXIT,
-		     "erlang:processes/0: Invalid state: %d\n",
-		     (int) pbdp->state);
-	}
-
-	
-    } while (have_reds || pbdp->state == RETURN_RESULT);
-
-    return 0;
-}
-
-/*
- * processes_trap/2 is a hidden BIF that processes/0 traps to.
- */
-
-static BIF_RETTYPE processes_trap(BIF_ALIST_2)
-{
-    Eterm res_acc;
-    Binary *mbp;
-
-    /*
-     * This bif cannot be called from erlang code. It can only be
-     * trapped to from processes/0; therefore, a bad argument
-     * is a processes/0 internal error.
-     */
-
-    ERTS_PROCS_DBG_TRACE(BIF_P->id, processes_trap, call);
-    ERTS_PROCS_ASSERT(is_nil(BIF_ARG_1) || is_list(BIF_ARG_1));
-
-    res_acc = BIF_ARG_1;
-
-    ERTS_PROCS_ASSERT(ERTS_TERM_IS_MAGIC_BINARY(BIF_ARG_2));
-
-    mbp = ((ProcBin *) binary_val(BIF_ARG_2))->val;
-
-    ERTS_PROCS_ASSERT(ERTS_MAGIC_BIN_DESTRUCTOR(mbp)
-		      == cleanup_processes_bif_data);
-    ERTS_PROCS_ASSERT(
-	((ErtsProcessesBifData *) ERTS_MAGIC_BIN_DATA(mbp))->debug.caller
-	== BIF_P->id);
-
-    if (processes_bif_engine(BIF_P, &res_acc, mbp)) {
-	ERTS_PROCS_DBG_TRACE(BIF_P->id, processes_trap, return);
-	BIF_RET(res_acc);
-    }
-    else {
-	ERTS_PROCS_DBG_TRACE(BIF_P->id, processes_trap, trap);
-	ERTS_BIF_YIELD2(&processes_trap_export, BIF_P, res_acc, BIF_ARG_2);
-    }
-}
-
-
-
-/*
- * The actual processes/0 BIF.
- */
-
-BIF_RETTYPE processes_0(BIF_ALIST_0)
-{
-    /*
-     * A requirement: The list of pids returned should be a consistent
-     *                snapshot of all processes existing at some point
-     *                in time during the execution of processes/0. Since
-     *                processes might terminate while processes/0 is
-     *                executing, we have to keep track of terminated
-     *                processes and add them to the result. We also
-     *                ignore processes created after processes/0 has
-     *                begun executing.
-     */
-    Eterm res_acc = NIL;
-    Binary *mbp = erts_create_magic_binary(sizeof(ErtsProcessesBifData),
-					   cleanup_processes_bif_data);
-    ErtsProcessesBifData *pbdp = ERTS_MAGIC_BIN_DATA(mbp);
-
-    ERTS_PROCS_DBG_TRACE(BIF_P->id, processes_0, call);
-    pbdp->state = INITIALIZING;
-    ERTS_PROCS_DBG_INIT(BIF_P, pbdp);
-
-    if (ERTS_BIF_REDS_LEFT(BIF_P) >= ERTS_PROCESSES_BIF_MIN_START_REDS
-	&& processes_bif_engine(BIF_P, &res_acc, mbp)) {
-	erts_bin_free(mbp);
-	ERTS_PROCS_DBG_CHK_RESLIST(res_acc);
-	ERTS_PROCS_DBG_TRACE(BIF_P->id, processes_0, return);
-	BIF_RET(res_acc);
-    }
-    else {
-	Eterm *hp;
-	Eterm magic_bin;
-	ERTS_PROCS_DBG_CHK_RESLIST(res_acc);
-	hp = HAlloc(BIF_P, PROC_BIN_SIZE);
-	ERTS_PROCS_DBG_SAVE_HEAP_ALLOC(pbdp, hp, PROC_BIN_SIZE);
-	magic_bin = erts_mk_magic_binary_term(&hp, &MSO(BIF_P), mbp);
-	ERTS_PROCS_DBG_VERIFY_HEAP_ALLOC_USED(pbdp, hp);
-	ERTS_PROCS_DBG_TRACE(BIF_P->id, processes_0, trap);
-	ERTS_BIF_YIELD2(&processes_trap_export, BIF_P, res_acc, magic_bin);
-    }
-}
-
-static void
-init_processes_bif(void)
-{
-    saved_term_procs.start = NULL;
-    saved_term_procs.end = NULL;
-    processes_bif_tab_chunks = (((erts_proc.max - 1)
-				 / ERTS_PROCESSES_BIF_TAB_CHUNK_SIZE)
-				+ 1);
-
-    /* processes_trap/2 is a hidden BIF that the processes/0 BIF traps to. */
-    erts_init_trap_export(&processes_trap_export, am_erlang, am_processes_trap, 2,
-			  &processes_trap);
-
-}
-
-/*
- * Debug stuff
- */
-
-#if defined(ERTS_SMP) && defined(ERTS_ENABLE_LOCK_CHECK)
-int
-erts_dbg_check_halloc_lock(Process *p)
-{
-    if (ERTS_PROC_LOCK_MAIN & erts_proc_lc_my_proc_locks(p))
-	return 1;
-    if (p->id == ERTS_INVALID_PID)
-	return 1;
-    if (p->scheduler_data && p == p->scheduler_data->match_pseudo_process)
-	return 1;
-    if (erts_thr_progress_is_blocking())
-	return 1;
-    return 0;
-}
-#endif
-
-Eterm
-erts_debug_processes(Process *c_p)
-{
-    /* This is the old processes/0 BIF. */
-    int i;
-    Uint need;
-    Eterm res;
-    Eterm* hp;
-    Process *p;
-    Eterm *hp_end;
-
-    erts_smp_rwmtx_rwlock(&erts_proc_tab_rwmtx);
-
-    res = NIL;
-    need = erts_process_count() * 2;
-    hp = HAlloc(c_p, need); /* we need two heap words for each pid */
-    hp_end = hp + need;
-     
-    /* make the list by scanning bakward */
-
-
-    for (i = erts_proc.max-1; i >= 0; i--) {
-	p = erts_pix2proc(i);
-	if (p) {
-	    res = CONS(hp, p->id, res);
-	    hp += 2;
-	}
-    }
-
-    erts_smp_rwmtx_rwunlock(&erts_proc_tab_rwmtx);
-
-    HRelease(c_p, hp_end, hp);
-
-    return res;
-}
-
-Eterm
-erts_debug_processes_bif_info(Process *c_p)
-{
-    ERTS_DECL_AM(processes_bif_info);
-    Eterm elements[] = {
-	AM_processes_bif_info,
-	make_small((Uint) ERTS_PROCESSES_BIF_MIN_START_REDS),
-	make_small((Uint) processes_bif_tab_chunks),
-	make_small((Uint) ERTS_PROCESSES_BIF_TAB_CHUNK_SIZE),
-	make_small((Uint) ERTS_PROCESSES_BIF_TAB_INSPECT_INDICES_PER_RED),
-	make_small((Uint) ERTS_PROCESSES_BIF_TAB_FREE_TERM_PROC_REDS),
-	make_small((Uint) ERTS_PROCESSES_BIF_INSPECT_TERM_PROC_PER_RED),
-	make_small((Uint) ERTS_PROCESSES_INSPECT_TERM_PROC_MAX_REDS),
-	make_small((Uint) ERTS_PROCESSES_BIF_BUILD_RESULT_CONSES_PER_RED),
-	make_small((Uint) ERTS_PROCESSES_BIF_DEBUGLEVEL)
-    };
-    Uint sz = 0;
-    Eterm *hp;
-    (void) erts_bld_tuplev(NULL, &sz, sizeof(elements)/sizeof(Eterm), elements);
-    hp = HAlloc(c_p, sz);
-    return erts_bld_tuplev(&hp, NULL, sizeof(elements)/sizeof(Eterm), elements);
-}
-
-#if ERTS_PROCESSES_BIF_DEBUGLEVEL >= ERTS_PROCS_DBGLVL_CHK_FOUND_PIDS
-static void
-debug_processes_check_found_pid(ErtsProcessesBifData *pbdp,
-				Eterm pid,
-				Uint64 ic,
-				int pid_should_be_found)
-{
-    int i;
-    for (i = 0; i < pbdp->pid_ix; i++) {
-	if (pbdp->pid[i] == pid && pbdp->debug.pid_started[i] == ic) {
-	    ERTS_PROCS_ASSERT(pid_should_be_found);
-	    return;
-	}
-    }
-    ERTS_PROCS_ASSERT(!pid_should_be_found);
-}
-#endif
-
-#if ERTS_PROCESSES_BIF_DEBUGLEVEL >= ERTS_PROCS_DBGLVL_CHK_RESLIST
-static void
-debug_processes_check_res_list(Eterm list)
-{
-    while (is_list(list)) {
-	Eterm* consp = list_val(list);
-	Eterm hd = CAR(consp);
-	ERTS_PROCS_ASSERT(is_internal_pid(hd));
-	list = CDR(consp);
-    }
-
-    ERTS_PROCS_ASSERT(is_nil(list));
-}
-#endif
-
-#if ERTS_PROCESSES_BIF_DEBUGLEVEL >= ERTS_PROCS_DBGLVL_CHK_PIDS
-
-static void
-debug_processes_save_all_pids(ErtsProcessesBifData *pbdp)
-{
-    int ix, tix, cpix;
-    pbdp->debug.correct_pids_verified = 0;
-    pbdp->debug.correct_pids = erts_alloc(ERTS_ALC_T_PROCS_PIDS,
-					  sizeof(Eterm)*pbdp->pid_sz);
-
-    for (tix = 0, cpix = 0; tix < erts_proc.max; tix++) {
-	Process *rp = erts_pix2proc(tix);
-	if (rp) {
-	    ERTS_PROCS_ASSERT(is_internal_pid(rp->id));
-	    pbdp->debug.correct_pids[cpix++] = rp->id;
-	    ERTS_PROCS_ASSERT(cpix <= pbdp->pid_sz);
-	}
-    }
-    ERTS_PROCS_ASSERT(cpix == pbdp->pid_sz);
-
-    for (ix = 0; ix < pbdp->pid_sz; ix++)
-	pbdp->pid[ix] = make_small(ix);
-}
-
-static void
-debug_processes_verify_all_pids(ErtsProcessesBifData *pbdp)
-{
-    int ix, cpix;
-
-    ERTS_PROCS_ASSERT(pbdp->pid_ix == pbdp->pid_sz);
-
-    for (ix = 0; ix < pbdp->pid_sz; ix++) {
-	int found = 0;
-	Eterm pid = pbdp->pid[ix];
-	ERTS_PROCS_ASSERT(is_internal_pid(pid));
-	for (cpix = ix; cpix < pbdp->pid_sz; cpix++) {
-	    if (pbdp->debug.correct_pids[cpix] == pid) {
-		pbdp->debug.correct_pids[cpix] = NIL;
-		found = 1;
-		break;
-	    }
-	}
-	if (!found) {
-	    for (cpix = 0; cpix < ix; cpix++) {
-		if (pbdp->debug.correct_pids[cpix] == pid) {
-		    pbdp->debug.correct_pids[cpix] = NIL;
-		    found = 1;
-		    break;
-		}
-	    }
-	}
-	ERTS_PROCS_ASSERT(found);
-    }
-    pbdp->debug.correct_pids_verified = 1;
-
-    erts_free(ERTS_ALC_T_PROCS_PIDS, pbdp->debug.correct_pids);
-    pbdp->debug.correct_pids = NULL;
-}
-#endif /* ERTS_PROCESSES_BIF_DEBUGLEVEL >= ERTS_PROCS_DBGLVL_CHK_PIDS */
-
-#if ERTS_PROCESSES_BIF_DEBUGLEVEL >= ERTS_PROCS_DBGLVL_CHK_TERM_PROC_LIST
-static void
-debug_processes_check_term_proc_list(void)
-{
-    ERTS_SMP_LC_ASSERT(erts_lc_rwmtx_is_rwlocked(&erts_proc_tab_rwmtx));
-    if (!saved_term_procs.start)
-	ERTS_PROCS_ASSERT(!saved_term_procs.end);
-    else {
-	Uint64 curr_interval = get_proc_interval();
-	Uint64 *prev_x_interval_p = NULL;
-	ErtsTermProcElement *tpep;
-
-	for (tpep = saved_term_procs.start; tpep; tpep = tpep->next) {
-	    if (!tpep->prev)
-		ERTS_PROCS_ASSERT(saved_term_procs.start == tpep);
-	    else
-		ERTS_PROCS_ASSERT(tpep->prev->next == tpep);
-	    if (!tpep->next)
-		ERTS_PROCS_ASSERT(saved_term_procs.end == tpep);
-	    else
-		ERTS_PROCS_ASSERT(tpep->next->prev == tpep);
-	    if (tpep->ix < 0) {
-		Uint64 interval = tpep->u.bif_invocation.interval;
-		ERTS_PROCS_ASSERT(interval <= curr_interval);
-	    }
-	    else {
-		Uint64 s_interval = tpep->u.process.spawned;
-		Uint64 x_interval = tpep->u.process.exited;
-		
-		ERTS_PROCS_ASSERT(s_interval <= x_interval);
-		if (prev_x_interval_p)
-		    ERTS_PROCS_ASSERT(*prev_x_interval_p <= x_interval);
-		prev_x_interval_p = &tpep->u.process.exited;
-		ERTS_PROCS_ASSERT(is_internal_pid(tpep->u.process.pid));
-		ERTS_PROCS_ASSERT(tpep->ix
-				  == internal_pid_index(tpep->u.process.pid));
-	    }
-	}
-	
-    }
-}
-
-static void
-debug_processes_check_term_proc_free_list(ErtsTermProcElement *free_list)
-{
-    if (saved_term_procs.start) {
-	ErtsTermProcElement *ftpep;
-	ErtsTermProcElement *tpep;
-
-	for (ftpep = free_list; ftpep; ftpep = ftpep->next) {
-	    for (tpep = saved_term_procs.start; tpep; tpep = tpep->next)
-		ERTS_PROCS_ASSERT(ftpep != tpep);
-	}
-    }
-}
-
-#endif
-
-#if ERTS_PROCESSES_BIF_DEBUGLEVEL != 0
-
-static void
-debug_processes_assert_error(char* expr, char* file, int line)
-{   
-    fflush(stdout);
-    erts_fprintf(stderr, "%s:%d: Assertion failed: %s\n", file, line, expr);
-    fflush(stderr);
-    abort();
-}
-
-#endif
-
-/*                                                                           *\
- * End of the processes/0 BIF implementation.                                *
-\* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
-
 /*
  * A nice system halt closing all open port goes as follows:
  * 1) This function schedules the aux work ERTS_SSI_AUX_WORK_REAP_PORTS
@@ -10499,3 +9043,19 @@ void erl_halt(int code)
 	notify_reap_ports_relb();
     }
 }
+
+#if defined(ERTS_SMP) && defined(ERTS_ENABLE_LOCK_CHECK)
+int
+erts_dbg_check_halloc_lock(Process *p)
+{
+    if (ERTS_PROC_LOCK_MAIN & erts_proc_lc_my_proc_locks(p))
+	return 1;
+    if (p->common.id == ERTS_INVALID_PID)
+	return 1;
+    if (p->scheduler_data && p == p->scheduler_data->match_pseudo_process)
+	return 1;
+    if (erts_thr_progress_is_blocking())
+	return 1;
+    return 0;
+}
+#endif
diff --git a/erts/emulator/beam/erl_process.h b/erts/emulator/beam/erl_process.h
index e789c873fb..6d1032c292 100644
--- a/erts/emulator/beam/erl_process.h
+++ b/erts/emulator/beam/erl_process.h
@@ -42,6 +42,9 @@ typedef struct process Process;
 #include "erl_process_lock.h" /* Only pull out important types... */
 #undef ERTS_PROCESS_LOCK_ONLY_PROC_LOCK_TYPE__
 
+#define ERL_PORT_GET_PORT_TYPE_ONLY__
+#include "erl_port.h"
+#undef ERL_PORT_GET_PORT_TYPE_ONLY__
 #include "erl_vm.h"
 #include "erl_smp.h"
 #include "erl_message.h"
@@ -66,11 +69,10 @@ typedef struct process Process;
 #undef ERL_THR_PROGRESS_TSD_TYPE_ONLY
 
 struct ErtsNodesMonitor_;
-struct port;
 
 #define ERTS_MAX_NO_OF_SCHEDULERS 1024
 
-#define ERTS_DEFAULT_MAX_PROCESSES (1 << 15)
+#define ERTS_DEFAULT_MAX_PROCESSES (1 << 18)
 
 #define ERTS_HEAP_ALLOC(Type, Size)					\
      erts_alloc((Type), (Size))
@@ -205,32 +207,10 @@ extern int erts_sched_thread_suggested_stack_size;
     ((Uint32) erts_smp_atomic32_read_nob(&(RQ)->flags))
 #define ERTS_RUNQ_FLGS_GET_MB(RQ)					\
     ((Uint32) erts_smp_atomic32_read_mb(&(RQ)->flags))
-#define ERTS_RUNQ_FLGS_MASK_SET(RQ, MSK, FLGS)		  		\
-    ((Uint32) erts_smp_atomic32_mask_set_relb(&(RQ)->flags, 		\
-					      (erts_aint32_t) (MSK),	\
-					      (erts_aint32_t) (FLGS)))
-
-ERTS_GLB_INLINE erts_aint32_t
-erts_smp_atomic32_mask_set_relb(erts_smp_atomic32_t *a32p,
-				erts_aint32_t mask,
-				erts_aint32_t set);
-#if ERTS_GLB_INLINE_INCL_FUNC_DEF
-ERTS_GLB_INLINE erts_aint32_t
-erts_smp_atomic32_mask_set_relb(erts_smp_atomic32_t *a32p,
-				erts_aint32_t mask,
-				erts_aint32_t set)
-{
-    erts_aint32_t act = erts_smp_atomic32_read_nob(a32p);
-    while (1) {
-	erts_aint32_t exp = act;
-	erts_aint32_t new = exp & ~mask;
-	new |= (mask & set);
-	act = erts_smp_atomic32_cmpxchg_relb(a32p, new, exp);
-	if (act == exp)
-	    return act;
-    }
-}	
-#endif
+#define ERTS_RUNQ_FLGS_READ_BSET(RQ, MSK, FLGS)		  		\
+    ((Uint32) erts_smp_atomic32_read_bset_relb(&(RQ)->flags, 		\
+					       (erts_aint32_t) (MSK),	\
+					       (erts_aint32_t) (FLGS)))
 
 typedef enum {
     ERTS_SCHDLR_SSPND_DONE_MSCHED_BLOCKED,
@@ -311,6 +291,7 @@ struct ErtsProcList_ {
     Eterm pid;
     Uint64 started_interval;
     ErtsProcList* next;
+    ErtsProcList* prev;
 };
 
 typedef struct ErtsMiscOpList_ ErtsMiscOpList;
@@ -401,8 +382,8 @@ struct ErtsRunQueue_ {
 
     struct {
 	ErtsRunQueueInfo info;
-	struct port *start;
-	struct port *end;
+	Port *start;
+	Port *end;
     } ports;
 };
 
@@ -512,7 +493,7 @@ struct ErtsSchedulerData_ {
     ErtsSchedulerSleepInfo *ssi;
     Process *current_process;
     Uint no;			/* Scheduler number */
-    struct port *current_port;
+    Port *current_port;
     ErtsRunQueue *run_queue;
     int virtual_reds;
     int cpu_id;			/* >= 0 when bound */
@@ -737,8 +718,8 @@ struct ErtsPendingSuspend_ {
 #  define BIN_OLD_VHEAP(p)    (p)->bin_old_vheap
 
 struct process {
-    Eterm id;			/* The pid of this process
-				   (need to be first in struct) */
+    ErtsPTabElementCommon common; /* *Need* to be first in struct */
+
     /* All fields in the PCB that differs between different heap
      * architectures, have been moved to the end of this struct to
      * make sure that as few offsets as possible differ. Different
@@ -782,12 +763,8 @@ struct process {
 				 * Only valid for the current process.
 				 */
     Uint32 rcount;		/* suspend count */
-    int  prio;			/* Priority of process */
     int  schedule_count;	/* Times left to reschedule a low prio process */
     Uint reds;			/* No of reductions for this process  */
-    Eterm tracer_proc;		/* If proc is traced, this is the tracer
-				   (can NOT be boxed) */
-    Uint trace_flags;		/* Trace flags (used to be in flags) */
     Eterm group_leader;		/* Pid in charge
 				   (can be boxed) */
     Uint flags;			/* Trap exit, etc (no trace flags anymore) */
@@ -797,10 +774,6 @@ struct process {
 
     Process *next;		/* Pointer to next process in run queue */
 
-    struct reg_proc *reg;	/* NULL iff not registered */
-    ErtsLink *nlinks;
-    ErtsMonitor *monitors;      /* The process monitors, both ends */
-
     struct ErtsNodesMonitor_ *nodes_monitors;
 
     ErtsSuspendMonitor *suspend_monitors; /* Processes suspended by
@@ -809,7 +782,10 @@ struct process {
 
     ErlMessageQueue msg;	/* Message queue */
 
-    ErtsBifTimer *bif_timers;	/* Bif timers aiming at this process */
+    union {
+	ErtsBifTimer *bif_timers;	/* Bif timers aiming at this process */
+	void *terminate;
+    } u;
 
     ProcDict  *dictionary;       /* Process dictionary, may be NULL */
 
@@ -834,7 +810,6 @@ struct process {
      */
     Eterm parent;		/* Pid of process that created this process. */
     erts_approx_time_t approx_started; /* Time when started. */
-    Uint64 started_interval;
 
     /* This is the place, where all fields that differs between memory
      * architectures, have gone to.
@@ -856,25 +831,11 @@ struct process {
     Uint64 bin_old_vheap_sz;	/* Virtual old heap block size for binaries */
     Uint64 bin_old_vheap;	/* Virtual old heap size for binaries */
 
-    union {
-	struct {
-#ifdef ERTS_SMP
-	    ErtsSmpPTimer *ptimer;
-	    ErlMessageInQueue msg_inq;
-	    ErtsPendExit pending_exit;
-#else
-	    ErlTimer tm;		/* Timer entry */
-#endif
-	} alive; /* when process is alive */
-#ifdef ERTS_SMP
-	ErtsThrPrgrLaterOp release_data; /* when releasing process struct */
-#endif
-	void *exit_data;	/* Misc data referred during termination */
-    } u;
-
     erts_smp_atomic32_t state;  /* Process state flags (see ERTS_PSFLG_*) */
 
 #ifdef ERTS_SMP
+    ErlMessageInQueue msg_inq;
+    ErtsPendExit pending_exit;
     erts_proc_lock_t lock;
     ErtsSchedulerData *scheduler_data;
     Eterm suspendee;
@@ -904,6 +865,8 @@ struct process {
 #endif
 };
 
+extern const Process erts_invalid_process;
+
 #ifdef CHECK_FOR_HOLES
 # define INIT_HOLE_CHECK(p)			\
 do {						\
@@ -1028,8 +991,6 @@ Eterm* erts_heap_alloc(Process* p, Uint need, Uint xtra);
 Eterm* erts_set_hole_marker(Eterm* ptr, Uint sz);
 #endif
 
-extern erts_smp_rwmtx_t erts_proc_tab_rwmtx;
-extern erts_smp_atomic_t *erts_proc_tab;
 extern Uint erts_default_process_flags;
 extern erts_smp_rwmtx_t erts_cpu_bind_rwmtx;
 /* If any of the erts_system_monitor_* variables are set (enabled),
@@ -1057,10 +1018,6 @@ struct erts_system_profile_flags_t {
     unsigned int exclusive : 1;
 };
 extern struct erts_system_profile_flags_t erts_system_profile_flags;
- 
-#define IS_TRACED(p)             ( (p)->tracer_proc != NIL )
-#define ARE_TRACE_FLAGS_ON(p,tf) ( ((p)->trace_flags & (tf|F_SENSITIVE)) == (tf) )
-#define IS_TRACED_FL(p,tf)       ( IS_TRACED(p) && ARE_TRACE_FLAGS_ON(p,tf) )
 
 /* process flags */
 #define F_HIBERNATE_SCHED    (1 <<  0) /* Schedule out after hibernate op */
@@ -1171,7 +1128,172 @@ Uint64 erts_step_proc_interval(void);
 
 ErtsProcList *erts_proclist_create(Process *);
 void erts_proclist_destroy(ErtsProcList *);
-int erts_proclist_same(ErtsProcList *, Process *);
+
+ERTS_GLB_INLINE int erts_proclist_same(ErtsProcList *, Process *);
+ERTS_GLB_INLINE void erts_proclist_store_first(ErtsProcList **, ErtsProcList *);
+ERTS_GLB_INLINE void erts_proclist_store_last(ErtsProcList **, ErtsProcList *);
+ERTS_GLB_INLINE ErtsProcList *erts_proclist_peek_first(ErtsProcList *);
+ERTS_GLB_INLINE ErtsProcList *erts_proclist_peek_last(ErtsProcList *);
+ERTS_GLB_INLINE ErtsProcList *erts_proclist_peek_next(ErtsProcList *, ErtsProcList *);
+ERTS_GLB_INLINE ErtsProcList *erts_proclist_peek_prev(ErtsProcList *, ErtsProcList *);
+ERTS_GLB_INLINE ErtsProcList *erts_proclist_fetch_first(ErtsProcList **);
+ERTS_GLB_INLINE ErtsProcList *erts_proclist_fetch_last(ErtsProcList **);
+ERTS_GLB_INLINE int erts_proclist_fetch(ErtsProcList **, ErtsProcList **);
+ERTS_GLB_INLINE void erts_proclist_remove(ErtsProcList **, ErtsProcList *);
+ERTS_GLB_INLINE int erts_proclist_is_empty(ErtsProcList *);
+ERTS_GLB_INLINE int erts_proclist_is_first(ErtsProcList *, ErtsProcList *);
+ERTS_GLB_INLINE int erts_proclist_is_last(ErtsProcList *, ErtsProcList *);
+
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+
+ERTS_GLB_INLINE int
+erts_proclist_same(ErtsProcList *plp, Process *p)
+{
+    return (plp->pid == p->common.id
+	    && (plp->started_interval
+		== p->common.u.alive.started_interval));
+}
+
+ERTS_GLB_INLINE void erts_proclist_store_first(ErtsProcList **list,
+					       ErtsProcList *element)
+{
+    if (!*list)
+	element->next = element->prev = element;
+    else {
+	element->prev = (*list)->prev;
+	element->next = *list;
+	element->prev->next = element;
+	element->next->prev = element;
+    }
+    *list = element;
+}
+
+ERTS_GLB_INLINE void erts_proclist_store_last(ErtsProcList **list,
+					      ErtsProcList *element)
+{
+    if (!*list) {
+	element->next = element->prev = element;
+	*list = element;
+    }
+    else {
+	element->prev = (*list)->prev;
+	element->next = *list;
+	element->prev->next = element;
+	element->next->prev = element;
+    }
+}
+
+ERTS_GLB_INLINE ErtsProcList *erts_proclist_peek_first(ErtsProcList *list)
+{
+    return list;
+}
+
+ERTS_GLB_INLINE ErtsProcList *erts_proclist_peek_last(ErtsProcList *list)
+{
+    if (!list)
+	return NULL;
+    else
+	return list->prev;
+}
+
+ERTS_GLB_INLINE ErtsProcList *erts_proclist_peek_next(ErtsProcList *list,
+						      ErtsProcList *element)
+{
+    ErtsProcList *next;
+    ASSERT(list && element);
+    next = element->next;
+    return list == next ? NULL : next;
+}
+
+ERTS_GLB_INLINE ErtsProcList *erts_proclist_peek_prev(ErtsProcList *list,
+						      ErtsProcList *element)
+{
+    ErtsProcList *prev;
+    ASSERT(list && element);
+    prev = element->prev;
+    return list == element ? NULL : prev;
+}
+
+ERTS_GLB_INLINE ErtsProcList *erts_proclist_fetch_first(ErtsProcList **list)
+{
+    if (!*list)
+	return NULL;
+    else {
+	ErtsProcList *res = *list;
+	if (res == *list)
+	    *list = NULL;
+	else
+	    *list = res->next;
+	res->next->prev = res->prev;
+	res->prev->next = res->next;
+	return res;
+    }
+}
+
+ERTS_GLB_INLINE ErtsProcList *erts_proclist_fetch_last(ErtsProcList **list)
+{
+    if (!*list)
+	return NULL;
+    else {
+	ErtsProcList *res = (*list)->prev;
+	if (res == *list)
+	    *list = NULL;
+	res->next->prev = res->prev;
+	res->prev->next = res->next;
+	return res;
+    }
+}
+
+ERTS_GLB_INLINE int erts_proclist_fetch(ErtsProcList **list_first,
+					ErtsProcList **list_last)
+{
+    if (!*list_first) {
+	if (list_last)
+	    *list_last = NULL;
+	return 0;
+    }
+    else {
+	if (list_last)
+	    *list_last = (*list_first)->prev;
+	(*list_first)->prev->next = NULL;
+	(*list_first)->prev = NULL;
+	return !0;
+    }
+}
+
+ERTS_GLB_INLINE void erts_proclist_remove(ErtsProcList **list,
+					  ErtsProcList *element)
+{
+    ASSERT(list && *list);
+    if (*list == element) {
+	*list = element->next;
+	if (*list == element)
+	    *list = NULL;
+    }
+    element->next->prev = element->prev;
+    element->prev->next = element->next;
+}
+
+ERTS_GLB_INLINE int erts_proclist_is_empty(ErtsProcList *list)
+{
+    return list == NULL;
+}
+
+ERTS_GLB_INLINE int erts_proclist_is_first(ErtsProcList *list,
+					   ErtsProcList *element)
+{
+    ASSERT(list && element);
+    return list == element;
+}
+
+ERTS_GLB_INLINE int erts_proclist_is_last(ErtsProcList *list,
+					  ErtsProcList *element)
+{
+    ASSERT(list && element);
+    return list->prev == element;
+}
+
+#endif
 
 int erts_sched_set_wakeup_other_thresold(char *str);
 int erts_sched_set_wakeup_other_type(char *str);
@@ -1221,7 +1343,7 @@ void erts_schedule_multi_misc_aux_work(int ignore_self,
 erts_aint32_t erts_set_aux_work_timeout(int, erts_aint32_t, int);
 void erts_sched_notify_check_cpu_bind(void);
 Uint erts_active_schedulers(void);
-void erts_init_process(int);
+void erts_init_process(int, int);
 Eterm erts_process_status(Process *, ErtsProcLocks, Process *, Eterm);
 Uint erts_run_queues_len(Uint *);
 void erts_add_to_runq(Process *);
@@ -1240,7 +1362,6 @@ void set_timer(Process*, Uint);
 void cancel_timer(Process*);
 /* Begin System profile */
 Uint erts_runnable_process_count(void);
-Uint erts_process_count(void);
 /* End System profile */
 void erts_init_empty_process(Process *p);
 void erts_cleanup_empty_process(Process* p);
@@ -1264,7 +1385,7 @@ Eterm erts_sched_stat_term(Process *p, int total);
 
 void erts_free_proc(Process *);
 
-void erts_suspend(Process*, ErtsProcLocks, struct port*);
+void erts_suspend(Process*, ErtsProcLocks, Port*);
 void erts_resume(Process*, ErtsProcLocks);
 int erts_resume_processes(ErtsProcList *);
 
@@ -1289,9 +1410,6 @@ void erts_deep_process_dump(int, void *);
 Eterm erts_get_reader_groups_map(Process *c_p);
 Eterm erts_debug_reader_groups_map(Process *c_p, int groups);
 
-Sint erts_test_next_pid(int, Uint);
-Eterm erts_debug_processes(Process *c_p);
-Eterm erts_debug_processes_bif_info(Process *c_p);
 Uint erts_debug_nbalance(void);
 int erts_debug_wait_deallocations(Process *c_p);
 
@@ -1603,7 +1721,7 @@ ERTS_GLB_INLINE
 Eterm erts_get_current_pid(void)
 {
     Process *proc = erts_get_current_process();
-    return proc ? proc->id : THE_NON_VALUE;
+    return proc ? proc->common.id : THE_NON_VALUE;
 }
 
 ERTS_GLB_INLINE
@@ -1812,10 +1930,10 @@ extern int erts_disable_proc_not_running_opt;
 
 
 /* Minimum NUMBER of processes for a small system to start */
-#ifdef ERTS_SMP
+#define ERTS_MIN_PROCESSES		1024
+#if defined(ERTS_SMP) && ERTS_MIN_PROCESSES < ERTS_NO_OF_PIX_LOCKS
+#undef ERTS_MIN_PROCESSES
 #define ERTS_MIN_PROCESSES		ERTS_NO_OF_PIX_LOCKS
-#else
-#define ERTS_MIN_PROCESSES		16
 #endif
 
 void erts_smp_notify_inc_runq(ErtsRunQueue *runq);
diff --git a/erts/emulator/beam/erl_process_dict.c b/erts/emulator/beam/erl_process_dict.c
index 93466da3aa..bf384c66e1 100644
--- a/erts/emulator/beam/erl_process_dict.c
+++ b/erts/emulator/beam/erl_process_dict.c
@@ -360,7 +360,7 @@ static void pd_hash_erase(Process *p, Eterm id, Eterm *ret)
 	erts_fprintf(stderr,
 		     "Process dictionary for process %T is broken, trying to "
 		     "display term found in line %d:\n"
-		     "%T\n", p->id, __LINE__, old);
+		     "%T\n", p->common.id, __LINE__, old);
 #endif
 	erl_exit(1, "Damaged process dictionary found during erase/1.");
     }
@@ -405,7 +405,7 @@ Eterm erts_pd_hash_get(Process *p, Eterm id)
 	erts_fprintf(stderr,
 		     "Process dictionary for process %T is broken, trying to "
 		     "display term found in line %d:\n"
-		     "%T\n", p->id, __LINE__, tmp);
+		     "%T\n", p->common.id, __LINE__, tmp);
 #endif
 	erl_exit(1, "Damaged process dictionary found during get/1.");
     }
@@ -614,7 +614,7 @@ static Eterm pd_hash_put(Process *p, Eterm id, Eterm value)
 	erts_fprintf(stderr,
 		     "Process dictionary for process %T is broken, trying to "
 		     "display term found in line %d:\n"
-		     "%T\n", p->id, __LINE__, old);
+		     "%T\n", p->common.id, __LINE__, old);
 #endif
 
 	erl_exit(1, "Damaged process dictionary found during put/2.");
diff --git a/erts/emulator/beam/erl_process_dump.c b/erts/emulator/beam/erl_process_dump.c
index 542c5ed0d9..ba74dfd6a1 100644
--- a/erts/emulator/beam/erl_process_dump.c
+++ b/erts/emulator/beam/erl_process_dump.c
@@ -60,11 +60,11 @@ extern BeamInstr beam_continue_exit[];
 void
 erts_deep_process_dump(int to, void *to_arg)
 {
-    int i;
+    int i, max = erts_ptab_max(&erts_proc);
 
     all_binaries = NULL;
     
-    for (i = 0; i < erts_max_processes; i++) {
+    for (i = 0; i < max; i++) {
 	Process *p = erts_pix2proc(i);
 	if (p && p->i != ENULL) {
 	    erts_aint32_t state = erts_smp_atomic32_read_acqb(&p->state);
@@ -85,8 +85,8 @@ dump_process_info(int to, void *to_arg, Process *p)
 
     ERTS_SMP_MSGQ_MV_INQ2PRIVQ(p);
 
-    if ((p->trace_flags & F_SENSITIVE) == 0 && p->msg.first) {
-	erts_print(to, to_arg, "=proc_messages:%T\n", p->id);
+    if ((ERTS_TRACE_FLAGS(p) & F_SENSITIVE) == 0 && p->msg.first) {
+	erts_print(to, to_arg, "=proc_messages:%T\n", p->common.id);
 	for (mp = p->msg.first; mp != NULL; mp = mp->next) {
 	    Eterm mesg = ERL_MESSAGE_TERM(mp);
 	    if (is_value(mesg))
@@ -100,21 +100,21 @@ dump_process_info(int to, void *to_arg, Process *p)
 	}
     }
 
-    if ((p->trace_flags & F_SENSITIVE) == 0) {
+    if ((ERTS_TRACE_FLAGS(p) & F_SENSITIVE) == 0) {
 	if (p->dictionary) {
-	    erts_print(to, to_arg, "=proc_dictionary:%T\n", p->id);
+	    erts_print(to, to_arg, "=proc_dictionary:%T\n", p->common.id);
 	    erts_deep_dictionary_dump(to, to_arg,
 				      p->dictionary, dump_element_nl);
 	}
     }
 
-    if ((p->trace_flags & F_SENSITIVE) == 0) {
-	erts_print(to, to_arg, "=proc_stack:%T\n", p->id);
+    if ((ERTS_TRACE_FLAGS(p) & F_SENSITIVE) == 0) {
+	erts_print(to, to_arg, "=proc_stack:%T\n", p->common.id);
 	for (sp = p->stop; sp < STACK_START(p); sp++) {
 	    yreg = stack_element_dump(to, to_arg, p, sp, yreg);
 	}
 
-	erts_print(to, to_arg, "=proc_heap:%T\n", p->id);
+	erts_print(to, to_arg, "=proc_heap:%T\n", p->common.id);
 	for (sp = p->stop; sp < STACK_START(p); sp++) {
 	    Eterm term = *sp;
 	    
diff --git a/erts/emulator/beam/erl_process_lock.c b/erts/emulator/beam/erl_process_lock.c
index 84a8270d06..2db5df06b4 100644
--- a/erts/emulator/beam/erl_process_lock.c
+++ b/erts/emulator/beam/erl_process_lock.c
@@ -66,8 +66,7 @@
 #endif
 
 #include "erl_process.h"
-
-const Process erts_proc_lock_busy = {ERTS_INVALID_PID};
+#include "erl_thr_progress.h"
 
 #ifdef ERTS_SMP
 
@@ -399,7 +398,7 @@ wait_for_locks(Process *p,
                ErtsProcLocks need_locks,
                ErtsProcLocks olflgs)
 {
-    erts_pix_lock_t *pix_lock = pixlck ? pixlck : ERTS_PID2PIXLOCK(p->id);
+    erts_pix_lock_t *pix_lock = pixlck ? pixlck : ERTS_PID2PIXLOCK(p->common.id);
     erts_tse_t *wtr;
 
     /* Acquire a waiter object on which this thread can wait. */
@@ -553,7 +552,7 @@ erts_proc_unlock_failed(Process *p,
 			erts_pix_lock_t *pixlck,
 			ErtsProcLocks wait_locks)
 {
-    erts_pix_lock_t *pix_lock = pixlck ? pixlck : ERTS_PID2PIXLOCK(p->id);
+    erts_pix_lock_t *pix_lock = pixlck ? pixlck : ERTS_PID2PIXLOCK(p->common.id);
 
 #if ERTS_PROC_LOCK_ATOMIC_IMPL
     erts_pix_lock(pix_lock);
@@ -580,7 +579,7 @@ erts_proc_lock_prepare_proc_lock_waiter(void)
  */
 
 static void
-proc_safelock(int is_sched,
+proc_safelock(int is_managed,
 	      Process *a_proc,
 	      ErtsProcLocks a_have_locks,
 	      ErtsProcLocks a_need_locks,
@@ -603,40 +602,40 @@ proc_safelock(int is_sched,
      * Locks with the same lock order should be locked on p1 before p2.
      */
     if (a_proc) {
-	if (a_proc->id < b_proc->id) {
+	if (a_proc->common.id < b_proc->common.id) {
 	    p1 = a_proc;
 #ifdef ERTS_ENABLE_LOCK_CHECK
-	    pid1 = a_proc->id;
+	    pid1 = a_proc->common.id;
 #endif
 	    need_locks1 = a_need_locks;
 	    have_locks1 = a_have_locks;
 	    p2 = b_proc;
 #ifdef ERTS_ENABLE_LOCK_CHECK
-	    pid2 = b_proc->id;
+	    pid2 = b_proc->common.id;
 #endif
 	    need_locks2 = b_need_locks;
 	    have_locks2 = b_have_locks;
 	}
-	else if (a_proc->id > b_proc->id) {
+	else if (a_proc->common.id > b_proc->common.id) {
 	    p1 = b_proc;
 #ifdef ERTS_ENABLE_LOCK_CHECK
-	    pid1 = b_proc->id;
+	    pid1 = b_proc->common.id;
 #endif
 	    need_locks1 = b_need_locks;
 	    have_locks1 = b_have_locks;
 	    p2 = a_proc;
 #ifdef ERTS_ENABLE_LOCK_CHECK
-	    pid2 = a_proc->id;
+	    pid2 = a_proc->common.id;
 #endif
 	    need_locks2 = a_need_locks;
 	    have_locks2 = a_have_locks;
 	}
 	else {
 	    ERTS_LC_ASSERT(a_proc == b_proc);
-	    ERTS_LC_ASSERT(a_proc->id == b_proc->id);
+	    ERTS_LC_ASSERT(a_proc->common.id == b_proc->common.id);
 	    p1 = a_proc;
 #ifdef ERTS_ENABLE_LOCK_CHECK
-	    pid1 = a_proc->id;
+	    pid1 = a_proc->common.id;
 #endif
 	    need_locks1 = a_need_locks | b_need_locks;
 	    have_locks1 = a_have_locks | b_have_locks;
@@ -651,7 +650,7 @@ proc_safelock(int is_sched,
     else {
 	p1 = b_proc;
 #ifdef ERTS_ENABLE_LOCK_CHECK
-	pid1 = b_proc->id;
+	pid1 = b_proc->common.id;
 #endif
 	need_locks1 = b_need_locks;
 	have_locks1 = b_have_locks;
@@ -706,7 +705,7 @@ proc_safelock(int is_sched,
 	if (unlock_locks) {
 	    have_locks1 &= ~unlock_locks;
 	    need_locks1 |= unlock_locks;
-	    if (!is_sched && !have_locks1) {
+	    if (!is_managed && !have_locks1) {
 		refc1 = 1;
 		erts_smp_proc_inc_refc(p1);
 	    }
@@ -716,7 +715,7 @@ proc_safelock(int is_sched,
 	if (unlock_locks) {
 	    have_locks2 &= ~unlock_locks;
 	    need_locks2 |= unlock_locks;
-	    if (!is_sched && !have_locks2) {
+	    if (!is_managed && !have_locks2) {
 		refc2 = 1;
 		erts_smp_proc_inc_refc(p2);
 	    }
@@ -797,7 +796,7 @@ proc_safelock(int is_sched,
     }
 #endif
 
-    if (!is_sched) {
+    if (!is_managed) {
 	if (refc1)
 	    erts_smp_proc_dec_refc(p1);
 	if (refc2)
@@ -830,7 +829,7 @@ erts_pid2proc_opt(Process *c_p,
 		  int flags)
 {
     Process *dec_refc_proc = NULL;
-    int need_ptl;
+    ErtsThrPrgrDelayHandle dhndl;
     ErtsProcLocks need_locks;
     Uint pix;
     Process *proc;
@@ -853,8 +852,8 @@ erts_pid2proc_opt(Process *c_p,
     ERTS_LC_ASSERT((pid_need_locks & ERTS_PROC_LOCKS_ALL) == pid_need_locks);
     need_locks = pid_need_locks;
 
-    if (c_p && c_p->id == pid) {
-	ASSERT(c_p->id != ERTS_INVALID_PID);
+    if (c_p && c_p->common.id == pid) {
+	ASSERT(c_p->common.id != ERTS_INVALID_PID);
 	ASSERT(c_p == erts_pix2proc(pix));
 
 	if (!(flags & ERTS_P2P_FLG_ALLOW_OTHER_X)
@@ -868,15 +867,12 @@ erts_pid2proc_opt(Process *c_p,
 	}
     }
 
-    need_ptl = !erts_get_scheduler_id();
-
-    if (need_ptl)
-	erts_smp_rwmtx_rwlock(&erts_proc_tab_rwmtx);
+    dhndl = erts_thr_progress_unmanaged_delay();
 
-    proc = (Process *) erts_smp_atomic_read_ddrb(&erts_proc.tab[pix]);
+    proc = (Process *) erts_ptab_pix2intptr_ddrb(&erts_proc, pix);
 
     if (proc) {
-	if (proc->id != pid)
+	if (proc->common.id != pid)
 	    proc = NULL;
 	else if (!need_locks) {
 	    if (flags & ERTS_P2P_FLG_SMP_INC_REFC)
@@ -935,6 +931,7 @@ erts_pid2proc_opt(Process *c_p,
 		if (flags & ERTS_P2P_FLG_TRY_LOCK)
 		    proc = ERTS_PROC_LOCK_BUSY;
 		else {
+		    int managed;
 		    if (flags & ERTS_P2P_FLG_SMP_INC_REFC)
 			erts_smp_proc_inc_refc(proc);
 
@@ -942,14 +939,21 @@ erts_pid2proc_opt(Process *c_p,
 		    erts_lcnt_proc_lock_unaquire(&proc->lock, lcnt_locks);
 #endif
 
-		    if (need_ptl) {
+		    managed = dhndl == ERTS_THR_PRGR_DHANDLE_MANAGED;
+		    if (!managed) {
 			erts_smp_proc_inc_refc(proc);
+			erts_thr_progress_unmanaged_continue(dhndl);
 			dec_refc_proc = proc;
-			erts_smp_rwmtx_rwunlock(&erts_proc_tab_rwmtx);
-			need_ptl = 0;
+
+			/*
+			 * We don't want to call
+			 * erts_thr_progress_unmanaged_continue()
+			 * again.
+			 */
+			dhndl = ERTS_THR_PRGR_DHANDLE_MANAGED;
 		    }
 
-		    proc_safelock(!need_ptl,
+		    proc_safelock(managed,
 				  c_p,
 				  c_p_have_locks,
 				  c_p_have_locks,
@@ -961,8 +965,8 @@ erts_pid2proc_opt(Process *c_p,
         }
     }
 
-    if (need_ptl)
-	erts_smp_rwmtx_rwunlock(&erts_proc_tab_rwmtx);
+    if (dhndl != ERTS_THR_PRGR_DHANDLE_MANAGED)
+	erts_thr_progress_unmanaged_continue(dhndl);
 
     if (need_locks
 	&& proc
@@ -970,7 +974,7 @@ erts_pid2proc_opt(Process *c_p,
 	&& (!(flags & ERTS_P2P_FLG_ALLOW_OTHER_X)
 	    ? ERTS_PROC_IS_EXITING(proc)
 	    : (proc
-	       != (Process *) erts_smp_atomic_read_nob(&erts_proc.tab[pix])))) {
+	       != (Process *) erts_ptab_pix2intptr_nob(&erts_proc, pix)))) {
 
 	erts_smp_proc_unlock(proc, need_locks);
 
@@ -1012,22 +1016,22 @@ erts_proc_lock_init(Process *p)
     erts_proc_lc_trylock(p, ERTS_PROC_LOCKS_ALL, 1);
 #endif
 #elif ERTS_PROC_LOCK_RAW_MUTEX_IMPL
-    erts_mtx_init_x(&p->lock.main, "proc_main", p->id);
+    erts_mtx_init_x(&p->lock.main, "proc_main", p->common.id);
     ethr_mutex_lock(&p->lock.main.mtx);
 #ifdef ERTS_ENABLE_LOCK_CHECK
     erts_lc_trylock(1, &p->lock.main.lc);
 #endif
-    erts_mtx_init_x(&p->lock.link, "proc_link", p->id);
+    erts_mtx_init_x(&p->lock.link, "proc_link", p->common.id);
     ethr_mutex_lock(&p->lock.link.mtx);
 #ifdef ERTS_ENABLE_LOCK_CHECK
     erts_lc_trylock(1, &p->lock.link.lc);
 #endif
-    erts_mtx_init_x(&p->lock.msgq, "proc_msgq", p->id);
+    erts_mtx_init_x(&p->lock.msgq, "proc_msgq", p->common.id);
     ethr_mutex_lock(&p->lock.msgq.mtx);
 #ifdef ERTS_ENABLE_LOCK_CHECK
     erts_lc_trylock(1, &p->lock.msgq.lc);
 #endif
-    erts_mtx_init_x(&p->lock.status, "proc_status", p->id);
+    erts_mtx_init_x(&p->lock.status, "proc_status", p->common.id);
     ethr_mutex_lock(&p->lock.status.mtx);
 #ifdef ERTS_ENABLE_LOCK_CHECK
     erts_lc_trylock(1, &p->lock.status.lc);
@@ -1064,11 +1068,11 @@ erts_proc_lock_fin(Process *p)
 #if ERTS_PROC_LOCK_OWN_IMPL && defined(ERTS_ENABLE_LOCK_COUNT)
 void erts_lcnt_proc_lock_init(Process *p) {
     if (erts_lcnt_rt_options & ERTS_LCNT_OPT_PROCLOCK) {
-    if (p->id != ERTS_INVALID_PID) {
-	erts_lcnt_init_lock_x(&(p->lock.lcnt_main),   "proc_main",   ERTS_LCNT_LT_PROCLOCK, p->id);
-	erts_lcnt_init_lock_x(&(p->lock.lcnt_msgq),   "proc_msgq",   ERTS_LCNT_LT_PROCLOCK, p->id);
-	erts_lcnt_init_lock_x(&(p->lock.lcnt_link),   "proc_link",   ERTS_LCNT_LT_PROCLOCK, p->id);
-	erts_lcnt_init_lock_x(&(p->lock.lcnt_status), "proc_status", ERTS_LCNT_LT_PROCLOCK, p->id);
+    if (p->common.id != ERTS_INVALID_PID) {
+	erts_lcnt_init_lock_x(&(p->lock.lcnt_main),   "proc_main",   ERTS_LCNT_LT_PROCLOCK, p->common.id);
+	erts_lcnt_init_lock_x(&(p->lock.lcnt_msgq),   "proc_msgq",   ERTS_LCNT_LT_PROCLOCK, p->common.id);
+	erts_lcnt_init_lock_x(&(p->lock.lcnt_link),   "proc_link",   ERTS_LCNT_LT_PROCLOCK, p->common.id);
+	erts_lcnt_init_lock_x(&(p->lock.lcnt_status), "proc_status", ERTS_LCNT_LT_PROCLOCK, p->common.id);
     } else {
 	erts_lcnt_init_lock(&(p->lock.lcnt_main),   "proc_main",   ERTS_LCNT_LT_PROCLOCK);
 	erts_lcnt_init_lock(&(p->lock.lcnt_msgq),   "proc_msgq",   ERTS_LCNT_LT_PROCLOCK);
@@ -1176,10 +1180,11 @@ void erts_lcnt_proc_trylock(erts_proc_lock_t *lock, ErtsProcLocks locks, int res
 }
 
 
-void erts_lcnt_enable_proc_lock_count(int enable) {
-    int i;
+void erts_lcnt_enable_proc_lock_count(int enable)
+{
+    int i, max = erts_ptab_max(&erts_proc);
 
-    for (i = 0; i < erts_max_processes; ++i) {
+    for (i = 0; i < max; ++i) {
 	Process* p = erts_pix2proc(i);
 	if (p) {
 	    if (enable) {
@@ -1208,7 +1213,7 @@ void
 erts_proc_lc_lock(Process *p, ErtsProcLocks locks)
 {
     erts_lc_lock_t lck = ERTS_LC_LOCK_INIT(-1,
-					   p->id,
+					   p->common.id,
 					   ERTS_LC_FLG_LT_PROCLOCK);
     if (locks & ERTS_PROC_LOCK_MAIN) {
 	lck.id = lc_id.proc_lock_main;
@@ -1232,7 +1237,7 @@ void
 erts_proc_lc_trylock(Process *p, ErtsProcLocks locks, int locked)
 {
     erts_lc_lock_t lck = ERTS_LC_LOCK_INIT(-1,
-					   p->id,
+					   p->common.id,
 					   ERTS_LC_FLG_LT_PROCLOCK);
     if (locks & ERTS_PROC_LOCK_MAIN) {
 	lck.id = lc_id.proc_lock_main;
@@ -1256,7 +1261,7 @@ void
 erts_proc_lc_unlock(Process *p, ErtsProcLocks locks)
 {
     erts_lc_lock_t lck = ERTS_LC_LOCK_INIT(-1,
-					   p->id,
+					   p->common.id,
 					   ERTS_LC_FLG_LT_PROCLOCK);
     if (locks & ERTS_PROC_LOCK_STATUS) {
 	lck.id = lc_id.proc_lock_status;
@@ -1283,7 +1288,7 @@ erts_proc_lc_might_unlock(Process *p, ErtsProcLocks locks)
 {
 #if ERTS_PROC_LOCK_OWN_IMPL
     erts_lc_lock_t lck = ERTS_LC_LOCK_INIT(-1,
-					   p->id,
+					   p->common.id,
 					   ERTS_LC_FLG_LT_PROCLOCK);
     if (locks & ERTS_PROC_LOCK_STATUS) {
 	lck.id = lc_id.proc_lock_status;
@@ -1318,7 +1323,7 @@ erts_proc_lc_require_lock(Process *p, ErtsProcLocks locks)
 {
 #if ERTS_PROC_LOCK_OWN_IMPL
     erts_lc_lock_t lck = ERTS_LC_LOCK_INIT(-1,
-					   p->id,
+					   p->common.id,
 					   ERTS_LC_FLG_LT_PROCLOCK);
     if (locks & ERTS_PROC_LOCK_MAIN) {
 	lck.id = lc_id.proc_lock_main;
@@ -1353,7 +1358,7 @@ erts_proc_lc_unrequire_lock(Process *p, ErtsProcLocks locks)
 {
 #if ERTS_PROC_LOCK_OWN_IMPL
     erts_lc_lock_t lck = ERTS_LC_LOCK_INIT(-1,
-					   p->id,
+					   p->common.id,
 					   ERTS_LC_FLG_LT_PROCLOCK);
     if (locks & ERTS_PROC_LOCK_STATUS) {
 	lck.id = lc_id.proc_lock_status;
@@ -1390,7 +1395,7 @@ erts_proc_lc_trylock_force_busy(Process *p, ErtsProcLocks locks)
 {
     if (locks & ERTS_PROC_LOCKS_ALL) {
 	erts_lc_lock_t lck = ERTS_LC_LOCK_INIT(-1,
-					       p->id,
+					       p->common.id,
 					       ERTS_LC_FLG_LT_PROCLOCK);
 
 	if (locks & ERTS_PROC_LOCK_MAIN)
@@ -1415,7 +1420,7 @@ void erts_proc_lc_chk_only_proc_main(Process *p)
 {
 #if ERTS_PROC_LOCK_OWN_IMPL
     erts_lc_lock_t proc_main = ERTS_LC_LOCK_INIT(lc_id.proc_lock_main,
-						 p->id,
+						 p->common.id,
 						 ERTS_LC_FLG_LT_PROCLOCK);
     erts_lc_check_exact(&proc_main, 1);
 #elif ERTS_PROC_LOCK_RAW_MUTEX_IMPL
@@ -1439,19 +1444,19 @@ erts_proc_lc_chk_have_proc_locks(Process *p, ErtsProcLocks locks)
 				    ERTS_PROC_LC_EMPTY_LOCK_INIT};
     if (locks & ERTS_PROC_LOCK_MAIN) {
 	have_locks[have_locks_len].id = lc_id.proc_lock_main;
-	have_locks[have_locks_len++].extra = p->id;
+	have_locks[have_locks_len++].extra = p->common.id;
     }
     if (locks & ERTS_PROC_LOCK_LINK) {
 	have_locks[have_locks_len].id = lc_id.proc_lock_link;
-	have_locks[have_locks_len++].extra = p->id;
+	have_locks[have_locks_len++].extra = p->common.id;
     }
     if (locks & ERTS_PROC_LOCK_MSGQ) {
 	have_locks[have_locks_len].id = lc_id.proc_lock_msgq;
-	have_locks[have_locks_len++].extra = p->id;
+	have_locks[have_locks_len++].extra = p->common.id;
     }
     if (locks & ERTS_PROC_LOCK_STATUS) {
 	have_locks[have_locks_len].id = lc_id.proc_lock_status;
-	have_locks[have_locks_len++].extra = p->id;
+	have_locks[have_locks_len++].extra = p->common.id;
     }
 #elif ERTS_PROC_LOCK_RAW_MUTEX_IMPL
     erts_lc_lock_t have_locks[4];
@@ -1484,35 +1489,35 @@ erts_proc_lc_chk_proc_locks(Process *p, ErtsProcLocks locks)
 
     if (locks & ERTS_PROC_LOCK_MAIN) {
 	have_locks[have_locks_len].id = lc_id.proc_lock_main;
-	have_locks[have_locks_len++].extra = p->id;
+	have_locks[have_locks_len++].extra = p->common.id;
     }
     else {
 	have_not_locks[have_not_locks_len].id = lc_id.proc_lock_main;
-	have_not_locks[have_not_locks_len++].extra = p->id;
+	have_not_locks[have_not_locks_len++].extra = p->common.id;
     }
     if (locks & ERTS_PROC_LOCK_LINK) {
 	have_locks[have_locks_len].id = lc_id.proc_lock_link;
-	have_locks[have_locks_len++].extra = p->id;
+	have_locks[have_locks_len++].extra = p->common.id;
     }
     else {
 	have_not_locks[have_not_locks_len].id = lc_id.proc_lock_link;
-	have_not_locks[have_not_locks_len++].extra = p->id;
+	have_not_locks[have_not_locks_len++].extra = p->common.id;
     }
     if (locks & ERTS_PROC_LOCK_MSGQ) {
 	have_locks[have_locks_len].id = lc_id.proc_lock_msgq;
-	have_locks[have_locks_len++].extra = p->id;
+	have_locks[have_locks_len++].extra = p->common.id;
     }
     else {
 	have_not_locks[have_not_locks_len].id = lc_id.proc_lock_msgq;
-	have_not_locks[have_not_locks_len++].extra = p->id;
+	have_not_locks[have_not_locks_len++].extra = p->common.id;
     }
     if (locks & ERTS_PROC_LOCK_STATUS) {
 	have_locks[have_locks_len].id = lc_id.proc_lock_status;
-	have_locks[have_locks_len++].extra = p->id;
+	have_locks[have_locks_len++].extra = p->common.id;
     }
     else {
 	have_not_locks[have_not_locks_len].id = lc_id.proc_lock_status;
-	have_not_locks[have_not_locks_len++].extra = p->id;
+	have_not_locks[have_not_locks_len++].extra = p->common.id;
     }
 #elif ERTS_PROC_LOCK_RAW_MUTEX_IMPL
     erts_lc_lock_t have_locks[4];
@@ -1547,16 +1552,16 @@ erts_proc_lc_my_proc_locks(Process *p)
     ErtsProcLocks res = 0;
 #if ERTS_PROC_LOCK_OWN_IMPL
     erts_lc_lock_t locks[4] = {ERTS_LC_LOCK_INIT(lc_id.proc_lock_main,
-						 p->id,
+						 p->common.id,
 						 ERTS_LC_FLG_LT_PROCLOCK),
 			       ERTS_LC_LOCK_INIT(lc_id.proc_lock_link,
-						 p->id,
+						 p->common.id,
 						 ERTS_LC_FLG_LT_PROCLOCK),
 			       ERTS_LC_LOCK_INIT(lc_id.proc_lock_msgq,
-						 p->id,
+						 p->common.id,
 						 ERTS_LC_FLG_LT_PROCLOCK),
 			       ERTS_LC_LOCK_INIT(lc_id.proc_lock_status,
-						 p->id,
+						 p->common.id,
 						 ERTS_LC_FLG_LT_PROCLOCK)};
 #elif ERTS_PROC_LOCK_RAW_MUTEX_IMPL
     erts_lc_lock_t locks[4] = {p->lock.main.lc,
diff --git a/erts/emulator/beam/erl_process_lock.h b/erts/emulator/beam/erl_process_lock.h
index 4aec19c8c3..9dd503f3cb 100644
--- a/erts/emulator/beam/erl_process_lock.h
+++ b/erts/emulator/beam/erl_process_lock.h
@@ -176,8 +176,8 @@ typedef struct erts_proc_lock_t_ {
  *   on multiple processes, locks on processes with low process ids
  *   have to be locked before locks on processes with high process
  *   ids. E.g., if the main and the message queue locks are to be
- *   locked on processes p1 and p2 and p1->id < p2->id, then locks
- *   should be locked in the following order:
+ *   locked on processes p1 and p2 and p1->common.id < p2->common.id,
+ *   then locks should be locked in the following order:
  *     1. main lock on p1
  *     2. main lock on p2
  *     3. message queue lock on p1
@@ -203,7 +203,7 @@ typedef struct erts_proc_lock_t_ {
 					 & ~ERTS_PROC_LOCK_MAIN)
 
 
-#define ERTS_PIX_LOCKS_BITS		8
+#define ERTS_PIX_LOCKS_BITS		10
 #define ERTS_NO_OF_PIX_LOCKS		(1 << ERTS_PIX_LOCKS_BITS)
 
 
@@ -767,7 +767,7 @@ erts_smp_proc_lock(Process *p, ErtsProcLocks locks)
 #if ERTS_PROC_LOCK_ATOMIC_IMPL
 			 NULL,
 #else
-			 ERTS_PID2PIXLOCK(p->id),
+			 ERTS_PID2PIXLOCK(p->common.id),
 #endif /*ERTS_PROC_LOCK_ATOMIC_IMPL*/
 			 locks, file, line);
 #elif defined(ERTS_SMP)
@@ -775,7 +775,7 @@ erts_smp_proc_lock(Process *p, ErtsProcLocks locks)
 #if ERTS_PROC_LOCK_ATOMIC_IMPL
 			 NULL,
 #else
-			 ERTS_PID2PIXLOCK(p->id),
+			 ERTS_PID2PIXLOCK(p->common.id),
 #endif /*ERTS_PROC_LOCK_ATOMIC_IMPL*/
 			 locks);
 #endif /*ERTS_SMP*/
@@ -789,7 +789,7 @@ erts_smp_proc_unlock(Process *p, ErtsProcLocks locks)
 #if ERTS_PROC_LOCK_ATOMIC_IMPL
 			   NULL,
 #else
-			   ERTS_PID2PIXLOCK(p->id),
+			   ERTS_PID2PIXLOCK(p->common.id),
 #endif
 			   locks);
 #endif
@@ -805,7 +805,7 @@ erts_smp_proc_trylock(Process *p, ErtsProcLocks locks)
 #if ERTS_PROC_LOCK_ATOMIC_IMPL
 				   NULL,
 #else
-				   ERTS_PID2PIXLOCK(p->id),
+				   ERTS_PID2PIXLOCK(p->common.id),
 #endif
 				   locks);
 #endif
@@ -814,21 +814,15 @@ erts_smp_proc_trylock(Process *p, ErtsProcLocks locks)
 ERTS_GLB_INLINE void erts_smp_proc_inc_refc(Process *p)
 {
 #ifdef ERTS_SMP
-#ifdef ERTS_ENABLE_LOCK_CHECK
-    erts_aint32_t refc = erts_atomic32_inc_read_nob(&p->lock.refc);
-    ERTS_SMP_LC_ASSERT(refc > 1);
-#else
-    erts_atomic32_inc_nob(&p->lock.refc);
-#endif
+    erts_ptab_inc_refc(&p->common);
 #endif
 }
 
 ERTS_GLB_INLINE void erts_smp_proc_dec_refc(Process *p)
 {
 #ifdef ERTS_SMP
-    erts_aint32_t refc = erts_atomic32_dec_read_nob(&p->lock.refc);
-    ERTS_SMP_LC_ASSERT(refc >= 0);
-    if (refc == 0)
+    int referred = erts_ptab_dec_test_refc(&p->common);
+    if (!referred)
 	erts_free_proc(p);
 #endif
 }
@@ -836,10 +830,8 @@ ERTS_GLB_INLINE void erts_smp_proc_dec_refc(Process *p)
 ERTS_GLB_INLINE void erts_smp_proc_add_refc(Process *p, Sint32 add_refc)
 {
 #ifdef ERTS_SMP
-    erts_aint32_t refc = erts_atomic32_add_read_nob(&p->lock.refc,
-						    (erts_aint32_t) add_refc);
-    ERTS_SMP_LC_ASSERT(refc >= 0);
-    if (refc == 0)
+    int referred = erts_ptab_add_test_refc(&p->common, add_refc);
+    if (!referred)
 	erts_free_proc(p);
 #endif
 }
@@ -875,8 +867,7 @@ void erts_proc_safelock(Process *a_proc,
 #define ERTS_P2P_FLG_TRY_LOCK		(1 <<  1)
 #define ERTS_P2P_FLG_SMP_INC_REFC	(1 <<  2)
 
-#define ERTS_PROC_LOCK_BUSY ((Process *) &erts_proc_lock_busy)
-extern const Process erts_proc_lock_busy;
+#define ERTS_PROC_LOCK_BUSY ((Process *) &erts_invalid_process)
 
 #define erts_pid2proc(PROC, HL, PID, NL) \
   erts_pid2proc_opt((PROC), (HL), (PID), (NL), 0)
@@ -896,33 +887,24 @@ Process *erts_pid2proc_opt(Process *, ErtsProcLocks, Eterm, ErtsProcLocks, int);
 ERTS_GLB_INLINE Process *erts_pix2proc(int ix)
 {
     Process *proc;
-    ASSERT(0 <= ix && ix < erts_proc.max);
-    proc = (Process *) erts_smp_atomic_read_nob(&erts_proc.tab[ix]);
+    ASSERT(0 <= ix && ix < erts_ptab_max(&erts_proc));
+    proc = (Process *) erts_ptab_pix2intptr_nob(&erts_proc, ix);
     return proc == ERTS_PROC_LOCK_BUSY ? NULL : proc;
 }
 
 ERTS_GLB_INLINE Process *erts_proc_lookup_raw(Eterm pid)
 {
     Process *proc;
-    int pix;
 
-    /*
-     * In SMP case: Only scheduler threads are allowed
-     * to use this function. Other threads need to
-     * atomicaly increment refc at lookup, i.e., use
-     * erts_pid2proc_opt() with ERTS_P2P_FLG_SMP_INC_REFC.
-     */
-    ERTS_SMP_LC_ASSERT(erts_get_scheduler_id());
+    ERTS_SMP_LC_ASSERT(erts_thr_progress_lc_is_delaying());
 
     if (is_not_internal_pid(pid))
 	return NULL;
-    pix = internal_pid_index(pid);
 
-    proc = (Process *) erts_smp_atomic_read_ddrb(&erts_proc.tab[pix]);
-
-    if (proc && proc->id != pid)
+    proc = (Process *) erts_ptab_pix2intptr_ddrb(&erts_proc,
+						 internal_pid_index(pid));
+    if (proc && proc->common.id != pid)
 	return NULL;
-
     return proc;
 }
 
diff --git a/erts/emulator/beam/erl_ptab.c b/erts/emulator/beam/erl_ptab.c
new file mode 100644
index 0000000000..87beeafa1a
--- /dev/null
+++ b/erts/emulator/beam/erl_ptab.c
@@ -0,0 +1,1566 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2012. All Rights Reserved.
+ *
+ * The contents of this file are subject to the Erlang Public License,
+ * Version 1.1, (the "License"); you may not use this file except in
+ * compliance with the License. You should have received a copy of the
+ * Erlang Public License along with this software. If not, it can be
+ * retrieved online at http://www.erlang.org/.
+ *
+ * Software distributed under the License is distributed on an "AS IS"
+ * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+ * the License for the specific language governing rights and limitations
+ * under the License.
+ *
+ * %CopyrightEnd%
+ */
+
+/*
+ * Description:	Process/Port table implementation.
+ *
+ * Author: 	Rickard Green
+ */
+
+#ifdef HAVE_CONFIG_H
+#  include "config.h"
+#endif
+#define ERTS_PTAB_WANT_BIF_IMPL__
+#define ERTS_PTAB_WANT_DEBUG_FUNCS__
+#include "erl_ptab.h"
+#include "global.h"
+#include "erl_binary.h"
+
+typedef struct ErtsPTabListBifData_ ErtsPTabListBifData;
+
+#define ERTS_PTAB_LIST_BIF_TAB_INSPECT_INDICES_PER_RED 25
+#define ERTS_PTAB_LIST_BIF_TAB_CHUNK_SIZE 1000
+#define ERTS_PTAB_LIST_BIF_MIN_START_REDS				\
+ (ERTS_PTAB_LIST_BIF_TAB_CHUNK_SIZE					\
+  / ERTS_PTAB_LIST_BIF_TAB_INSPECT_INDICES_PER_RED)
+
+#define ERTS_PTAB_LIST_BIF_TAB_FREE_DELETED_REDS 1
+
+#define ERTS_PTAB_LIST_BIF_INSPECT_DELETED_PER_RED 10
+
+#define ERTS_PTAB_LIST_INSPECT_DELETED_MAX_REDS				\
+ (ERTS_PTAB_LIST_BIF_TAB_CHUNK_SIZE					\
+  / ERTS_PTAB_LIST_BIF_TAB_INSPECT_INDICES_PER_RED)
+ 
+
+#define ERTS_PTAB_LIST_BIF_BUILD_RESULT_CONSES_PER_RED 75
+
+#define ERTS_PTAB_LIST_DBG_DO_TRACE 0
+
+#ifdef DEBUG
+#  define ERTS_PTAB_LIST_BIF_DEBUGLEVEL 100
+#else
+#  define ERTS_PTAB_LIST_BIF_DEBUGLEVEL 0
+#endif
+
+#define ERTS_PTAB_LIST_DBGLVL_CHK_HALLOC 1
+#define ERTS_PTAB_LIST_DBGLVL_CHK_FOUND_PIDS 5
+#define ERTS_PTAB_LIST_DBGLVL_CHK_PIDS 10
+#define ERTS_PTAB_LIST_DBGLVL_CHK_DEL_LIST 20
+#define ERTS_PTAB_LIST_DBGLVL_CHK_RESLIST 20
+
+#if ERTS_PTAB_LIST_BIF_DEBUGLEVEL == 0
+#  define ERTS_PTAB_LIST_ASSERT(EXP)
+#else
+#  define ERTS_PTAB_LIST_ASSERT(EXP)					\
+    ((void) ((EXP)							\
+	     ? 1							\
+	     : (debug_ptab_list_assert_error(#EXP,			\
+					     __FILE__,			\
+					     __LINE__,			\
+					     __func__),			\
+		0)))
+#endif
+
+
+#if ERTS_PTAB_LIST_BIF_DEBUGLEVEL >=  ERTS_PTAB_LIST_DBGLVL_CHK_HALLOC
+#  define ERTS_PTAB_LIST_DBG_SAVE_HEAP_ALLOC(PTLBDP, HP, SZ)		\
+do {									\
+    ERTS_PTAB_LIST_ASSERT(!(PTLBDP)->debug.heap);			\
+    ERTS_PTAB_LIST_ASSERT(!(PTLBDP)->debug.heap_size);			\
+    (PTLBDP)->debug.heap = (HP);					\
+    (PTLBDP)->debug.heap_size = (SZ);					\
+} while (0)
+#  define ERTS_PTAB_LIST_DBG_VERIFY_HEAP_ALLOC_USED(PTLBDP, HP)		\
+do {									\
+    ERTS_PTAB_LIST_ASSERT((PTLBDP)->debug.heap);			\
+    ERTS_PTAB_LIST_ASSERT((PTLBDP)->debug.heap_size);			\
+    ERTS_PTAB_LIST_ASSERT(((PTLBDP)->debug.heap				\
+			   + (PTLBDP)->debug.heap_size)			\
+			  == (HP));					\
+    (PTLBDP)->debug.heap = NULL;					\
+    (PTLBDP)->debug.heap_size = 0;					\
+} while (0)
+#  define ERTS_PTAB_LIST_DBG_HEAP_ALLOC_INIT(PTLBDP)			\
+do {									\
+    (PTLBDP)->debug.heap = NULL;					\
+    (PTLBDP)->debug.heap_size = 0;					\
+} while (0)
+#else
+#  define ERTS_PTAB_LIST_DBG_SAVE_HEAP_ALLOC(PTLBDP, HP, SZ)
+#  define ERTS_PTAB_LIST_DBG_VERIFY_HEAP_ALLOC_USED(PTLBDP, HP)
+#  define ERTS_PTAB_LIST_DBG_HEAP_ALLOC_INIT(PTLBDP)
+#endif
+
+#if ERTS_PTAB_LIST_BIF_DEBUGLEVEL >= ERTS_PTAB_LIST_DBGLVL_CHK_RESLIST
+#  define ERTS_PTAB_LIST_DBG_CHK_RESLIST(R)				\
+    debug_ptab_list_check_res_list((R))
+#else
+#  define ERTS_PTAB_LIST_DBG_CHK_RESLIST(R)
+#endif
+
+#if ERTS_PTAB_LIST_BIF_DEBUGLEVEL >= ERTS_PTAB_LIST_DBGLVL_CHK_PIDS
+#  define ERTS_PTAB_LIST_DBG_SAVE_PIDS(PTLBDP)				\
+    debug_ptab_list_save_all_pids((PTLBDP))
+#  define ERTS_PTAB_LIST_DBG_VERIFY_PIDS(PTLBDP)			\
+do {									\
+    if (!(PTLBDP)->debug.correct_pids_verified)				\
+	debug_ptab_list_verify_all_pids((PTLBDP));			\
+} while (0)
+#  define ERTS_PTAB_LIST_DBG_CLEANUP_CHK_PIDS(PTLBDP)			\
+do {									\
+    if ((PTLBDP)->debug.correct_pids) {					\
+	erts_free(ERTS_ALC_T_PTAB_LIST_PIDS,				\
+		  (PTLBDP)->debug.correct_pids);			\
+	(PTLBDP)->debug.correct_pids = NULL;				\
+    }									\
+} while(0)
+#  define ERTS_PTAB_LIST_DBG_CHK_PIDS_INIT(PTLBDP)			\
+do {									\
+    (PTLBDP)->debug.correct_pids_verified = 0;				\
+    (PTLBDP)->debug.correct_pids = NULL;				\
+} while (0)
+#else
+#  define ERTS_PTAB_LIST_DBG_SAVE_PIDS(PTLBDP)
+#  define ERTS_PTAB_LIST_DBG_VERIFY_PIDS(PTLBDP)
+#  define ERTS_PTAB_LIST_DBG_CLEANUP_CHK_PIDS(PTLBDP)
+#  define ERTS_PTAB_LIST_DBG_CHK_PIDS_INIT(PTLBDP)
+#endif
+
+#if ERTS_PTAB_LIST_BIF_DEBUGLEVEL >= ERTS_PTAB_LIST_DBGLVL_CHK_FOUND_PIDS
+#  define ERTS_PTAB_LIST_DBG_CHK_PID_FOUND(PTLBDP, PID, IC)		\
+  debug_ptab_list_check_found_pid((PTLBDP), (PID), (IC), 1)
+#  define ERTS_PTAB_LIST_DBG_CHK_PID_NOT_FOUND(PTLBDP, PID, IC)		\
+  debug_ptab_list_check_found_pid((PTLBDP), (PID), (IC), 0)
+#else
+#  define ERTS_PTAB_LIST_DBG_CHK_PID_FOUND(PTLBDP, PID, IC)
+#  define ERTS_PTAB_LIST_DBG_CHK_PID_NOT_FOUND(PTLBDP, PID, IC)
+#endif
+
+#if ERTS_PTAB_LIST_BIF_DEBUGLEVEL >= ERTS_PTAB_LIST_DBGLVL_CHK_DEL_LIST
+#  define ERTS_PTAB_LIST_DBG_CHK_DEL_LIST(PTab)				\
+    debug_ptab_list_check_del_list((PTab))
+#  define ERTS_PTAB_LIST_DBG_CHK_FREELIST(PTab, FL)			\
+    debug_ptab_list_check_del_free_list((PTab), (FL))
+#else
+#  define ERTS_PTAB_LIST_DBG_CHK_DEL_LIST(PTab)
+#  define ERTS_PTAB_LIST_DBG_CHK_FREELIST(PTab, FL)
+#endif
+
+#if ERTS_PTAB_LIST_BIF_DEBUGLEVEL == 0
+#if ERTS_PTAB_LIST_DBG_DO_TRACE
+#    define ERTS_PTAB_LIST_DBG_INIT(P, PTLBDP)				\
+    (PTLBDP)->debug.caller = (P)->common.id
+#  else
+#    define ERTS_PTAB_LIST_DBG_INIT(P, PTLBDP)
+#  endif
+#  define ERTS_PTAB_LIST_DBG_CLEANUP(PTLBDP)
+#else
+#  define ERTS_PTAB_LIST_DBG_INIT(P, PTLBDP)				\
+do {									\
+    (PTLBDP)->debug.caller = (P)->common.id;				\
+    ERTS_PTAB_LIST_DBG_HEAP_ALLOC_INIT((PTLBDP));			\
+    ERTS_PTAB_LIST_DBG_CHK_PIDS_INIT((PTLBDP));				\
+} while (0)
+#  define ERTS_PTAB_LIST_DBG_CLEANUP(PTLBDP)				\
+do {									\
+    ERTS_PTAB_LIST_DBG_CLEANUP_CHK_PIDS((PTLBDP));			\
+} while (0)
+#endif
+
+#if ERTS_PTAB_LIST_DBG_DO_TRACE
+#  define ERTS_PTAB_LIST_DBG_TRACE(PID, WHAT)				\
+     erts_fprintf(stderr, "%T %s:%d:%s(): %s\n",			\
+		  (PID), __FILE__, __LINE__, __func__, #WHAT)
+#else
+#  define ERTS_PTAB_LIST_DBG_TRACE(PID, WHAT)
+#endif
+
+
+#if ERTS_PTAB_LIST_BIF_DEBUGLEVEL != 0
+static void debug_ptab_list_assert_error(char* expr,
+					 const char* file,
+					 int line,
+					 const char *func);
+#endif
+#if ERTS_PTAB_LIST_BIF_DEBUGLEVEL >= ERTS_PTAB_LIST_DBGLVL_CHK_RESLIST
+static void debug_ptab_list_check_res_list(Eterm list);
+#endif
+#if ERTS_PTAB_LIST_BIF_DEBUGLEVEL >= ERTS_PTAB_LIST_DBGLVL_CHK_PIDS
+static void debug_ptab_list_save_all_pids(ErtsPTabListBifData *ptlbdp);
+static void debug_ptab_list_verify_all_pids(ErtsPTabListBifData *ptlbdp);
+#endif
+#if ERTS_PTAB_LIST_BIF_DEBUGLEVEL >= ERTS_PTAB_LIST_DBGLVL_CHK_FOUND_PIDS
+static void debug_ptab_list_check_found_pid(ErtsPTabListBifData *ptlbdp,
+					    Eterm pid,
+					    Uint64 ic,
+					    int pid_should_be_found);
+#endif
+#if ERTS_PTAB_LIST_BIF_DEBUGLEVEL >= ERTS_PTAB_LIST_DBGLVL_CHK_DEL_LIST
+static void debug_ptab_list_check_del_list(ErtsPTab *ptab);
+static void debug_ptab_list_check_del_free_list(ErtsPTab *ptab,
+						ErtsPTabDeletedElement *ptdep);
+#endif
+
+struct ErtsPTabDeletedElement_ {
+    ErtsPTabDeletedElement *next;
+    ErtsPTabDeletedElement *prev;
+    int ix;
+    union {
+	struct {
+	    Eterm id;
+	    Uint64 inserted;
+	    Uint64 deleted;
+	} element;
+	struct {
+	    Uint64 interval;
+	} bif_invocation;
+    } u;
+};
+
+static Export ptab_list_continue_export;
+
+typedef struct {
+    Uint64 interval;
+} ErtsPTabListBifChunkInfo;
+
+typedef enum {
+    INITIALIZING,
+    INSPECTING_TABLE,
+    INSPECTING_DELETED,
+    BUILDING_RESULT,
+    RETURN_RESULT
+} ErtsPTabListBifState;
+
+struct ErtsPTabListBifData_ {
+    ErtsPTab *ptab;
+    ErtsPTabListBifState state;
+    Eterm caller;
+    ErtsPTabListBifChunkInfo *chunk;
+    int tix;
+    int pid_ix;
+    int pid_sz;
+    Eterm *pid;
+    ErtsPTabDeletedElement *bif_invocation; /* Only used when > 1 chunk */
+
+#if ERTS_PTAB_LIST_BIF_DEBUGLEVEL != 0 || ERTS_PTAB_LIST_DBG_DO_TRACE
+    struct {
+	Eterm caller;
+#if ERTS_PTAB_LIST_BIF_DEBUGLEVEL >= ERTS_PTAB_LIST_DBGLVL_CHK_FOUND_PIDS
+	Uint64 *pid_started;
+#endif
+#if ERTS_PTAB_LIST_BIF_DEBUGLEVEL >= ERTS_PTAB_LIST_DBGLVL_CHK_HALLOC
+	Eterm *heap;
+	Uint heap_size;
+#endif
+#if ERTS_PTAB_LIST_BIF_DEBUGLEVEL >= ERTS_PTAB_LIST_DBGLVL_CHK_PIDS
+	int correct_pids_verified;
+	Eterm *correct_pids;
+#endif
+    } debug;
+#endif
+
+};
+
+#ifdef ARCH_32
+
+static ERTS_INLINE Uint64
+dw_aint_to_uint64(erts_dw_aint_t *dw)
+{
+#ifdef ETHR_SU_DW_NAINT_T__
+    return (Uint64) dw->dw_sint;
+#else
+    Uint64 res;
+    res = (Uint64) ((Uint32) dw->sint[ERTS_DW_AINT_HIGH_WORD]);
+    res <<= 32;
+    res |= (Uint64) ((Uint32) dw->sint[ERTS_DW_AINT_LOW_WORD]);
+    return res;
+#endif
+}
+
+static void
+unint64_to_dw_aint(erts_dw_aint_t *dw, Uint64 val)
+{
+#ifdef ETHR_SU_DW_NAINT_T__
+    dw->dw_sint = (ETHR_SU_DW_NAINT_T__) val;
+#else
+    dw->sint[ERTS_DW_AINT_LOW_WORD] = (erts_aint_t) (val & 0xffffffff);
+    dw->sint[ERTS_DW_AINT_HIGH_WORD] = (erts_aint_t) ((val >> 32) & 0xffffffff);
+#endif
+}
+
+static ERTS_INLINE void
+last_data_init_nob(ErtsPTab *ptab, Uint64 val)
+{
+    erts_dw_aint_t dw;
+    unint64_to_dw_aint(&dw, val);
+    erts_smp_dw_atomic_init_nob(&ptab->vola.tile.last_data, &dw);
+}
+
+static ERTS_INLINE void
+last_data_set_relb(ErtsPTab *ptab, Uint64 val)
+{
+    erts_dw_aint_t dw;
+    unint64_to_dw_aint(&dw, val);
+    erts_smp_dw_atomic_set_relb(&ptab->vola.tile.last_data, &dw);
+}
+
+static ERTS_INLINE Uint64
+last_data_read_nob(ErtsPTab *ptab)
+{
+    erts_dw_aint_t dw;
+    erts_smp_dw_atomic_read_nob(&ptab->vola.tile.last_data, &dw);
+    return dw_aint_to_uint64(&dw);
+}
+
+static ERTS_INLINE Uint64
+last_data_read_acqb(ErtsPTab *ptab)
+{
+    erts_dw_aint_t dw;
+    erts_smp_dw_atomic_read_acqb(&ptab->vola.tile.last_data, &dw);
+    return dw_aint_to_uint64(&dw);
+}
+
+static ERTS_INLINE Uint64
+last_data_cmpxchg_relb(ErtsPTab *ptab, Uint64 new, Uint64 exp)
+{
+    erts_dw_aint_t dw_new, dw_xchg;
+
+    unint64_to_dw_aint(&dw_new, new);
+    unint64_to_dw_aint(&dw_xchg, exp);
+
+    if (erts_smp_dw_atomic_cmpxchg_relb(&ptab->vola.tile.last_data,
+					&dw_new,
+					&dw_xchg))
+	return exp;
+    else
+	return dw_aint_to_uint64(&dw_xchg);
+}
+
+#elif defined(ARCH_64)
+
+union {
+    erts_smp_atomic_t pid_data;
+    char align[ERTS_CACHE_LINE_SIZE];
+} last erts_align_attribute(ERTS_CACHE_LINE_SIZE);
+
+static ERTS_INLINE void
+last_data_init_nob(ErtsPTab *ptab, Uint64 val)
+{
+    erts_smp_atomic_init_nob(&ptab->vola.tile.last_data, (erts_aint_t) val);
+}
+
+static ERTS_INLINE void
+last_data_set_relb(ErtsPTab *ptab, Uint64 val)
+{
+    erts_smp_atomic_set_relb(&ptab->vola.tile.last_data, (erts_aint_t) val);
+}
+
+static ERTS_INLINE Uint64
+last_data_read_nob(ErtsPTab *ptab)
+{
+    return (Uint64) erts_smp_atomic_read_nob(&ptab->vola.tile.last_data);
+}
+
+static ERTS_INLINE Uint64
+last_data_read_acqb(ErtsPTab *ptab)
+{
+    return (Uint64) erts_smp_atomic_read_acqb(&ptab->vola.tile.last_data);
+}
+
+static ERTS_INLINE Uint64
+last_data_cmpxchg_relb(ErtsPTab *ptab, Uint64 new, Uint64 exp)
+{
+    return (Uint64) erts_smp_atomic_cmpxchg_relb(&ptab->vola.tile.last_data,
+						 (erts_aint_t) new,
+						 (erts_aint_t) exp);
+}
+
+#else
+#  error "Not 64-bit, nor 32-bit architecture..."
+#endif
+
+static ERTS_INLINE int
+last_data_cmp(Uint64 ld1, Uint64 ld2)
+{
+    Uint64 ld1_wrap;
+
+    if (ld1 == ld2)
+	return 0;
+
+    ld1_wrap = ld1 + (((Uint64) 1) << 63);
+
+    if (ld1 < ld1_wrap)
+	return (ld1 < ld2 && ld2 < ld1_wrap) ? -1 : 1;
+    else
+	return (ld1_wrap <= ld2 && ld2 < ld1) ? 1 : -1;
+}
+
+#define ERTS_PTAB_LastData2EtermData(LD) \
+    ((Eterm) ((LD) & ~(~((Uint64) 0) << ERTS_PTAB_ID_DATA_SIZE)))
+
+void
+erts_ptab_init_table(ErtsPTab *ptab,
+		     ErtsAlcType_t atype,
+		     void (*release_element)(void *),
+		     ErtsPTabElementCommon *invalid_element,
+		     int size,
+		     char *name)
+{
+    size_t tab_sz;
+    int bits;
+    char *tab_end;
+    erts_smp_atomic_t *tab_entry;
+    erts_smp_rwmtx_opt_t rwmtx_opts = ERTS_SMP_RWMTX_OPT_DEFAULT_INITER;
+    rwmtx_opts.type = ERTS_SMP_RWMTX_TYPE_EXTREMELY_FREQUENT_READ;
+    rwmtx_opts.lived = ERTS_SMP_RWMTX_LONG_LIVED;
+
+    erts_smp_rwmtx_init_opt(&ptab->list.data.rwmtx, &rwmtx_opts, name);
+    erts_smp_atomic32_init_nob(&ptab->vola.tile.count, 0);
+    last_data_init_nob(ptab, ~((Uint64) 0));
+
+    /* A size that is a power of 2 is to prefer performance wise */
+    bits = erts_fit_in_bits_int32(size-1);
+    size = 1 << bits;
+    if (size > ERTS_PTAB_MAX_SIZE) {
+	size = ERTS_PTAB_MAX_SIZE;
+	bits = erts_fit_in_bits_int32((Sint32) size - 1);
+    }
+
+    ptab->r.o.max = size;
+
+    tab_sz = ERTS_ALC_CACHE_LINE_ALIGN_SIZE(size*sizeof(erts_smp_atomic_t));
+    ptab->r.o.tab = erts_alloc_permanent_cache_aligned(atype, tab_sz);
+    tab_end = ((char *) ptab->r.o.tab) + tab_sz;
+    tab_entry = ptab->r.o.tab;
+    while (tab_end > ((char *) tab_entry)) {
+	erts_smp_atomic_init_nob(tab_entry, ERTS_AINT_NULL);
+	tab_entry++;
+    }
+
+    ptab->r.o.tab_cache_lines = tab_sz/ERTS_CACHE_LINE_SIZE;
+    ptab->r.o.pix_per_cache_line = (ERTS_CACHE_LINE_SIZE
+				    / sizeof(erts_smp_atomic_t));
+    ASSERT((ptab->r.o.max & (ptab->r.o.max - 1)) == 0); /* power of 2 */
+    ASSERT((ptab->r.o.pix_per_cache_line
+	    & (ptab->r.o.pix_per_cache_line - 1)) == 0); /* power of 2 */
+    ASSERT((ptab->r.o.tab_cache_lines
+	    & (ptab->r.o.tab_cache_lines - 1)) == 0); /* power of 2 */
+
+    ptab->r.o.pix_mask
+	= (1 << bits) - 1;
+    ptab->r.o.pix_cl_mask
+	= ptab->r.o.tab_cache_lines-1;
+    ptab->r.o.pix_cl_shift
+	= erts_fit_in_bits_int32(ptab->r.o.pix_per_cache_line-1);
+    ptab->r.o.pix_cli_shift
+	= erts_fit_in_bits_int32(ptab->r.o.pix_cl_mask);
+    ptab->r.o.pix_cli_mask
+	= (1 << (bits - ptab->r.o.pix_cli_shift)) - 1;
+
+    ASSERT(ptab->r.o.pix_cl_shift + ptab->r.o.pix_cli_shift == bits);
+
+    ptab->r.o.invalid_element = invalid_element;
+    ptab->r.o.invalid_data = erts_ptab_id2data(ptab, invalid_element->id);
+    ptab->r.o.release_element = release_element;
+
+    erts_smp_interval_init(&ptab->list.data.interval);
+    ptab->list.data.deleted.start = NULL;
+    ptab->list.data.deleted.end = NULL;
+    ptab->list.data.chunks = (((ptab->r.o.max - 1)
+			       / ERTS_PTAB_LIST_BIF_TAB_CHUNK_SIZE)
+			      + 1);
+
+    if (size == ERTS_PTAB_MAX_SIZE) {
+	int pix;
+	/*
+	 * We want a table size of a power of 2 which ERTS_PTAB_MAX_SIZE
+	 * is. We only have ERTS_PTAB_MAX_SIZE-1 unique identifiers and
+	 * we don't want to shrink the size to ERTS_PTAB_MAX_SIZE/2.
+	 *
+	 * In order to fix this, we insert a pointer from the table
+	 * to the invalid_element, wich will be interpreted as a
+	 * slot currently being modified. This way we will be able to
+	 * have ERTS_PTAB_MAX_SIZE-1 valid elements in the table while
+	 * still having a table size of the power of 2.
+	 */
+	erts_smp_atomic32_inc_nob(&ptab->vola.tile.count);
+	pix = erts_ptab_data2pix(ptab, ptab->r.o.invalid_data);
+	erts_smp_atomic_set_relb(&ptab->r.o.tab[pix],
+				 (erts_aint_t) ptab->r.o.invalid_element);
+    }
+
+}
+
+int
+erts_ptab_initialized(ErtsPTab *ptab)
+{
+    return ptab->r.o.tab != NULL;
+}
+
+int
+erts_ptab_new_element(ErtsPTab *ptab,
+		      ErtsPTabElementCommon *ptab_el,
+		      void *init_arg,
+		      void (*init_ptab_el)(void *, Eterm))
+{
+    int pix;
+    Uint64 ld, exp_ld;
+    Eterm data;
+    erts_aint32_t count;
+    erts_aint_t invalid = (erts_aint_t) ptab->r.o.invalid_element;
+
+    erts_ptab_rlock(ptab);
+
+    count = erts_smp_atomic32_inc_read_acqb(&ptab->vola.tile.count);
+    if (count > ptab->r.o.max) {
+	while (1) {
+	    erts_aint32_t act_count;
+
+	    act_count = erts_smp_atomic32_cmpxchg_relb(&ptab->vola.tile.count,
+						       count-1,
+						       count);
+	    if (act_count == count) {
+		erts_ptab_runlock(ptab);
+		return 0;
+	    }
+	    count = act_count;
+	    if (count <= ptab->r.o.max)
+		break;
+	}
+    }
+
+    ptab_el->u.alive.started_interval
+	= erts_smp_current_interval_nob(erts_ptab_interval(ptab));
+
+    ld = last_data_read_acqb(ptab);
+
+    /* Reserve slot */
+    while (1) {
+	ld++;
+	pix = erts_ptab_data2pix(ptab, ERTS_PTAB_LastData2EtermData(ld));
+	if (erts_smp_atomic_read_nob(&ptab->r.o.tab[pix]) == ERTS_AINT_NULL) {
+	    erts_aint_t val;
+	    val = erts_smp_atomic_cmpxchg_relb(&ptab->r.o.tab[pix],
+					       invalid,	
+					       ERTS_AINT_NULL);
+
+	    if (ERTS_AINT_NULL == val)
+		break;
+	}
+    }
+
+    data = ERTS_PTAB_LastData2EtermData(ld);
+
+    if (data == ptab->r.o.invalid_data) {
+	/* Do not use invalid data; fix it... */
+	ld += ptab->r.o.max;
+	ASSERT(pix == erts_ptab_data2pix(ptab,
+					 ERTS_PTAB_LastData2EtermData(ld)));
+	data = ERTS_PTAB_LastData2EtermData(ld);
+	ASSERT(data != ptab->r.o.invalid_data);
+    }
+
+    exp_ld = last_data_read_nob(ptab);
+
+    /* Move last data forward */
+    while (1) {
+	Uint64 act_ld;
+	if (last_data_cmp(ld, exp_ld) < 0)
+	    break;
+	act_ld = last_data_cmpxchg_relb(ptab, ld, exp_ld);
+	if (act_ld == exp_ld)
+	    break;
+	exp_ld = act_ld;
+    }
+
+    init_ptab_el(init_arg, data);
+
+#ifdef ERTS_SMP
+    erts_smp_atomic32_init_nob(&ptab_el->refc, 1);
+#endif
+
+    /* Move into slot reserved */
+#ifdef DEBUG
+    ASSERT(invalid == erts_smp_atomic_xchg_relb(&ptab->r.o.tab[pix],
+						(erts_aint_t) ptab_el));
+#else
+    erts_smp_atomic_set_relb(&ptab->r.o.tab[pix], (erts_aint_t) ptab_el);
+#endif
+
+    erts_ptab_runlock(ptab);
+
+    return 1;
+}
+
+static void
+save_deleted_element(ErtsPTab *ptab, ErtsPTabElementCommon *ptab_el)
+{
+    ErtsPTabDeletedElement *ptdep = erts_alloc(ERTS_ALC_T_PTAB_LIST_DEL,
+					       sizeof(ErtsPTabDeletedElement));
+    ERTS_PTAB_LIST_ASSERT(ptab->list.data.deleted.start
+			  && ptab->list.data.deleted.end);
+    ERTS_SMP_LC_ASSERT(erts_smp_lc_ptab_is_rwlocked(ptab));
+
+    ERTS_PTAB_LIST_DBG_CHK_DEL_LIST(ptab);
+
+    ptdep->prev = ptab->list.data.deleted.end;
+    ptdep->next = NULL;
+    ptdep->ix = erts_ptab_id2pix(ptab, ptab_el->id);
+    ptdep->u.element.id = ptab_el->id;
+    ptdep->u.element.inserted = ptab_el->u.alive.started_interval;
+    ptdep->u.element.deleted =
+	erts_smp_current_interval_nob(erts_ptab_interval(ptab));
+
+    ptab->list.data.deleted.end->next = ptdep;
+    ptab->list.data.deleted.end = ptdep;
+
+    ERTS_PTAB_LIST_DBG_CHK_DEL_LIST(ptab);
+
+    ERTS_PTAB_LIST_ASSERT(ptdep->prev->ix >= 0
+			  ? (ptdep->u.element.deleted
+			     >= ptdep->prev->u.element.deleted)
+			  : (ptdep->u.element.deleted
+			     >= ptdep->prev->u.bif_invocation.interval));
+}
+
+void
+erts_ptab_delete_element(ErtsPTab *ptab,
+			 ErtsPTabElementCommon *ptab_el)
+{
+    int maybe_save;
+    int pix = erts_ptab_id2pix(ptab, ptab_el->id);
+
+    ASSERT(erts_get_scheduler_id()); /* *Need* to be a scheduler */
+
+    erts_ptab_rlock(ptab);
+    maybe_save = ptab->list.data.deleted.end != NULL;
+    if (maybe_save) {
+	erts_ptab_runlock(ptab);
+	erts_ptab_rwlock(ptab);
+    }
+
+    erts_smp_atomic_set_relb(&ptab->r.o.tab[pix], ERTS_AINT_NULL);
+
+    ASSERT(erts_smp_atomic32_read_nob(&ptab->vola.tile.count) > 0);
+    erts_smp_atomic32_dec_relb(&ptab->vola.tile.count);
+
+    if (!maybe_save)
+	erts_ptab_runlock(ptab);
+    else {
+	if (ptab->list.data.deleted.end)
+	    save_deleted_element(ptab, ptab_el);
+	erts_ptab_rwunlock(ptab);
+    }
+
+    if (ptab->r.o.release_element)
+	erts_schedule_thr_prgr_later_op(ptab->r.o.release_element,
+					(void *) ptab_el,
+					&ptab_el->u.release);
+}
+
+/*
+ * erts_ptab_list() implements BIFs listing the content of the table,
+ * e.g. erlang:processes/0.
+ */
+static void cleanup_ptab_list_bif_data(Binary *bp);
+static int ptab_list_bif_engine(Process *c_p, Eterm *res_accp, Binary *mbp);
+
+
+BIF_RETTYPE
+erts_ptab_list(Process *c_p, ErtsPTab *ptab)
+{
+    /*
+     * A requirement: The list of identifiers returned should be a
+     *                consistent snapshot of all elements existing
+     *                in the table at some point in time during the
+     *                execution of the BIF calling this function.
+     *                Since elements might be deleted while the BIF
+     *                is executing, we have to keep track of all
+     *                deleted elements and add them to the result.
+     *                We also ignore elements created after the BIF
+     *                has begun executing.
+     */
+    BIF_RETTYPE ret_val;
+    Eterm res_acc = NIL;
+    Binary *mbp = erts_create_magic_binary(sizeof(ErtsPTabListBifData),
+					   cleanup_ptab_list_bif_data);
+    ErtsPTabListBifData *ptlbdp = ERTS_MAGIC_BIN_DATA(mbp);
+
+    ERTS_PTAB_LIST_DBG_TRACE(c_p->common.id, call);
+    ptlbdp->ptab = ptab;
+    ptlbdp->state = INITIALIZING;
+    ERTS_PTAB_LIST_DBG_INIT(c_p, ptlbdp);
+
+    if (ERTS_BIF_REDS_LEFT(c_p) >= ERTS_PTAB_LIST_BIF_MIN_START_REDS
+	&& ptab_list_bif_engine(c_p, &res_acc, mbp)) {
+	erts_bin_free(mbp);
+	ERTS_PTAB_LIST_DBG_CHK_RESLIST(res_acc);
+	ERTS_PTAB_LIST_DBG_TRACE(c_p->common.id, return);
+	ERTS_BIF_PREP_RET(ret_val, res_acc);
+    }
+    else {
+	Eterm *hp;
+	Eterm magic_bin;
+	ERTS_PTAB_LIST_DBG_CHK_RESLIST(res_acc);
+	hp = HAlloc(c_p, PROC_BIN_SIZE);
+	ERTS_PTAB_LIST_DBG_SAVE_HEAP_ALLOC(ptlbdp, hp, PROC_BIN_SIZE);
+	magic_bin = erts_mk_magic_binary_term(&hp, &MSO(c_p), mbp);
+	ERTS_PTAB_LIST_DBG_VERIFY_HEAP_ALLOC_USED(ptlbdp, hp);
+	ERTS_PTAB_LIST_DBG_TRACE(c_p->common.id, trap);
+	ERTS_BIF_PREP_YIELD2(ret_val,
+			     &ptab_list_continue_export,
+			     c_p,
+			     res_acc,
+			     magic_bin);
+    }
+    return ret_val;
+}
+
+static void
+cleanup_ptab_list_bif_data(Binary *bp)
+{
+    ErtsPTabListBifData *ptlbdp = ERTS_MAGIC_BIN_DATA(bp);
+    ErtsPTab *ptab = ptlbdp->ptab;
+
+    ERTS_PTAB_LIST_DBG_TRACE(ptlbdp->debug.caller, call);
+
+    if (ptlbdp->state != INITIALIZING) {
+
+	if (ptlbdp->chunk) {
+	    erts_free(ERTS_ALC_T_PTAB_LIST_CNKI, ptlbdp->chunk);
+	    ptlbdp->chunk = NULL;
+	}
+	if (ptlbdp->pid) {
+	    erts_free(ERTS_ALC_T_PTAB_LIST_PIDS, ptlbdp->pid);
+	    ptlbdp->pid = NULL;
+	}
+
+#if ERTS_PTAB_LIST_BIF_DEBUGLEVEL >= ERTS_PTAB_LIST_DBGLVL_CHK_FOUND_PIDS
+	if (ptlbdp->debug.pid_started) {
+	    erts_free(ERTS_ALC_T_PTAB_LIST_PIDS, ptlbdp->debug.pid_started);
+	    ptlbdp->debug.pid_started = NULL;
+	}
+#endif
+
+	if (ptlbdp->bif_invocation) {
+	    ErtsPTabDeletedElement *ptdep;
+
+	    erts_ptab_rwlock(ptab);
+
+	    ERTS_PTAB_LIST_DBG_TRACE(ptlbdp->debug.caller, deleted_cleanup);
+
+	    ptdep = ptlbdp->bif_invocation;
+	    ptlbdp->bif_invocation = NULL;
+
+	    ERTS_PTAB_LIST_DBG_CHK_DEL_LIST(ptab);
+
+	    if (ptdep->prev) {
+		/*
+		 * Only remove this bif invokation when we
+		 * have preceding invokations.
+		 */
+		ptdep->prev->next = ptdep->next;
+		if (ptdep->next)
+		    ptdep->next->prev = ptdep->prev;
+		else {
+		    /*
+		     * At the time of writing this branch cannot be
+		     * reached. I don't want to remove this code though
+		     * since it may be possible to reach this line
+		     * in the future if the cleanup order in
+		     * erts_do_exit_process() is changed. The ASSERT(0)
+		     * is only here to make us aware that the reorder
+		     * has happened. /rickard
+		     */
+		    ASSERT(0);
+		    ptab->list.data.deleted.end = ptdep->prev;
+		}
+		erts_free(ERTS_ALC_T_PTAB_LIST_DEL, ptdep);
+	    }
+	    else {
+		/*
+		 * Free all elements until next bif invokation
+		 * is found.
+		 */
+		ERTS_PTAB_LIST_ASSERT(ptab->list.data.deleted.start == ptdep);
+		do {
+		    ErtsPTabDeletedElement *fptdep = ptdep;
+		    ptdep = ptdep->next;
+		    erts_free(ERTS_ALC_T_PTAB_LIST_DEL, fptdep);
+		} while (ptdep && ptdep->ix >= 0);
+		ptab->list.data.deleted.start = ptdep;
+		if (ptdep)
+		    ptdep->prev = NULL;
+		else
+		    ptab->list.data.deleted.end = NULL;
+	    }
+
+	    ERTS_PTAB_LIST_DBG_CHK_DEL_LIST(ptab);
+
+	    erts_ptab_rwunlock(ptab);
+
+	}
+    }
+
+    ERTS_PTAB_LIST_DBG_TRACE(ptlbdp->debug.caller, return);
+    ERTS_PTAB_LIST_DBG_CLEANUP(ptlbdp);
+}
+
+static int
+ptab_list_bif_engine(Process *c_p, Eterm *res_accp, Binary *mbp)
+{
+    ErtsPTabListBifData *ptlbdp = ERTS_MAGIC_BIN_DATA(mbp);
+    ErtsPTab *ptab = ptlbdp->ptab;
+    int have_reds;
+    int reds;
+    int locked = 0;
+
+    do {
+	switch (ptlbdp->state) {
+	case INITIALIZING:
+	    ptlbdp->chunk = erts_alloc(ERTS_ALC_T_PTAB_LIST_CNKI,
+				       (sizeof(ErtsPTabListBifChunkInfo)
+					* ptab->list.data.chunks));
+	    ptlbdp->tix = 0;
+	    ptlbdp->pid_ix = 0;
+
+	    erts_ptab_rwlock(ptab);
+	    locked = 1;
+
+	    ERTS_PTAB_LIST_DBG_TRACE(c_p->common.id, init);
+
+	    ptlbdp->pid_sz = erts_ptab_count(ptab);
+	    ptlbdp->pid = erts_alloc(ERTS_ALC_T_PTAB_LIST_PIDS,
+				     sizeof(Eterm)*ptlbdp->pid_sz);
+
+#if ERTS_PTAB_LIST_BIF_DEBUGLEVEL >= ERTS_PTAB_LIST_DBGLVL_CHK_FOUND_PIDS
+	    ptlbdp->debug.pid_started
+		= erts_alloc(ERTS_ALC_T_PTAB_LIST_PIDS,
+			     sizeof(Uint64)*ptlbdp->pid_sz);
+#endif
+
+	    ERTS_PTAB_LIST_DBG_SAVE_PIDS(ptlbdp);
+
+	    if (ptab->list.data.chunks == 1)
+		ptlbdp->bif_invocation = NULL;
+	    else {
+		/*
+		 * We will have to access the table multiple times
+		 * releasing the table lock in between chunks.
+		 */
+		ptlbdp->bif_invocation
+		    = erts_alloc(ERTS_ALC_T_PTAB_LIST_DEL,
+				 sizeof(ErtsPTabDeletedElement));
+		ptlbdp->bif_invocation->ix = -1;
+		ptlbdp->bif_invocation->u.bif_invocation.interval
+		    = erts_smp_step_interval_nob(erts_ptab_interval(ptab));
+		ERTS_PTAB_LIST_DBG_CHK_DEL_LIST(ptab);
+
+		ptlbdp->bif_invocation->next = NULL;
+		if (ptab->list.data.deleted.end) {
+		    ptlbdp->bif_invocation->prev = ptab->list.data.deleted.end;
+		    ptab->list.data.deleted.end->next = ptlbdp->bif_invocation;
+		    ERTS_PTAB_LIST_ASSERT(ptab->list.data.deleted.start);
+		}
+		else {
+		    ptlbdp->bif_invocation->prev = NULL;
+		    ptab->list.data.deleted.start = ptlbdp->bif_invocation;
+		}
+		ptab->list.data.deleted.end = ptlbdp->bif_invocation;
+
+		ERTS_PTAB_LIST_DBG_CHK_DEL_LIST(ptab);
+
+	    }
+
+	    ptlbdp->state = INSPECTING_TABLE;
+	    /* Fall through */
+
+	case INSPECTING_TABLE: {
+	    int ix = ptlbdp->tix;
+	    int indices = ERTS_PTAB_LIST_BIF_TAB_CHUNK_SIZE;
+	    int cix = ix / ERTS_PTAB_LIST_BIF_TAB_CHUNK_SIZE;
+	    int end_ix = ix + indices;
+	    Uint64 *invocation_interval_p;
+	    ErtsPTabElementCommon *invalid_element;
+
+	    invocation_interval_p
+		= (ptlbdp->bif_invocation
+		   ? &ptlbdp->bif_invocation->u.bif_invocation.interval
+		   : NULL);
+
+	    ERTS_PTAB_LIST_ASSERT(is_nil(*res_accp));
+	    if (!locked) {
+		erts_ptab_rwlock(ptab);
+		locked = 1;
+	    }
+
+	    ERTS_SMP_LC_ASSERT(erts_smp_lc_ptab_is_rwlocked(ptab));
+	    ERTS_PTAB_LIST_DBG_TRACE(p->common.id, insp_table);
+
+	    if (cix != 0)
+		ptlbdp->chunk[cix].interval
+		    = erts_smp_step_interval_nob(erts_ptab_interval(ptab));
+	    else if (ptlbdp->bif_invocation)
+		ptlbdp->chunk[0].interval = *invocation_interval_p;
+	    /* else: interval is irrelevant */
+
+	    if (end_ix >= ptab->r.o.max) {
+		ERTS_PTAB_LIST_ASSERT(cix+1 == ptab->list.data.chunks);
+		end_ix = ptab->r.o.max;
+		indices = end_ix - ix;
+		/* What to do when done with this chunk */
+		ptlbdp->state = (ptab->list.data.chunks == 1
+				 ? BUILDING_RESULT
+				 : INSPECTING_DELETED);
+	    }
+
+	    invalid_element = ptab->r.o.invalid_element;
+	    for (; ix < end_ix; ix++) {
+		ErtsPTabElementCommon *el;
+		el = (ErtsPTabElementCommon *) erts_ptab_pix2intptr_nob(ptab,
+									ix);
+		if (el
+		    && el != invalid_element
+		    && (!invocation_interval_p
+			|| el->u.alive.started_interval < *invocation_interval_p)) {
+		    ERTS_PTAB_LIST_ASSERT(erts_ptab_is_valid_id(el->id));
+		    ptlbdp->pid[ptlbdp->pid_ix] = el->id;
+
+#if ERTS_PTAB_LIST_BIF_DEBUGLEVEL >= ERTS_PTAB_LIST_DBGLVL_CHK_FOUND_PIDS
+		    ptlbdp->debug.pid_started[ptlbdp->pid_ix]
+			= el->u.alive.started_interval;
+#endif
+
+		    ptlbdp->pid_ix++;
+		    ERTS_PTAB_LIST_ASSERT(ptlbdp->pid_ix <= ptlbdp->pid_sz);
+		}
+	    }
+
+	    ptlbdp->tix = end_ix;
+	    
+	    erts_ptab_rwunlock(ptab);
+	    locked = 0;
+
+	    reds = indices/ERTS_PTAB_LIST_BIF_TAB_INSPECT_INDICES_PER_RED;
+	    BUMP_REDS(c_p, reds);
+
+	    have_reds = ERTS_BIF_REDS_LEFT(c_p);
+
+	    if (have_reds && ptlbdp->state == INSPECTING_TABLE) {
+		ix = ptlbdp->tix;
+		indices = ERTS_PTAB_LIST_BIF_TAB_CHUNK_SIZE;
+		end_ix = ix + indices;
+		if (end_ix > ptab->r.o.max) {
+		    end_ix = ptab->r.o.max;
+		    indices = end_ix - ix;
+		}
+		
+		reds = indices/ERTS_PTAB_LIST_BIF_TAB_INSPECT_INDICES_PER_RED;
+
+		/* Pretend we have no reds left if we haven't got enough
+		   reductions to complete next chunk */
+		if (reds > have_reds)
+		    have_reds = 0;
+	    }
+
+	    break;
+	}
+
+	case INSPECTING_DELETED: {
+	    int i;
+	    int max_reds;
+	    int free_deleted = 0;
+	    Uint64 invocation_interval;
+	    ErtsPTabDeletedElement *ptdep;
+	    ErtsPTabDeletedElement *free_list = NULL;
+
+	    ptdep = ptlbdp->bif_invocation;
+	    ERTS_PTAB_LIST_ASSERT(ptdep);
+	    invocation_interval = ptdep->u.bif_invocation.interval;
+
+	    max_reds = have_reds = ERTS_BIF_REDS_LEFT(c_p);
+	    if (max_reds > ERTS_PTAB_LIST_INSPECT_DELETED_MAX_REDS)
+		max_reds = ERTS_PTAB_LIST_INSPECT_DELETED_MAX_REDS;
+
+	    reds = 0;
+	    erts_ptab_rwlock(ptab);
+	    ERTS_PTAB_LIST_DBG_TRACE(p->common.id, insp_term_procs);
+
+	    ERTS_PTAB_LIST_DBG_CHK_DEL_LIST(ptab);
+
+	    if (ptdep->prev)
+		ptdep->prev->next = ptdep->next;
+	    else {
+		ERTS_PTAB_LIST_ASSERT(ptab->list.data.deleted.start == ptdep);
+		ptab->list.data.deleted.start = ptdep->next;
+
+		if (ptab->list.data.deleted.start
+		    && ptab->list.data.deleted.start->ix >= 0) {
+		    free_list = ptab->list.data.deleted.start;
+		    free_deleted = 1;
+		}
+	    }
+
+	    if (ptdep->next)
+		ptdep->next->prev = ptdep->prev;
+	    else
+		ptab->list.data.deleted.end = ptdep->prev;
+
+	    ptdep = ptdep->next;
+
+	    i = 0;
+	    while (reds < max_reds && ptdep) {
+		if (ptdep->ix < 0) {
+		    if (free_deleted) {
+			ERTS_PTAB_LIST_ASSERT(free_list);
+			ERTS_PTAB_LIST_ASSERT(ptdep->prev);
+
+			ptdep->prev->next = NULL; /* end of free_list */
+			ptab->list.data.deleted.start = ptdep;
+			ptdep->prev = NULL;
+			free_deleted = 0;
+		    }
+		}
+		else {
+		    int cix = ptdep->ix/ERTS_PTAB_LIST_BIF_TAB_CHUNK_SIZE;
+		    Uint64 chunk_interval = ptlbdp->chunk[cix].interval;
+		    Eterm pid = ptdep->u.element.id;
+		    ERTS_PTAB_LIST_ASSERT(erts_ptab_is_valid_id(pid));
+
+		    if (ptdep->u.element.inserted < invocation_interval) {
+			if (ptdep->u.element.deleted < chunk_interval) {
+			    ERTS_PTAB_LIST_DBG_CHK_PID_NOT_FOUND(
+				ptlbdp,
+				pid,
+				ptdep->u.element.inserted);
+			    ptlbdp->pid[ptlbdp->pid_ix] = pid;
+#if ERTS_PTAB_LIST_BIF_DEBUGLEVEL >= ERTS_PTAB_LIST_DBGLVL_CHK_FOUND_PIDS
+			    ptlbdp->debug.pid_started[ptlbdp->pid_ix]
+				= ptdep->u.element.inserted;
+#endif
+			    ptlbdp->pid_ix++;
+			    ERTS_PTAB_LIST_ASSERT(ptlbdp->pid_ix
+						  <= ptlbdp->pid_sz);
+			}
+			else {
+			    ERTS_PTAB_LIST_DBG_CHK_PID_FOUND(
+				ptlbdp,
+				pid,
+				ptdep->u.element.inserted);
+			}
+		    }
+		    else {
+			ERTS_PTAB_LIST_DBG_CHK_PID_NOT_FOUND(
+			    ptlbdp,
+			    pid,
+			    ptdep->u.element.inserted);
+		    }
+
+		    i++;
+		    if (i == ERTS_PTAB_LIST_BIF_INSPECT_DELETED_PER_RED) {
+			reds++;
+			i = 0;
+		    }
+		    if (free_deleted)
+			reds += ERTS_PTAB_LIST_BIF_TAB_FREE_DELETED_REDS;
+		}
+		ptdep = ptdep->next;
+	    }
+
+	    if (free_deleted) {
+ 		ERTS_PTAB_LIST_ASSERT(free_list);
+		ptab->list.data.deleted.start = ptdep;
+		if (!ptdep)
+		    ptab->list.data.deleted.end = NULL;
+		else {
+		    ERTS_PTAB_LIST_ASSERT(ptdep->prev);
+		    ptdep->prev->next = NULL; /* end of free_list */
+		    ptdep->prev = NULL;
+		}
+	    }
+
+	    if (!ptdep) {
+		/* Done */
+		ERTS_PTAB_LIST_ASSERT(ptlbdp->pid_ix == ptlbdp->pid_sz);
+		ptlbdp->state = BUILDING_RESULT;
+		ptlbdp->bif_invocation->next = free_list;
+		free_list = ptlbdp->bif_invocation;
+		ptlbdp->bif_invocation = NULL;
+	    }
+	    else {
+		/* Link in bif_invocation again where we left off */
+		ptlbdp->bif_invocation->prev = ptdep->prev;
+		ptlbdp->bif_invocation->next = ptdep;
+		ptdep->prev = ptlbdp->bif_invocation;
+		if (ptlbdp->bif_invocation->prev)
+		    ptlbdp->bif_invocation->prev->next = ptlbdp->bif_invocation;
+		else {
+		    ERTS_PTAB_LIST_ASSERT(ptab->list.data.deleted.start
+					  == ptdep);
+		    ptab->list.data.deleted.start = ptlbdp->bif_invocation;
+		}
+	    }
+
+	    ERTS_PTAB_LIST_DBG_CHK_DEL_LIST(ptab);
+	    ERTS_PTAB_LIST_DBG_CHK_FREELIST(ptab, free_list);
+	    erts_ptab_rwunlock(ptab);
+
+	    /*
+	     * We do the actual free of deleted structures now when we
+	     * have released the table lock instead of when we encountered
+	     * them. This since free() isn't for free and we don't want to
+	     * unnecessarily block other schedulers.
+	     */
+	    while (free_list) {
+		ptdep = free_list;
+		free_list = ptdep->next;
+		erts_free(ERTS_ALC_T_PTAB_LIST_DEL, ptdep);
+	    }
+
+	    have_reds -= reds;
+	    if (have_reds < 0)	
+		have_reds = 0;
+	    BUMP_REDS(c_p, reds);
+	    break;
+	}
+
+	case BUILDING_RESULT: {
+	    int conses, ix, min_ix;
+	    Eterm *hp;
+	    Eterm res = *res_accp;
+
+	    ERTS_PTAB_LIST_DBG_VERIFY_PIDS(ptlbdp);
+	    ERTS_PTAB_LIST_DBG_CHK_RESLIST(res);
+
+	    ERTS_PTAB_LIST_DBG_TRACE(p->common.id, begin_build_res);
+
+	    have_reds = ERTS_BIF_REDS_LEFT(c_p);
+	    conses = ERTS_PTAB_LIST_BIF_BUILD_RESULT_CONSES_PER_RED*have_reds;
+	    min_ix = ptlbdp->pid_ix - conses;
+	    if (min_ix < 0) {
+		min_ix = 0;
+		conses = ptlbdp->pid_ix;
+	    }
+
+	    if (conses) {
+		hp = HAlloc(c_p, conses*2);
+		ERTS_PTAB_LIST_DBG_SAVE_HEAP_ALLOC(ptlbdp, hp, conses*2);
+
+		for (ix = ptlbdp->pid_ix - 1; ix >= min_ix; ix--) {
+		    ERTS_PTAB_LIST_ASSERT(erts_ptab_is_valid_id(ptlbdp->pid[ix]));
+		    res = CONS(hp, ptlbdp->pid[ix], res);
+		    hp += 2;
+		}
+
+		ERTS_PTAB_LIST_DBG_VERIFY_HEAP_ALLOC_USED(ptlbdp, hp);
+	    }
+
+	    ptlbdp->pid_ix = min_ix;
+	    if (min_ix == 0)
+		ptlbdp->state = RETURN_RESULT;
+	    else {
+		ptlbdp->pid_sz = min_ix;
+		ptlbdp->pid = erts_realloc(ERTS_ALC_T_PTAB_LIST_PIDS,
+					   ptlbdp->pid,
+					   sizeof(Eterm)*ptlbdp->pid_sz);
+#if ERTS_PTAB_LIST_BIF_DEBUGLEVEL >= ERTS_PTAB_LIST_DBGLVL_CHK_FOUND_PIDS
+		ptlbdp->debug.pid_started
+		    = erts_realloc(ERTS_ALC_T_PTAB_LIST_PIDS,
+				   ptlbdp->debug.pid_started,
+				   sizeof(Uint64) * ptlbdp->pid_sz);
+#endif
+	    }
+	    reds = conses/ERTS_PTAB_LIST_BIF_BUILD_RESULT_CONSES_PER_RED;
+	    BUMP_REDS(c_p, reds);
+	    have_reds -= reds;
+
+	    ERTS_PTAB_LIST_DBG_CHK_RESLIST(res);
+	    ERTS_PTAB_LIST_DBG_TRACE(c_p->common.id, end_build_res);
+	    *res_accp = res;
+	    break;
+	}
+	case RETURN_RESULT:
+	    cleanup_ptab_list_bif_data(mbp);
+	    return 1;
+
+	default:
+	    erl_exit(ERTS_ABORT_EXIT,
+		     "%s:%d:ptab_list_bif_engine(): Invalid state: %d\n",
+		     __FILE__, __LINE__, (int) ptlbdp->state);
+	}
+
+	
+    } while (have_reds || ptlbdp->state == RETURN_RESULT);
+
+    return 0;
+}
+
+/*
+ * ptab_list_continue/2 is a hidden BIF that the original BIF traps to
+ * if there are too much work to do in one go.
+ */
+
+static BIF_RETTYPE ptab_list_continue(BIF_ALIST_2)
+{
+    Eterm res_acc;
+    Binary *mbp;
+
+    /*
+     * This bif cannot be called from erlang code. It can only be
+     * trapped to from other BIFs; therefore, a bad argument
+     * is an internal error and should never occur...
+     */
+
+    ERTS_PTAB_LIST_DBG_TRACE(BIF_P->common.id, call);
+    ERTS_PTAB_LIST_ASSERT(is_nil(BIF_ARG_1) || is_list(BIF_ARG_1));
+
+    res_acc = BIF_ARG_1;
+
+    ERTS_PTAB_LIST_ASSERT(ERTS_TERM_IS_MAGIC_BINARY(BIF_ARG_2));
+
+    mbp = ((ProcBin *) binary_val(BIF_ARG_2))->val;
+
+    ERTS_PTAB_LIST_ASSERT(ERTS_MAGIC_BIN_DESTRUCTOR(mbp)
+			  == cleanup_ptab_list_bif_data);
+    ERTS_PTAB_LIST_ASSERT(
+	((ErtsPTabListBifData *) ERTS_MAGIC_BIN_DATA(mbp))->debug.caller
+	== BIF_P->common.id);
+
+    if (ptab_list_bif_engine(BIF_P, &res_acc, mbp)) {
+	ERTS_PTAB_LIST_DBG_TRACE(BIF_P->common.id, return);
+	BIF_RET(res_acc);
+    }
+    else {
+	ERTS_PTAB_LIST_DBG_TRACE(BIF_P->common.id, trap);
+	ERTS_BIF_YIELD2(&ptab_list_continue_export, BIF_P, res_acc, BIF_ARG_2);
+    }
+}
+
+void
+erts_ptab_init(void)
+{
+    /* ptab_list_continue/2 is a hidden BIF that the original BIF traps to. */
+    erts_init_trap_export(&ptab_list_continue_export,
+			  am_erlang, am_ptab_list_continue, 2,
+			  &ptab_list_continue);
+
+}
+
+/*
+ * Debug stuff
+ */
+
+Sint
+erts_ptab_test_next_id(ErtsPTab *ptab, int set, Uint next)
+{
+    Uint64 ld;
+    Sint res;
+    Eterm data;
+    int first_pix = -1;
+
+    erts_ptab_rwlock(ptab);
+
+    if (!set)
+	ld = last_data_read_nob(ptab);
+    else {
+
+	ld = (Uint64) next;
+	data = ERTS_PTAB_LastData2EtermData(ld);
+	if (ptab->r.o.invalid_data == data) {
+	    ld += ptab->r.o.max;
+	    ASSERT(erts_ptab_data2pix(ptab, data)
+		   == erts_ptab_data2pix(ptab,
+					 ERTS_PTAB_LastData2EtermData(ld)));
+	}
+	last_data_set_relb(ptab, ld);
+    }
+
+    while (1) {
+	int pix;
+	ld++;
+	pix = (int) (ld % ptab->r.o.max);
+	if (first_pix < 0)
+	    first_pix = pix;
+	else if (pix == first_pix) {
+	    res = -1;
+	    break;
+	}
+	if (ERTS_AINT_NULL == erts_ptab_pix2intptr_nob(ptab, pix)) {
+	    data = ERTS_PTAB_LastData2EtermData(ld);
+	    if (ptab->r.o.invalid_data == data) {
+		ld += ptab->r.o.max;
+		ASSERT(erts_ptab_data2pix(ptab, data)
+		       == erts_ptab_data2pix(ptab,
+					     ERTS_PTAB_LastData2EtermData(ld)));
+		data = ERTS_PTAB_LastData2EtermData(ld);
+	    }
+	    res = data;
+	    break;
+	}
+    }
+
+    erts_ptab_rwunlock(ptab);
+
+    return res;
+}
+
+static ERTS_INLINE ErtsPTabElementCommon *
+ptab_pix2el(ErtsPTab *ptab, int ix)
+{
+    ErtsPTabElementCommon *ptab_el;
+    ASSERT(0 <= ix && ix < ptab->r.o.max);
+    ptab_el = (ErtsPTabElementCommon *) erts_ptab_pix2intptr_nob(ptab, ix);
+    if (ptab_el == ptab->r.o.invalid_element)
+	return NULL;
+    else
+	return ptab_el;
+}
+
+Eterm
+erts_debug_ptab_list(Process *c_p, ErtsPTab *ptab)
+{
+    int i;
+    Uint need;
+    Eterm res;
+    Eterm* hp;
+    Eterm *hp_end;
+
+    erts_ptab_rwlock(ptab);
+
+    res = NIL;
+    need = erts_ptab_count(ptab) * 2;
+    hp = HAlloc(c_p, need); /* we need two heap words for each id */
+    hp_end = hp + need;
+     
+    /* make the list by scanning bakward */
+
+
+    for (i = ptab->r.o.max-1; i >= 0; i--) {
+	ErtsPTabElementCommon *el = ptab_pix2el(ptab, i);
+	if (el) {
+	    res = CONS(hp, el->id, res);
+	    hp += 2;
+	}
+    }
+
+    erts_ptab_rwunlock(ptab);
+
+    HRelease(c_p, hp_end, hp);
+
+    return res;
+}
+
+Eterm
+erts_debug_ptab_list_bif_info(Process *c_p, ErtsPTab *ptab)
+{
+    ERTS_DECL_AM(ptab_list_bif_info);
+    Eterm elements[] = {
+	AM_ptab_list_bif_info,
+	make_small((Uint) ERTS_PTAB_LIST_BIF_MIN_START_REDS),
+	make_small((Uint) ptab->list.data.chunks),
+	make_small((Uint) ERTS_PTAB_LIST_BIF_TAB_CHUNK_SIZE),
+	make_small((Uint) ERTS_PTAB_LIST_BIF_TAB_INSPECT_INDICES_PER_RED),
+	make_small((Uint) ERTS_PTAB_LIST_BIF_TAB_FREE_DELETED_REDS),
+	make_small((Uint) ERTS_PTAB_LIST_BIF_INSPECT_DELETED_PER_RED),
+	make_small((Uint) ERTS_PTAB_LIST_INSPECT_DELETED_MAX_REDS),
+	make_small((Uint) ERTS_PTAB_LIST_BIF_BUILD_RESULT_CONSES_PER_RED),
+	make_small((Uint) ERTS_PTAB_LIST_BIF_DEBUGLEVEL)
+    };
+    Uint sz = 0;
+    Eterm *hp;
+    (void) erts_bld_tuplev(NULL, &sz, sizeof(elements)/sizeof(Eterm), elements);
+    hp = HAlloc(c_p, sz);
+    return erts_bld_tuplev(&hp, NULL, sizeof(elements)/sizeof(Eterm), elements);
+}
+
+#if ERTS_PTAB_LIST_BIF_DEBUGLEVEL >= ERTS_PTAB_LIST_DBGLVL_CHK_FOUND_PIDS
+static void
+debug_ptab_list_check_found_pid(ErtsPTabListBifData *ptlbdp,
+				Eterm pid,
+				Uint64 ic,
+				int pid_should_be_found)
+{
+    int i;
+    for (i = 0; i < ptlbdp->pid_ix; i++) {
+	if (ptlbdp->pid[i] == pid && ptlbdp->debug.pid_started[i] == ic) {
+	    ERTS_PTAB_LIST_ASSERT(pid_should_be_found);
+	    return;
+	}
+    }
+    ERTS_PTAB_LIST_ASSERT(!pid_should_be_found);
+}
+#endif
+
+#if ERTS_PTAB_LIST_BIF_DEBUGLEVEL >= ERTS_PTAB_LIST_DBGLVL_CHK_RESLIST
+static void
+debug_ptab_list_check_res_list(Eterm list)
+{
+    while (is_list(list)) {
+	Eterm* consp = list_val(list);
+	Eterm hd = CAR(consp);
+	ERTS_PTAB_LIST_ASSERT(erts_ptab_is_valid_id(hd));
+	list = CDR(consp);
+    }
+
+    ERTS_PTAB_LIST_ASSERT(is_nil(list));
+}
+#endif
+
+#if ERTS_PTAB_LIST_BIF_DEBUGLEVEL >= ERTS_PTAB_LIST_DBGLVL_CHK_PIDS
+
+static void
+debug_ptab_list_save_all_pids(ErtsPTabListBifData *ptlbdp)
+{
+    int ix, tix, cpix;
+    ErtsPTab *ptab = ptlbdp->ptab;
+    ptlbdp->debug.correct_pids_verified = 0;
+    ptlbdp->debug.correct_pids = erts_alloc(ERTS_ALC_T_PTAB_LIST_PIDS,
+					    sizeof(Eterm)*ptlbdp->pid_sz);
+
+    for (tix = 0, cpix = 0; tix < ptab->r.o.max; tix++) {
+	ErtsPTabElementCommon *el = ptab_pix2el(ptab, tix);
+	if (el) {
+	    ERTS_PTAB_LIST_ASSERT(erts_ptab_is_valid_id(el->id));
+	    ptlbdp->debug.correct_pids[cpix++] = el->id;
+	    ERTS_PTAB_LIST_ASSERT(cpix <= ptlbdp->pid_sz);
+	}
+    }
+    ERTS_PTAB_LIST_ASSERT(cpix == ptlbdp->pid_sz);
+
+    for (ix = 0; ix < ptlbdp->pid_sz; ix++)
+	ptlbdp->pid[ix] = make_small(ix);
+}
+
+static void
+debug_ptab_list_verify_all_pids(ErtsPTabListBifData *ptlbdp)
+{
+    int ix, cpix;
+
+    ERTS_PTAB_LIST_ASSERT(ptlbdp->pid_ix == ptlbdp->pid_sz);
+
+    for (ix = 0; ix < ptlbdp->pid_sz; ix++) {
+	int found = 0;
+	Eterm pid = ptlbdp->pid[ix];
+	ERTS_PTAB_LIST_ASSERT(erts_ptab_is_valid_id(pid));
+	for (cpix = ix; cpix < ptlbdp->pid_sz; cpix++) {
+	    if (ptlbdp->debug.correct_pids[cpix] == pid) {
+		ptlbdp->debug.correct_pids[cpix] = NIL;
+		found = 1;
+		break;
+	    }
+	}
+	if (!found) {
+	    for (cpix = 0; cpix < ix; cpix++) {
+		if (ptlbdp->debug.correct_pids[cpix] == pid) {
+		    ptlbdp->debug.correct_pids[cpix] = NIL;
+		    found = 1;
+		    break;
+		}
+	    }
+	}
+	ERTS_PTAB_LIST_ASSERT(found);
+    }
+    ptlbdp->debug.correct_pids_verified = 1;
+
+    erts_free(ERTS_ALC_T_PTAB_LIST_PIDS, ptlbdp->debug.correct_pids);
+    ptlbdp->debug.correct_pids = NULL;
+}
+#endif /* ERTS_PTAB_LIST_BIF_DEBUGLEVEL >= ERTS_PTAB_LIST_DBGLVL_CHK_PIDS */
+
+#if ERTS_PTAB_LIST_BIF_DEBUGLEVEL >= ERTS_PTAB_LIST_DBGLVL_CHK_DEL_LIST
+static void
+debug_ptab_list_check_del_list(ErtsPTab *ptab)
+{
+    ERTS_SMP_LC_ASSERT(erts_smp_lc_ptab_is_rwlocked(ptab));
+    if (!ptab->list.data.deleted.start)
+	ERTS_PTAB_LIST_ASSERT(!ptab->list.data.deleted.end);
+    else {
+	Uint64 curr_interval = erts_smp_current_interval_nob(erts_ptab_interval(ptab));
+	Uint64 *prev_x_interval_p = NULL;
+	ErtsPTabDeletedElement *ptdep;
+
+	for (ptdep = ptab->list.data.deleted.start;
+	     ptdep;
+	     ptdep = ptdep->next) {
+	    if (!ptdep->prev)
+		ERTS_PTAB_LIST_ASSERT(ptab->list.data.deleted.start == ptdep);
+	    else
+		ERTS_PTAB_LIST_ASSERT(ptdep->prev->next == ptdep);
+	    if (!ptdep->next)
+		ERTS_PTAB_LIST_ASSERT(ptab->list.data.deleted.end == ptdep);
+	    else
+		ERTS_PTAB_LIST_ASSERT(ptdep->next->prev == ptdep);
+	    if (ptdep->ix < 0) {
+		Uint64 interval = ptdep->u.bif_invocation.interval;
+		ERTS_PTAB_LIST_ASSERT(interval <= curr_interval);
+	    }
+	    else {
+		Uint64 s_interval = ptdep->u.element.inserted;
+		Uint64 x_interval = ptdep->u.element.deleted;
+		
+		ERTS_PTAB_LIST_ASSERT(s_interval <= x_interval);
+		if (prev_x_interval_p)
+		    ERTS_PTAB_LIST_ASSERT(*prev_x_interval_p <= x_interval);
+		prev_x_interval_p = &ptdep->u.element.deleted;
+		ERTS_PTAB_LIST_ASSERT(
+		    erts_ptab_is_valid_id(ptdep->u.element.id));
+		ERTS_PTAB_LIST_ASSERT(erts_ptab_id2pix(ptab,
+						       ptdep->u.element.id)
+				      == ptdep->ix);
+
+	    }
+	}
+	
+    }
+}
+
+static void
+debug_ptab_list_check_del_free_list(ErtsPTab *ptab,
+				    ErtsPTabDeletedElement *free_list)
+{
+    if (ptab->list.data.deleted.start) {
+	ErtsPTabDeletedElement *fptdep;
+	ErtsPTabDeletedElement *ptdep;
+
+	for (fptdep = free_list; fptdep; fptdep = fptdep->next) {
+	    for (ptdep = ptab->list.data.deleted.start;
+		 ptdep;
+		 ptdep = ptdep->next) {
+		ERTS_PTAB_LIST_ASSERT(fptdep != ptdep);
+	    }
+	}
+    }
+}
+
+#endif
+
+#if ERTS_PTAB_LIST_BIF_DEBUGLEVEL != 0
+
+static void
+debug_ptab_list_assert_error(char* expr, const char* file, int line, const char *func)
+{   
+    fflush(stdout);
+    erts_fprintf(stderr, "%s:%d:%s(): Assertion failed: %s\n",
+		 (char *) file, line, (char *) func, expr);
+    fflush(stderr);
+    abort();
+}
+
+#endif
diff --git a/erts/emulator/beam/erl_ptab.h b/erts/emulator/beam/erl_ptab.h
new file mode 100644
index 0000000000..8a130f42a3
--- /dev/null
+++ b/erts/emulator/beam/erl_ptab.h
@@ -0,0 +1,472 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2012. All Rights Reserved.
+ *
+ * The contents of this file are subject to the Erlang Public License,
+ * Version 1.1, (the "License"); you may not use this file except in
+ * compliance with the License. You should have received a copy of the
+ * Erlang Public License along with this software. If not, it can be
+ * retrieved online at http://www.erlang.org/.
+ *
+ * Software distributed under the License is distributed on an "AS IS"
+ * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+ * the License for the specific language governing rights and limitations
+ * under the License.
+ *
+ * %CopyrightEnd%
+ */
+
+/*
+ * Description:	Process/Port table implementation.
+ *
+ * Author: 	Rickard Green
+ */
+
+#ifndef ERL_PTAB_H__
+#define ERL_PTAB_H__
+
+#include "sys.h"
+#include "erl_term.h"
+#include "erl_time.h"
+#include "erl_utils.h"
+#define ERL_THR_PROGRESS_TSD_TYPE_ONLY
+#include "erl_thr_progress.h"
+#undef ERL_THR_PROGRESS_TSD_TYPE_ONLY
+#include "erl_alloc.h"
+#include "erl_monitors.h"
+
+#define ERTS_TRACER_PROC(P) 	((P)->common.tracer_proc)
+#define ERTS_TRACE_FLAGS(P)	((P)->common.trace_flags)
+
+#define ERTS_P_LINKS(P)		((P)->common.u.alive.links)
+#define ERTS_P_MONITORS(P)	((P)->common.u.alive.monitors)
+
+#define IS_TRACED(p) \
+    (ERTS_TRACER_PROC((p)) != NIL)
+#define ARE_TRACE_FLAGS_ON(p,tf) \
+    ((ERTS_TRACE_FLAGS((p)) & (tf|F_SENSITIVE)) == (tf))
+#define IS_TRACED_FL(p,tf) \
+    ( IS_TRACED(p) && ARE_TRACE_FLAGS_ON(p,tf) )
+
+typedef struct {
+    Eterm id;
+#ifdef ERTS_SMP
+    erts_atomic32_t refc;
+#endif
+    Eterm tracer_proc;
+    Uint trace_flags;
+    union {
+	/* --- While being alive --- */
+	struct {
+	    Uint64 started_interval;
+	    struct reg_proc *reg;
+	    ErtsLink *links;
+	    ErtsMonitor *monitors;
+#ifdef ERTS_SMP
+	    ErtsSmpPTimer *ptimer;
+#else
+	    ErlTimer tm;
+#endif
+	} alive;
+
+	/* --- While being released --- */
+	ErtsThrPrgrLaterOp release;
+    } u;
+} ErtsPTabElementCommon;
+
+typedef struct ErtsPTabDeletedElement_ ErtsPTabDeletedElement;
+
+typedef struct {
+    erts_smp_rwmtx_t rwmtx;
+    erts_interval_t interval;
+    struct {
+	ErtsPTabDeletedElement *start;
+	ErtsPTabDeletedElement *end;
+    } deleted;
+    int chunks;
+} ErtsPTabListData;
+
+typedef struct {
+#ifdef ARCH_32
+    erts_smp_dw_atomic_t last_data;
+#else
+    erts_smp_atomic_t last_data;
+#endif
+    erts_smp_atomic32_t count;
+} ErtsPTabVolatileData;
+
+typedef struct {
+    erts_smp_atomic_t *tab;
+    Uint32 max;
+    Uint32 tab_cache_lines;
+    Uint32 pix_per_cache_line;
+    Uint32 pix_mask;
+    Uint32 pix_cl_mask;
+    Uint32 pix_cl_shift;
+    Uint32 pix_cli_mask;
+    Uint32 pix_cli_shift;
+    ErtsPTabElementCommon *invalid_element;
+    Eterm invalid_data;
+    void (*release_element)(void *);
+} ErtsPTabReadOnlyData;
+
+typedef struct {
+    /*
+     * Data mainly modified when someone is listing
+     * the content of the table.
+     */
+    union {
+	ErtsPTabListData data;
+	char algn[ERTS_ALC_CACHE_LINE_ALIGN_SIZE(sizeof(ErtsPTabListData))];
+    } list;
+
+    /*
+     * Frequently modified data.
+     */
+    union {
+	ErtsPTabVolatileData tile;
+	char algn[ERTS_ALC_CACHE_LINE_ALIGN_SIZE(sizeof(ErtsPTabVolatileData))];
+    } vola;
+
+    /*
+     * Read only data.
+     */
+    union {
+	ErtsPTabReadOnlyData o;
+	char algn[ERTS_ALC_CACHE_LINE_ALIGN_SIZE(sizeof(ErtsPTabReadOnlyData))];
+    } r;
+} ErtsPTab;
+
+#define ERTS_PTAB_ID_DATA_SIZE	28
+#define ERTS_PTAB_ID_DATA_SHIFT	(_TAG_IMMED1_SIZE)
+/* ERTS_PTAB_MAX_SIZE must be a power of 2 */
+#define ERTS_PTAB_MAX_SIZE (SWORD_CONSTANT(1) << 27)
+#if (ERTS_PTAB_MAX_SIZE-1) > MAX_SMALL
+# error "The maximum number of processes/ports must fit in a SMALL."
+#endif
+
+
+/*
+ * Currently pids and ports are allowed.
+ */
+#if _PID_DATA_SIZE != ERTS_PTAB_ID_DATA_SIZE
+# error "Unexpected pid data size"
+#endif
+#if _PID_DATA_SHIFT != ERTS_PTAB_ID_DATA_SHIFT
+# error "Unexpected pid tag size"
+#endif
+#if _PORT_DATA_SIZE != ERTS_PTAB_ID_DATA_SIZE
+# error "Unexpected port data size"
+#endif
+#if _PORT_DATA_SHIFT != ERTS_PTAB_ID_DATA_SHIFT
+# error "Unexpected port tag size"
+#endif
+
+#define ERTS_PTAB_INVALID_ID(TAG)					\
+    ((Eterm)								\
+     ((((1 << ERTS_PTAB_ID_DATA_SIZE) - 1) << ERTS_PTAB_ID_DATA_SHIFT)	\
+      | (TAG)))
+
+#define erts_ptab_is_valid_id(ID)					\
+    (is_internal_pid((ID)) || is_internal_port((ID)))
+
+void erts_ptab_init(void);
+void erts_ptab_init_table(ErtsPTab *ptab,
+			  ErtsAlcType_t atype,
+			  void (*release_element)(void *),
+			  ErtsPTabElementCommon *invalid_element,
+			  int size,
+			  char *name);
+int erts_ptab_new_element(ErtsPTab *ptab,
+			  ErtsPTabElementCommon *ptab_el,
+			  void *init_arg,
+			  void (*init_ptab_el)(void *, Eterm));
+void erts_ptab_delete_element(ErtsPTab *ptab,
+			      ErtsPTabElementCommon *ptab_el);
+int erts_ptab_initialized(ErtsPTab *ptab);
+
+ERTS_GLB_INLINE erts_interval_t *erts_ptab_interval(ErtsPTab *ptab);
+ERTS_GLB_INLINE int erts_ptab_max(ErtsPTab *ptab);
+ERTS_GLB_INLINE int erts_ptab_count(ErtsPTab *ptab);
+ERTS_GLB_INLINE Uint erts_ptab_pixdata2data(ErtsPTab *ptab, Eterm pixdata);
+ERTS_GLB_INLINE Uint32 erts_ptab_pixdata2pix(ErtsPTab *ptab, Eterm pixdata);
+ERTS_GLB_INLINE Uint32 erts_ptab_data2pix(ErtsPTab *ptab, Eterm data);
+ERTS_GLB_INLINE Uint erts_ptab_data2pixdata(ErtsPTab *ptab, Eterm data);
+ERTS_GLB_INLINE Eterm erts_ptab_make_id(ErtsPTab *ptab, Eterm data, Eterm tag);
+ERTS_GLB_INLINE int erts_ptab_id2pix(ErtsPTab *ptab, Eterm id);
+ERTS_GLB_INLINE Uint erts_ptab_id2data(ErtsPTab *ptab, Eterm id);
+ERTS_GLB_INLINE erts_aint_t erts_ptab_pix2intptr_nob(ErtsPTab *ptab, int ix);
+ERTS_GLB_INLINE erts_aint_t erts_ptab_pix2intptr_ddrb(ErtsPTab *ptab, int ix);
+ERTS_GLB_INLINE erts_aint_t erts_ptab_pix2intptr_rb(ErtsPTab *ptab, int ix);
+ERTS_GLB_INLINE erts_aint_t erts_ptab_pix2intptr_acqb(ErtsPTab *ptab, int ix);
+ERTS_GLB_INLINE void erts_ptab_inc_refc(ErtsPTabElementCommon *ptab_el);
+ERTS_GLB_INLINE int erts_ptab_dec_test_refc(ErtsPTabElementCommon *ptab_el);
+ERTS_GLB_INLINE int erts_ptab_add_test_refc(ErtsPTabElementCommon *ptab_el,
+					    Sint32 add_refc);
+ERTS_GLB_INLINE void erts_ptab_rlock(ErtsPTab *ptab);
+ERTS_GLB_INLINE int erts_ptab_tryrlock(ErtsPTab *ptab);
+ERTS_GLB_INLINE void erts_ptab_runlock(ErtsPTab *ptab);
+ERTS_GLB_INLINE void erts_ptab_rwlock(ErtsPTab *ptab);
+ERTS_GLB_INLINE int erts_ptab_tryrwlock(ErtsPTab *ptab);
+ERTS_GLB_INLINE void erts_ptab_rwunlock(ErtsPTab *ptab);
+ERTS_GLB_INLINE int erts_smp_lc_ptab_is_rlocked(ErtsPTab *ptab);
+ERTS_GLB_INLINE int erts_smp_lc_ptab_is_rwlocked(ErtsPTab *ptab);
+
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+
+ERTS_GLB_INLINE erts_interval_t *
+erts_ptab_interval(ErtsPTab *ptab)
+{
+    return &ptab->list.data.interval;
+}
+
+ERTS_GLB_INLINE int
+erts_ptab_max(ErtsPTab *ptab)
+{
+    int max = ptab->r.o.max;
+    return max == ERTS_PTAB_MAX_SIZE ? max - 1 : max;
+}
+
+ERTS_GLB_INLINE int
+erts_ptab_count(ErtsPTab *ptab)
+{
+    int max = ptab->r.o.max;
+    erts_aint32_t res = erts_smp_atomic32_read_nob(&ptab->vola.tile.count);
+    if (max == ERTS_PTAB_MAX_SIZE) {
+	max--;
+	res--;
+    }
+    if (res > max)
+	return max;
+    ASSERT(res >= 0);
+    return (int) res;
+
+}
+
+ERTS_GLB_INLINE Uint erts_ptab_pixdata2data(ErtsPTab *ptab, Eterm pixdata)
+{
+    Uint32 data = ((Uint32) pixdata) & ~ptab->r.o.pix_mask;
+    data |= (pixdata >> ptab->r.o.pix_cl_shift) & ptab->r.o.pix_cl_mask;
+    data |= (pixdata & ptab->r.o.pix_cli_mask) << ptab->r.o.pix_cli_shift;
+    return data;
+}
+
+ERTS_GLB_INLINE Uint32 erts_ptab_pixdata2pix(ErtsPTab *ptab, Eterm pixdata)
+{
+    return ((Uint32) pixdata) & ptab->r.o.pix_mask;
+}
+
+ERTS_GLB_INLINE Uint32 erts_ptab_data2pix(ErtsPTab *ptab, Eterm data)
+{
+    Uint32 n, pix;
+    n = (Uint32) data;
+    pix = ((n & ptab->r.o.pix_cl_mask) << ptab->r.o.pix_cl_shift);
+    pix += ((n >> ptab->r.o.pix_cli_shift) & ptab->r.o.pix_cli_mask);
+    ASSERT(0 <= pix && pix < ptab->r.o.max);
+    return pix;
+}
+
+ERTS_GLB_INLINE Uint erts_ptab_data2pixdata(ErtsPTab *ptab, Eterm data)
+{
+    Uint pixdata = data & ~((Uint) ptab->r.o.pix_mask);
+    pixdata |= (Uint) erts_ptab_data2pix(ptab, data);
+    ASSERT(data == erts_ptab_pixdata2data(ptab, pixdata));
+    return pixdata;
+}
+
+#if ERTS_SIZEOF_TERM == 8
+
+ERTS_GLB_INLINE Eterm
+erts_ptab_make_id(ErtsPTab *ptab, Eterm data, Eterm tag)
+{
+    HUint huint;
+    Uint32 low_data = (Uint32) data;
+    low_data &= (1 << ERTS_PTAB_ID_DATA_SIZE) - 1;
+    low_data <<= ERTS_PTAB_ID_DATA_SHIFT;
+    huint.hval[ERTS_HUINT_HVAL_HIGH] = erts_ptab_data2pix(ptab, data);
+    huint.hval[ERTS_HUINT_HVAL_LOW] = low_data | ((Uint32) tag);
+    return (Eterm) huint.val;
+}
+
+ERTS_GLB_INLINE int
+erts_ptab_id2pix(ErtsPTab *ptab, Eterm id)
+{
+    HUint huint;
+    huint.val = id;
+    return (int) huint.hval[ERTS_HUINT_HVAL_HIGH];
+}
+
+ERTS_GLB_INLINE Uint
+erts_ptab_id2data(ErtsPTab *ptab, Eterm id)
+{
+    HUint huint;
+    huint.val = id;
+    return (Uint) (huint.hval[ERTS_HUINT_HVAL_LOW] >> ERTS_PTAB_ID_DATA_SHIFT);
+}
+
+#elif ERTS_SIZEOF_TERM == 4
+
+ERTS_GLB_INLINE Eterm
+erts_ptab_make_id(ErtsPTab *ptab, Eterm data, Eterm tag)
+{
+    Eterm id;
+    data &= ((1 << ERTS_PTAB_ID_DATA_SIZE) - 1);
+    id = (Eterm) erts_ptab_data2pixdata(ptab, data);
+    return (id << ERTS_PTAB_ID_DATA_SHIFT) | tag;
+}
+
+ERTS_GLB_INLINE int
+erts_ptab_id2pix(ErtsPTab *ptab, Eterm id)
+{
+    Uint pixdata = (Uint) id;
+    pixdata >>= ERTS_PTAB_ID_DATA_SHIFT;
+    return (int) erts_ptab_pixdata2pix(ptab, pixdata);
+}
+
+ERTS_GLB_INLINE Uint
+erts_ptab_id2data(ErtsPTab *ptab, Eterm id)
+{
+    Uint pixdata = (Uint) id;
+    pixdata >>= ERTS_PTAB_ID_DATA_SHIFT;
+    return erts_ptab_pixdata2data(ptab, pixdata);
+}
+
+#else
+#error "Unsupported size of term"
+#endif
+
+ERTS_GLB_INLINE erts_aint_t erts_ptab_pix2intptr_nob(ErtsPTab *ptab, int ix)
+{
+    ASSERT(0 <= ix && ix < ptab->r.o.max);
+    return erts_smp_atomic_read_nob(&ptab->r.o.tab[ix]);
+}
+
+ERTS_GLB_INLINE erts_aint_t erts_ptab_pix2intptr_ddrb(ErtsPTab *ptab, int ix)
+{
+    ASSERT(0 <= ix && ix < ptab->r.o.max);
+    return erts_smp_atomic_read_ddrb(&ptab->r.o.tab[ix]);
+}
+
+ERTS_GLB_INLINE erts_aint_t erts_ptab_pix2intptr_rb(ErtsPTab *ptab, int ix)
+{
+    ASSERT(0 <= ix && ix < ptab->r.o.max);
+    return erts_smp_atomic_read_rb(&ptab->r.o.tab[ix]);
+}
+
+ERTS_GLB_INLINE erts_aint_t erts_ptab_pix2intptr_acqb(ErtsPTab *ptab, int ix)
+{
+    ASSERT(0 <= ix && ix < ptab->r.o.max);
+    return erts_smp_atomic_read_acqb(&ptab->r.o.tab[ix]);
+}
+
+ERTS_GLB_INLINE void erts_ptab_inc_refc(ErtsPTabElementCommon *ptab_el)
+{
+#ifdef ERTS_SMP
+#ifdef ERTS_ENABLE_LOCK_CHECK
+    erts_aint32_t refc = erts_atomic32_inc_read_nob(&ptab_el->refc);
+    ERTS_SMP_LC_ASSERT(refc > 1);
+#else
+    erts_atomic32_inc_nob(&ptab_el->refc);
+#endif
+#endif
+}
+
+ERTS_GLB_INLINE int erts_ptab_dec_test_refc(ErtsPTabElementCommon *ptab_el)
+{
+#ifdef ERTS_SMP
+    erts_aint32_t refc = erts_atomic32_dec_read_nob(&ptab_el->refc);
+    ERTS_SMP_LC_ASSERT(refc >= 0);
+    return (int) refc;
+#else
+    return 0;
+#endif
+}
+
+ERTS_GLB_INLINE int erts_ptab_add_test_refc(ErtsPTabElementCommon *ptab_el,
+					    Sint32 add_refc)
+{
+#ifdef ERTS_SMP
+    erts_aint32_t refc;
+
+#ifndef ERTS_ENABLE_LOCK_CHECK
+    if (add_refc >= 0) {
+	erts_atomic32_add_nob(&ptab_el->refc,
+			      (erts_aint32_t) add_refc);
+	return 1;
+    }
+#endif
+
+    refc = erts_atomic32_add_read_nob(&ptab_el->refc,
+				      (erts_aint32_t) add_refc);
+    ERTS_SMP_LC_ASSERT(refc >= 0);
+    return (int) refc;
+#else
+    return 0;
+#endif
+}
+
+ERTS_GLB_INLINE void erts_ptab_rlock(ErtsPTab *ptab)
+{
+    erts_smp_rwmtx_rlock(&ptab->list.data.rwmtx);
+}
+
+ERTS_GLB_INLINE int erts_ptab_tryrlock(ErtsPTab *ptab)
+{
+    return erts_smp_rwmtx_tryrlock(&ptab->list.data.rwmtx);
+}
+
+ERTS_GLB_INLINE void erts_ptab_runlock(ErtsPTab *ptab)
+{
+    erts_smp_rwmtx_runlock(&ptab->list.data.rwmtx);
+}
+
+ERTS_GLB_INLINE void erts_ptab_rwlock(ErtsPTab *ptab)
+{
+    erts_smp_rwmtx_rwlock(&ptab->list.data.rwmtx);
+}
+
+ERTS_GLB_INLINE int erts_ptab_tryrwlock(ErtsPTab *ptab)
+{
+    return erts_smp_rwmtx_tryrwlock(&ptab->list.data.rwmtx);
+}
+
+ERTS_GLB_INLINE void erts_ptab_rwunlock(ErtsPTab *ptab)
+{
+    erts_smp_rwmtx_rwunlock(&ptab->list.data.rwmtx);
+}
+
+ERTS_GLB_INLINE int erts_smp_lc_ptab_is_rlocked(ErtsPTab *ptab)
+{
+    return erts_smp_lc_rwmtx_is_rlocked(&ptab->list.data.rwmtx);
+}
+
+ERTS_GLB_INLINE int erts_smp_lc_ptab_is_rwlocked(ErtsPTab *ptab)
+{
+    return erts_smp_lc_rwmtx_is_rwlocked(&ptab->list.data.rwmtx);
+}
+
+#endif
+
+#endif
+
+#if defined(ERTS_PTAB_WANT_BIF_IMPL__) && !defined(ERTS_PTAB_LIST__)
+#define ERTS_PTAB_LIST__
+
+#include "erl_process.h"
+#include "bif.h"
+
+BIF_RETTYPE erts_ptab_list(struct process *c_p, ErtsPTab *ptab);
+
+#endif
+
+#if defined(ERTS_PTAB_WANT_DEBUG_FUNCS__) && !defined(ERTS_PTAB_DEBUG_FUNCS__)
+#define ERTS_PTAB_DEBUG_FUNCS__
+#include "erl_process.h"
+
+/* Debug functions */
+Sint erts_ptab_test_next_id(ErtsPTab *ptab, int set, Uint next);
+Eterm erts_debug_ptab_list(Process *c_p, ErtsPTab *ptab);
+Eterm erts_debug_ptab_list_bif_info(Process *c_p, ErtsPTab *ptab);
+
+#endif
diff --git a/erts/emulator/beam/erl_smp.h b/erts/emulator/beam/erl_smp.h
index a32e9d9d7c..34c90c0bda 100644
--- a/erts/emulator/beam/erl_smp.h
+++ b/erts/emulator/beam/erl_smp.h
@@ -274,6 +274,7 @@ ERTS_GLB_INLINE void erts_smp_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_smp_atomic_read_band_nob erts_atomic_read_band_nob
 #define erts_smp_atomic_xchg_nob erts_atomic_xchg_nob
 #define erts_smp_atomic_cmpxchg_nob erts_atomic_cmpxchg_nob
+#define erts_smp_atomic_read_bset_nob erts_atomic_read_bset_nob
 
 #define erts_smp_atomic_init_mb erts_atomic_init_mb
 #define erts_smp_atomic_set_mb erts_atomic_set_mb
@@ -288,6 +289,7 @@ ERTS_GLB_INLINE void erts_smp_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_smp_atomic_read_band_mb erts_atomic_read_band_mb
 #define erts_smp_atomic_xchg_mb erts_atomic_xchg_mb
 #define erts_smp_atomic_cmpxchg_mb erts_atomic_cmpxchg_mb
+#define erts_smp_atomic_read_bset_mb erts_atomic_read_bset_mb
 
 #define erts_smp_atomic_init_acqb erts_atomic_init_acqb
 #define erts_smp_atomic_set_acqb erts_atomic_set_acqb
@@ -302,6 +304,7 @@ ERTS_GLB_INLINE void erts_smp_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_smp_atomic_read_band_acqb erts_atomic_read_band_acqb
 #define erts_smp_atomic_xchg_acqb erts_atomic_xchg_acqb
 #define erts_smp_atomic_cmpxchg_acqb erts_atomic_cmpxchg_acqb
+#define erts_smp_atomic_read_bset_acqb erts_atomic_read_bset_acqb
 
 #define erts_smp_atomic_init_relb erts_atomic_init_relb
 #define erts_smp_atomic_set_relb erts_atomic_set_relb
@@ -316,6 +319,7 @@ ERTS_GLB_INLINE void erts_smp_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_smp_atomic_read_band_relb erts_atomic_read_band_relb
 #define erts_smp_atomic_xchg_relb erts_atomic_xchg_relb
 #define erts_smp_atomic_cmpxchg_relb erts_atomic_cmpxchg_relb
+#define erts_smp_atomic_read_bset_relb erts_atomic_read_bset_relb
 
 #define erts_smp_atomic_init_ddrb erts_atomic_init_ddrb
 #define erts_smp_atomic_set_ddrb erts_atomic_set_ddrb
@@ -330,6 +334,7 @@ ERTS_GLB_INLINE void erts_smp_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_smp_atomic_read_band_ddrb erts_atomic_read_band_ddrb
 #define erts_smp_atomic_xchg_ddrb erts_atomic_xchg_ddrb
 #define erts_smp_atomic_cmpxchg_ddrb erts_atomic_cmpxchg_ddrb
+#define erts_smp_atomic_read_bset_ddrb erts_atomic_read_bset_ddrb
 
 #define erts_smp_atomic_init_rb erts_atomic_init_rb
 #define erts_smp_atomic_set_rb erts_atomic_set_rb
@@ -344,6 +349,7 @@ ERTS_GLB_INLINE void erts_smp_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_smp_atomic_read_band_rb erts_atomic_read_band_rb
 #define erts_smp_atomic_xchg_rb erts_atomic_xchg_rb
 #define erts_smp_atomic_cmpxchg_rb erts_atomic_cmpxchg_rb
+#define erts_smp_atomic_read_bset_rb erts_atomic_read_bset_rb
 
 #define erts_smp_atomic_init_wb erts_atomic_init_wb
 #define erts_smp_atomic_set_wb erts_atomic_set_wb
@@ -358,6 +364,7 @@ ERTS_GLB_INLINE void erts_smp_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_smp_atomic_read_band_wb erts_atomic_read_band_wb
 #define erts_smp_atomic_xchg_wb erts_atomic_xchg_wb
 #define erts_smp_atomic_cmpxchg_wb erts_atomic_cmpxchg_wb
+#define erts_smp_atomic_read_bset_wb erts_atomic_read_bset_wb
 
 /* 32-bit atomics */
 
@@ -374,6 +381,7 @@ ERTS_GLB_INLINE void erts_smp_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_smp_atomic32_read_band_nob erts_atomic32_read_band_nob
 #define erts_smp_atomic32_xchg_nob erts_atomic32_xchg_nob
 #define erts_smp_atomic32_cmpxchg_nob erts_atomic32_cmpxchg_nob
+#define erts_smp_atomic32_read_bset_nob erts_atomic32_read_bset_nob
 
 #define erts_smp_atomic32_init_mb erts_atomic32_init_mb
 #define erts_smp_atomic32_set_mb erts_atomic32_set_mb
@@ -388,6 +396,7 @@ ERTS_GLB_INLINE void erts_smp_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_smp_atomic32_read_band_mb erts_atomic32_read_band_mb
 #define erts_smp_atomic32_xchg_mb erts_atomic32_xchg_mb
 #define erts_smp_atomic32_cmpxchg_mb erts_atomic32_cmpxchg_mb
+#define erts_smp_atomic32_read_bset_mb erts_atomic32_read_bset_mb
 
 #define erts_smp_atomic32_init_acqb erts_atomic32_init_acqb
 #define erts_smp_atomic32_set_acqb erts_atomic32_set_acqb
@@ -402,6 +411,7 @@ ERTS_GLB_INLINE void erts_smp_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_smp_atomic32_read_band_acqb erts_atomic32_read_band_acqb
 #define erts_smp_atomic32_xchg_acqb erts_atomic32_xchg_acqb
 #define erts_smp_atomic32_cmpxchg_acqb erts_atomic32_cmpxchg_acqb
+#define erts_smp_atomic32_read_bset_acqb erts_atomic32_read_bset_acqb
 
 #define erts_smp_atomic32_init_relb erts_atomic32_init_relb
 #define erts_smp_atomic32_set_relb erts_atomic32_set_relb
@@ -416,6 +426,7 @@ ERTS_GLB_INLINE void erts_smp_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_smp_atomic32_read_band_relb erts_atomic32_read_band_relb
 #define erts_smp_atomic32_xchg_relb erts_atomic32_xchg_relb
 #define erts_smp_atomic32_cmpxchg_relb erts_atomic32_cmpxchg_relb
+#define erts_smp_atomic32_read_bset_relb erts_atomic32_read_bset_relb
 
 #define erts_smp_atomic32_init_ddrb erts_atomic32_init_ddrb
 #define erts_smp_atomic32_set_ddrb erts_atomic32_set_ddrb
@@ -430,6 +441,7 @@ ERTS_GLB_INLINE void erts_smp_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_smp_atomic32_read_band_ddrb erts_atomic32_read_band_ddrb
 #define erts_smp_atomic32_xchg_ddrb erts_atomic32_xchg_ddrb
 #define erts_smp_atomic32_cmpxchg_ddrb erts_atomic32_cmpxchg_ddrb
+#define erts_smp_atomic32_read_bset_ddrb erts_atomic32_read_bset_ddrb
 
 #define erts_smp_atomic32_init_rb erts_atomic32_init_rb
 #define erts_smp_atomic32_set_rb erts_atomic32_set_rb
@@ -444,6 +456,7 @@ ERTS_GLB_INLINE void erts_smp_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_smp_atomic32_read_band_rb erts_atomic32_read_band_rb
 #define erts_smp_atomic32_xchg_rb erts_atomic32_xchg_rb
 #define erts_smp_atomic32_cmpxchg_rb erts_atomic32_cmpxchg_rb
+#define erts_smp_atomic32_read_bset_rb erts_atomic32_read_bset_rb
 
 #define erts_smp_atomic32_init_wb erts_atomic32_init_wb
 #define erts_smp_atomic32_set_wb erts_atomic32_set_wb
@@ -458,6 +471,7 @@ ERTS_GLB_INLINE void erts_smp_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_smp_atomic32_read_band_wb erts_atomic32_read_band_wb
 #define erts_smp_atomic32_xchg_wb erts_atomic32_xchg_wb
 #define erts_smp_atomic32_cmpxchg_wb erts_atomic32_cmpxchg_wb
+#define erts_smp_atomic32_read_bset_wb erts_atomic32_read_bset_wb
 
 #else /* !ERTS_SMP */
 
@@ -513,6 +527,7 @@ ERTS_GLB_INLINE void erts_smp_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_smp_atomic_read_band_nob erts_no_atomic_read_band
 #define erts_smp_atomic_xchg_nob erts_no_atomic_xchg
 #define erts_smp_atomic_cmpxchg_nob erts_no_atomic_cmpxchg
+#define erts_smp_atomic_read_bset_nob erts_no_atomic_read_bset
 
 #define erts_smp_atomic_init_mb erts_no_atomic_set
 #define erts_smp_atomic_set_mb erts_no_atomic_set
@@ -527,6 +542,7 @@ ERTS_GLB_INLINE void erts_smp_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_smp_atomic_read_band_mb erts_no_atomic_read_band
 #define erts_smp_atomic_xchg_mb erts_no_atomic_xchg
 #define erts_smp_atomic_cmpxchg_mb erts_no_atomic_cmpxchg
+#define erts_smp_atomic_read_bset_mb erts_no_atomic_read_bset
 
 #define erts_smp_atomic_init_acqb erts_no_atomic_set
 #define erts_smp_atomic_set_acqb erts_no_atomic_set
@@ -541,6 +557,7 @@ ERTS_GLB_INLINE void erts_smp_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_smp_atomic_read_band_acqb erts_no_atomic_read_band
 #define erts_smp_atomic_xchg_acqb erts_no_atomic_xchg
 #define erts_smp_atomic_cmpxchg_acqb erts_no_atomic_cmpxchg
+#define erts_smp_atomic_read_bset_acqb erts_no_atomic_read_bset
 
 #define erts_smp_atomic_init_relb erts_no_atomic_set
 #define erts_smp_atomic_set_relb erts_no_atomic_set
@@ -555,6 +572,7 @@ ERTS_GLB_INLINE void erts_smp_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_smp_atomic_read_band_relb erts_no_atomic_read_band
 #define erts_smp_atomic_xchg_relb erts_no_atomic_xchg
 #define erts_smp_atomic_cmpxchg_relb erts_no_atomic_cmpxchg
+#define erts_smp_atomic_read_bset_relb erts_no_atomic_read_bset
 
 #define erts_smp_atomic_init_ddrb erts_no_atomic_set
 #define erts_smp_atomic_set_ddrb erts_no_atomic_set
@@ -569,6 +587,7 @@ ERTS_GLB_INLINE void erts_smp_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_smp_atomic_read_band_ddrb erts_no_atomic_read_band
 #define erts_smp_atomic_xchg_ddrb erts_no_atomic_xchg
 #define erts_smp_atomic_cmpxchg_ddrb erts_no_atomic_cmpxchg
+#define erts_smp_atomic_read_bset_ddrb erts_no_atomic_read_bset
 
 #define erts_smp_atomic_init_rb erts_no_atomic_set
 #define erts_smp_atomic_set_rb erts_no_atomic_set
@@ -583,6 +602,7 @@ ERTS_GLB_INLINE void erts_smp_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_smp_atomic_read_band_rb erts_no_atomic_read_band
 #define erts_smp_atomic_xchg_rb erts_no_atomic_xchg
 #define erts_smp_atomic_cmpxchg_rb erts_no_atomic_cmpxchg
+#define erts_smp_atomic_read_bset_rb erts_no_atomic_read_bset
 
 #define erts_smp_atomic_init_wb erts_no_atomic_set
 #define erts_smp_atomic_set_wb erts_no_atomic_set
@@ -597,6 +617,7 @@ ERTS_GLB_INLINE void erts_smp_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_smp_atomic_read_band_wb erts_no_atomic_read_band
 #define erts_smp_atomic_xchg_wb erts_no_atomic_xchg
 #define erts_smp_atomic_cmpxchg_wb erts_no_atomic_cmpxchg
+#define erts_smp_atomic_read_bset_wb erts_no_atomic_read_bset
 
 /* 32-bit atomics */
 
@@ -613,6 +634,7 @@ ERTS_GLB_INLINE void erts_smp_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_smp_atomic32_read_band_nob erts_no_atomic32_read_band
 #define erts_smp_atomic32_xchg_nob erts_no_atomic32_xchg
 #define erts_smp_atomic32_cmpxchg_nob erts_no_atomic32_cmpxchg
+#define erts_smp_atomic32_read_bset_nob erts_no_atomic32_read_bset
 
 #define erts_smp_atomic32_init_mb erts_no_atomic32_set
 #define erts_smp_atomic32_set_mb erts_no_atomic32_set
@@ -627,6 +649,7 @@ ERTS_GLB_INLINE void erts_smp_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_smp_atomic32_read_band_mb erts_no_atomic32_read_band
 #define erts_smp_atomic32_xchg_mb erts_no_atomic32_xchg
 #define erts_smp_atomic32_cmpxchg_mb erts_no_atomic32_cmpxchg
+#define erts_smp_atomic32_read_bset_mb erts_no_atomic32_read_bset
 
 #define erts_smp_atomic32_init_acqb erts_no_atomic32_set
 #define erts_smp_atomic32_set_acqb erts_no_atomic32_set
@@ -641,6 +664,7 @@ ERTS_GLB_INLINE void erts_smp_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_smp_atomic32_read_band_acqb erts_no_atomic32_read_band
 #define erts_smp_atomic32_xchg_acqb erts_no_atomic32_xchg
 #define erts_smp_atomic32_cmpxchg_acqb erts_no_atomic32_cmpxchg
+#define erts_smp_atomic32_read_bset_acqb erts_no_atomic32_read_bset
 
 #define erts_smp_atomic32_init_relb erts_no_atomic32_set
 #define erts_smp_atomic32_set_relb erts_no_atomic32_set
@@ -655,6 +679,7 @@ ERTS_GLB_INLINE void erts_smp_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_smp_atomic32_read_band_relb erts_no_atomic32_read_band
 #define erts_smp_atomic32_xchg_relb erts_no_atomic32_xchg
 #define erts_smp_atomic32_cmpxchg_relb erts_no_atomic32_cmpxchg
+#define erts_smp_atomic32_read_bset_relb erts_no_atomic32_read_bset
 
 #define erts_smp_atomic32_init_ddrb erts_no_atomic32_set
 #define erts_smp_atomic32_set_ddrb erts_no_atomic32_set
@@ -669,6 +694,7 @@ ERTS_GLB_INLINE void erts_smp_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_smp_atomic32_read_band_ddrb erts_no_atomic32_read_band
 #define erts_smp_atomic32_xchg_ddrb erts_no_atomic32_xchg
 #define erts_smp_atomic32_cmpxchg_ddrb erts_no_atomic32_cmpxchg
+#define erts_smp_atomic32_read_bset_ddrb erts_no_atomic32_read_bset
 
 #define erts_smp_atomic32_init_rb erts_no_atomic32_set
 #define erts_smp_atomic32_set_rb erts_no_atomic32_set
@@ -683,6 +709,7 @@ ERTS_GLB_INLINE void erts_smp_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_smp_atomic32_read_band_rb erts_no_atomic32_read_band
 #define erts_smp_atomic32_xchg_rb erts_no_atomic32_xchg
 #define erts_smp_atomic32_cmpxchg_rb erts_no_atomic32_cmpxchg
+#define erts_smp_atomic32_read_bset_rb erts_no_atomic32_read_bset
 
 #define erts_smp_atomic32_init_wb erts_no_atomic32_set
 #define erts_smp_atomic32_set_wb erts_no_atomic32_set
@@ -697,6 +724,7 @@ ERTS_GLB_INLINE void erts_smp_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_smp_atomic32_read_band_wb erts_no_atomic32_read_band
 #define erts_smp_atomic32_xchg_wb erts_no_atomic32_xchg
 #define erts_smp_atomic32_cmpxchg_wb erts_no_atomic32_cmpxchg
+#define erts_smp_atomic32_read_bset_wb erts_no_atomic32_read_bset
 
 #endif /* !ERTS_SMP */
 
diff --git a/erts/emulator/beam/erl_sys_driver.h b/erts/emulator/beam/erl_sys_driver.h
index d429d0ce96..b991a2840c 100644
--- a/erts/emulator/beam/erl_sys_driver.h
+++ b/erts/emulator/beam/erl_sys_driver.h
@@ -31,7 +31,6 @@
 #define ERL_SYS_DRV
 
 typedef long ErlDrvEvent; /* An event to be selected on. */
-typedef long ErlDrvPort; /* A port descriptor. */
 
 /* typedef struct _SysDriverOpts SysDriverOpts; defined in sys.h */
 
diff --git a/erts/emulator/beam/erl_term.c b/erts/emulator/beam/erl_term.c
index bf7774f882..6a04c6fc0b 100644
--- a/erts/emulator/beam/erl_term.c
+++ b/erts/emulator/beam/erl_term.c
@@ -144,9 +144,7 @@ ET_DEFINE_CHECKED(Uint,bignum_header_arity,Eterm,_is_bignum_header);
 ET_DEFINE_CHECKED(Eterm*,big_val,Wterm,is_big);
 ET_DEFINE_CHECKED(Eterm*,float_val,Wterm,is_float);
 ET_DEFINE_CHECKED(Eterm*,tuple_val,Wterm,is_tuple);
-ET_DEFINE_CHECKED(Uint,internal_pid_data,Eterm,is_internal_pid);
 ET_DEFINE_CHECKED(struct erl_node_*,internal_pid_node,Eterm,is_internal_pid);
-ET_DEFINE_CHECKED(Uint,internal_port_data,Eterm,is_internal_port);
 ET_DEFINE_CHECKED(struct erl_node_*,internal_port_node,Eterm,is_internal_port);
 ET_DEFINE_CHECKED(Eterm*,internal_ref_val,Wterm,is_internal_ref);
 ET_DEFINE_CHECKED(Uint,internal_ref_data_words,Wterm,is_internal_ref);
diff --git a/erts/emulator/beam/erl_term.h b/erts/emulator/beam/erl_term.h
index c270d13365..bc4c3a09a0 100644
--- a/erts/emulator/beam/erl_term.h
+++ b/erts/emulator/beam/erl_term.h
@@ -542,12 +542,6 @@ _ET_DECLARE_CHECKED(Eterm*,tuple_val,Wterm)
 #define _GETBITS(X,Pos,Size) (((X) >> (Pos)) & ~(~((Uint) 0) << (Size)))
 
 /*
- * Observe! New layout for pids, ports and references in R9 (see also note
- * in erl_node_container_utils.h).
- */
-
-
-/*
  * Creation in node specific data (pids, ports, refs)
  */
 
@@ -584,7 +578,6 @@ _ET_DECLARE_CHECKED(Eterm*,tuple_val,Wterm)
  *
  */
 
-#define _PID_R9_SER_SIZE	3
 #define _PID_SER_SIZE		(_PID_DATA_SIZE - _PID_NUM_SIZE)
 #define _PID_NUM_SIZE 		15
 
@@ -598,23 +591,13 @@ _ET_DECLARE_CHECKED(Eterm*,tuple_val,Wterm)
 #define make_pid_data(Ser, Num) \
   ((Uint) ((Ser) << _PID_NUM_SIZE | (Num)))
 
-#define make_internal_pid(X) \
-  ((Eterm) (((X) << _PID_DATA_SHIFT) | _TAG_IMMED1_PID))
-
 #define is_internal_pid(x)	(((x) & _TAG_IMMED1_MASK) == _TAG_IMMED1_PID)
 #define is_not_internal_pid(x)	(!is_internal_pid((x)))
 
-#define _unchecked_internal_pid_data(x) _GET_PID_DATA((x))
-_ET_DECLARE_CHECKED(Uint,internal_pid_data,Eterm)
-#define internal_pid_data(x) _ET_APPLY(internal_pid_data,(x))
-
 #define _unchecked_internal_pid_node(x) erts_this_node
 _ET_DECLARE_CHECKED(struct erl_node_*,internal_pid_node,Eterm)
 #define internal_pid_node(x) _ET_APPLY(internal_pid_node,(x))
 
-#define internal_pid_number(x) _GET_PID_NUM(internal_pid_data((x)))
-#define internal_pid_serial(x) _GET_PID_SER(internal_pid_data((x)))
-
 #define internal_pid_data_words(x) (1)
 
 /* 
@@ -644,7 +627,6 @@ _ET_DECLARE_CHECKED(struct erl_node_*,internal_pid_node,Eterm)
  *  N : node number
  *
  */
-#define _PORT_R9_NUM_SIZE	18
 #define _PORT_NUM_SIZE		_PORT_DATA_SIZE
 
 #define _PORT_DATA_SIZE		28
@@ -654,18 +636,9 @@ _ET_DECLARE_CHECKED(struct erl_node_*,internal_pid_node,Eterm)
 #define _GET_PORT_NUM(X)	_GETBITS((X), 0, _PORT_NUM_SIZE)
 
 
-#define make_internal_port(X) \
-  ((Eterm) (((X) << _PORT_DATA_SHIFT) | _TAG_IMMED1_PORT))
-
 #define is_internal_port(x)	(((x) & _TAG_IMMED1_MASK) == _TAG_IMMED1_PORT)
 #define is_not_internal_port(x)	(!is_internal_port(x))
 
-#define _unchecked_internal_port_data(x) _GET_PORT_DATA((x))
-_ET_DECLARE_CHECKED(Uint,internal_port_data,Eterm)
-#define internal_port_data(x) _ET_APPLY(internal_port_data,(x))
-
-#define internal_port_number(x) _GET_PORT_NUM(internal_port_data((x)))
-
 #define _unchecked_internal_port_node(x) erts_this_node
 _ET_DECLARE_CHECKED(struct erl_node_*,internal_port_node,Eterm)
 #define internal_port_node(x) _ET_APPLY(internal_port_node,(x))
diff --git a/erts/emulator/beam/erl_thr_progress.c b/erts/emulator/beam/erl_thr_progress.c
index 88524bdd4c..3b2f95d43b 100644
--- a/erts/emulator/beam/erl_thr_progress.c
+++ b/erts/emulator/beam/erl_thr_progress.c
@@ -96,17 +96,14 @@
 
 #define ERTS_THR_PRGR_LFLG_BLOCK	(((erts_aint32_t) 1) << 31)
 #define ERTS_THR_PRGR_LFLG_NO_LEADER	(((erts_aint32_t) 1) << 30)
-#define ERTS_THR_PRGR_LFLG_ACTIVE_MASK	(~(ERTS_THR_PRGR_LFLG_NO_LEADER \
-					   | ERTS_THR_PRGR_LFLG_BLOCK))
+#define ERTS_THR_PRGR_LFLG_WAITING_UM	(((erts_aint32_t) 1) << 29)
+#define ERTS_THR_PRGR_LFLG_ACTIVE_MASK	(~(ERTS_THR_PRGR_LFLG_NO_LEADER	\
+					   | ERTS_THR_PRGR_LFLG_BLOCK	\
+					   | ERTS_THR_PRGR_LFLG_WAITING_UM))
 
-#define ERTS_THR_PRGR_LFLGS_ACTIVE(LFLGS) \
+#define ERTS_THR_PRGR_LFLGS_ACTIVE(LFLGS)				\
     ((LFLGS) & ERTS_THR_PRGR_LFLG_ACTIVE_MASK)
 
-#define ERTS_THR_PRGR_LFLGS_ALL_WAITING(LFLGS) \
-    (((LFLGS) & (ERTS_THR_PRGR_LFLG_NO_LEADER \
-		 |ERTS_THR_PRGR_LFLG_ACTIVE_MASK)) \
-     == ERTS_THR_PRGR_LFLG_NO_LEADER)
-
 /*
  * We use a 64-bit value for thread progress. By this wrapping of
  * the thread progress will more or less never occur.
@@ -262,6 +259,11 @@ typedef struct {
     erts_atomic32_t managed_count;
     erts_atomic32_t managed_id;
     erts_atomic32_t unmanaged_id;    
+    int chk_next_ix;
+    struct {
+	int waiting;
+	erts_atomic32_t current;
+    } umrefc_ix;
 } ErtsThrPrgrMiscData;
 
 typedef struct {
@@ -276,12 +278,18 @@ typedef union {
     char align__[ERTS_ALC_CACHE_LINE_ALIGN_SIZE(sizeof(ErtsThrPrgrElement))];
 } ErtsThrPrgrArray;
 
+typedef union {
+    erts_atomic_t refc;
+    char align__[ERTS_ALC_CACHE_LINE_ALIGN_SIZE(sizeof(erts_atomic_t))];
+} ErtsThrPrgrUnmanagedRefc;
+
 typedef struct {
     union {
 	ErtsThrPrgrMiscData data;
 	char align__[ERTS_ALC_CACHE_LINE_ALIGN_SIZE(
 		sizeof(ErtsThrPrgrMiscData))];
     } misc;
+    ErtsThrPrgrUnmanagedRefc umrefc[2];
     ErtsThrPrgrArray *thr;
     struct {
 	int no;
@@ -346,7 +354,9 @@ init_tmp_thr_prgr_data(ErtsThrPrgrData *tpd)
     tpd->is_managed = 0;
     tpd->is_blocking = 0;
     tpd->is_temporary = 1;
-
+#ifdef ERTS_ENABLE_LOCK_CHECK
+    tpd->is_delaying = 0;
+#endif
     erts_tsd_set(erts_thr_prgr_data_key__, (void *) tpd);
 }
 
@@ -461,6 +471,9 @@ erts_thr_progress_init(int no_schedulers, int managed, int unmanaged)
     erts_atomic32_init_nob(&intrnl->misc.data.managed_count, 0);
     erts_atomic32_init_nob(&intrnl->misc.data.managed_id, no_schedulers);
     erts_atomic32_init_nob(&intrnl->misc.data.unmanaged_id, -1);
+    intrnl->misc.data.chk_next_ix = 0;
+    intrnl->misc.data.umrefc_ix.waiting = -1;
+    erts_atomic32_init_nob(&intrnl->misc.data.umrefc_ix.current, 0);
 
     intrnl->thr = (ErtsThrPrgrArray *) ptr;
     ptr += thr_arr_sz;
@@ -547,6 +560,9 @@ erts_thr_progress_register_unmanaged_thread(ErtsThrPrgrCallbacks *callbacks)
     tpd->is_managed = 0;
     tpd->is_blocking = is_blocking;
     tpd->is_temporary = 0;
+#ifdef ERTS_ENABLE_LOCK_CHECK
+    tpd->is_delaying = 0;
+#endif
     ASSERT(tpd->id >= 0);
     if (tpd->id >= intrnl->unmanaged.no)
 	erl_exit(ERTS_ABORT_EXIT,
@@ -600,6 +616,9 @@ erts_thr_progress_register_managed_thread(ErtsSchedulerData *esdp,
     tpd->is_managed = 1;
     tpd->is_blocking = is_blocking;
     tpd->is_temporary = 0;
+#ifdef ERTS_ENABLE_LOCK_CHECK
+    tpd->is_delaying = 1;
+#endif
 
     init_wakeup_request_array(&tpd->wakeup_request[0]);
 
@@ -607,8 +626,8 @@ erts_thr_progress_register_managed_thread(ErtsSchedulerData *esdp,
 
     tpd->leader = 0;
     tpd->active = 1;
-    tpd->previous.local = 0;
-    tpd->previous.current = ERTS_THR_PRGR_VAL_WAITING;
+    tpd->confirmed = 0;
+    tpd->leader_state.current = ERTS_THR_PRGR_VAL_WAITING;
     erts_tsd_set(erts_thr_prgr_data_key__, (void *) tpd);
 
     erts_atomic32_inc_nob(&intrnl->misc.data.lflgs);
@@ -651,60 +670,113 @@ leader_update(ErtsThrPrgrData *tpd)
 	block_thread(tpd);
     }
     else {
+	ErtsThrPrgrVal current;
+	int ix, chk_next_ix, umrefc_ix, my_ix, no_managed, waiting_unmanaged;
 	erts_aint32_t lflgs;
 	ErtsThrPrgrVal next;
-	int ix, sz, make_progress;
+	erts_aint_t refc;
 
-	if (tpd->previous.current == ERTS_THR_PRGR_VAL_WAITING) {
-	    /* Took over as leader from another thread */
-	    tpd->previous.current = read_acqb(&erts_thr_prgr__.current);
-	    tpd->previous.next = tpd->previous.current;
-	    tpd->previous.next++;
-	    if (tpd->previous.next == ERTS_THR_PRGR_VAL_WAITING)
-		tpd->previous.next = 0;
-	}
+	my_ix = tpd->id;
 
-	if (tpd->previous.local == tpd->previous.current) {
-	    ErtsThrPrgrVal val = tpd->previous.current + 1;
-	    if (val == ERTS_THR_PRGR_VAL_WAITING)
-		val = 0;
-	    tpd->previous.local = val;
-	    set_mb(&intrnl->thr[tpd->id].data.current, val);
+	if (tpd->leader_state.current == ERTS_THR_PRGR_VAL_WAITING) {
+	    /* Took over as leader from another thread */
+	    tpd->leader_state.current = read_nob(&erts_thr_prgr__.current);
+	    tpd->leader_state.next = tpd->leader_state.current;
+	    tpd->leader_state.next++;
+	    if (tpd->leader_state.next == ERTS_THR_PRGR_VAL_WAITING)
+		tpd->leader_state.next = 0;
+	    tpd->leader_state.chk_next_ix = intrnl->misc.data.chk_next_ix;
+	    tpd->leader_state.umrefc_ix.waiting = intrnl->misc.data.umrefc_ix.waiting;
+	    tpd->leader_state.umrefc_ix.current =
+		(int) erts_atomic32_read_nob(&intrnl->misc.data.umrefc_ix.current);
+
+	    if (tpd->confirmed == tpd->leader_state.current) {
+		ErtsThrPrgrVal val = tpd->leader_state.current + 1;
+		if (val == ERTS_THR_PRGR_VAL_WAITING)
+		    val = 0;
+		tpd->confirmed = val;
+		set_mb(&intrnl->thr[my_ix].data.current, val);
+	    }
 	}
 
-	next = tpd->previous.next;
 
-	make_progress = 1;
-	sz = intrnl->managed.no;
-	for (ix = 0; ix < sz; ix++) {
-	    ErtsThrPrgrVal tmp;
-	    tmp = read_nob(&intrnl->thr[ix].data.current);
-	    if (tmp != next && tmp != ERTS_THR_PRGR_VAL_WAITING) {
-		make_progress = 0;
-		ASSERT(erts_thr_progress_has_passed__(next, tmp));
-		break;
+	next = tpd->leader_state.next;
+
+	waiting_unmanaged = 0;
+	umrefc_ix = -1; /* Shut up annoying warning */
+
+	chk_next_ix = tpd->leader_state.chk_next_ix;
+	no_managed = intrnl->managed.no;
+	ASSERT(0 <= chk_next_ix && chk_next_ix <= no_managed);
+	/* Check manged threads */
+	if (chk_next_ix < no_managed) {
+	    for (ix = chk_next_ix; ix < no_managed; ix++) {
+		ErtsThrPrgrVal tmp;
+		if (ix == my_ix)
+		    continue;
+		tmp = read_nob(&intrnl->thr[ix].data.current);
+		if (tmp != next && tmp != ERTS_THR_PRGR_VAL_WAITING) {
+		    tpd->leader_state.chk_next_ix = ix;
+		    ASSERT(erts_thr_progress_has_passed__(next, tmp));
+		    goto done;
+		}
 	    }
 	}
 
-	if (make_progress) {
-	    ErtsThrPrgrVal current = next;
+	/* Check unmanged threads */
+	waiting_unmanaged = tpd->leader_state.umrefc_ix.waiting != -1;
+	umrefc_ix = (waiting_unmanaged
+		     ? tpd->leader_state.umrefc_ix.waiting
+		     : tpd->leader_state.umrefc_ix.current);
+	refc = erts_atomic_read_nob(&intrnl->umrefc[umrefc_ix].refc);
+	ASSERT(refc >= 0);
+	if (refc != 0) {
+	    int new_umrefc_ix;
+
+	    if (waiting_unmanaged)
+		goto done;
+
+	    new_umrefc_ix = (umrefc_ix + 1) & 0x1;
+	    tpd->leader_state.umrefc_ix.waiting = umrefc_ix;
+	    tpd->leader_state.chk_next_ix = no_managed;
+	    erts_atomic32_set_nob(&intrnl->misc.data.umrefc_ix.current,
+				  (erts_aint32_t) new_umrefc_ix);
+	    ETHR_MEMBAR(ETHR_StoreLoad);
+	    refc = erts_atomic_read_nob(&intrnl->umrefc[umrefc_ix].refc);
+	    ASSERT(refc >= 0);
+	    waiting_unmanaged = 1;
+	    if (refc != 0)
+		goto done;
+	}
+
+	/* Make progress */
+	current = next;
 
-	    next++;
-	    if (next == ERTS_THR_PRGR_VAL_WAITING)
-		next = 0;
+	next++;
+	if (next == ERTS_THR_PRGR_VAL_WAITING)
+	    next = 0;
 
-	    set_nob(&intrnl->thr[tpd->id].data.current, next);
-	    set_mb(&erts_thr_prgr__.current, current);
-	    tpd->previous.local = next;
-	    tpd->previous.next = next;
-	    tpd->previous.current = current;
+	set_nob(&intrnl->thr[my_ix].data.current, next);
+	set_mb(&erts_thr_prgr__.current, current);
+	tpd->confirmed = next;
+	tpd->leader_state.next = next;
+	tpd->leader_state.current = current;
 
 #if ERTS_THR_PRGR_PRINT_VAL
-	    if (current % 1000 == 0)
-		erts_fprintf(stderr, "%b64u\n", current);
+	if (current % 1000 == 0)
+	    erts_fprintf(stderr, "%b64u\n", current);
 #endif
-	    handle_wakeup_requests(current);
+	handle_wakeup_requests(current);
+
+	if (waiting_unmanaged) {
+	    waiting_unmanaged = 0;
+	    tpd->leader_state.umrefc_ix.waiting = -1;
+	    erts_atomic32_read_band_nob(&intrnl->misc.data.lflgs,
+					~ERTS_THR_PRGR_LFLG_WAITING_UM);
 	}
+	tpd->leader_state.chk_next_ix = 0;
+
+    done:
 
 	if (tpd->active) {
 	    lflgs = erts_atomic32_read_nob(&intrnl->misc.data.lflgs);
@@ -712,20 +784,44 @@ leader_update(ErtsThrPrgrData *tpd)
 		(void) block_thread(tpd);
 	}
 	else {
+	    int force_wakeup_check = 0;
+	    erts_aint32_t set_flags = ERTS_THR_PRGR_LFLG_NO_LEADER;
 	    tpd->leader = 0;
-	    tpd->previous.current = ERTS_THR_PRGR_VAL_WAITING;
+	    tpd->leader_state.current = ERTS_THR_PRGR_VAL_WAITING;
 #if ERTS_THR_PRGR_PRINT_LEADER
 	    erts_fprintf(stderr, "L <- %d\n", tpd->id);
 #endif
 
 	    ERTS_THR_PROGRESS_STATE_DEBUG_SET_LEADER(tpd->id, 0);
 
+	    if (waiting_unmanaged)
+		set_flags |= ERTS_THR_PRGR_LFLG_WAITING_UM;
+
 	    lflgs = erts_atomic32_read_bor_relb(&intrnl->misc.data.lflgs,
-						ERTS_THR_PRGR_LFLG_NO_LEADER);
+						set_flags);
+	    lflgs |= set_flags;
 	    if (lflgs & ERTS_THR_PRGR_LFLG_BLOCK)
 		lflgs = block_thread(tpd);
-	    if (ERTS_THR_PRGR_LFLGS_ACTIVE(lflgs) == 0 && got_sched_wakeups())
+
+	    if (waiting_unmanaged) {
+		/* Need to check umrefc again */
+		ETHR_MEMBAR(ETHR_StoreLoad);
+		refc = erts_atomic_read_nob(&intrnl->umrefc[umrefc_ix].refc);
+		if (refc == 0) {
+		    /* Need to force wakeup check */
+		    force_wakeup_check = 1;
+		}
+	    }
+
+	    if ((force_wakeup_check
+		 || ((lflgs & (ERTS_THR_PRGR_LFLG_NO_LEADER
+			       | ERTS_THR_PRGR_LFLG_WAITING_UM
+			       | ERTS_THR_PRGR_LFLG_ACTIVE_MASK))
+		     == ERTS_THR_PRGR_LFLG_NO_LEADER))
+		&& got_sched_wakeups()) {
+		/* Someone need to make progress */
 		wakeup_managed(0);
+	    }
 	}
     }
 
@@ -744,11 +840,11 @@ update(ErtsThrPrgrData *tpd)
 	erts_aint32_t lflgs;
 	res = 0;
 	val = read_acqb(&erts_thr_prgr__.current);
-	if (tpd->previous.local == val) {
+	if (tpd->confirmed == val) {
 	    val++;
 	    if (val == ERTS_THR_PRGR_VAL_WAITING)
 		val = 0;
-	    tpd->previous.local = val;
+	    tpd->confirmed = val;
 	    set_mb(&intrnl->thr[tpd->id].data.current, val);
 	}
 
@@ -801,12 +897,19 @@ erts_thr_progress_prepare_wait(ErtsSchedulerData *esdp)
 
     block_count_dec();
 
-    tpd->previous.local = ERTS_THR_PRGR_VAL_WAITING;
+    tpd->confirmed = ERTS_THR_PRGR_VAL_WAITING;
     set_mb(&intrnl->thr[tpd->id].data.current, ERTS_THR_PRGR_VAL_WAITING);
 
     lflgs = erts_atomic32_read_nob(&intrnl->misc.data.lflgs);
-    if (ERTS_THR_PRGR_LFLGS_ALL_WAITING(lflgs) && got_sched_wakeups())
-	wakeup_managed(0); /* Someone need to make progress */
+
+    if ((lflgs & (ERTS_THR_PRGR_LFLG_NO_LEADER
+		  | ERTS_THR_PRGR_LFLG_WAITING_UM
+		  | ERTS_THR_PRGR_LFLG_ACTIVE_MASK))
+	== ERTS_THR_PRGR_LFLG_NO_LEADER 
+	&& got_sched_wakeups()) {
+	/* Someone need to make progress */
+	wakeup_managed(0);
+    }
 }
 
 void
@@ -828,7 +931,7 @@ erts_thr_progress_finalize_wait(ErtsSchedulerData *esdp)
 	val++;
 	if (val == ERTS_THR_PRGR_VAL_WAITING)
 	    val = 0;
-	tpd->previous.local = val;
+	tpd->confirmed = val;
 	set_mb(&intrnl->thr[tpd->id].data.current, val);
 	val = read_acqb(&erts_thr_prgr__.current);
 	if (current == val)
@@ -875,6 +978,68 @@ erts_thr_progress_active(ErtsSchedulerData *esdp, int on)
 
 }
 
+static ERTS_INLINE void
+unmanaged_continue(ErtsThrPrgrDelayHandle handle)
+{
+    int umrefc_ix = (int) handle;
+    erts_aint_t refc;
+
+    ASSERT(umrefc_ix == 0 || umrefc_ix == 1);
+    refc = erts_atomic_dec_read_relb(&intrnl->umrefc[umrefc_ix].refc);
+    ASSERT(refc >= 0);
+    if (refc == 0) {
+	erts_aint_t lflgs;
+	ERTS_THR_READ_MEMORY_BARRIER;
+	lflgs = erts_atomic32_read_nob(&intrnl->misc.data.lflgs);
+	if ((lflgs & (ERTS_THR_PRGR_LFLG_NO_LEADER
+		      | ERTS_THR_PRGR_LFLG_WAITING_UM
+		      | ERTS_THR_PRGR_LFLG_ACTIVE_MASK))
+	    == (ERTS_THR_PRGR_LFLG_NO_LEADER|ERTS_THR_PRGR_LFLG_WAITING_UM)
+	    && got_sched_wakeups()) {
+	    /* Others waiting for us... */
+	    wakeup_managed(0);
+	}
+    }
+}
+
+void
+erts_thr_progress_unmanaged_continue__(ErtsThrPrgrDelayHandle handle)
+{
+#ifdef ERTS_ENABLE_LOCK_CHECK
+    ErtsThrPrgrData *tpd = perhaps_thr_prgr_data(NULL);
+    ERTS_LC_ASSERT(tpd && tpd->is_delaying);
+    tpd->is_delaying = 0;
+    return_tmp_thr_prgr_data(tpd);
+#endif
+    ASSERT(!erts_thr_progress_is_managed_thread());
+
+    unmanaged_continue(handle);
+}
+
+ErtsThrPrgrDelayHandle
+erts_thr_progress_unmanaged_delay__(void)
+{
+    int umrefc_ix;
+    ASSERT(!erts_thr_progress_is_managed_thread());
+    umrefc_ix = (int) erts_atomic32_read_acqb(&intrnl->misc.data.umrefc_ix.current);
+    while (1) {
+	int tmp_ix;
+	erts_atomic_inc_acqb(&intrnl->umrefc[umrefc_ix].refc);
+	tmp_ix = (int) erts_atomic32_read_acqb(&intrnl->misc.data.umrefc_ix.current);
+	if (tmp_ix == umrefc_ix)
+	    break;
+	unmanaged_continue(umrefc_ix);
+	umrefc_ix = tmp_ix;
+    }
+#ifdef ERTS_ENABLE_LOCK_CHECK
+    {
+	ErtsThrPrgrData *tpd = tmp_thr_prgr_data(NULL);
+	tpd->is_delaying = 1;
+    }
+#endif
+    return (ErtsThrPrgrDelayHandle) umrefc_ix;
+}
+
 static ERTS_INLINE int
 has_reached_wakeup(ErtsThrPrgrVal wakeup)
 {
@@ -931,7 +1096,7 @@ request_wakeup_managed(ErtsThrPrgrData *tpd, ErtsThrPrgrVal value)
      */
 
     ASSERT(tpd->is_managed);
-    ASSERT(tpd->previous.local != ERTS_THR_PRGR_VAL_WAITING);
+    ASSERT(tpd->confirmed != ERTS_THR_PRGR_VAL_WAITING);
 
     if (has_reached_wakeup(value)) {
 	wakeup_managed(tpd->id);
@@ -946,7 +1111,7 @@ request_wakeup_managed(ErtsThrPrgrData *tpd, ErtsThrPrgrVal value)
 					  tpd->wakeup_request[wix]));
 
 
-    if (tpd->previous.local == value) {
+    if (tpd->confirmed == value) {
 	/*
 	 * We have already confirmed this value. We need to request
 	 * wakeup for a value later than our latest confirmed value in
diff --git a/erts/emulator/beam/erl_thr_progress.h b/erts/emulator/beam/erl_thr_progress.h
index e72321cf48..1416aa6166 100644
--- a/erts/emulator/beam/erl_thr_progress.h
+++ b/erts/emulator/beam/erl_thr_progress.h
@@ -53,9 +53,22 @@ typedef Uint64 ErtsThrPrgrVal;
 #define ERTS_THR_PRGR_WAKEUP_DATA_SIZE 4 /* Need to be an even power of 2. */
 
 typedef struct {
+    ErtsThrPrgrVal next;
+    ErtsThrPrgrVal current;
+    int chk_next_ix;
+    struct {
+	int current;
+	int waiting;
+    } umrefc_ix;
+} ErtsThrPrgrLeaderState;
+
+typedef struct {
     int id;
     int is_managed;
     int is_blocking;
+#ifdef ERTS_ENABLE_LOCK_CHECK
+    int is_delaying; /* managed is always delaying */
+#endif
     int is_temporary;
 
     /* --- Part below only for registered threads --- */
@@ -66,11 +79,8 @@ typedef struct {
 
     int leader; /* Needs to be first in the managed threads part */
     int active;
-    struct {
-	ErtsThrPrgrVal local;
-	ErtsThrPrgrVal next;
-	ErtsThrPrgrVal current;
-    } previous;
+    ErtsThrPrgrVal confirmed;
+    ErtsThrPrgrLeaderState leader_state;
 } ErtsThrPrgrData;
 
 void erts_thr_progress_fatal_error_block(SWord timeout,
@@ -121,6 +131,11 @@ typedef struct {
     ERTS_THR_PRGR_ATOMIC current;
 } ErtsThrPrgr;
 
+typedef int ErtsThrPrgrDelayHandle;
+#define ERTS_THR_PRGR_DHANDLE_MANAGED ((ErtsThrPrgrDelayHandle) -1)
+/* ERTS_THR_PRGR_DHANDLE_MANAGED implies managed thread */
+#define ERTS_THR_PRGR_DHANDLE_INVALID ((ErtsThrPrgrDelayHandle) -2)
+
 extern ErtsThrPrgr erts_thr_prgr__;
 
 void erts_thr_progress_pre_init(void);
@@ -136,6 +151,8 @@ int erts_thr_progress_update(ErtsSchedulerData *esdp);
 int erts_thr_progress_leader_update(ErtsSchedulerData *esdp);
 void erts_thr_progress_prepare_wait(ErtsSchedulerData *esdp);
 void erts_thr_progress_finalize_wait(ErtsSchedulerData *esdp);
+ErtsThrPrgrDelayHandle erts_thr_progress_unmanaged_delay__(void);
+void erts_thr_progress_unmanaged_continue__(int umrefc_ix);
 
 void erts_thr_progress_dbg_print_state(void);
 
@@ -148,6 +165,11 @@ ERTS_GLB_INLINE ErtsThrPrgrVal erts_thr_prgr_read_acqb__(ERTS_THR_PRGR_ATOMIC *a
 ERTS_GLB_INLINE ErtsThrPrgrVal erts_thr_prgr_read_mb__(ERTS_THR_PRGR_ATOMIC *atmc);
 
 ERTS_GLB_INLINE int erts_thr_progress_is_managed_thread(void);
+ERTS_GLB_INLINE ErtsThrPrgrDelayHandle erts_thr_progress_unmanaged_delay(void);
+ERTS_GLB_INLINE void erts_thr_progress_unmanaged_continue(ErtsThrPrgrDelayHandle handle);
+#ifdef ERTS_ENABLE_LOCK_CHECK
+ERTS_GLB_INLINE int erts_thr_progress_lc_is_delaying(void);
+#endif
 ERTS_GLB_INLINE ErtsThrPrgrVal erts_thr_progress_current_to_later__(ErtsThrPrgrVal val);
 ERTS_GLB_INLINE ErtsThrPrgrVal erts_thr_progress_later(ErtsSchedulerData *);
 ERTS_GLB_INLINE ErtsThrPrgrVal erts_thr_progress_current(void);
@@ -229,6 +251,35 @@ erts_thr_progress_is_managed_thread(void)
     return tpd && tpd->is_managed;
 }
 
+ERTS_GLB_INLINE ErtsThrPrgrDelayHandle
+erts_thr_progress_unmanaged_delay(void)
+{
+    if (erts_thr_progress_is_managed_thread())
+	return ERTS_THR_PRGR_DHANDLE_MANAGED; /* Nothing to do */
+    else
+	return erts_thr_progress_unmanaged_delay__();
+}
+
+ERTS_GLB_INLINE void
+erts_thr_progress_unmanaged_continue(ErtsThrPrgrDelayHandle handle)
+{
+    ASSERT(handle != ERTS_THR_PRGR_DHANDLE_MANAGED
+	   || erts_thr_progress_is_managed_thread());
+    if (handle != ERTS_THR_PRGR_DHANDLE_MANAGED)
+	erts_thr_progress_unmanaged_continue__(handle);
+}
+
+#ifdef ERTS_ENABLE_LOCK_CHECK
+
+ERTS_GLB_INLINE int
+erts_thr_progress_lc_is_delaying(void)
+{
+    ErtsThrPrgrData *tpd = erts_tsd_get(erts_thr_prgr_data_key__);
+    return tpd && tpd->is_delaying;
+}
+
+#endif
+
 ERTS_GLB_INLINE ErtsThrPrgrVal
 erts_thr_progress_current_to_later__(ErtsThrPrgrVal val)
 {
@@ -248,7 +299,7 @@ erts_thr_progress_later(ErtsSchedulerData *esdp)
     if (esdp) {
 	tpd = &esdp->thr_progress_data;
     managed_thread:
-	val = tpd->previous.local;
+	val = tpd->confirmed;
 	ERTS_THR_MEMORY_BARRIER;
     }
     else {
diff --git a/erts/emulator/beam/erl_threads.h b/erts/emulator/beam/erl_threads.h
index 17628286bc..0e759a1eec 100644
--- a/erts/emulator/beam/erl_threads.h
+++ b/erts/emulator/beam/erl_threads.h
@@ -533,6 +533,9 @@ ERTS_GLB_INLINE erts_aint_t erts_no_atomic_xchg(erts_no_atomic_t *xchgp,
 ERTS_GLB_INLINE erts_aint_t erts_no_atomic_cmpxchg(erts_no_atomic_t *xchgp,
 						   erts_aint_t new,
 						   erts_aint_t expected);
+ERTS_GLB_INLINE erts_aint_t erts_no_atomic_read_bset(erts_no_atomic_t *var,
+						     erts_aint_t mask,
+						     erts_aint_t set);
 ERTS_GLB_INLINE void erts_no_atomic32_set(erts_no_atomic32_t *var,
 					  erts_aint32_t i);
 ERTS_GLB_INLINE erts_aint32_t erts_no_atomic32_read(erts_no_atomic32_t *var);
@@ -553,6 +556,9 @@ ERTS_GLB_INLINE erts_aint32_t erts_no_atomic32_xchg(erts_no_atomic32_t *xchgp,
 ERTS_GLB_INLINE erts_aint32_t erts_no_atomic32_cmpxchg(erts_no_atomic32_t *xchgp,
 						       erts_aint32_t new,
 						       erts_aint32_t expected);
+ERTS_GLB_INLINE erts_aint32_t erts_no_atomic32_read_bset(erts_no_atomic32_t *var,
+							 erts_aint32_t mask,
+							 erts_aint32_t set);
 
 ERTS_GLB_INLINE void erts_spinlock_init_x_opt(erts_spinlock_t *lock,
 					      char *name,
@@ -612,6 +618,78 @@ ERTS_GLB_INLINE void erts_thr_sigwait(const sigset_t *set, int *sig);
 
 #ifdef USE_THREADS
 
+ERTS_GLB_INLINE erts_aint_t
+erts_atomic_read_bset_nob(erts_atomic_t *var,
+			  erts_aint_t mask,
+			  erts_aint_t set);
+ERTS_GLB_INLINE erts_aint_t
+erts_atomic_read_bset_ddrb(erts_atomic_t *var,
+			   erts_aint_t mask,
+			   erts_aint_t set);
+ERTS_GLB_INLINE erts_aint_t
+erts_atomic_read_bset_rb(erts_atomic_t *var,
+			 erts_aint_t mask,
+			 erts_aint_t set);
+ERTS_GLB_INLINE erts_aint_t
+erts_atomic_read_bset_wb(erts_atomic_t *var,
+			 erts_aint_t mask,
+			 erts_aint_t set);
+ERTS_GLB_INLINE erts_aint_t
+erts_atomic_read_bset_acqb(erts_atomic_t *var,
+			   erts_aint_t mask,
+			   erts_aint_t set);
+ERTS_GLB_INLINE erts_aint_t
+erts_atomic_read_bset_relb(erts_atomic_t *var,
+			   erts_aint_t mask,
+			   erts_aint_t set);
+ERTS_GLB_INLINE erts_aint_t
+erts_atomic_read_bset_mb(erts_atomic_t *var,
+			 erts_aint_t mask,
+			 erts_aint_t set);
+ERTS_GLB_INLINE erts_aint32_t
+erts_atomic32_read_bset_nob(erts_atomic32_t *var,
+			    erts_aint32_t mask,
+			    erts_aint32_t set);
+ERTS_GLB_INLINE erts_aint32_t
+erts_atomic32_read_bset_ddrb(erts_atomic32_t *var,
+			     erts_aint32_t mask,
+			     erts_aint32_t set);
+ERTS_GLB_INLINE erts_aint32_t
+erts_atomic32_read_bset_rb(erts_atomic32_t *var,
+			   erts_aint32_t mask,
+			   erts_aint32_t set);
+ERTS_GLB_INLINE erts_aint32_t
+erts_atomic32_read_bset_wb(erts_atomic32_t *var,
+			   erts_aint32_t mask,
+			   erts_aint32_t set);
+ERTS_GLB_INLINE erts_aint32_t
+erts_atomic32_read_bset_acqb(erts_atomic32_t *var,
+			     erts_aint32_t mask,
+			     erts_aint32_t set);
+ERTS_GLB_INLINE erts_aint32_t
+erts_atomic32_read_bset_relb(erts_atomic32_t *var,
+			     erts_aint32_t mask,
+			     erts_aint32_t set);
+ERTS_GLB_INLINE erts_aint32_t
+erts_atomic32_read_bset_mb(erts_atomic32_t *var,
+			   erts_aint32_t mask,
+			   erts_aint32_t set);
+
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+#define ERTS_ATOMIC_BSET_IMPL__(Type, ReadOp, CmpxchgOp, VarP, Mask, Set) \
+do {									\
+    Type act = ReadOp((VarP));						\
+    while (1) {								\
+	Type exp = act;							\
+	Type new = exp & ~(Mask);					\
+	new |= ((Mask) & (Set));					\
+	act = CmpxchgOp((VarP), new, exp);				\
+	if (act == exp)							\
+	    return act;							\
+    }									\
+} while (0)
+#endif
+
 /*
  * See "Documentation of atomics and memory barriers" at the top
  * of this file for info on atomics.
@@ -670,6 +748,19 @@ ERTS_GLB_INLINE void erts_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_atomic_xchg_nob ethr_atomic_xchg
 #define erts_atomic_cmpxchg_nob ethr_atomic_cmpxchg
 
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+ERTS_GLB_INLINE erts_aint_t
+erts_atomic_read_bset_nob(erts_atomic_t *var,
+			  erts_aint_t mask,
+			  erts_aint_t set)
+{
+    ERTS_ATOMIC_BSET_IMPL__(erts_aint_t,
+			    ethr_atomic_read,
+			    ethr_atomic_cmpxchg,
+			    var, mask, set);
+}
+#endif
+
 #define erts_atomic_init_mb ethr_atomic_init_mb
 #define erts_atomic_set_mb ethr_atomic_set_mb
 #define erts_atomic_read_mb ethr_atomic_read_mb
@@ -684,6 +775,19 @@ ERTS_GLB_INLINE void erts_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_atomic_xchg_mb ethr_atomic_xchg_mb
 #define erts_atomic_cmpxchg_mb ethr_atomic_cmpxchg_mb
 
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+ERTS_GLB_INLINE erts_aint_t
+erts_atomic_read_bset_mb(erts_atomic_t *var,
+			 erts_aint_t mask,
+			 erts_aint_t set)
+{
+    ERTS_ATOMIC_BSET_IMPL__(erts_aint_t,
+			    ethr_atomic_read,
+			    ethr_atomic_cmpxchg_mb,
+			    var, mask, set);
+}
+#endif
+
 #define erts_atomic_init_acqb ethr_atomic_init_acqb
 #define erts_atomic_set_acqb ethr_atomic_set_acqb
 #define erts_atomic_read_acqb ethr_atomic_read_acqb
@@ -698,6 +802,19 @@ ERTS_GLB_INLINE void erts_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_atomic_xchg_acqb ethr_atomic_xchg_acqb
 #define erts_atomic_cmpxchg_acqb ethr_atomic_cmpxchg_acqb
 
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+ERTS_GLB_INLINE erts_aint_t
+erts_atomic_read_bset_acqb(erts_atomic_t *var,
+			   erts_aint_t mask,
+			   erts_aint_t set)
+{
+    ERTS_ATOMIC_BSET_IMPL__(erts_aint_t,
+			    ethr_atomic_read,
+			    ethr_atomic_cmpxchg_acqb,
+			    var, mask, set);
+}
+#endif
+
 #define erts_atomic_init_relb ethr_atomic_init_relb
 #define erts_atomic_set_relb ethr_atomic_set_relb
 #define erts_atomic_read_relb ethr_atomic_read_relb
@@ -712,6 +829,19 @@ ERTS_GLB_INLINE void erts_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_atomic_xchg_relb ethr_atomic_xchg_relb
 #define erts_atomic_cmpxchg_relb ethr_atomic_cmpxchg_relb
 
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+ERTS_GLB_INLINE erts_aint_t
+erts_atomic_read_bset_relb(erts_atomic_t *var,
+			   erts_aint_t mask,
+			   erts_aint_t set)
+{
+    ERTS_ATOMIC_BSET_IMPL__(erts_aint_t,
+			    ethr_atomic_read,
+			    ethr_atomic_cmpxchg_relb,
+			    var, mask, set);
+}
+#endif
+
 #define erts_atomic_init_ddrb ethr_atomic_init_ddrb
 #define erts_atomic_set_ddrb ethr_atomic_set_ddrb
 #define erts_atomic_read_ddrb ethr_atomic_read_ddrb
@@ -726,6 +856,19 @@ ERTS_GLB_INLINE void erts_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_atomic_xchg_ddrb ethr_atomic_xchg_ddrb
 #define erts_atomic_cmpxchg_ddrb ethr_atomic_cmpxchg_ddrb
 
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+ERTS_GLB_INLINE erts_aint_t
+erts_atomic_read_bset_ddrb(erts_atomic_t *var,
+			   erts_aint_t mask,
+			   erts_aint_t set)
+{
+    ERTS_ATOMIC_BSET_IMPL__(erts_aint_t,
+			    ethr_atomic_read,
+			    ethr_atomic_cmpxchg_ddrb,
+			    var, mask, set);
+}
+#endif
+
 #define erts_atomic_init_rb ethr_atomic_init_rb
 #define erts_atomic_set_rb ethr_atomic_set_rb
 #define erts_atomic_read_rb ethr_atomic_read_rb
@@ -740,6 +883,19 @@ ERTS_GLB_INLINE void erts_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_atomic_xchg_rb ethr_atomic_xchg_rb
 #define erts_atomic_cmpxchg_rb ethr_atomic_cmpxchg_rb
 
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+ERTS_GLB_INLINE erts_aint_t
+erts_atomic_read_bset_rb(erts_atomic_t *var,
+			 erts_aint_t mask,
+			 erts_aint_t set)
+{
+    ERTS_ATOMIC_BSET_IMPL__(erts_aint_t,
+			    ethr_atomic_read,
+			    ethr_atomic_cmpxchg_rb,
+			    var, mask, set);
+}
+#endif
+
 #define erts_atomic_init_wb ethr_atomic_init_wb
 #define erts_atomic_set_wb ethr_atomic_set_wb
 #define erts_atomic_read_wb ethr_atomic_read_wb
@@ -754,6 +910,19 @@ ERTS_GLB_INLINE void erts_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_atomic_xchg_wb ethr_atomic_xchg_wb
 #define erts_atomic_cmpxchg_wb ethr_atomic_cmpxchg_wb
 
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+ERTS_GLB_INLINE erts_aint_t
+erts_atomic_read_bset_wb(erts_atomic_t *var,
+			 erts_aint_t mask,
+			 erts_aint_t set)
+{
+    ERTS_ATOMIC_BSET_IMPL__(erts_aint_t,
+			    ethr_atomic_read,
+			    ethr_atomic_cmpxchg_wb,
+			    var, mask, set);
+}
+#endif
+
 /* 32-bit atomics */
 
 #define erts_atomic32_init_nob ethr_atomic32_init
@@ -770,6 +939,19 @@ ERTS_GLB_INLINE void erts_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_atomic32_xchg_nob ethr_atomic32_xchg
 #define erts_atomic32_cmpxchg_nob ethr_atomic32_cmpxchg
 
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+ERTS_GLB_INLINE erts_aint32_t
+erts_atomic32_read_bset_nob(erts_atomic32_t *var,
+			    erts_aint32_t mask,
+			    erts_aint32_t set)
+{
+    ERTS_ATOMIC_BSET_IMPL__(erts_aint32_t,
+			    ethr_atomic32_read,
+			    ethr_atomic32_cmpxchg,
+			    var, mask, set);
+}
+#endif
+
 #define erts_atomic32_init_mb ethr_atomic32_init_mb
 #define erts_atomic32_set_mb ethr_atomic32_set_mb
 #define erts_atomic32_read_mb ethr_atomic32_read_mb
@@ -784,6 +966,19 @@ ERTS_GLB_INLINE void erts_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_atomic32_xchg_mb ethr_atomic32_xchg_mb
 #define erts_atomic32_cmpxchg_mb ethr_atomic32_cmpxchg_mb
 
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+ERTS_GLB_INLINE erts_aint32_t
+erts_atomic32_read_bset_mb(erts_atomic32_t *var,
+			   erts_aint32_t mask,
+			   erts_aint32_t set)
+{
+    ERTS_ATOMIC_BSET_IMPL__(erts_aint32_t,
+			    ethr_atomic32_read,
+			    ethr_atomic32_cmpxchg_mb,
+			    var, mask, set);
+}
+#endif
+
 #define erts_atomic32_init_acqb ethr_atomic32_init_acqb
 #define erts_atomic32_set_acqb ethr_atomic32_set_acqb
 #define erts_atomic32_read_acqb ethr_atomic32_read_acqb
@@ -798,6 +993,19 @@ ERTS_GLB_INLINE void erts_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_atomic32_xchg_acqb ethr_atomic32_xchg_acqb
 #define erts_atomic32_cmpxchg_acqb ethr_atomic32_cmpxchg_acqb
 
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+ERTS_GLB_INLINE erts_aint32_t
+erts_atomic32_read_bset_acqb(erts_atomic32_t *var,
+			     erts_aint32_t mask,
+			     erts_aint32_t set)
+{
+    ERTS_ATOMIC_BSET_IMPL__(erts_aint32_t,
+			    ethr_atomic32_read,
+			    ethr_atomic32_cmpxchg_acqb,
+			    var, mask, set);
+}
+#endif
+
 #define erts_atomic32_init_relb ethr_atomic32_init_relb
 #define erts_atomic32_set_relb ethr_atomic32_set_relb
 #define erts_atomic32_read_relb ethr_atomic32_read_relb
@@ -812,6 +1020,19 @@ ERTS_GLB_INLINE void erts_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_atomic32_xchg_relb ethr_atomic32_xchg_relb
 #define erts_atomic32_cmpxchg_relb ethr_atomic32_cmpxchg_relb
 
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+ERTS_GLB_INLINE erts_aint32_t
+erts_atomic32_read_bset_relb(erts_atomic32_t *var,
+			     erts_aint32_t mask,
+			     erts_aint32_t set)
+{
+    ERTS_ATOMIC_BSET_IMPL__(erts_aint32_t,
+			    ethr_atomic32_read,
+			    ethr_atomic32_cmpxchg_relb,
+			    var, mask, set);
+}
+#endif
+
 #define erts_atomic32_init_ddrb ethr_atomic32_init_ddrb
 #define erts_atomic32_set_ddrb ethr_atomic32_set_ddrb
 #define erts_atomic32_read_ddrb ethr_atomic32_read_ddrb
@@ -826,6 +1047,19 @@ ERTS_GLB_INLINE void erts_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_atomic32_xchg_ddrb ethr_atomic32_xchg_ddrb
 #define erts_atomic32_cmpxchg_ddrb ethr_atomic32_cmpxchg_ddrb
 
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+ERTS_GLB_INLINE erts_aint32_t
+erts_atomic32_read_bset_ddrb(erts_atomic32_t *var,
+			     erts_aint32_t mask,
+			     erts_aint32_t set)
+{
+    ERTS_ATOMIC_BSET_IMPL__(erts_aint32_t,
+			    ethr_atomic32_read,
+			    ethr_atomic32_cmpxchg_ddrb,
+			    var, mask, set);
+}
+#endif
+
 #define erts_atomic32_init_rb ethr_atomic32_init_rb
 #define erts_atomic32_set_rb ethr_atomic32_set_rb
 #define erts_atomic32_read_rb ethr_atomic32_read_rb
@@ -840,6 +1074,19 @@ ERTS_GLB_INLINE void erts_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_atomic32_xchg_rb ethr_atomic32_xchg_rb
 #define erts_atomic32_cmpxchg_rb ethr_atomic32_cmpxchg_rb
 
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+ERTS_GLB_INLINE erts_aint32_t
+erts_atomic32_read_bset_rb(erts_atomic32_t *var,
+			   erts_aint32_t mask,
+			   erts_aint32_t set)
+{
+    ERTS_ATOMIC_BSET_IMPL__(erts_aint32_t,
+			    ethr_atomic32_read,
+			    ethr_atomic32_cmpxchg_rb,
+			    var, mask, set);
+}
+#endif
+
 #define erts_atomic32_init_wb ethr_atomic32_init_wb
 #define erts_atomic32_set_wb ethr_atomic32_set_wb
 #define erts_atomic32_read_wb ethr_atomic32_read_wb
@@ -854,6 +1101,21 @@ ERTS_GLB_INLINE void erts_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_atomic32_xchg_wb ethr_atomic32_xchg_wb
 #define erts_atomic32_cmpxchg_wb ethr_atomic32_cmpxchg_wb
 
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+ERTS_GLB_INLINE erts_aint32_t
+erts_atomic32_read_bset_wb(erts_atomic32_t *var,
+			   erts_aint32_t mask,
+			   erts_aint32_t set)
+{
+    ERTS_ATOMIC_BSET_IMPL__(erts_aint32_t,
+			    ethr_atomic32_read,
+			    ethr_atomic32_cmpxchg_wb,
+			    var, mask, set);
+}
+#endif
+
+#undef ERTS_ATOMIC_BSET_IMPL__
+
 #else /* !USE_THREADS */
 
 /* Double word size atomics */
@@ -908,6 +1170,7 @@ ERTS_GLB_INLINE void erts_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_atomic_read_band_nob erts_no_atomic_read_band
 #define erts_atomic_xchg_nob erts_no_atomic_xchg
 #define erts_atomic_cmpxchg_nob erts_no_atomic_cmpxchg
+#define erts_atomic_read_bset_nob erts_no_atomic_read_bset
 
 #define erts_atomic_init_mb erts_no_atomic_set
 #define erts_atomic_set_mb erts_no_atomic_set
@@ -922,6 +1185,7 @@ ERTS_GLB_INLINE void erts_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_atomic_read_band_mb erts_no_atomic_read_band
 #define erts_atomic_xchg_mb erts_no_atomic_xchg
 #define erts_atomic_cmpxchg_mb erts_no_atomic_cmpxchg
+#define erts_atomic_read_bset_mb erts_no_atomic_read_bset
 
 #define erts_atomic_init_acqb erts_no_atomic_set
 #define erts_atomic_set_acqb erts_no_atomic_set
@@ -936,6 +1200,7 @@ ERTS_GLB_INLINE void erts_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_atomic_read_band_acqb erts_no_atomic_read_band
 #define erts_atomic_xchg_acqb erts_no_atomic_xchg
 #define erts_atomic_cmpxchg_acqb erts_no_atomic_cmpxchg
+#define erts_atomic_read_bset_acqb erts_no_atomic_read_bset
 
 #define erts_atomic_init_relb erts_no_atomic_set
 #define erts_atomic_set_relb erts_no_atomic_set
@@ -950,6 +1215,7 @@ ERTS_GLB_INLINE void erts_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_atomic_read_band_relb erts_no_atomic_read_band
 #define erts_atomic_xchg_relb erts_no_atomic_xchg
 #define erts_atomic_cmpxchg_relb erts_no_atomic_cmpxchg
+#define erts_atomic_read_bset_relb erts_no_atomic_read_bset
 
 #define erts_atomic_init_ddrb erts_no_atomic_set
 #define erts_atomic_set_ddrb erts_no_atomic_set
@@ -964,6 +1230,7 @@ ERTS_GLB_INLINE void erts_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_atomic_read_band_ddrb erts_no_atomic_read_band
 #define erts_atomic_xchg_ddrb erts_no_atomic_xchg
 #define erts_atomic_cmpxchg_ddrb erts_no_atomic_cmpxchg
+#define erts_atomic_read_bset_ddrb erts_no_atomic_read_bset
 
 #define erts_atomic_init_rb erts_no_atomic_set
 #define erts_atomic_set_rb erts_no_atomic_set
@@ -978,6 +1245,7 @@ ERTS_GLB_INLINE void erts_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_atomic_read_band_rb erts_no_atomic_read_band
 #define erts_atomic_xchg_rb erts_no_atomic_xchg
 #define erts_atomic_cmpxchg_rb erts_no_atomic_cmpxchg
+#define erts_atomic_read_bset_rb erts_no_atomic_read_bset
 
 #define erts_atomic_init_wb erts_no_atomic_set
 #define erts_atomic_set_wb erts_no_atomic_set
@@ -992,6 +1260,7 @@ ERTS_GLB_INLINE void erts_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_atomic_read_band_wb erts_no_atomic_read_band
 #define erts_atomic_xchg_wb erts_no_atomic_xchg
 #define erts_atomic_cmpxchg_wb erts_no_atomic_cmpxchg
+#define erts_atomic_read_bset_wb erts_no_atomic_read_bset
 
 /* 32-bit atomics */
 
@@ -1008,6 +1277,7 @@ ERTS_GLB_INLINE void erts_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_atomic32_read_band_nob erts_no_atomic32_read_band
 #define erts_atomic32_xchg_nob erts_no_atomic32_xchg
 #define erts_atomic32_cmpxchg_nob erts_no_atomic32_cmpxchg
+#define erts_atomic32_read_bset_nob erts_no_atomic32_read_bset
 
 #define erts_atomic32_init_mb erts_no_atomic32_set
 #define erts_atomic32_set_mb erts_no_atomic32_set
@@ -1022,6 +1292,7 @@ ERTS_GLB_INLINE void erts_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_atomic32_read_band_mb erts_no_atomic32_read_band
 #define erts_atomic32_xchg_mb erts_no_atomic32_xchg
 #define erts_atomic32_cmpxchg_mb erts_no_atomic32_cmpxchg
+#define erts_atomic32_read_bset_mb erts_no_atomic32_read_bset
 
 #define erts_atomic32_init_acqb erts_no_atomic32_set
 #define erts_atomic32_set_acqb erts_no_atomic32_set
@@ -1036,6 +1307,7 @@ ERTS_GLB_INLINE void erts_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_atomic32_read_band_acqb erts_no_atomic32_read_band
 #define erts_atomic32_xchg_acqb erts_no_atomic32_xchg
 #define erts_atomic32_cmpxchg_acqb erts_no_atomic32_cmpxchg
+#define erts_atomic32_read_bset_acqb erts_no_atomic32_read_bset
 
 #define erts_atomic32_init_relb erts_no_atomic32_set
 #define erts_atomic32_set_relb erts_no_atomic32_set
@@ -1050,6 +1322,7 @@ ERTS_GLB_INLINE void erts_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_atomic32_read_band_relb erts_no_atomic32_read_band
 #define erts_atomic32_xchg_relb erts_no_atomic32_xchg
 #define erts_atomic32_cmpxchg_relb erts_no_atomic32_cmpxchg
+#define erts_atomic32_read_bset_relb erts_no_atomic32_read_bset
 
 #define erts_atomic32_init_ddrb erts_no_atomic32_set
 #define erts_atomic32_set_ddrb erts_no_atomic32_set
@@ -1064,6 +1337,7 @@ ERTS_GLB_INLINE void erts_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_atomic32_read_band_ddrb erts_no_atomic32_read_band
 #define erts_atomic32_xchg_ddrb erts_no_atomic32_xchg
 #define erts_atomic32_cmpxchg_ddrb erts_no_atomic32_cmpxchg
+#define erts_atomic32_read_bset_ddrb erts_no_atomic32_read_bset
 
 #define erts_atomic32_init_rb erts_no_atomic32_set
 #define erts_atomic32_set_rb erts_no_atomic32_set
@@ -1078,6 +1352,7 @@ ERTS_GLB_INLINE void erts_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_atomic32_read_band_rb erts_no_atomic32_read_band
 #define erts_atomic32_xchg_rb erts_no_atomic32_xchg
 #define erts_atomic32_cmpxchg_rb erts_no_atomic32_cmpxchg
+#define erts_atomic32_read_bset_rb erts_no_atomic32_read_bset
 
 #define erts_atomic32_init_wb erts_no_atomic32_set
 #define erts_atomic32_set_wb erts_no_atomic32_set
@@ -1092,6 +1367,7 @@ ERTS_GLB_INLINE void erts_thr_sigwait(const sigset_t *set, int *sig);
 #define erts_atomic32_read_band_wb erts_no_atomic32_read_band
 #define erts_atomic32_xchg_wb erts_no_atomic32_xchg
 #define erts_atomic32_cmpxchg_wb erts_no_atomic32_cmpxchg
+#define erts_atomic32_read_bset_wb erts_no_atomic32_read_bset
 
 #endif /* !USE_THREADS */
 
@@ -1856,6 +2132,16 @@ erts_no_atomic_cmpxchg(erts_no_atomic_t *xchgp,
     return old;
 }
 
+ERTS_GLB_INLINE erts_aint_t
+erts_no_atomic_read_bset(erts_no_atomic_t *var,
+			 erts_aint_t mask,
+			 erts_aint_t set)
+{
+    erts_aint_t old = *var;
+    *var |= (mask & set);
+    return old;
+}
+
 /* atomic32 */
 
 ERTS_GLB_INLINE void
@@ -1943,6 +2229,16 @@ erts_no_atomic32_cmpxchg(erts_no_atomic32_t *xchgp,
     return old;
 }
 
+ERTS_GLB_INLINE erts_aint32_t
+erts_no_atomic32_read_bset(erts_no_atomic32_t *var,
+			   erts_aint32_t mask,
+			   erts_aint32_t set)
+{
+    erts_aint32_t old = *var;
+    *var |= (mask & set);
+    return old;
+}
+
 /* spinlock */
 
 ERTS_GLB_INLINE void
diff --git a/erts/emulator/beam/erl_trace.c b/erts/emulator/beam/erl_trace.c
index d04a91f18c..41f33efa79 100644
--- a/erts/emulator/beam/erl_trace.c
+++ b/erts/emulator/beam/erl_trace.c
@@ -156,8 +156,8 @@ do { (RES) = (TPID); } while(0)
 #define ERTS_TRACER_REF_TYPE Process *
 #define ERTS_GET_TRACER_REF(RES, TPID, TRACEE_FLGS) \
 do { \
-    (RES) = erts_proc_lookup((TPID));					\
-    if (!(RES) || !((RES)->trace_flags & F_TRACER)) {			\
+    (RES) = erts_proc_lookup((TPID)); \
+    if (!(RES) || !(ERTS_TRACE_FLAGS((RES)) & F_TRACER)) { \
 	(TPID) = NIL; \
 	(TRACEE_FLGS) &= ~TRACEE_FLAGS; \
 	return; \
@@ -409,7 +409,7 @@ WRITE_SYS_MSG_TO_PORT(Eterm unused_to,
     }
 
 #ifndef ERTS_SMP
-    if (!INVALID_TRACER_PORT(trace_port, trace_port->id))
+    if (!INVALID_TRACER_PORT(trace_port, trace_port->common.id))
 #endif
 	erts_raw_port_command(trace_port, buffer, ptr-buffer);
 
@@ -441,7 +441,7 @@ do_send_schedfix_to_port(Port *trace_port, Eterm pid, Eterm timestamp) {
     message = TUPLE5(hp, am_trace_ts, pid, am_out, mfarity, timestamp);
     /* Note, hp is deliberately NOT incremented since it will be reused */
 
-    do_send_to_port(trace_port->id,
+    do_send_to_port(trace_port->common.id,
 		    trace_port,
 		    pid,
 		    SYS_MSG_TYPE_UNDEFINED,
@@ -451,7 +451,7 @@ do_send_schedfix_to_port(Port *trace_port, Eterm pid, Eterm timestamp) {
     hp += 5;
     hp = patch_ts(message, hp);
 
-    do_send_to_port(trace_port->id,
+    do_send_to_port(trace_port->common.id,
 		    trace_port,
 		    pid,
 		    SYS_MSG_TYPE_UNDEFINED,
@@ -508,7 +508,7 @@ send_to_port(Process *c_p, Eterm message,
 #endif
 	do_send_to_port(*tracer_pid,
 			trace_port,
-			c_p ? c_p->id : NIL,
+			c_p ? c_p->common.id : NIL,
 			SYS_MSG_TYPE_TRACE,
 			message);
 #ifndef ERTS_SMP
@@ -543,7 +543,7 @@ send_to_port(Process *c_p, Eterm message,
     trace_port->control_flags &= ~PORT_CONTROL_FLAG_HEAVY;
     do_send_to_port(*tracer_pid,
 		    trace_port,
-		    c_p ? c_p->id : NIL,
+		    c_p ? c_p->common.id : NIL,
 		    SYS_MSG_TYPE_TRACE,
 		    message);
 
@@ -557,7 +557,7 @@ send_to_port(Process *c_p, Eterm message,
 	 * just after writning the real trace message, and now gets scheduled
 	 * in again.
 	 */
-	do_send_schedfix_to_port(trace_port, c_p->id, ts);
+	do_send_schedfix_to_port(trace_port, c_p->common.id, ts);
     }
 
     erts_port_release(trace_port);
@@ -599,15 +599,14 @@ profile_send(Eterm from, Eterm message) {
 	if (profiler_port) {
 	    do_send_to_port(profiler,
 			    profiler_port,
-			    NIL, /* or current process->id */
+			    NIL, /* or current process->common.id */
 			    SYS_MSG_TYPE_SYSPROF,
 			    message);
 	    erts_port_release(profiler_port);
 	}
     	
     } else {
-	ASSERT(is_internal_pid(profiler)
-                && internal_pid_index(profiler) < erts_max_processes);
+	ASSERT(is_internal_pid(profiler));
         
 	profile_p = erts_proc_lookup(profiler);
 
@@ -673,7 +672,7 @@ seq_trace_send_to_port(Process *c_p,
 #endif
 	do_send_to_port(seq_tracer,
 			trace_port,
-			c_p ? c_p->id : NIL,
+			c_p ? c_p->common.id : NIL,
 			SYS_MSG_TYPE_SEQTRACE,
 			message);
 
@@ -704,7 +703,7 @@ seq_trace_send_to_port(Process *c_p,
     trace_port->control_flags &= ~PORT_CONTROL_FLAG_HEAVY;
     do_send_to_port(seq_tracer,
 		    trace_port,
-		    c_p ? c_p->id : NIL,
+		    c_p ? c_p->common.id : NIL,
 		    SYS_MSG_TYPE_SEQTRACE,
 		    message);
 
@@ -718,7 +717,7 @@ seq_trace_send_to_port(Process *c_p,
 	 * just after writing the real trace message, and now gets scheduled
 	 * in again.
 	 */
-	do_send_schedfix_to_port(trace_port, c_p->id, ts);
+	do_send_schedfix_to_port(trace_port, c_p->common.id, ts);
     }
 
     erts_port_release(trace_port);
@@ -729,7 +728,9 @@ seq_trace_send_to_port(Process *c_p,
 }
 
 #define TS_HEAP_WORDS 5
-#define TS_SIZE(p) (((p)->trace_flags & F_TIMESTAMP) ? TS_HEAP_WORDS : 0)
+#define TS_SIZE(p) ((ERTS_TRACE_FLAGS((p)) & F_TIMESTAMP) \
+		    ? TS_HEAP_WORDS \
+		    : 0)
 
 /*
  * Patch a timestamp into a tuple.  The tuple must be the last thing
@@ -764,17 +765,17 @@ send_to_tracer(Process *tracee,
 
     erts_smp_mtx_lock(&smq_mtx);
 
-    if (tracee->trace_flags & F_TIMESTAMP)
+    if (ERTS_TRACE_FLAGS(tracee) & F_TIMESTAMP)
 	*hpp = patch_ts(msg, *hpp);
 
-    if (is_internal_pid(tracee->tracer_proc))
-	ERTS_ENQ_TRACE_MSG(tracee->id, tracer_ref, msg, bp);
+    if (is_internal_pid(ERTS_TRACER_PROC(tracee)))
+	ERTS_ENQ_TRACE_MSG(tracee->common.id, tracer_ref, msg, bp);
     else {
-	ASSERT(is_internal_port(tracee->tracer_proc));
+	ASSERT(is_internal_port(ERTS_TRACER_PROC(tracee)));
 	send_to_port(no_fake_sched ? NULL : tracee,
 		     msg,
-		     &tracee->tracer_proc,
-		     &tracee->trace_flags);
+		     &ERTS_TRACER_PROC(tracee),
+		     &ERTS_TRACE_FLAGS(tracee));
     }
 
     erts_smp_mtx_unlock(&smq_mtx);
@@ -792,7 +793,7 @@ trace_sched_aux(Process *p, Eterm what, int never_fake_sched)
     ERTS_TRACER_REF_TYPE tracer_ref = ERTS_NULL_TRACER_REF;
     int sched_no, curr_func, to_port, no_fake_sched;
 
-    if (is_nil(p->tracer_proc))
+    if (is_nil(ERTS_TRACER_PROC(p)))
 	return;
 
     no_fake_sched = never_fake_sched;
@@ -812,13 +813,14 @@ trace_sched_aux(Process *p, Eterm what, int never_fake_sched)
     }
 
     sched_no = IS_TRACED_FL(p, F_TRACE_SCHED_NO);
-    to_port = is_internal_port(p->tracer_proc);
+    to_port = is_internal_port(ERTS_TRACER_PROC(p));
 
     if (!to_port) {
-	ASSERT(is_internal_pid(p->tracer_proc)
-	       && internal_pid_index(p->tracer_proc) < erts_max_processes);
+	ASSERT(is_internal_pid(ERTS_TRACER_PROC(p)));
 
-	ERTS_GET_TRACER_REF(tracer_ref, p->tracer_proc, p->trace_flags);
+	ERTS_GET_TRACER_REF(tracer_ref,
+			    ERTS_TRACER_PROC(p),
+			    ERTS_TRACE_FLAGS(p));
     }
 
     if (ERTS_PROC_IS_EXITING(p))
@@ -851,7 +853,7 @@ trace_sched_aux(Process *p, Eterm what, int never_fake_sched)
     }
 
     if (!sched_no) {
-	mess = TUPLE4(hp, am_trace, p->id, what, tmp);
+	mess = TUPLE4(hp, am_trace, p->common.id, what, tmp);
 	hp += 5;
     }
     else {
@@ -860,7 +862,7 @@ trace_sched_aux(Process *p, Eterm what, int never_fake_sched)
 #else
 	Eterm sched_id = make_small(1);
 #endif
-	mess = TUPLE5(hp, am_trace, p->id, what, sched_id, tmp);
+	mess = TUPLE5(hp, am_trace, p->common.id, what, sched_id, tmp);
 	hp += 6;
     }
 
@@ -912,19 +914,19 @@ trace_send(Process *p, Eterm to, Eterm msg)
 	operation = am_atom_put(s, sys_strlen(s));
     }
 
-    if (is_internal_port(p->tracer_proc)) {
+    if (is_internal_port(ERTS_TRACER_PROC(p))) {
 #define LOCAL_HEAP_SIZE (11)
 	DeclareTmpHeapNoproc(local_heap,LOCAL_HEAP_SIZE);
 	UseTmpHeapNoproc(LOCAL_HEAP_SIZE);
 
 	hp = local_heap;
-	mess = TUPLE5(hp, am_trace, p->id, operation, msg, to);
+	mess = TUPLE5(hp, am_trace, p->common.id, operation, msg, to);
 	hp += 6;
 	erts_smp_mtx_lock(&smq_mtx);
-	if (p->trace_flags & F_TIMESTAMP) {
+	if (ERTS_TRACE_FLAGS(p) & F_TIMESTAMP) {
 	    hp = patch_ts(mess, hp);
 	}
-	send_to_port(p, mess, &p->tracer_proc, &p->trace_flags);
+	send_to_port(p, mess, &ERTS_TRACER_PROC(p), &ERTS_TRACE_FLAGS(p));
 	UnUseTmpHeapNoproc(LOCAL_HEAP_SIZE);
 #undef LOCAL_HEAP_SIZE
 	erts_smp_mtx_unlock(&smq_mtx);
@@ -934,10 +936,11 @@ trace_send(Process *p, Eterm to, Eterm msg)
 	ErlOffHeap *off_heap;
 	ERTS_TRACER_REF_TYPE tracer_ref;
 
-	ASSERT(is_internal_pid(p->tracer_proc)
-	       && internal_pid_index(p->tracer_proc) < erts_max_processes);
+	ASSERT(is_internal_pid(ERTS_TRACER_PROC(p)));
 
-	ERTS_GET_TRACER_REF(tracer_ref, p->tracer_proc, p->trace_flags);
+	ERTS_GET_TRACER_REF(tracer_ref,
+			    ERTS_TRACER_PROC(p),
+			    ERTS_TRACE_FLAGS(p));
 
 	sz_msg = size_object(msg);
 	sz_to  = size_object(to);
@@ -953,16 +956,16 @@ trace_send(Process *p, Eterm to, Eterm msg)
 			  sz_msg,
 			  &hp,
 			  off_heap);
-	mess = TUPLE5(hp, am_trace, p->id/* Local pid */, operation, msg, to);
+	mess = TUPLE5(hp, am_trace, p->common.id, operation, msg, to);
 	hp += 6;
 
 	erts_smp_mtx_lock(&smq_mtx);
 
-	if (p->trace_flags & F_TIMESTAMP) {
+	if (ERTS_TRACE_FLAGS(p) & F_TIMESTAMP) {
 	    patch_ts(mess, hp);
 	}
 
-	ERTS_ENQ_TRACE_MSG(p->id, tracer_ref, mess, bp);
+	ERTS_ENQ_TRACE_MSG(p->common.id, tracer_ref, mess, bp);
 	erts_smp_mtx_unlock(&smq_mtx);
     }
 }
@@ -977,19 +980,19 @@ trace_receive(Process *rp, Eterm msg)
     size_t sz_msg;
     Eterm* hp;
 
-    if (is_internal_port(rp->tracer_proc)) {
+    if (is_internal_port(ERTS_TRACER_PROC(rp))) {
 #define LOCAL_HEAP_SIZE (10)
 	DeclareTmpHeapNoproc(local_heap,LOCAL_HEAP_SIZE);
 	UseTmpHeapNoproc(LOCAL_HEAP_SIZE);
 
 	hp = local_heap;
-	mess = TUPLE4(hp, am_trace, rp->id, am_receive, msg);
+	mess = TUPLE4(hp, am_trace, rp->common.id, am_receive, msg);
 	hp += 5;
 	erts_smp_mtx_lock(&smq_mtx);
-	if (rp->trace_flags & F_TIMESTAMP) {
+	if (ERTS_TRACE_FLAGS(rp) & F_TIMESTAMP) {
 	    hp = patch_ts(mess, hp);
 	}
-	send_to_port(rp, mess, &rp->tracer_proc, &rp->trace_flags);
+	send_to_port(rp, mess, &ERTS_TRACER_PROC(rp), &ERTS_TRACE_FLAGS(rp));
 	UnUseTmpHeapNoproc(LOCAL_HEAP_SIZE);
 #undef LOCAL_HEAP_SIZE
 	erts_smp_mtx_unlock(&smq_mtx);
@@ -999,10 +1002,11 @@ trace_receive(Process *rp, Eterm msg)
 	ErlOffHeap *off_heap;
 	ERTS_TRACER_REF_TYPE tracer_ref;
 
-	ASSERT(is_internal_pid(rp->tracer_proc)
-	       && internal_pid_index(rp->tracer_proc) < erts_max_processes);
+	ASSERT(is_internal_pid(ERTS_TRACER_PROC(rp)));
 
-	ERTS_GET_TRACER_REF(tracer_ref, rp->tracer_proc, rp->trace_flags);
+	ERTS_GET_TRACER_REF(tracer_ref,
+			    ERTS_TRACER_PROC(rp),
+			    ERTS_TRACE_FLAGS(rp));
 
 	sz_msg = size_object(msg);
 
@@ -1011,16 +1015,16 @@ trace_receive(Process *rp, Eterm msg)
 	hp = ERTS_ALLOC_SYSMSG_HEAP(hsz, &bp, &off_heap, tracer_ref);
 
 	msg = copy_struct(msg, sz_msg, &hp, off_heap);
-	mess = TUPLE4(hp, am_trace, rp->id/* Local pid */, am_receive, msg);
+	mess = TUPLE4(hp, am_trace, rp->common.id, am_receive, msg);
 	hp += 5;
 
 	erts_smp_mtx_lock(&smq_mtx);
 
-	if (rp->trace_flags & F_TIMESTAMP) {
+	if (ERTS_TRACE_FLAGS(rp) & F_TIMESTAMP) {
 	    patch_ts(mess, hp);
 	}
 
-	ERTS_ENQ_TRACE_MSG(rp->id, tracer_ref, mess, bp);
+	ERTS_ENQ_TRACE_MSG(rp->common.id, tracer_ref, mess, bp);
 	erts_smp_mtx_unlock(&smq_mtx);
     }
 }
@@ -1030,14 +1034,14 @@ seq_trace_update_send(Process *p)
 {
     Eterm seq_tracer = erts_get_system_seq_tracer();
     ASSERT((is_tuple(SEQ_TRACE_TOKEN(p)) || is_nil(SEQ_TRACE_TOKEN(p))));
-    if ( (p->id == seq_tracer) || (SEQ_TRACE_TOKEN(p) == NIL)
+    if ( (p->common.id == seq_tracer) || (SEQ_TRACE_TOKEN(p) == NIL)
 #ifdef USE_VM_PROBES
 	 || (SEQ_TRACE_TOKEN(p) == am_have_dt_utag)
 #endif
 	 ) {
 	return 0;
     }
-    SEQ_TRACE_TOKEN_SENDER(p) = p->id; /* Internal pid */
+    SEQ_TRACE_TOKEN_SENDER(p) = p->common.id;
     SEQ_TRACE_TOKEN_SERIAL(p) = 
 	make_small(++(p -> seq_trace_clock));
     SEQ_TRACE_TOKEN_LASTCNT(p) = 
@@ -1074,7 +1078,7 @@ seq_trace_output_generic(Eterm token, Eterm msg, Uint type,
 
     ASSERT(is_tuple(token) || is_nil(token));
     if (SEQ_TRACE_T_SENDER(token) == seq_tracer || token == NIL ||
-	(process && process->trace_flags & F_SENSITIVE)) {
+	(process && ERTS_TRACE_FLAGS(process) & F_SENSITIVE)) {
 	return;
     }
 
@@ -1138,8 +1142,7 @@ seq_trace_output_generic(Eterm token, Eterm msg, Uint type,
 	Uint sz_label, sz_lastcnt_serial, sz_msg, sz_ts, sz_sender,
 	    sz_exitfrom, sz_receiver;
 
-	ASSERT(is_internal_pid(seq_tracer)
-	       && internal_pid_index(seq_tracer) < erts_max_processes);
+	ASSERT(is_internal_pid(seq_tracer));
 
 #ifndef ERTS_SMP
 
@@ -1253,17 +1256,17 @@ erts_trace_return_to(Process *p, BeamInstr *pc)
 	hp += 4;
     }
 	
-    mess = TUPLE4(hp, am_trace, p->id, am_return_to, mfa);
+    mess = TUPLE4(hp, am_trace, p->common.id, am_return_to, mfa);
     hp += 5;
 
     erts_smp_mtx_lock(&smq_mtx);
 
-    if (p->trace_flags & F_TIMESTAMP) {
+    if (ERTS_TRACE_FLAGS(p) & F_TIMESTAMP) {
 	hp = patch_ts(mess, hp);
     }
 
-    if (is_internal_port(p->tracer_proc)) {
-	send_to_port(p, mess, &p->tracer_proc, &p->trace_flags);
+    if (is_internal_port(ERTS_TRACER_PROC(p))) {
+	send_to_port(p, mess, &ERTS_TRACER_PROC(p), &ERTS_TRACE_FLAGS(p));
     } else {
 	ErlHeapFragment *bp;
 	ErlOffHeap *off_heap;
@@ -1273,10 +1276,11 @@ erts_trace_return_to(Process *p, BeamInstr *pc)
 	/*
 	 * Find the tracer.
 	 */
-	ASSERT(is_internal_pid(p->tracer_proc)
-	       && internal_pid_index(p->tracer_proc) < erts_max_processes);
+	ASSERT(is_internal_pid(ERTS_TRACER_PROC(p)));
 
-	ERTS_GET_TRACER_REF(tracer_ref, p->tracer_proc, p->trace_flags);
+	ERTS_GET_TRACER_REF(tracer_ref,
+			    ERTS_TRACER_PROC(p),
+			    ERTS_TRACE_FLAGS(p));
 
 	size = size_object(mess);
 
@@ -1286,7 +1290,7 @@ erts_trace_return_to(Process *p, BeamInstr *pc)
 	 * Copy the trace message into the buffer and enqueue it.
 	 */
 	mess = copy_struct(mess, size, &hp, off_heap);
-	ERTS_ENQ_TRACE_MSG(p->id, tracer_ref, mess, bp);
+	ERTS_ENQ_TRACE_MSG(p->common.id, tracer_ref, mess, bp);
     }
     UnUseTmpHeapNoproc(LOCAL_HEAP_SIZE);
 #undef LOCAL_HEAP_SIZE
@@ -1315,25 +1319,25 @@ erts_trace_return(Process* p, BeamInstr* fi, Eterm retval, Eterm *tracer_pid)
 	/* Breakpoint trace enabled without specifying tracer =>
 	 *   use process tracer and flags
 	 */
-	tracer_pid = &p->tracer_proc;
+	tracer_pid = &ERTS_TRACER_PROC(p);
     }
     if (is_nil(*tracer_pid)) {
 	/* Trace disabled */
 	return;
     }
     ASSERT(is_internal_pid(*tracer_pid) || is_internal_port(*tracer_pid));
-    if (*tracer_pid == p->id) {
+    if (*tracer_pid == p->common.id) {
 	/* Do not generate trace messages to oneself */
 	return;
     }
-    if (tracer_pid == &p->tracer_proc) {
+    if (tracer_pid == &ERTS_TRACER_PROC(p)) {
 	/* Tracer specified in process structure =>
 	 *   non-breakpoint trace =>
 	 *     use process flags
 	 */
-	tracee_flags = &p->trace_flags;
+	tracee_flags = &ERTS_TRACE_FLAGS(p);
 #ifdef ERTS_SMP
-	tracee = p->id;
+	tracee = p->common.id;
 #endif
     } else {
 	/* Tracer not specified in process structure =>
@@ -1362,7 +1366,7 @@ erts_trace_return(Process* p, BeamInstr* fi, Eterm retval, Eterm *tracer_pid)
 	hp = local_heap;
 	mfa = TUPLE3(hp, mod, name, make_small(arity));
 	hp += 4;
-	mess = TUPLE5(hp, am_trace, p->id, am_return_from, mfa, retval);
+	mess = TUPLE5(hp, am_trace, p->common.id, am_return_from, mfa, retval);
 	hp += 6;
 	erts_smp_mtx_lock(&smq_mtx);
 	if (*tracee_flags & F_TIMESTAMP) {
@@ -1382,8 +1386,7 @@ erts_trace_return(Process* p, BeamInstr* fi, Eterm retval, Eterm *tracer_pid)
 	Eterm* limit;
 #endif
 
-	ASSERT(is_internal_pid(*tracer_pid)
-	       && internal_pid_index(*tracer_pid) < erts_max_processes);
+	ASSERT(is_internal_pid(*tracer_pid));
 
 	ERTS_GET_TRACER_REF(tracer_ref, *tracer_pid, *tracee_flags);
 	
@@ -1405,7 +1408,7 @@ erts_trace_return(Process* p, BeamInstr* fi, Eterm retval, Eterm *tracer_pid)
 	mfa = TUPLE3(hp, mod, name, make_small(arity));
 	hp += 4;
 	retval = copy_struct(retval, retval_size, &hp, off_heap);
-	mess = TUPLE5(hp, am_trace, p->id/* Local pid */, am_return_from, mfa, retval);
+	mess = TUPLE5(hp, am_trace, p->common.id, am_return_from, mfa, retval);
 	hp += 6;
 
 	erts_smp_mtx_lock(&smq_mtx);
@@ -1446,25 +1449,25 @@ erts_trace_exception(Process* p, BeamInstr mfa[3], Eterm class, Eterm value,
 	/* Breakpoint trace enabled without specifying tracer =>
 	 *   use process tracer and flags
 	 */
-	tracer_pid = &p->tracer_proc;
+	tracer_pid = &ERTS_TRACER_PROC(p);
     }
     if (is_nil(*tracer_pid)) {
 	/* Trace disabled */
 	return;
     }
     ASSERT(is_internal_pid(*tracer_pid) || is_internal_port(*tracer_pid));
-    if (*tracer_pid == p->id) {
+    if (*tracer_pid == p->common.id) {
 	/* Do not generate trace messages to oneself */
 	return;
     }
-    if (tracer_pid == &p->tracer_proc) {
+    if (tracer_pid == &ERTS_TRACER_PROC(p)) {
 	/* Tracer specified in process structure =>
 	 *   non-breakpoint trace =>
 	 *     use process flags
 	 */
-	tracee_flags = &p->trace_flags;
+	tracee_flags = &ERTS_TRACE_FLAGS(p);
 #ifdef ERTS_SMP
-	tracee = p->id;
+	tracee = p->common.id;
 #endif
 	if (! (*tracee_flags & F_TRACE_CALLS)) {
 	    return;
@@ -1492,7 +1495,7 @@ erts_trace_exception(Process* p, BeamInstr mfa[3], Eterm class, Eterm value,
 	hp += 4;
 	cv = TUPLE2(hp, class, value);
 	hp += 3;
-	mess = TUPLE5(hp, am_trace, p->id, am_exception_from, mfa_tuple, cv);
+	mess = TUPLE5(hp, am_trace, p->common.id, am_exception_from, mfa_tuple, cv);
 	hp += 6;
 	ASSERT((hp - local_heap) <= LOCAL_HEAP_SIZE);
 	erts_smp_mtx_lock(&smq_mtx);
@@ -1514,8 +1517,7 @@ erts_trace_exception(Process* p, BeamInstr mfa[3], Eterm class, Eterm value,
 	Eterm* limit;
 #endif
 
-	ASSERT(is_internal_pid(*tracer_pid)
-	       && internal_pid_index(*tracer_pid) < erts_max_processes);
+	ASSERT(is_internal_pid(*tracer_pid));
 
 	ERTS_GET_TRACER_REF(tracer_ref, *tracer_pid, *tracee_flags);
 	
@@ -1539,7 +1541,7 @@ erts_trace_exception(Process* p, BeamInstr mfa[3], Eterm class, Eterm value,
 	value = copy_struct(value, value_size, &hp, off_heap);
 	cv = TUPLE2(hp, class, value);
 	hp += 3;
-	mess = TUPLE5(hp, am_trace, p->id/* Local pid */, 
+	mess = TUPLE5(hp, am_trace, p->common.id, 
 		      am_exception_from, mfa_tuple, cv);
 	hp += 6;
 
@@ -1593,25 +1595,25 @@ erts_call_trace(Process* p, BeamInstr mfa[3], Binary *match_spec,
 	/* Breakpoint trace enabled without specifying tracer =>
 	 *   use process tracer and flags
 	 */
-	tracer_pid = &p->tracer_proc;
+	tracer_pid = &ERTS_TRACER_PROC(p);
     } 
     if (is_nil(*tracer_pid)) {
 	/* Trace disabled */
 	return 0;
     }
     ASSERT(is_internal_pid(*tracer_pid) || is_internal_port(*tracer_pid));
-    if (*tracer_pid == p->id) {
+    if (*tracer_pid == p->common.id) {
 	/* Do not generate trace messages to oneself */
 	return 0;
     }
-    if (tracer_pid == &p->tracer_proc) {
+    if (tracer_pid == &ERTS_TRACER_PROC(p)) {
 	/* Tracer specified in process structure =>
 	 *   non-breakpoint trace =>
 	 *     use process flags
 	 */
-	tracee_flags = &p->trace_flags;
+	tracee_flags = &ERTS_TRACE_FLAGS(p);
 #ifdef ERTS_SMP
-	tracee = p->id;
+	tracee = p->common.id;
 #endif
     } else {
 	/* Tracer not specified in process structure =>
@@ -1619,7 +1621,7 @@ erts_call_trace(Process* p, BeamInstr mfa[3], Binary *match_spec,
 	 *     meta trace =>
 	 *       use fixed flag set instead of process flags
 	 */	    
-	if (p->trace_flags & F_SENSITIVE) {
+	if (ERTS_TRACE_FLAGS(p) & F_SENSITIVE) {
 	    /* No trace messages for sensitive processes. */
 	    return 0;
 	}
@@ -1677,7 +1679,7 @@ erts_call_trace(Process* p, BeamInstr mfa[3], Binary *match_spec,
 
 	if (!erts_is_valid_tracer_port(*tracer_pid)) {
 #ifdef ERTS_SMP
-	    ASSERT(is_nil(tracee) || tracer_pid == &p->tracer_proc);
+	    ASSERT(is_nil(tracee) || tracer_pid == &ERTS_TRACER_PROC(p));
 	    if (is_not_nil(tracee))
 		erts_smp_proc_lock(p, ERTS_PROC_LOCKS_ALL_MINOR);
 #endif
@@ -1779,7 +1781,7 @@ erts_call_trace(Process* p, BeamInstr mfa[3], Binary *match_spec,
 	 * Build the trace tuple and send it to the port.
 	 */
 	
-	mess = TUPLE4(hp, am_trace, p->id, am_call, mfa_tuple);
+	mess = TUPLE4(hp, am_trace, p->common.id, am_call, mfa_tuple);
 	hp += 5;
 	if (pam_result != am_true) {
 	    hp[-5] = make_arityval(5);
@@ -1814,21 +1816,21 @@ erts_call_trace(Process* p, BeamInstr mfa[3], Binary *match_spec,
 	Eterm* limit;
 #endif
 
-	ASSERT(is_internal_pid(*tracer_pid)
-	       && internal_pid_index(*tracer_pid) < erts_max_processes);
+	ASSERT(is_internal_pid(*tracer_pid));
 	
 	tracer = erts_pid2proc(p, ERTS_PROC_LOCK_MAIN,
 			       *tracer_pid, ERTS_PROC_LOCK_STATUS);
 	if (!tracer)
 	    invalid_tracer = 1;
 	else {
-	    invalid_tracer = (tracer->trace_flags & F_TRACER) == 0;
+	    invalid_tracer = !(ERTS_TRACE_FLAGS(tracer) & F_TRACER);
 	    erts_smp_proc_unlock(tracer, ERTS_PROC_LOCK_STATUS);
 	}
 
 	if (invalid_tracer) {
 #ifdef ERTS_SMP
-	    ASSERT(is_nil(tracee) || tracer_pid == &p->tracer_proc);
+	    ASSERT(is_nil(tracee)
+		   || tracer_pid == &ERTS_TRACER_PROC(p));
 	    if (is_not_nil(tracee))
 		erts_smp_proc_lock(p, ERTS_PROC_LOCKS_ALL_MINOR);
 #endif
@@ -1952,7 +1954,7 @@ erts_call_trace(Process* p, BeamInstr mfa[3], Binary *match_spec,
 	 * Build the trace tuple and enqueue it.
 	 */
 	
-	mess = TUPLE4(hp, am_trace, p->id/* Local pid */, am_call, mfa_tuple);
+	mess = TUPLE4(hp, am_trace, p->common.id, am_call, mfa_tuple);
 	hp += 5;
 	if (pam_result != am_true) {
 	    hp[-5] = make_arityval(5);
@@ -1990,17 +1992,17 @@ trace_proc(Process *c_p, Process *t_p, Eterm what, Eterm data)
 
     ERTS_SMP_LC_ASSERT((erts_proc_lc_my_proc_locks(t_p) != 0)
 		       || erts_thr_progress_is_blocking());
-    if (is_internal_port(t_p->tracer_proc)) {
+    if (is_internal_port(ERTS_TRACER_PROC(t_p))) {
 #define LOCAL_HEAP_SIZE (5+5)
 	DeclareTmpHeapNoproc(local_heap,LOCAL_HEAP_SIZE);
 	UseTmpHeapNoproc(LOCAL_HEAP_SIZE);
 
 
 	hp = local_heap;
-	mess = TUPLE4(hp, am_trace, t_p->id, what, data);
+	mess = TUPLE4(hp, am_trace, t_p->common.id, what, data);
 	hp += 5;
 	erts_smp_mtx_lock(&smq_mtx);
-	if (t_p->trace_flags & F_TIMESTAMP) {
+	if (ERTS_TRACE_FLAGS(t_p) & F_TIMESTAMP) {
 	    hp = patch_ts(mess, hp);
 	}
 	send_to_port(
@@ -2011,7 +2013,9 @@ trace_proc(Process *c_p, Process *t_p, Eterm what, Eterm data)
 	    /* Fake schedule out and in are never sent when smp enabled */
 	    c_p,
 #endif
-	    mess, &t_p->tracer_proc, &t_p->trace_flags);
+	    mess,
+	    &ERTS_TRACER_PROC(t_p),
+	    &ERTS_TRACE_FLAGS(t_p));
 	UnUseTmpHeapNoproc(LOCAL_HEAP_SIZE);
 #undef LOCAL_HEAP_SIZE
 	erts_smp_mtx_unlock(&smq_mtx);
@@ -2022,10 +2026,11 @@ trace_proc(Process *c_p, Process *t_p, Eterm what, Eterm data)
 	ERTS_TRACER_REF_TYPE tracer_ref;
 	size_t sz_data;
 
-	ASSERT(is_internal_pid(t_p->tracer_proc)
-	       && internal_pid_index(t_p->tracer_proc) < erts_max_processes);
+	ASSERT(is_internal_pid(ERTS_TRACER_PROC(t_p)));
 
-	ERTS_GET_TRACER_REF(tracer_ref, t_p->tracer_proc, t_p->trace_flags);
+	ERTS_GET_TRACER_REF(tracer_ref,
+			    ERTS_TRACER_PROC(t_p),
+			    ERTS_TRACE_FLAGS(t_p));
 
 	sz_data = size_object(data);
 
@@ -2034,16 +2039,16 @@ trace_proc(Process *c_p, Process *t_p, Eterm what, Eterm data)
 	hp = ERTS_ALLOC_SYSMSG_HEAP(need, &bp, &off_heap, tracer_ref);
 
 	tmp = copy_struct(data, sz_data, &hp, off_heap);
-	mess = TUPLE4(hp, am_trace, t_p->id/* Local pid */, what, tmp);
+	mess = TUPLE4(hp, am_trace, t_p->common.id, what, tmp);
 	hp += 5;
 
 	erts_smp_mtx_lock(&smq_mtx);
 
-	if (t_p->trace_flags & F_TIMESTAMP) {
+	if (ERTS_TRACE_FLAGS(t_p) & F_TIMESTAMP) {
 	    hp = patch_ts(mess, hp);
 	}
 
-	ERTS_ENQ_TRACE_MSG(t_p->id, tracer_ref, mess, bp);
+	ERTS_ENQ_TRACE_MSG(t_p->common.id, tracer_ref, mess, bp);
 	erts_smp_mtx_unlock(&smq_mtx);
     }
 }
@@ -2064,7 +2069,7 @@ trace_proc_spawn(Process *p, Eterm pid,
     Eterm mess;
     Eterm* hp;
 
-    if (is_internal_port(p->tracer_proc)) {
+    if (is_internal_port(ERTS_TRACER_PROC(p))) {
 #define LOCAL_HEAP_SIZE (4+6+5)
 	DeclareTmpHeapNoproc(local_heap,LOCAL_HEAP_SIZE);
 	UseTmpHeapNoproc(LOCAL_HEAP_SIZE);
@@ -2072,13 +2077,13 @@ trace_proc_spawn(Process *p, Eterm pid,
 	hp = local_heap;
 	mfa = TUPLE3(hp, mod, func, args);
 	hp += 4;
-	mess = TUPLE5(hp, am_trace, p->id, am_spawn, pid, mfa);
+	mess = TUPLE5(hp, am_trace, p->common.id, am_spawn, pid, mfa);
 	hp += 6;
 	erts_smp_mtx_lock(&smq_mtx);
-	if (p->trace_flags & F_TIMESTAMP) {
+	if (ERTS_TRACE_FLAGS(p) & F_TIMESTAMP) {
 	    hp = patch_ts(mess, hp);
 	}
-	send_to_port(p, mess, &p->tracer_proc, &p->trace_flags);
+	send_to_port(p, mess, &ERTS_TRACER_PROC(p), &ERTS_TRACE_FLAGS(p));
 	UnUseTmpHeapNoproc(LOCAL_HEAP_SIZE);
 #undef LOCAL_HEAP_SIZE
 	erts_smp_mtx_unlock(&smq_mtx);
@@ -2090,10 +2095,11 @@ trace_proc_spawn(Process *p, Eterm pid,
 	size_t sz_args, sz_pid;
 	Uint need;
 
-	ASSERT(is_internal_pid(p->tracer_proc)
-	       && internal_pid_index(p->tracer_proc) < erts_max_processes);
+	ASSERT(is_internal_pid(ERTS_TRACER_PROC(p)));
 
-	ERTS_GET_TRACER_REF(tracer_ref, p->tracer_proc, p->trace_flags);
+	ERTS_GET_TRACER_REF(tracer_ref,
+			    ERTS_TRACER_PROC(p),
+			    ERTS_TRACE_FLAGS(p));
 
 	sz_args = size_object(args);
 	sz_pid = size_object(pid);
@@ -2105,16 +2111,16 @@ trace_proc_spawn(Process *p, Eterm pid,
 	mfa = TUPLE3(hp, mod, func, tmp);
 	hp += 4;
 	tmp = copy_struct(pid, sz_pid, &hp, off_heap);
-	mess = TUPLE5(hp, am_trace, p->id, am_spawn, tmp, mfa);
+	mess = TUPLE5(hp, am_trace, p->common.id, am_spawn, tmp, mfa);
 	hp += 6;
 
 	erts_smp_mtx_lock(&smq_mtx);
 
-	if (p->trace_flags & F_TIMESTAMP) {
+	if (ERTS_TRACE_FLAGS(p) & F_TIMESTAMP) {
 	    hp = patch_ts(mess, hp);
 	}
 
-	ERTS_ENQ_TRACE_MSG(p->id, tracer_ref, mess, bp);
+	ERTS_ENQ_TRACE_MSG(p->common.id, tracer_ref, mess, bp);
 	erts_smp_mtx_unlock(&smq_mtx);
     }
 }
@@ -2204,7 +2210,7 @@ trace_gc(Process *p, Eterm what)
 
     UseTmpHeap(LOCAL_HEAP_SIZE,p);
 
-    if (is_internal_port(p->tracer_proc)) {
+    if (is_internal_port(ERTS_TRACER_PROC(p))) {
 	hp = local_heap;
 #ifdef DEBUG
 	size = 0;
@@ -2216,10 +2222,11 @@ trace_gc(Process *p, Eterm what)
 	size += 5/*4-tuple*/ + TS_SIZE(p);
 #endif
     } else {
-	ASSERT(is_internal_pid(p->tracer_proc)
-	       && internal_pid_index(p->tracer_proc) < erts_max_processes);
+	ASSERT(is_internal_pid(ERTS_TRACER_PROC(p)));
 
-	ERTS_GET_TRACER_REF(tracer_ref, p->tracer_proc, p->trace_flags);
+	ERTS_GET_TRACER_REF(tracer_ref,
+			    ERTS_TRACER_PROC(p),
+			    ERTS_TRACE_FLAGS(p));
 
 	size = 0;
 	(void) erts_bld_atom_uint_2tup_list(NULL,
@@ -2243,19 +2250,19 @@ trace_gc(Process *p, Eterm what)
 				       tags,
 				       values);
 
-    msg = TUPLE4(hp, am_trace, p->id/* Local pid */, what, msg);
+    msg = TUPLE4(hp, am_trace, p->common.id, what, msg);
     hp += 5;
 
     erts_smp_mtx_lock(&smq_mtx);
 
-    if (p->trace_flags & F_TIMESTAMP) {
+    if (ERTS_TRACE_FLAGS(p) & F_TIMESTAMP) {
 	hp = patch_ts(msg, hp);
     }
     ASSERT(hp == limit);
-    if (is_internal_port(p->tracer_proc))
-	send_to_port(p, msg, &p->tracer_proc, &p->trace_flags);
+    if (is_internal_port(ERTS_TRACER_PROC(p)))
+	send_to_port(p, msg, &ERTS_TRACER_PROC(p), &ERTS_TRACE_FLAGS(p));
     else
-	ERTS_ENQ_TRACE_MSG(p->id, tracer_ref, msg, bp);
+	ERTS_ENQ_TRACE_MSG(p->common.id, tracer_ref, msg, bp);
     erts_smp_mtx_unlock(&smq_mtx);
     UnUseTmpHeap(LOCAL_HEAP_SIZE,p);
 #undef LOCAL_HEAP_SIZE
@@ -2295,8 +2302,7 @@ monitor_long_gc(Process *p, Uint time) {
 #endif
 	
 #ifndef ERTS_SMP
-    ASSERT(is_internal_pid(system_monitor)
-	   && internal_pid_index(system_monitor) < erts_max_processes);
+    ASSERT(is_internal_pid(system_monitor));
     monitor_p = erts_proc_lookup(system_monitor);
     if (!monitor_p || p == monitor_p)
 	return;
@@ -2321,7 +2327,7 @@ monitor_long_gc(Process *p, Uint time) {
 					sizeof(values)/sizeof(Uint),
 					tags,
 					values);
-    msg = TUPLE4(hp, am_monitor, p->id/* Local pid */, am_long_gc, list); 
+    msg = TUPLE4(hp, am_monitor, p->common.id, am_long_gc, list); 
 
 #ifdef DEBUG
     hp += 5 /* 4-tuple */;
@@ -2329,7 +2335,7 @@ monitor_long_gc(Process *p, Uint time) {
 #endif
 
 #ifdef ERTS_SMP
-    enqueue_sys_msg(SYS_MSG_TYPE_SYSMON, p->id, NIL, msg, bp);
+    enqueue_sys_msg(SYS_MSG_TYPE_SYSMON, p->common.id, NIL, msg, bp);
 #else
     erts_queue_message(monitor_p, NULL, bp, msg, NIL
 #ifdef USE_VM_PROBES
@@ -2370,8 +2376,7 @@ monitor_large_heap(Process *p) {
 
 
 #ifndef ERTS_SMP 
-    ASSERT(is_internal_pid(system_monitor)
-	   && internal_pid_index(system_monitor) < erts_max_processes);
+    ASSERT(is_internal_pid(system_monitor));
     monitor_p = erts_proc_lookup(system_monitor);
     if (monitor_p || p == monitor_p) {
 	return;
@@ -2397,7 +2402,7 @@ monitor_large_heap(Process *p) {
 					sizeof(values)/sizeof(Uint),
 					tags,
 					values);
-    msg = TUPLE4(hp, am_monitor, p->id/* Local pid */, am_large_heap, list); 
+    msg = TUPLE4(hp, am_monitor, p->common.id, am_large_heap, list); 
 
 #ifdef DEBUG
     hp += 5 /* 4-tuple */;
@@ -2405,7 +2410,7 @@ monitor_large_heap(Process *p) {
 #endif
 
 #ifdef ERTS_SMP
-    enqueue_sys_msg(SYS_MSG_TYPE_SYSMON, p->id, NIL, msg, bp);
+    enqueue_sys_msg(SYS_MSG_TYPE_SYSMON, p->common.id, NIL, msg, bp);
 #else
     erts_queue_message(monitor_p, NULL, bp, msg, NIL
 #ifdef USE_VM_PROBES
@@ -2425,8 +2430,7 @@ monitor_generic(Process *p, Eterm type, Eterm spec) {
     Eterm *hp, msg;
 
 #ifndef ERTS_SMP
-    ASSERT(is_internal_pid(system_monitor)
-	   && internal_pid_index(system_monitor) < erts_max_processes);
+    ASSERT(is_internal_pid(system_monitor));
     monitor_p = erts_proc_lookup(system_monitor);
     if (!monitor_p || p == monitor_p)
 	return;
@@ -2434,11 +2438,11 @@ monitor_generic(Process *p, Eterm type, Eterm spec) {
 
     hp = ERTS_ALLOC_SYSMSG_HEAP(5, &bp, &off_heap, monitor_p);
 
-    msg = TUPLE4(hp, am_monitor, p->id/* Local pid */, type, spec); 
+    msg = TUPLE4(hp, am_monitor, p->common.id, type, spec); 
     hp += 5;
 
 #ifdef ERTS_SMP
-    enqueue_sys_msg(SYS_MSG_TYPE_SYSMON, p->id, NIL, msg, bp);
+    enqueue_sys_msg(SYS_MSG_TYPE_SYSMON, p->common.id, NIL, msg, bp);
 #else
     erts_queue_message(monitor_p, NULL, bp, msg, NIL
 #ifdef USE_VM_PROBES
@@ -2560,21 +2564,21 @@ trace_port_open(Port *p, Eterm calling_pid, Eterm drv_name) {
     Eterm mess;
     Eterm* hp;
 
-    if (is_internal_port(p->tracer_proc)) {
+    if (is_internal_port(ERTS_TRACER_PROC(p))) {
 #define LOCAL_HEAP_SIZE (5+6)
 	DeclareTmpHeapNoproc(local_heap,LOCAL_HEAP_SIZE);
 	UseTmpHeapNoproc(LOCAL_HEAP_SIZE);
 
 	hp = local_heap;
 
-	mess = TUPLE5(hp, am_trace, calling_pid, am_open, p->id, drv_name);
+	mess = TUPLE5(hp, am_trace, calling_pid, am_open, p->common.id, drv_name);
 	hp += 6;
 	erts_smp_mtx_lock(&smq_mtx);
-	if (p->trace_flags & F_TIMESTAMP) {
+	if (ERTS_TRACE_FLAGS(p) & F_TIMESTAMP) {
 	    hp = patch_ts(mess, hp);
 	}
 	/* No fake schedule */
-	send_to_port(NULL, mess, &p->tracer_proc, &p->trace_flags);
+	send_to_port(NULL, mess, &ERTS_TRACER_PROC(p), &ERTS_TRACE_FLAGS(p));
 	UnUseTmpHeapNoproc(LOCAL_HEAP_SIZE);
 #undef LOCAL_HEAP_SIZE
 	erts_smp_mtx_unlock(&smq_mtx);
@@ -2584,25 +2588,26 @@ trace_port_open(Port *p, Eterm calling_pid, Eterm drv_name) {
 	size_t sz_data;
 	ERTS_TRACER_REF_TYPE tracer_ref;
 	
-	ASSERT(is_internal_pid(p->tracer_proc)
-	       && internal_pid_index(p->tracer_proc) < erts_max_processes);
+	ASSERT(is_internal_pid(ERTS_TRACER_PROC(p)));
 
 	sz_data = 6 + TS_SIZE(p);
 
-	ERTS_GET_TRACER_REF(tracer_ref, p->tracer_proc, p->trace_flags);
+	ERTS_GET_TRACER_REF(tracer_ref,
+			    ERTS_TRACER_PROC(p),
+			    ERTS_TRACE_FLAGS(p));
 
 	hp = ERTS_ALLOC_SYSMSG_HEAP(sz_data, &bp, &off_heap, tracer_ref);
 
-	mess = TUPLE5(hp, am_trace, calling_pid, am_open, p->id, drv_name);
+	mess = TUPLE5(hp, am_trace, calling_pid, am_open, p->common.id, drv_name);
 	hp += 6;
 
 	erts_smp_mtx_lock(&smq_mtx);
 
-	if (p->trace_flags & F_TIMESTAMP) {
+	if (ERTS_TRACE_FLAGS(p) & F_TIMESTAMP) {
 	    hp = patch_ts(mess, hp);
 	}
 
-	ERTS_ENQ_TRACE_MSG(p->id, tracer_ref, mess, bp);
+	ERTS_ENQ_TRACE_MSG(p->common.id, tracer_ref, mess, bp);
 	erts_smp_mtx_unlock(&smq_mtx);
     }
 
@@ -2623,20 +2628,20 @@ trace_port(Port *t_p, Eterm what, Eterm data) {
     ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(t_p)
 		       || erts_thr_progress_is_blocking());
 
-    if (is_internal_port(t_p->tracer_proc)) {
+    if (is_internal_port(ERTS_TRACER_PROC(t_p))) {
 #define LOCAL_HEAP_SIZE (5+5)
 	DeclareTmpHeapNoproc(local_heap,LOCAL_HEAP_SIZE);
 	UseTmpHeapNoproc(LOCAL_HEAP_SIZE);
 
 	hp = local_heap;
-	mess = TUPLE4(hp, am_trace, t_p->id, what, data);
+	mess = TUPLE4(hp, am_trace, t_p->common.id, what, data);
 	hp += 5;
 	erts_smp_mtx_lock(&smq_mtx);
-	if (t_p->trace_flags & F_TIMESTAMP) {
+	if (ERTS_TRACE_FLAGS(t_p) & F_TIMESTAMP) {
 	    hp = patch_ts(mess, hp);
 	}
 	/* No fake schedule */
-	send_to_port(NULL, mess, &t_p->tracer_proc, &t_p->trace_flags);
+	send_to_port(NULL,mess,&ERTS_TRACER_PROC(t_p),&ERTS_TRACE_FLAGS(t_p));
 	UnUseTmpHeapNoproc(LOCAL_HEAP_SIZE);
 #undef LOCAL_HEAP_SIZE
 	erts_smp_mtx_unlock(&smq_mtx);
@@ -2646,25 +2651,26 @@ trace_port(Port *t_p, Eterm what, Eterm data) {
 	size_t sz_data;
 	ERTS_TRACER_REF_TYPE tracer_ref;
 
-	ASSERT(is_internal_pid(t_p->tracer_proc)
-	       && internal_pid_index(t_p->tracer_proc) < erts_max_processes);
+	ASSERT(is_internal_pid(ERTS_TRACER_PROC(t_p)));
 
 	sz_data = 5 + TS_SIZE(t_p);
 
-	ERTS_GET_TRACER_REF(tracer_ref, t_p->tracer_proc, t_p->trace_flags);
+	ERTS_GET_TRACER_REF(tracer_ref,
+			    ERTS_TRACER_PROC(t_p),
+			    ERTS_TRACE_FLAGS(t_p));
 
 	hp = ERTS_ALLOC_SYSMSG_HEAP(sz_data, &bp, &off_heap, tracer_ref);
 
-	mess = TUPLE4(hp, am_trace, t_p->id, what, data);
+	mess = TUPLE4(hp, am_trace, t_p->common.id, what, data);
 	hp += 5;
 
 	erts_smp_mtx_lock(&smq_mtx);
 
-	if (t_p->trace_flags & F_TIMESTAMP) {
+	if (ERTS_TRACE_FLAGS(t_p) & F_TIMESTAMP) {
 	    hp = patch_ts(mess, hp);
 	}
 
-	ERTS_ENQ_TRACE_MSG(t_p->id, tracer_ref, mess, bp);
+	ERTS_ENQ_TRACE_MSG(t_p->common.id, tracer_ref, mess, bp);
 	erts_smp_mtx_unlock(&smq_mtx);
     }
 }
@@ -2689,7 +2695,7 @@ trace_sched_ports_where(Port *p, Eterm what, Eterm where) {
     int ws = 5;	
     Eterm sched_id = am_undefined;
     
-    if (is_internal_port(p->tracer_proc)) {
+    if (is_internal_port(ERTS_TRACER_PROC(p))) {
 #define LOCAL_HEAP_SIZE (5+6)
 	DeclareTmpHeapNoproc(local_heap,LOCAL_HEAP_SIZE);
 	UseTmpHeapNoproc(LOCAL_HEAP_SIZE);
@@ -2704,21 +2710,21 @@ trace_sched_ports_where(Port *p, Eterm what, Eterm where) {
 #else
 		sched_id = make_small(1);
 #endif
-		mess = TUPLE5(hp, am_trace, p->id, what, sched_id, where);
+		mess = TUPLE5(hp, am_trace, p->common.id, what, sched_id, where);
 		ws = 6;
 	} else {
-		mess = TUPLE4(hp, am_trace, p->id, what, where);
+		mess = TUPLE4(hp, am_trace, p->common.id, what, where);
 		ws = 5;
 	}
 	hp += ws;
 	
 	erts_smp_mtx_lock(&smq_mtx);
-	if (p->trace_flags & F_TIMESTAMP) {
+	if (ERTS_TRACE_FLAGS(p) & F_TIMESTAMP) {
 	    hp = patch_ts(mess, hp);
 	}
 	
 	/* No fake scheduling */
-	send_to_port(NULL, mess, &p->tracer_proc, &p->trace_flags);
+	send_to_port(NULL, mess, &ERTS_TRACER_PROC(p), &ERTS_TRACE_FLAGS(p));
 	UnUseTmpHeapNoproc(LOCAL_HEAP_SIZE);
 #undef LOCAL_HEAP_SIZE
 	erts_smp_mtx_unlock(&smq_mtx);
@@ -2727,12 +2733,13 @@ trace_sched_ports_where(Port *p, Eterm what, Eterm where) {
     	ErlOffHeap *off_heap;
 	ERTS_TRACER_REF_TYPE tracer_ref;
 
-	ASSERT(is_internal_pid(p->tracer_proc)
-	       && internal_pid_index(p->tracer_proc) < erts_max_processes);
+	ASSERT(is_internal_pid(ERTS_TRACER_PROC(p)));
 	
 	if (IS_TRACED_FL(p, F_TRACE_SCHED_NO)) ws = 6; /* Make place for scheduler id */
 
-	ERTS_GET_TRACER_REF(tracer_ref, p->tracer_proc, p->trace_flags);
+	ERTS_GET_TRACER_REF(tracer_ref,
+			    ERTS_TRACER_PROC(p),
+			    ERTS_TRACE_FLAGS(p));
 
 	hp = ERTS_ALLOC_SYSMSG_HEAP(ws+TS_SIZE(p), &bp, &off_heap, tracer_ref);
 
@@ -2744,19 +2751,19 @@ trace_sched_ports_where(Port *p, Eterm what, Eterm where) {
 #else
 		sched_id = make_small(1);
 #endif
-		mess = TUPLE5(hp, am_trace, p->id, what, sched_id, where);
+		mess = TUPLE5(hp, am_trace, p->common.id, what, sched_id, where);
 	} else {
-		mess = TUPLE4(hp, am_trace, p->id, what, where);
+		mess = TUPLE4(hp, am_trace, p->common.id, what, where);
 	}
 	hp += ws;
 
 	erts_smp_mtx_lock(&smq_mtx);
 
-	if (p->trace_flags & F_TIMESTAMP) {
+	if (ERTS_TRACE_FLAGS(p) & F_TIMESTAMP) {
 	    hp = patch_ts(mess, hp);
 	}
 
-	ERTS_ENQ_TRACE_MSG(p->id, tracer_ref, mess, bp);
+	ERTS_ENQ_TRACE_MSG(p->common.id, tracer_ref, mess, bp);
 	erts_smp_mtx_unlock(&smq_mtx);
     }
 }
@@ -2792,14 +2799,14 @@ profile_runnable_port(Port *p, Eterm status) {
 
     GET_NOW(&Ms, &s, &us);
     timestamp = TUPLE3(hp, make_small(Ms), make_small(s), make_small(us)); hp += 4;
-    msg = TUPLE5(hp, am_profile, p->id, status, count, timestamp); hp += 6;
+    msg = TUPLE5(hp, am_profile, p->common.id, status, count, timestamp); hp += 6;
 
 #ifndef ERTS_SMP
-    profile_send(p->id, msg);
+    profile_send(p->common.id, msg);
     UnUseTmpHeapNoproc(LOCAL_HEAP_SIZE);
 #undef LOCAL_HEAP_SIZE
 #else
-    enqueue_sys_msg_unlocked(SYS_MSG_TYPE_SYSPROF, p->id, NIL, msg, bp);
+    enqueue_sys_msg_unlocked(SYS_MSG_TYPE_SYSPROF, p->common.id, NIL, msg, bp);
 #endif
     erts_smp_mtx_unlock(&smq_mtx);
 }
@@ -2846,13 +2853,13 @@ profile_runnable_proc(Process *p, Eterm status){
 
     GET_NOW(&Ms, &s, &us);
     timestamp = TUPLE3(hp, make_small(Ms), make_small(s), make_small(us)); hp += 4;
-    msg = TUPLE5(hp, am_profile, p->id, status, where, timestamp); hp += 6;
+    msg = TUPLE5(hp, am_profile, p->common.id, status, where, timestamp); hp += 6;
 #ifndef ERTS_SMP
-    profile_send(p->id, msg);
+    profile_send(p->common.id, msg);
     UnUseTmpHeapNoproc(LOCAL_HEAP_SIZE);
 #undef LOCAL_HEAP_SIZE
 #else
-    enqueue_sys_msg_unlocked(SYS_MSG_TYPE_SYSPROF, p->id, NIL, msg, bp);
+    enqueue_sys_msg_unlocked(SYS_MSG_TYPE_SYSPROF, p->common.id, NIL, msg, bp);
 #endif
     erts_smp_mtx_unlock(&smq_mtx);
 }
@@ -2865,16 +2872,19 @@ profile_runnable_proc(Process *p, Eterm status){
 void
 erts_check_my_tracer_proc(Process *p)
 {
-    if (is_internal_pid(p->tracer_proc)) {
-	Process *tracer = erts_pid2proc(p, ERTS_PROC_LOCK_MAIN,
-					p->tracer_proc, ERTS_PROC_LOCK_STATUS);
-	int invalid_tracer = !tracer || !(tracer->trace_flags & F_TRACER);
+    if (is_internal_pid(ERTS_TRACER_PROC(p))) {
+	Process *tracer = erts_pid2proc(p,
+					ERTS_PROC_LOCK_MAIN,
+					ERTS_TRACER_PROC(p),
+					ERTS_PROC_LOCK_STATUS);
+	int invalid_tracer = (!tracer
+			      || !(ERTS_TRACE_FLAGS(tracer) & F_TRACER));
 	if (tracer)
 	    erts_smp_proc_unlock(tracer, ERTS_PROC_LOCK_STATUS);
 	if (invalid_tracer) {
 	    erts_smp_proc_lock(p, ERTS_PROC_LOCKS_ALL_MINOR);
-	    p->trace_flags &= ~TRACEE_FLAGS;
-	    p->tracer_proc = NIL;
+	    ERTS_TRACE_FLAGS(p) &= ~TRACEE_FLAGS;
+	    ERTS_TRACER_PROC(p) = NIL;
 	    erts_smp_proc_unlock(p, ERTS_PROC_LOCKS_ALL_MINOR);
 	}
     }
@@ -3218,7 +3228,7 @@ sys_msg_dispatcher_func(void *unused)
 		proc = erts_pid2proc(NULL, 0, receiver, proc_locks);
 		if (!proc
 		    || (smqp->type == SYS_MSG_TYPE_TRACE
-			&& !(proc->trace_flags & F_TRACER))) {
+			&& !(ERTS_TRACE_FLAGS(proc) & F_TRACER))) {
 		    /* Bad tracer */
 #ifdef DEBUG_PRINTOUTS
 		    if (smqp->type == SYS_MSG_TYPE_TRACE && proc)
@@ -3245,16 +3255,14 @@ sys_msg_dispatcher_func(void *unused)
 		proc = erts_whereis_process(NULL,0,receiver,proc_locks,0);
 		if (!proc)
 		    goto failure;
-		else if (smqp->from == proc->id)
+		else if (smqp->from == proc->common.id)
 		    goto drop_sys_msg;
 		else
 		    goto queue_proc_msg;
 	    }
 	    else if (is_internal_port(receiver)) {
-		port = erts_id2port_sflgs(receiver,
-					  NULL,
-					  0,
-					  ERTS_PORT_SFLGS_INVALID_TRACER_LOOKUP);
+		port = erts_thr_id2port_sflgs(receiver,
+					      ERTS_PORT_SFLGS_INVALID_TRACER_LOOKUP);
 		if (!port)
 		    goto failure;
 		else {
@@ -3268,7 +3276,7 @@ sys_msg_dispatcher_func(void *unused)
 #ifdef DEBUG_PRINTOUTS
 		    erts_fprintf(stderr, "delivered\n");
 #endif
-		    erts_port_release(port);
+		    erts_thr_port_release(port);
 		    if (smqp->bp)
 			free_message_buffer(smqp->bp);
 		}
diff --git a/erts/emulator/beam/erl_trace.h b/erts/emulator/beam/erl_trace.h
new file mode 100644
index 0000000000..50fb27aab0
--- /dev/null
+++ b/erts/emulator/beam/erl_trace.h
@@ -0,0 +1,141 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2012. All Rights Reserved.
+ *
+ * The contents of this file are subject to the Erlang Public License,
+ * Version 1.1, (the "License"); you may not use this file except in
+ * compliance with the License. You should have received a copy of the
+ * Erlang Public License along with this software. If not, it can be
+ * retrieved online at http://www.erlang.org/.
+ *
+ * Software distributed under the License is distributed on an "AS IS"
+ * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+ * the License for the specific language governing rights and limitations
+ * under the License.
+ *
+ * %CopyrightEnd%
+ */
+
+
+#ifndef ERL_TRACE_H__
+#define ERL_TRACE_H__
+
+struct binary;
+
+/* erl_bif_trace.c */
+Eterm erl_seq_trace_info(Process *p, Eterm arg1);
+void erts_system_monitor_clear(Process *c_p);
+void erts_system_profile_clear(Process *c_p);
+
+/* erl_trace.c */
+void erts_init_trace(void);
+void erts_trace_check_exiting(Eterm exiting);
+Eterm erts_set_system_seq_tracer(Process *c_p,
+				 ErtsProcLocks c_p_locks,
+				 Eterm new);
+Eterm erts_get_system_seq_tracer(void);
+void erts_change_default_tracing(int setflags, Uint *flagsp, Eterm *tracerp);
+void erts_get_default_tracing(Uint *flagsp, Eterm *tracerp);
+void erts_set_system_monitor(Eterm monitor);
+Eterm erts_get_system_monitor(void);
+
+#ifdef ERTS_SMP
+void erts_check_my_tracer_proc(Process *);
+void erts_block_sys_msg_dispatcher(void);
+void erts_release_sys_msg_dispatcher(void);
+void erts_foreach_sys_msg_in_q(void (*func)(Eterm,
+					    Eterm,
+					    Eterm,
+					    ErlHeapFragment *));
+void erts_queue_error_logger_message(Eterm, Eterm, ErlHeapFragment *);
+#endif
+
+void erts_send_sys_msg_proc(Eterm, Eterm, Eterm, ErlHeapFragment *);
+void trace_send(Process*, Eterm, Eterm);
+void trace_receive(Process*, Eterm);
+Uint32 erts_call_trace(Process *p, BeamInstr mfa[], struct binary *match_spec, Eterm* args,
+		       int local, Eterm *tracer_pid);
+void erts_trace_return(Process* p, BeamInstr* fi, Eterm retval, Eterm *tracer_pid);
+void erts_trace_exception(Process* p, BeamInstr mfa[], Eterm class, Eterm value,
+			  Eterm *tracer);
+void erts_trace_return_to(Process *p, BeamInstr *pc);
+void trace_sched(Process*, Eterm);
+void trace_proc(Process*, Process*, Eterm, Eterm);
+void trace_proc_spawn(Process*, Eterm pid, Eterm mod, Eterm func, Eterm args);
+void save_calls(Process *p, Export *);
+void trace_gc(Process *p, Eterm what);
+/* port tracing */
+void trace_virtual_sched(Process*, Eterm);
+void trace_sched_ports(Port *pp, Eterm);
+void trace_sched_ports_where(Port *pp, Eterm, Eterm);
+void trace_port(Port *, Eterm what, Eterm data);
+void trace_port_open(Port *, Eterm calling_pid, Eterm drv_name);
+
+/* system_profile */
+void erts_set_system_profile(Eterm profile);
+Eterm erts_get_system_profile(void);
+void profile_scheduler(Eterm scheduler_id, Eterm);
+void profile_scheduler_q(Eterm scheduler_id, Eterm state, Eterm no_schedulers, Uint Ms, Uint s, Uint us);
+void profile_runnable_proc(Process* p, Eterm status);
+void profile_runnable_port(Port* p, Eterm status);
+void erts_system_profile_setup_active_schedulers(void);
+
+/* system_monitor */
+void monitor_long_gc(Process *p, Uint time);
+void monitor_large_heap(Process *p);
+void monitor_generic(Process *p, Eterm type, Eterm spec);
+Uint erts_trace_flag2bit(Eterm flag);
+int erts_trace_flags(Eterm List, 
+		 Uint *pMask, Eterm *pTracer, int *pCpuTimestamp);
+Eterm erts_bif_trace(int bif_index, Process* p, Eterm* args, BeamInstr *I);
+
+#ifdef ERTS_SMP
+void erts_send_pending_trace_msgs(ErtsSchedulerData *esdp);
+#define ERTS_SMP_CHK_PEND_TRACE_MSGS(ESDP)				\
+do {									\
+    if ((ESDP)->pending_trace_msgs)					\
+	erts_send_pending_trace_msgs((ESDP));				\
+} while (0)
+#else
+#define ERTS_SMP_CHK_PEND_TRACE_MSGS(ESDP)
+#endif
+
+#define seq_trace_output(token, msg, type, receiver, process) \
+seq_trace_output_generic((token), (msg), (type), (receiver), (process), NIL)
+#define seq_trace_output_exit(token, msg, type, receiver, exitfrom) \
+seq_trace_output_generic((token), (msg), (type), (receiver), NULL, (exitfrom))
+void seq_trace_output_generic(Eterm token, Eterm msg, Uint type, 
+			      Eterm receiver, Process *process, Eterm exitfrom);
+
+int seq_trace_update_send(Process *process);
+
+Eterm erts_seq_trace(Process *process, 
+		     Eterm atom_type, Eterm atom_true_or_false, 
+		     int build_result);
+
+struct trace_pattern_flags {
+    unsigned int breakpoint : 1; /* Set if any other is set */
+    unsigned int local      : 1; /* Local call trace breakpoint */
+    unsigned int meta       : 1; /* Metadata trace breakpoint */
+    unsigned int call_count : 1; /* Fast call count breakpoint */
+    unsigned int call_time  : 1; /* Fast call time breakpoint */
+};
+extern const struct trace_pattern_flags erts_trace_pattern_flags_off;
+extern int erts_call_time_breakpoint_tracing;
+int erts_set_trace_pattern(Process*p, Eterm* mfa, int specified,
+			   struct binary* match_prog_set,
+			   struct binary *meta_match_prog_set,
+			   int on, struct trace_pattern_flags,
+			   Eterm meta_tracer_pid, int is_blocking);
+void
+erts_get_default_trace_pattern(int *trace_pattern_is_on,
+			       struct binary **match_spec,
+			       struct binary **meta_match_spec,
+			       struct trace_pattern_flags *trace_pattern_flags,
+			       Eterm *meta_tracer_pid);
+int erts_is_default_trace_enabled(void);
+void erts_bif_trace_init(void);
+int erts_finish_breakpointing(void);
+
+#endif /* ERL_TRACE_H__ */
diff --git a/erts/emulator/beam/erl_utils.h b/erts/emulator/beam/erl_utils.h
new file mode 100644
index 0000000000..a2064bd8a3
--- /dev/null
+++ b/erts/emulator/beam/erl_utils.h
@@ -0,0 +1,215 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2012. All Rights Reserved.
+ *
+ * The contents of this file are subject to the Erlang Public License,
+ * Version 1.1, (the "License"); you may not use this file except in
+ * compliance with the License. You should have received a copy of the
+ * Erlang Public License along with this software. If not, it can be
+ * retrieved online at http://www.erlang.org/.
+ *
+ * Software distributed under the License is distributed on an "AS IS"
+ * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+ * the License for the specific language governing rights and limitations
+ * under the License.
+ *
+ * %CopyrightEnd%
+ */
+
+#ifndef ERL_UTILS_H__
+#define ERL_UTILS_H__
+
+#include "sys.h"
+#include "erl_smp.h"
+#include "erl_printf.h"
+
+typedef struct {
+#ifdef DEBUG
+    int smp_api;
+#endif
+    union {
+	Uint64 not_atomic;
+#ifdef ARCH_64
+	erts_atomic_t atomic;
+#else
+	erts_dw_atomic_t atomic;
+#endif
+    } counter;
+} erts_interval_t;
+
+void erts_interval_init(erts_interval_t *);
+void erts_smp_interval_init(erts_interval_t *);
+Uint64 erts_step_interval_nob(erts_interval_t *);
+Uint64 erts_step_interval_relb(erts_interval_t *);
+Uint64 erts_smp_step_interval_nob(erts_interval_t *);
+Uint64 erts_smp_step_interval_relb(erts_interval_t *);
+Uint64 erts_ensure_later_interval_nob(erts_interval_t *, Uint64);
+Uint64 erts_ensure_later_interval_acqb(erts_interval_t *, Uint64);
+Uint64 erts_smp_ensure_later_interval_nob(erts_interval_t *, Uint64);
+Uint64 erts_smp_ensure_later_interval_acqb(erts_interval_t *, Uint64);
+#ifdef ARCH_32
+ERTS_GLB_INLINE Uint64 erts_interval_dw_aint_to_val__(erts_dw_aint_t *);
+#endif
+ERTS_GLB_INLINE Uint64 erts_current_interval_nob__(erts_interval_t *);
+ERTS_GLB_INLINE Uint64 erts_current_interval_acqb__(erts_interval_t *);
+ERTS_GLB_INLINE Uint64 erts_current_interval_nob(erts_interval_t *);
+ERTS_GLB_INLINE Uint64 erts_current_interval_acqb(erts_interval_t *);
+ERTS_GLB_INLINE Uint64 erts_smp_current_interval_nob(erts_interval_t *);
+ERTS_GLB_INLINE Uint64 erts_smp_current_interval_acqb(erts_interval_t *);
+
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+
+#ifdef ARCH_32
+
+ERTS_GLB_INLINE Uint64
+erts_interval_dw_aint_to_val__(erts_dw_aint_t *dw)
+{
+#ifdef ETHR_SU_DW_NAINT_T__
+    return (Uint64) dw->dw_sint;
+#else
+    Uint64 res;
+    res = (Uint64) ((Uint32) dw->sint[ERTS_DW_AINT_HIGH_WORD]);
+    res <<= 32;
+    res |= (Uint64) ((Uint32) dw->sint[ERTS_DW_AINT_LOW_WORD]);
+    return res;
+#endif
+}
+
+#endif
+
+ERTS_GLB_INLINE Uint64
+erts_current_interval_nob__(erts_interval_t *icp)
+{
+#ifdef ARCH_64
+    return (Uint64) erts_atomic_read_nob(&icp->counter.atomic);
+#else
+    erts_dw_aint_t dw;
+    erts_dw_atomic_read_nob(&icp->counter.atomic, &dw);
+    return erts_interval_dw_aint_to_val__(&dw);
+#endif
+}
+
+ERTS_GLB_INLINE Uint64
+erts_current_interval_acqb__(erts_interval_t *icp)
+{
+#ifdef ARCH_64
+    return (Uint64) erts_atomic_read_acqb(&icp->counter.atomic);
+#else
+    erts_dw_aint_t dw;
+    erts_dw_atomic_read_acqb(&icp->counter.atomic, &dw);
+    return erts_interval_dw_aint_to_val__(&dw);
+#endif
+}
+
+ERTS_GLB_INLINE Uint64
+erts_current_interval_nob(erts_interval_t *icp)
+{
+    ASSERT(!icp->smp_api);
+    return erts_current_interval_nob__(icp);
+}
+
+ERTS_GLB_INLINE Uint64
+erts_current_interval_acqb(erts_interval_t *icp)
+{
+    ASSERT(!icp->smp_api);
+    return erts_current_interval_acqb__(icp);
+}
+
+ERTS_GLB_INLINE Uint64
+erts_smp_current_interval_nob(erts_interval_t *icp)
+{
+    ASSERT(icp->smp_api);
+#ifdef ERTS_SMP
+    return erts_current_interval_nob__(icp);
+#else
+    return icp->counter.not_atomic;
+#endif
+}
+
+ERTS_GLB_INLINE Uint64
+erts_smp_current_interval_acqb(erts_interval_t *icp)
+{
+    ASSERT(icp->smp_api);
+#ifdef ERTS_SMP
+    return erts_current_interval_acqb__(icp);
+#else
+    return icp->counter.not_atomic;
+#endif
+}
+
+#endif /* ERTS_GLB_INLINE_INCL_FUNC_DEF */
+
+/*
+ * To be used to silence unused result warnings, but do not abuse it.
+ */
+void erts_silence_warn_unused_result(long unused);
+
+
+int erts_fit_in_bits_int64(Sint64);
+int erts_fit_in_bits_int32(Sint32);
+int list_length(Eterm);
+int erts_is_builtin(Eterm, Eterm, int);
+Uint32 make_broken_hash(Eterm);
+Uint32 block_hash(byte *, unsigned, Uint32);
+Uint32 make_hash2(Eterm);
+Uint32 make_hash(Eterm);
+
+
+Eterm erts_bld_atom(Uint **hpp, Uint *szp, char *str);
+Eterm erts_bld_uint(Uint **hpp, Uint *szp, Uint ui);
+Eterm erts_bld_uword(Uint **hpp, Uint *szp, UWord uw);
+Eterm erts_bld_uint64(Uint **hpp, Uint *szp, Uint64 ui64);
+Eterm erts_bld_sint64(Uint **hpp, Uint *szp, Sint64 si64);
+Eterm erts_bld_cons(Uint **hpp, Uint *szp, Eterm car, Eterm cdr);
+Eterm erts_bld_tuple(Uint **hpp, Uint *szp, Uint arity, ...);
+Eterm erts_bld_tuplev(Uint **hpp, Uint *szp, Uint arity, Eterm terms[]);
+Eterm erts_bld_string_n(Uint **hpp, Uint *szp, const char *str, Sint len);
+#define erts_bld_string(hpp,szp,str) erts_bld_string_n(hpp,szp,str,strlen(str))
+Eterm erts_bld_list(Uint **hpp, Uint *szp, Sint length, Eterm terms[]);
+Eterm erts_bld_2tup_list(Uint **hpp, Uint *szp,
+			 Sint length, Eterm terms1[], Uint terms2[]);
+Eterm
+erts_bld_atom_uint_2tup_list(Uint **hpp, Uint *szp,
+			     Sint length, Eterm atoms[], Uint uints[]);
+Eterm
+erts_bld_atom_2uint_3tup_list(Uint **hpp, Uint *szp, Sint length,
+			      Eterm atoms[], Uint uints1[], Uint uints2[]);
+
+void erts_init_utils(void);
+void erts_init_utils_mem(void);
+
+erts_dsprintf_buf_t *erts_create_tmp_dsbuf(Uint);
+void erts_destroy_tmp_dsbuf(erts_dsprintf_buf_t *);
+
+#if HALFWORD_HEAP
+int eq_rel(Eterm a, Eterm* a_base, Eterm b, Eterm* b_base);
+#  define eq(A,B) eq_rel(A,NULL,B,NULL)
+#else
+int eq(Eterm, Eterm);
+#  define eq_rel(A,A_BASE,B,B_BASE) eq(A,B)
+#endif
+
+#define EQ(x,y) (((x) == (y)) || (is_not_both_immed((x),(y)) && eq((x),(y))))
+
+#if HALFWORD_HEAP
+Sint cmp_rel(Eterm, Eterm*, Eterm, Eterm*);
+#define CMP(A,B) cmp_rel(A,NULL,B,NULL)
+#else
+Sint cmp(Eterm, Eterm);
+#define cmp_rel(A,A_BASE,B,B_BASE) cmp(A,B)
+#define CMP(A,B) cmp(A,B)
+#endif
+#define cmp_lt(a,b)	(CMP((a),(b)) < 0)
+#define cmp_le(a,b)	(CMP((a),(b)) <= 0)
+#define cmp_eq(a,b)	(CMP((a),(b)) == 0)
+#define cmp_ne(a,b)	(CMP((a),(b)) != 0)
+#define cmp_ge(a,b)	(CMP((a),(b)) >= 0)
+#define cmp_gt(a,b)	(CMP((a),(b)) > 0)
+
+#define CMP_LT(a,b)	((a) != (b) && cmp_lt((a),(b)))
+#define CMP_GE(a,b)	((a) == (b) || cmp_ge((a),(b)))
+#define CMP_EQ(a,b)	((a) == (b) || cmp_eq((a),(b)))
+#define CMP_NE(a,b)	((a) != (b) && cmp_ne((a),(b)))
+
+#endif
diff --git a/erts/emulator/beam/global.h b/erts/emulator/beam/global.h
index 4c0d3421c8..298241618f 100755
--- a/erts/emulator/beam/global.h
+++ b/erts/emulator/beam/global.h
@@ -39,38 +39,8 @@
 #include "erl_sys_driver.h"
 #include "erl_debug.h"
 #include "error.h"
-
-typedef struct port Port;
-#include "erl_port_task.h"
-
-typedef struct erts_driver_t_ erts_driver_t;
-
-#define SMALL_IO_QUEUE 5   /* Number of fixed elements */
-
-typedef struct {
-    ErlDrvSizeT size;       /* total size in bytes */
-
-    SysIOVec* v_start;
-    SysIOVec* v_end;
-    SysIOVec* v_head;
-    SysIOVec* v_tail;
-    SysIOVec  v_small[SMALL_IO_QUEUE];
-
-    ErlDrvBinary** b_start;
-    ErlDrvBinary** b_end;
-    ErlDrvBinary** b_head;
-    ErlDrvBinary** b_tail;
-    ErlDrvBinary*  b_small[SMALL_IO_QUEUE];
-} ErlIOQueue;
-
-typedef struct line_buf {  /* Buffer used in line oriented I/O */
-    ErlDrvSizeT bufsiz;      /* Size of character buffer */
-    ErlDrvSizeT ovlen;       /* Length of overflow data */
-    ErlDrvSizeT ovsiz;       /* Actual size of overflow buffer */
-    char data[1];            /* Starting point of buffer data,
-			      data[0] is a flag indicating an unprocess CR,
-			      The rest is the overflow buffer. */
-} LineBuf;
+#include "erl_utils.h"
+#include "erl_port.h"
 
 struct enif_environment_t /* ErlNifEnv */
 {
@@ -90,162 +60,6 @@ extern void erts_print_nif_taints(int to, void* to_arg);
 void erts_unload_nif(struct erl_module_nif* nif);
 extern void erl_nif_init(void);
 
-/*
- * Port Specific Data.
- *
- * Only use PrtSD for very rarely used data.
- */
-
-#define ERTS_PRTSD_SCHED_ID 0
-
-#define ERTS_PRTSD_SIZE 1
-
-typedef struct {
-    void *data[ERTS_PRTSD_SIZE];
-} ErtsPrtSD;
-
-#ifdef ERTS_SMP
-typedef struct ErtsXPortsList_ ErtsXPortsList;
-#endif
-
-/*
- * Port locking:
- *
- * Locking is done either driver specific or port specific. When
- * driver specific locking is used, all instances of the driver,
- * i.e. ports running the driver, share the same lock. When port
- * specific locking is used each instance have its own lock.
- *
- * Most fields in the Port structure are protected by the lock
- * referred to by the lock field. I'v called it the port lock.
- * This lock is shared between all ports running the same driver
- * when driver specific locking is used.
- *
- * The 'sched' field is protected by the port tasks lock
- * (see erl_port_tasks.c)
- *
- * The 'status' field is protected by a combination of the port lock,
- * the port tasks lock, and the state_lck. It may be read if
- * the state_lck, or the port lock is held. It may only be
- * modified if both the port lock and the state_lck is held
- * (with one exception; see below). When changeing status from alive
- * to dead or vice versa, also the port task lock has to be held.
- * This in order to guarantee that tasks are scheduled only for
- * ports that are alive.
- *
- * The status field may be modified with only the state_lck
- * held when status is changed from dead to alive. This since no
- * threads can have any references to the port other than via the
- * port table.
- *
- * /rickard
- */
-
-struct port {
-    ErtsPortTaskSched sched;
-    ErtsPortTaskHandle timeout_task;
-    erts_smp_atomic_t refc;
-#ifdef ERTS_SMP
-    erts_smp_mtx_t *lock;
-    ErtsXPortsList *xports;
-    erts_smp_atomic_t run_queue;
-    erts_smp_spinlock_t state_lck;  /* protects: id, status, snapshot */
-#endif
-    Eterm id;                   /* The Port id of this port */
-    Eterm connected;            /* A connected process */
-    Eterm caller;		/* Current caller. */
-    Eterm data;			/* Data associated with port. */
-    ErlHeapFragment* bp;	/* Heap fragment holding data (NULL if imm data). */
-    ErtsLink *nlinks;
-    ErtsMonitor *monitors;      /* Only MON_ORIGIN monitors of pid's */
-    Uint bytes_in;		/* Number of bytes read */
-    Uint bytes_out;		/* Number of bytes written */
-#ifdef ERTS_SMP
-    ErtsSmpPTimer *ptimer;
-#else
-    ErlTimer tm;                 /* Timer entry */
-#endif
-    
-    Eterm tracer_proc;		/* If the port is traced, this is the tracer */
-    Uint trace_flags;		/* Trace flags */
-
-    ErlIOQueue ioq;              /* driver accessible i/o queue */
-    DistEntry *dist_entry;       /* Dist entry used in DISTRIBUTION */
-    char *name;		         /* String used in the open */
-    erts_driver_t* drv_ptr;
-    UWord drv_data;
-    SWord os_pid;                 /* Child process ID */
-    ErtsProcList *suspended;	 /* List of suspended processes. */
-    LineBuf *linebuf;            /* Buffer to hold data not ready for
-				    process to get (line oriented I/O)*/
-    Uint32 status;		 /* Status and type flags */
-    int control_flags;		 /* Flags for port_control()  */
-    erts_aint32_t snapshot;      /* Next snapshot that port should be part of */
-    struct reg_proc *reg;
-    ErlDrvPDL port_data_lock;
-
-    ErtsPrtSD *psd;		 /* Port specific data */
-};
-
-
-ERTS_GLB_INLINE ErtsRunQueue *erts_port_runq(Port *prt);
-
-#if ERTS_GLB_INLINE_INCL_FUNC_DEF
-
-ERTS_GLB_INLINE ErtsRunQueue *
-erts_port_runq(Port *prt)
-{
-#ifdef ERTS_SMP
-    ErtsRunQueue *rq1, *rq2;
-    rq1 = (ErtsRunQueue *) erts_smp_atomic_read_nob(&prt->run_queue);
-    if (!rq1)
-	return NULL;
-    while (1) {
-	erts_smp_runq_lock(rq1);
-	rq2 = (ErtsRunQueue *) erts_smp_atomic_read_nob(&prt->run_queue);
-	if (rq1 == rq2)
-	    return rq1;
-	erts_smp_runq_unlock(rq1);
-	rq1 = rq2;
-	if (!rq1)
-	    return NULL;
-    }
-#else
-    return ERTS_RUNQ_IX(0);
-#endif
-}
-
-#endif
-
-
-ERTS_GLB_INLINE void *erts_prtsd_get(Port *p, int ix);
-ERTS_GLB_INLINE void *erts_prtsd_set(Port *p, int ix, void *new);
-
-#if ERTS_GLB_INLINE_INCL_FUNC_DEF
-
-ERTS_GLB_INLINE void *
-erts_prtsd_get(Port *prt, int ix)
-{
-    return prt->psd ? prt->psd->data[ix] : NULL;
-}
-
-ERTS_GLB_INLINE void *
-erts_prtsd_set(Port *prt, int ix, void *data)
-{
-    if (prt->psd) {
-	void *old = prt->psd->data[ix];
-	prt->psd->data[ix] = data;
-	return old;
-    }
-    else {
-	prt->psd = erts_alloc(ERTS_ALC_T_PRTSD, sizeof(ErtsPrtSD));
-	prt->psd->data[ix] = data;
-	return NULL;
-    }
-}
-
-#endif
-
 /* Driver handle (wrapper for old plain handle) */
 #define ERL_DE_OK      0
 #define ERL_DE_UNLOAD  1
@@ -297,7 +111,7 @@ typedef struct {
 				         or that wait for it to change state */
     erts_refc_t  refc;                /* Number of ports/processes having
 					 references to the driver */
-    Uint         port_count;          /* Number of ports using the driver */
+    erts_smp_atomic32_t port_count;   /* Number of ports using the driver */
     Uint         flags;               /* ERL_DE_FL_KILL_PORTS */
     int          status;              /* ERL_DE_xxx */
     char         *full_path;          /* Full path of the driver */
@@ -349,7 +163,7 @@ struct erts_driver_t_ {
 };
 
 extern erts_driver_t *driver_list;
-extern erts_smp_mtx_t erts_driver_list_lock;
+extern erts_smp_rwmtx_t erts_driver_list_lock;
 
 extern void erts_ddll_init(void);
 extern void erts_ddll_lock_driver(DE_Handle *dh, char *name);
@@ -529,40 +343,9 @@ union erl_off_heap_ptr {
     void* voidp;
 };
 
-/* arrays that get malloced at startup */
-extern Port* erts_port;
-
-extern Uint erts_max_ports;
-extern Uint erts_port_tab_index_mask;
-extern erts_smp_atomic32_t erts_ports_snapshot;
-extern erts_smp_atomic_t erts_dead_ports_ptr;
-
-ERTS_GLB_INLINE void erts_may_save_closed_port(Port *prt);
-
-#if ERTS_GLB_INLINE_INCL_FUNC_DEF
-
-ERTS_GLB_INLINE void erts_may_save_closed_port(Port *prt)
-{
-    ERTS_SMP_LC_ASSERT(erts_smp_lc_spinlock_is_locked(&prt->state_lck));
-    if (prt->snapshot != erts_smp_atomic32_read_acqb(&erts_ports_snapshot)) {
-	/* Dead ports are added from the end of the snapshot buffer */
-	Eterm* tombstone;
-	tombstone = (Eterm*) erts_smp_atomic_add_read_nob(&erts_dead_ports_ptr,
-							  -(erts_aint_t)sizeof(Eterm));
-	ASSERT(tombstone+1 != NULL);
-	ASSERT(prt->snapshot == erts_smp_atomic32_read_nob(&erts_ports_snapshot) - 1);
-	*tombstone = prt->id;
-    }
-    /*else no ongoing snapshot or port was already included or created after snapshot */
-}
-
-#endif
-
 /* controls warning mapping in error_logger */
 
 extern Eterm node_cookie;
-extern erts_smp_atomic_t erts_bytes_out;	/* no bytes written out */
-extern erts_smp_atomic_t erts_bytes_in;		/* no bytes sent into the system */
 extern Uint display_items;	/* no of items to display in traces etc */
 
 extern int erts_backtrace_depth;
@@ -700,54 +483,6 @@ do {									\
 #define WSTACK_ISEMPTY(s) (WSTK_CONCAT(s,_sp) == WSTK_CONCAT(s,_start))
 #define WSTACK_POP(s) (*(--WSTK_CONCAT(s,_sp)))
 
-
-/* port status flags */
-
-#define ERTS_PORT_SFLG_CONNECTED	((Uint32) (1 <<  0))
-/* Port have begun exiting */
-#define ERTS_PORT_SFLG_EXITING		((Uint32) (1 <<  1))
-/* Distribution port */
-#define ERTS_PORT_SFLG_DISTRIBUTION	((Uint32) (1 <<  2))
-#define ERTS_PORT_SFLG_BINARY_IO	((Uint32) (1 <<  3))
-#define ERTS_PORT_SFLG_SOFT_EOF		((Uint32) (1 <<  4))
-/* Flow control */
-#define ERTS_PORT_SFLG_PORT_BUSY	((Uint32) (1 <<  5))
-/* Port is closing (no i/o accepted) */
-#define ERTS_PORT_SFLG_CLOSING		((Uint32) (1 <<  6))
-/* Send a closed message when terminating */
-#define ERTS_PORT_SFLG_SEND_CLOSED	((Uint32) (1 <<  7))
-/* Line orinted io on port */  
-#define ERTS_PORT_SFLG_LINEBUF_IO	((Uint32) (1 <<  8))
-/* Immortal port (only certain system ports) */
-#define ERTS_PORT_SFLG_IMMORTAL		((Uint32) (1 <<  9))
-#define ERTS_PORT_SFLG_FREE		((Uint32) (1 << 10))
-#define ERTS_PORT_SFLG_FREE_SCHEDULED	((Uint32) (1 << 11))
-#define ERTS_PORT_SFLG_INITIALIZING	((Uint32) (1 << 12))
-/* Port uses port specific locking (opposed to driver specific locking) */
-#define ERTS_PORT_SFLG_PORT_SPECIFIC_LOCK ((Uint32) (1 << 13))
-#define ERTS_PORT_SFLG_INVALID		((Uint32) (1 << 14))
-/* Last port to terminate halts the emulator */
-#define ERTS_PORT_SFLG_HALT		((Uint32) (1 << 15))
-#ifdef DEBUG
-/* Only debug: make sure all flags aren't cleared unintentionally */
-#define ERTS_PORT_SFLG_PORT_DEBUG	((Uint32) (1 << 31))
-#endif
-
-/* Combinations of port status flags */ 
-#define ERTS_PORT_SFLGS_DEAD						\
-  (ERTS_PORT_SFLG_FREE							\
-   | ERTS_PORT_SFLG_FREE_SCHEDULED					\
-   | ERTS_PORT_SFLG_INITIALIZING)
-#define ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP				\
-  (ERTS_PORT_SFLGS_DEAD | ERTS_PORT_SFLG_INVALID)
-#define ERTS_PORT_SFLGS_INVALID_LOOKUP					\
-  (ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP				\
-   | ERTS_PORT_SFLG_CLOSING)
-#define ERTS_PORT_SFLGS_INVALID_TRACER_LOOKUP				\
-  (ERTS_PORT_SFLGS_INVALID_LOOKUP					\
-   | ERTS_PORT_SFLG_PORT_BUSY						\
-   | ERTS_PORT_SFLG_DISTRIBUTION)
-
 /* binary.c */
 
 void erts_emasculate_writable_binary(ProcBin* pb);
@@ -758,11 +493,35 @@ Eterm erts_realloc_binary(Eterm bin, size_t size);
 
 /* erl_bif_info.c */
 
+Eterm
+erts_bld_port_info(Eterm **hpp,
+		   ErlOffHeap *ohp,
+		   Uint *szp,
+		   Port *prt,
+		   Eterm item); 
+
 void erts_bif_info_init(void);
 
 /* bif.c */
 Eterm erts_make_ref(Process *);
 Eterm erts_make_ref_in_buffer(Eterm buffer[REF_THING_SIZE]);
+void erts_make_ref_in_array(Uint32 ref[ERTS_MAX_REF_NUMBERS]);
+
+ERTS_GLB_INLINE Eterm
+erts_proc_store_ref(Process *c_p, Uint32 ref[ERTS_MAX_REF_NUMBERS]);
+
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+
+ERTS_GLB_INLINE Eterm
+erts_proc_store_ref(Process *c_p, Uint32 ref[ERTS_MAX_REF_NUMBERS])
+{
+    Eterm *hp = HAlloc(c_p, REF_THING_SIZE);
+    write_ref_thing(hp, ref[0], ref[1], ref[2]);
+    return make_internal_ref(hp);
+}
+
+#endif
+
 void erts_queue_monitor_message(Process *,
 				ErtsProcLocks*,
 				Eterm,
@@ -778,13 +537,6 @@ Eterm erl_send(Process *p, Eterm to, Eterm msg);
 
 Eterm erl_is_function(Process* p, Eterm arg1, Eterm arg2);
 
-/* erl_bif_port.c */
-
-/* erl_bif_trace.c */
-Eterm erl_seq_trace_info(Process *p, Eterm arg1);
-void erts_system_monitor_clear(Process *c_p);
-void erts_system_profile_clear(Process *c_p);
-
 /* beam_load.c */
 typedef struct {
     BeamInstr* current;		/* Pointer to: Mod, Name, Arity */
@@ -960,11 +712,6 @@ void erts_free_heap_frags(Process* p);
 
 /* io.c */
 
-struct erl_drv_port_data_lock {
-    erts_mtx_t mtx;
-    erts_atomic_t refc;
-};
-
 typedef struct {
     char *name;
     char *driver_name;
@@ -973,477 +720,33 @@ typedef struct {
 #define ERTS_SPAWN_DRIVER 1
 #define ERTS_SPAWN_EXECUTABLE 2
 #define ERTS_SPAWN_ANY (ERTS_SPAWN_DRIVER | ERTS_SPAWN_EXECUTABLE)
-
 int erts_add_driver_entry(ErlDrvEntry *drv, DE_Handle *handle, int driver_list_locked);
 void erts_destroy_driver(erts_driver_t *drv);
-void erts_wake_process_later(Port*, Process*);
-int erts_open_driver(erts_driver_t*, Eterm, char*, SysDriverOpts*, int *);
-int erts_is_port_ioq_empty(Port *);
-void erts_terminate_port(Port *);
-void close_port(Eterm);
-void init_io(void);
-void cleanup_io(void);
-void erts_do_exit_port(Port *, Eterm, Eterm);
-void erts_port_command(Process *, Eterm, Port *, Eterm);
-Eterm erts_port_control(Process*, Port*, Uint, Eterm);
-int erts_write_to_port(Eterm caller_id, Port *p, Eterm list);
-void print_port_info(int, void *, int);
+int erts_save_suspend_process_on_port(Port*, Process*);
+Port *erts_open_driver(erts_driver_t*, Eterm, char*, SysDriverOpts*, int *, int *);
+void erts_init_io(int, int);
 void erts_raw_port_command(Port*, byte*, Uint);
-void driver_report_exit(int, int);
+void driver_report_exit(ErlDrvPort, int);
 LineBuf* allocate_linebuf(int);
 int async_ready(Port *, void*);
-Sint erts_test_next_port(int, Uint);
 ErtsPortNames *erts_get_port_names(Eterm);
 void erts_free_port_names(ErtsPortNames *);
 Uint erts_port_ioq_size(Port *pp);
 void erts_stale_drv_select(Eterm, ErlDrvEvent, int, int);
-void erts_port_cleanup(Port *);
-void erts_fire_port_monitor(Port *prt, Eterm ref);
 
 Port *erts_get_heart_port(void);
 
-#ifdef ERTS_SMP
-void erts_smp_xports_unlock(Port *);
-#endif
-
 #if defined(ERTS_SMP) && defined(ERTS_ENABLE_LOCK_COUNT)
 void erts_lcnt_enable_io_lock_count(int enable);
 #endif
 
-#if defined(ERTS_SMP) && defined(ERTS_ENABLE_LOCK_CHECK)
-int erts_lc_is_port_locked(Port *);
-#endif
-
-ERTS_GLB_INLINE void erts_smp_port_state_lock(Port*);
-ERTS_GLB_INLINE void erts_smp_port_state_unlock(Port*);
-
-ERTS_GLB_INLINE int erts_smp_port_trylock(Port *prt);
-ERTS_GLB_INLINE void erts_smp_port_lock(Port *prt);
-ERTS_GLB_INLINE void erts_smp_port_unlock(Port *prt);
-
-#if ERTS_GLB_INLINE_INCL_FUNC_DEF
-
-ERTS_GLB_INLINE void
-erts_smp_port_state_lock(Port* prt)
-{
-#ifdef ERTS_SMP
-    erts_smp_spin_lock(&prt->state_lck);
-#endif
-}
-
-ERTS_GLB_INLINE void
-erts_smp_port_state_unlock(Port *prt)
-{
-#ifdef ERTS_SMP
-    erts_smp_spin_unlock(&prt->state_lck);
-#endif
-}
-
-
-ERTS_GLB_INLINE int
-erts_smp_port_trylock(Port *prt)
-{
-    int res;
-
-    ASSERT(erts_smp_atomic_read_nob(&prt->refc) > 0);
-    erts_smp_atomic_inc_nob(&prt->refc);
-
-#ifdef ERTS_SMP
-    res = erts_smp_mtx_trylock(prt->lock);
-    if (res == EBUSY) {
-	erts_smp_atomic_dec_nob(&prt->refc);
-    }
-#else
-    res = 0;
-#endif
-
-    return res;
-}
-
-ERTS_GLB_INLINE void
-erts_smp_port_lock(Port *prt)
-{
-    ASSERT(erts_smp_atomic_read_nob(&prt->refc) > 0);
-    erts_smp_atomic_inc_nob(&prt->refc);
-#ifdef ERTS_SMP
-    erts_smp_mtx_lock(prt->lock);
-#endif
-}
-
-ERTS_GLB_INLINE void
-erts_smp_port_unlock(Port *prt)
-{
-    erts_aint_t refc;
-#ifdef ERTS_SMP
-    erts_smp_mtx_unlock(prt->lock);
-#endif
-    refc = erts_smp_atomic_dec_read_nob(&prt->refc);
-    ASSERT(refc >= 0);
-    if (refc == 0)
-	erts_port_cleanup(prt);
-}
-
-#endif /* #if ERTS_GLB_INLINE_INCL_FUNC_DEF */
-
-
-#define ERTS_INVALID_PORT_OPT(PP, ID, FLGS) \
-  (!(PP) || ((PP)->status & (FLGS)) || (PP)->id != (ID))
-
-/* port lookup */
-
-#define INVALID_PORT(PP, ID) \
-  ERTS_INVALID_PORT_OPT((PP), (ID), ERTS_PORT_SFLGS_INVALID_LOOKUP)
-
-/* Invalidate trace port if anything suspicious, for instance
- * that the port is a distribution port or it is busy.
- */
-#define INVALID_TRACER_PORT(PP, ID)					\
-  ERTS_INVALID_PORT_OPT((PP), (ID), ERTS_PORT_SFLGS_INVALID_TRACER_LOOKUP)
-
-#define ERTS_PORT_SCHED_ID(P, ID) \
-  ((Uint) (UWord) erts_prtsd_set((P), ERTS_PSD_SCHED_ID, (void *) (UWord) (ID)))
-
-#ifdef ERTS_SMP
-Port *erts_de2port(DistEntry *, Process *, ErtsProcLocks);
-#endif
-
-#define erts_id2port(ID, P, PL) \
-  erts_id2port_sflgs((ID), (P), (PL), ERTS_PORT_SFLGS_INVALID_LOOKUP)
-
-ERTS_GLB_INLINE Port*erts_id2port_sflgs(Eterm, Process *, ErtsProcLocks, Uint32);
-ERTS_GLB_INLINE void erts_port_release(Port *);
-ERTS_GLB_INLINE Port*erts_drvport2port(ErlDrvPort);
-ERTS_GLB_INLINE Port*erts_drvportid2port(Eterm);
-ERTS_GLB_INLINE Uint32 erts_portid2status(Eterm id);
-ERTS_GLB_INLINE int erts_is_port_alive(Eterm id);
-ERTS_GLB_INLINE int erts_is_valid_tracer_port(Eterm id);
-ERTS_GLB_INLINE void erts_port_status_bandor_set(Port *, Uint32, Uint32);
-ERTS_GLB_INLINE void erts_port_status_band_set(Port *, Uint32);
-ERTS_GLB_INLINE void erts_port_status_bor_set(Port *, Uint32);
-ERTS_GLB_INLINE void erts_port_status_set(Port *, Uint32);
-ERTS_GLB_INLINE Uint32 erts_port_status_get(Port *);
-
-#if ERTS_GLB_INLINE_INCL_FUNC_DEF
-
-ERTS_GLB_INLINE Port*
-erts_id2port_sflgs(Eterm id, Process *c_p, ErtsProcLocks c_p_locks, Uint32 sflgs)
-{
-#ifdef ERTS_SMP
-    int no_proc_locks = !c_p || !c_p_locks;
-#endif
-    Port *prt;
-
-    if (is_not_internal_port(id))
-	return NULL;
-
-    prt = &erts_port[internal_port_index(id)];
-
-    erts_smp_port_state_lock(prt);
-    if (ERTS_INVALID_PORT_OPT(prt, id, sflgs)) {
-	erts_smp_port_state_unlock(prt);
-	prt = NULL;
-    }
-    else {
-	erts_smp_atomic_inc_nob(&prt->refc);
-	erts_smp_port_state_unlock(prt);
-
-#ifdef ERTS_SMP
- 	if (no_proc_locks)
-	    erts_smp_mtx_lock(prt->lock);
-	else if (erts_smp_mtx_trylock(prt->lock) == EBUSY) {
-	    /* Unlock process locks, and acquire locks in lock order... */
-	    erts_smp_proc_unlock(c_p, c_p_locks);
-	    erts_smp_mtx_lock(prt->lock);
-	    erts_smp_proc_lock(c_p, c_p_locks);
-	}
-
-	/* The id may not have changed... */
-	ERTS_SMP_LC_ASSERT(prt->id == id);
-	/* ... but status may have... */
-	if (prt->status & sflgs) {
-	    erts_smp_port_unlock(prt); /* Also decrements refc... */
-	    prt = NULL;
-	}
-#endif
-
-    }
-
-    return prt;
-}
-
-ERTS_GLB_INLINE void
-erts_port_release(Port *prt)
-{
-    erts_smp_port_unlock(prt);
-}
-
-ERTS_GLB_INLINE Port*
-erts_drvport2port(ErlDrvPort drvport)
-{
-    int ix = (int) drvport;
-    if (ix < 0 || erts_max_ports <= ix)
-	return NULL;
-    if (erts_port[ix].status & ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP)
-	return NULL;
-    ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(&erts_port[ix]));
-    return &erts_port[ix];
-}
-
-ERTS_GLB_INLINE Port*
-erts_drvportid2port(Eterm id)
-{
-    int ix;
-    if (is_not_internal_port(id))
-	return NULL;
-    ix = (int) internal_port_index(id);
-    if (erts_max_ports <= ix)
-	return NULL;
-    if (erts_port[ix].status & ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP)
-	return NULL;
-    if (erts_port[ix].id != id)
-	return NULL;
-    ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(&erts_port[ix]));
-    return &erts_port[ix];
-}
-
-ERTS_GLB_INLINE Uint32
-erts_portid2status(Eterm id)
-{
-    if (is_not_internal_port(id))
-	return ERTS_PORT_SFLG_INVALID;
-    else {
-	Uint32 status;
-	int ix = internal_port_index(id);
-	if (erts_max_ports <= ix)
-	    return ERTS_PORT_SFLG_INVALID;
-	erts_smp_port_state_lock(&erts_port[ix]);
-	if (erts_port[ix].id == id)
-	    status = erts_port[ix].status;
-	else
-	    status = ERTS_PORT_SFLG_INVALID;
-	erts_smp_port_state_unlock(&erts_port[ix]);
-	return status;
-    }
-}
-
-ERTS_GLB_INLINE int
-erts_is_port_alive(Eterm id)
-{
-    return !(erts_portid2status(id) & (ERTS_PORT_SFLG_INVALID
-				       | ERTS_PORT_SFLGS_DEAD));
-}
-
-ERTS_GLB_INLINE int
-erts_is_valid_tracer_port(Eterm id)
-{
-    return !(erts_portid2status(id) & ERTS_PORT_SFLGS_INVALID_TRACER_LOOKUP);
-}
-
-ERTS_GLB_INLINE void erts_port_status_bandor_set(Port *prt,
-						 Uint32 band_status,
-						 Uint32 bor_status)
-{
-    ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
-    erts_smp_port_state_lock(prt);
-    prt->status &= band_status;
-    prt->status |= bor_status;
-    erts_smp_port_state_unlock(prt);
-}
-
-ERTS_GLB_INLINE void erts_port_status_band_set(Port *prt, Uint32 status)
-{
-    ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
-    erts_smp_port_state_lock(prt);
-    prt->status &= status;
-    erts_smp_port_state_unlock(prt);
-}
-
-ERTS_GLB_INLINE void erts_port_status_bor_set(Port *prt, Uint32 status)
-{
-    ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
-    erts_smp_port_state_lock(prt);
-    prt->status |= status;
-    erts_smp_port_state_unlock(prt);
-}
-
-ERTS_GLB_INLINE void erts_port_status_set(Port *prt, Uint32 status)
-{
-    ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
-    erts_smp_port_state_lock(prt);
-    prt->status = status;
-    erts_smp_port_state_unlock(prt);
-}
-
-ERTS_GLB_INLINE Uint32 erts_port_status_get(Port *prt)
-{
-    Uint32 res;
-    erts_smp_port_state_lock(prt);
-    res = prt->status;
-    erts_smp_port_state_unlock(prt);
-    return res;
-}
-#endif /* #if ERTS_GLB_INLINE_INCL_FUNC_DEF */
-
 /* erl_drv_thread.c */
 void erl_drv_thr_init(void);
 
-/* time.c */
-
 /* utils.c */
-
-typedef struct {
-#ifdef DEBUG
-    int smp_api;
-#endif
-    union {
-	Uint64 not_atomic;
-#ifdef ARCH_64
-	erts_atomic_t atomic;
-#else
-	erts_dw_atomic_t atomic;
-#endif
-    } counter;
-} erts_interval_t;
-
-void erts_interval_init(erts_interval_t *);
-void erts_smp_interval_init(erts_interval_t *);
-Uint64 erts_step_interval_nob(erts_interval_t *);
-Uint64 erts_step_interval_relb(erts_interval_t *);
-Uint64 erts_smp_step_interval_nob(erts_interval_t *);
-Uint64 erts_smp_step_interval_relb(erts_interval_t *);
-Uint64 erts_ensure_later_interval_nob(erts_interval_t *, Uint64);
-Uint64 erts_ensure_later_interval_acqb(erts_interval_t *, Uint64);
-Uint64 erts_smp_ensure_later_interval_nob(erts_interval_t *, Uint64);
-Uint64 erts_smp_ensure_later_interval_acqb(erts_interval_t *, Uint64);
-#ifdef ARCH_32
-ERTS_GLB_INLINE Uint64 erts_interval_dw_aint_to_val__(erts_dw_aint_t *);
-#endif
-ERTS_GLB_INLINE Uint64 erts_current_interval_nob__(erts_interval_t *);
-ERTS_GLB_INLINE Uint64 erts_current_interval_acqb__(erts_interval_t *);
-ERTS_GLB_INLINE Uint64 erts_current_interval_nob(erts_interval_t *);
-ERTS_GLB_INLINE Uint64 erts_current_interval_acqb(erts_interval_t *);
-ERTS_GLB_INLINE Uint64 erts_smp_current_interval_nob(erts_interval_t *);
-ERTS_GLB_INLINE Uint64 erts_smp_current_interval_acqb(erts_interval_t *);
-
-#if ERTS_GLB_INLINE_INCL_FUNC_DEF
-
-#ifdef ARCH_32
-
-ERTS_GLB_INLINE Uint64
-erts_interval_dw_aint_to_val__(erts_dw_aint_t *dw)
-{
-#ifdef ETHR_SU_DW_NAINT_T__
-    return (Uint64) dw->dw_sint;
-#else
-    Uint64 res;
-    res = (Uint64) ((Uint32) dw->sint[ERTS_DW_AINT_HIGH_WORD]);
-    res <<= 32;
-    res |= (Uint64) ((Uint32) dw->sint[ERTS_DW_AINT_LOW_WORD]);
-    return res;
-#endif
-}
-
-#endif
-
-ERTS_GLB_INLINE Uint64
-erts_current_interval_nob__(erts_interval_t *icp)
-{
-#ifdef ARCH_64
-    return (Uint64) erts_atomic_read_nob(&icp->counter.atomic);
-#else
-    erts_dw_aint_t dw;
-    erts_dw_atomic_read_nob(&icp->counter.atomic, &dw);
-    return erts_interval_dw_aint_to_val__(&dw);
-#endif
-}
-
-ERTS_GLB_INLINE Uint64
-erts_current_interval_acqb__(erts_interval_t *icp)
-{
-#ifdef ARCH_64
-    return (Uint64) erts_atomic_read_acqb(&icp->counter.atomic);
-#else
-    erts_dw_aint_t dw;
-    erts_dw_atomic_read_acqb(&icp->counter.atomic, &dw);
-    return erts_interval_dw_aint_to_val__(&dw);
-#endif
-}
-
-ERTS_GLB_INLINE Uint64
-erts_current_interval_nob(erts_interval_t *icp)
-{
-    ASSERT(!icp->smp_api);
-    return erts_current_interval_nob__(icp);
-}
-
-ERTS_GLB_INLINE Uint64
-erts_current_interval_acqb(erts_interval_t *icp)
-{
-    ASSERT(!icp->smp_api);
-    return erts_current_interval_acqb__(icp);
-}
-
-ERTS_GLB_INLINE Uint64
-erts_smp_current_interval_nob(erts_interval_t *icp)
-{
-    ASSERT(icp->smp_api);
-#ifdef ERTS_SMP
-    return erts_current_interval_nob__(icp);
-#else
-    return icp->counter.not_atomic;
-#endif
-}
-
-ERTS_GLB_INLINE Uint64
-erts_smp_current_interval_acqb(erts_interval_t *icp)
-{
-    ASSERT(icp->smp_api);
-#ifdef ERTS_SMP
-    return erts_current_interval_acqb__(icp);
-#else
-    return icp->counter.not_atomic;
-#endif
-}
-
-#endif /* ERTS_GLB_INLINE_INCL_FUNC_DEF */
-
-/*
- * To be used to silence unused result warnings, but do not abuse it.
- */
-void erts_silence_warn_unused_result(long unused);
-
 void erts_cleanup_offheap(ErlOffHeap *offheap);
 
-int erts_fit_in_bits_int64(Sint64);
-int erts_fit_in_bits_int32(Sint32);
-int list_length(Eterm);
 Export* erts_find_function(Eterm, Eterm, unsigned int, ErtsCodeIndex);
-int erts_is_builtin(Eterm, Eterm, int);
-Uint32 make_broken_hash(Eterm);
-Uint32 block_hash(byte *, unsigned, Uint32);
-Uint32 make_hash2(Eterm);
-Uint32 make_hash(Eterm);
-
-
-Eterm erts_bld_atom(Uint **hpp, Uint *szp, char *str);
-Eterm erts_bld_uint(Uint **hpp, Uint *szp, Uint ui);
-Eterm erts_bld_uword(Uint **hpp, Uint *szp, UWord uw);
-Eterm erts_bld_uint64(Uint **hpp, Uint *szp, Uint64 ui64);
-Eterm erts_bld_sint64(Uint **hpp, Uint *szp, Sint64 si64);
-Eterm erts_bld_cons(Uint **hpp, Uint *szp, Eterm car, Eterm cdr);
-Eterm erts_bld_tuple(Uint **hpp, Uint *szp, Uint arity, ...);
-Eterm erts_bld_tuplev(Uint **hpp, Uint *szp, Uint arity, Eterm terms[]);
-Eterm erts_bld_string_n(Uint **hpp, Uint *szp, const char *str, Sint len);
-#define erts_bld_string(hpp,szp,str) erts_bld_string_n(hpp,szp,str,strlen(str))
-Eterm erts_bld_list(Uint **hpp, Uint *szp, Sint length, Eterm terms[]);
-Eterm erts_bld_2tup_list(Uint **hpp, Uint *szp,
-			 Sint length, Eterm terms1[], Uint terms2[]);
-Eterm
-erts_bld_atom_uint_2tup_list(Uint **hpp, Uint *szp,
-			     Sint length, Eterm atoms[], Uint uints[]);
-Eterm
-erts_bld_atom_2uint_3tup_list(Uint **hpp, Uint *szp, Sint length,
-			      Eterm atoms[], Uint uints1[], Uint uints2[]);
 
 Eterm store_external_or_ref_in_proc_(Process *, Eterm);
 Eterm store_external_or_ref_(Uint **, ErlOffHeap*, Eterm);
@@ -1458,42 +761,6 @@ Eterm store_external_or_ref_(Uint **, ErlOffHeap*, Eterm);
  (ASSERT_EXPR(is_node_container((NC))), \
   IS_CONST((NC)) ? (NC) : store_external_or_ref_in_proc_((Pp), (NC)))
 
-void erts_init_utils(void);
-void erts_init_utils_mem(void);
-
-erts_dsprintf_buf_t *erts_create_tmp_dsbuf(Uint);
-void erts_destroy_tmp_dsbuf(erts_dsprintf_buf_t *);
-
-#if HALFWORD_HEAP
-int eq_rel(Eterm a, Eterm* a_base, Eterm b, Eterm* b_base);
-#  define eq(A,B) eq_rel(A,NULL,B,NULL)
-#else
-int eq(Eterm, Eterm);
-#  define eq_rel(A,A_BASE,B,B_BASE) eq(A,B)
-#endif
-
-#define EQ(x,y) (((x) == (y)) || (is_not_both_immed((x),(y)) && eq((x),(y))))
-
-#if HALFWORD_HEAP
-Sint cmp_rel(Eterm, Eterm*, Eterm, Eterm*);
-#define CMP(A,B) cmp_rel(A,NULL,B,NULL)
-#else
-Sint cmp(Eterm, Eterm);
-#define cmp_rel(A,A_BASE,B,B_BASE) cmp(A,B)
-#define CMP(A,B) cmp(A,B)
-#endif
-#define cmp_lt(a,b)	(CMP((a),(b)) < 0)
-#define cmp_le(a,b)	(CMP((a),(b)) <= 0)
-#define cmp_eq(a,b)	(CMP((a),(b)) == 0)
-#define cmp_ne(a,b)	(CMP((a),(b)) != 0)
-#define cmp_ge(a,b)	(CMP((a),(b)) >= 0)
-#define cmp_gt(a,b)	(CMP((a),(b)) > 0)
-
-#define CMP_LT(a,b)	((a) != (b) && cmp_lt((a),(b)))
-#define CMP_GE(a,b)	((a) == (b) || cmp_ge((a),(b)))
-#define CMP_EQ(a,b)	((a) == (b) || cmp_eq((a),(b)))
-#define CMP_NE(a,b)	((a) != (b) && cmp_ne((a),(b)))
-
 /* duplicates from big.h */
 int term_to_Uint(Eterm term, Uint *up);
 int term_to_UWord(Eterm, UWord*);
@@ -1530,79 +797,6 @@ Eterm erts_convert_native_to_filename(Process *p, byte *bytes);
 #define ERTS_UTF8_ERROR 2
 #define ERTS_UTF8_ANALYZE_MORE 3
 
-/* erl_trace.c */
-void erts_init_trace(void);
-void erts_trace_check_exiting(Eterm exiting);
-Eterm erts_set_system_seq_tracer(Process *c_p,
-				 ErtsProcLocks c_p_locks,
-				 Eterm new);
-Eterm erts_get_system_seq_tracer(void);
-void erts_change_default_tracing(int setflags, Uint *flagsp, Eterm *tracerp);
-void erts_get_default_tracing(Uint *flagsp, Eterm *tracerp);
-void erts_set_system_monitor(Eterm monitor);
-Eterm erts_get_system_monitor(void);
-
-#ifdef ERTS_SMP
-void erts_check_my_tracer_proc(Process *);
-void erts_block_sys_msg_dispatcher(void);
-void erts_release_sys_msg_dispatcher(void);
-void erts_foreach_sys_msg_in_q(void (*func)(Eterm,
-					    Eterm,
-					    Eterm,
-					    ErlHeapFragment *));
-void erts_queue_error_logger_message(Eterm, Eterm, ErlHeapFragment *);
-#endif
-
-void erts_send_sys_msg_proc(Eterm, Eterm, Eterm, ErlHeapFragment *);
-void trace_send(Process*, Eterm, Eterm);
-void trace_receive(Process*, Eterm);
-Uint32 erts_call_trace(Process *p, BeamInstr mfa[], Binary *match_spec, Eterm* args,
-		       int local, Eterm *tracer_pid);
-void erts_trace_return(Process* p, BeamInstr* fi, Eterm retval, Eterm *tracer_pid);
-void erts_trace_exception(Process* p, BeamInstr mfa[], Eterm class, Eterm value,
-			  Eterm *tracer);
-void erts_trace_return_to(Process *p, BeamInstr *pc);
-void trace_sched(Process*, Eterm);
-void trace_proc(Process*, Process*, Eterm, Eterm);
-void trace_proc_spawn(Process*, Eterm pid, Eterm mod, Eterm func, Eterm args);
-void save_calls(Process *p, Export *);
-void trace_gc(Process *p, Eterm what);
-/* port tracing */
-void trace_virtual_sched(Process*, Eterm);
-void trace_sched_ports(Port *pp, Eterm);
-void trace_sched_ports_where(Port *pp, Eterm, Eterm);
-void trace_port(Port *, Eterm what, Eterm data);
-void trace_port_open(Port *, Eterm calling_pid, Eterm drv_name);
-
-/* system_profile */
-void erts_set_system_profile(Eterm profile);
-Eterm erts_get_system_profile(void);
-void profile_scheduler(Eterm scheduler_id, Eterm);
-void profile_scheduler_q(Eterm scheduler_id, Eterm state, Eterm no_schedulers, Uint Ms, Uint s, Uint us);
-void profile_runnable_proc(Process* p, Eterm status);
-void profile_runnable_port(Port* p, Eterm status);
-void erts_system_profile_setup_active_schedulers(void);
-
-/* system_monitor */
-void monitor_long_gc(Process *p, Uint time);
-void monitor_large_heap(Process *p);
-void monitor_generic(Process *p, Eterm type, Eterm spec);
-Uint erts_trace_flag2bit(Eterm flag);
-int erts_trace_flags(Eterm List, 
-		 Uint *pMask, Eterm *pTracer, int *pCpuTimestamp);
-Eterm erts_bif_trace(int bif_index, Process* p, Eterm* args, BeamInstr *I);
-
-#ifdef ERTS_SMP
-void erts_send_pending_trace_msgs(ErtsSchedulerData *esdp);
-#define ERTS_SMP_CHK_PEND_TRACE_MSGS(ESDP)				\
-do {									\
-    if ((ESDP)->pending_trace_msgs)					\
-	erts_send_pending_trace_msgs((ESDP));				\
-} while (0)
-#else
-#define ERTS_SMP_CHK_PEND_TRACE_MSGS(ESDP)
-#endif
-
 void bin_write(int, void*, byte*, size_t);
 int intlist_to_buf(Eterm, char*, int); /* most callers pass plain char*'s */
 
@@ -1620,9 +814,16 @@ char* Sint_to_buf(Sint, struct Sint_buf*);
 #define ERTS_IOLIST_TYPE 2
 
 Eterm buf_to_intlist(Eterm**, char*, size_t, Eterm); /* most callers pass plain char*'s */
-int io_list_to_buf(Eterm, char*, int);
-int io_list_to_buf2(Eterm, char*, int);
-int erts_iolist_size(Eterm, Uint *);
+
+#define ERTS_IOLIST_TO_BUF_OVERFLOW	(~((ErlDrvSizeT) 0))
+#define ERTS_IOLIST_TO_BUF_TYPE_ERROR	(~((ErlDrvSizeT) 1))
+#define ERTS_IOLIST_TO_BUF_FAILED(R) \
+    (((R) & (~((ErlDrvSizeT) 1))) == (~((ErlDrvSizeT) 1)))
+#define ERTS_IOLIST_TO_BUF_SUCCEEDED(R) \
+    (!ERTS_IOLIST_TO_BUF_FAILED((R)))
+
+ErlDrvSizeT erts_iolist_to_buf(Eterm, char*, ErlDrvSizeT);
+int erts_iolist_size(Eterm, ErlDrvSizeT *);
 int is_string(Eterm);
 void erl_at_exit(void (*) (void*), void*);
 Eterm collect_memory(Process *);
@@ -1667,41 +868,6 @@ Uint erts_current_reductions(Process* current, Process *p);
 int erts_print_system_version(int to, void *arg, Process *c_p);
 
 int erts_hibernate(Process* c_p, Eterm module, Eterm function, Eterm args, Eterm* reg);
-#define seq_trace_output(token, msg, type, receiver, process) \
-seq_trace_output_generic((token), (msg), (type), (receiver), (process), NIL)
-#define seq_trace_output_exit(token, msg, type, receiver, exitfrom) \
-seq_trace_output_generic((token), (msg), (type), (receiver), NULL, (exitfrom))
-void seq_trace_output_generic(Eterm token, Eterm msg, Uint type, 
-			      Eterm receiver, Process *process, Eterm exitfrom);
-
-int seq_trace_update_send(Process *process);
-
-Eterm erts_seq_trace(Process *process, 
-		     Eterm atom_type, Eterm atom_true_or_false, 
-		     int build_result);
-
-struct trace_pattern_flags {
-    unsigned int breakpoint : 1; /* Set if any other is set */
-    unsigned int local      : 1; /* Local call trace breakpoint */
-    unsigned int meta       : 1; /* Metadata trace breakpoint */
-    unsigned int call_count : 1; /* Fast call count breakpoint */
-    unsigned int call_time  : 1; /* Fast call time breakpoint */
-};
-extern const struct trace_pattern_flags erts_trace_pattern_flags_off;
-extern int erts_call_time_breakpoint_tracing;
-int erts_set_trace_pattern(Process*p, Eterm* mfa, int specified,
-			   Binary* match_prog_set, Binary *meta_match_prog_set,
-			   int on, struct trace_pattern_flags,
-			   Eterm meta_tracer_pid, int is_blocking);
-void
-erts_get_default_trace_pattern(int *trace_pattern_is_on,
-			       Binary **match_spec,
-			       Binary **meta_match_spec,
-			       struct trace_pattern_flags *trace_pattern_flags,
-			       Eterm *meta_tracer_pid);
-int erts_is_default_trace_enabled(void);
-void erts_bif_trace_init(void);
-int erts_finish_breakpointing(void);
 
 /*
 ** Call_trace uses this API for the parameter matching functions
@@ -1943,15 +1109,15 @@ dtrace_pid_str(Eterm pid, char *process_buf)
 ERTS_GLB_INLINE void
 dtrace_proc_str(Process *process, char *process_buf)
 {
-    dtrace_pid_str(process->id, process_buf);
+    dtrace_pid_str(process->common.id, process_buf);
 }
 
 ERTS_GLB_INLINE void
 dtrace_port_str(Port *port, char *port_buf)
 {
     erts_snprintf(port_buf, DTRACE_TERM_BUF_SIZE, "#Port<%lu.%lu>",
-                  port_channel_no(port->id),
-                  port_number(port->id));
+                  port_channel_no(port->common.id),
+                  port_number(port->common.id));
 }
 
 ERTS_GLB_INLINE void
diff --git a/erts/emulator/beam/io.c b/erts/emulator/beam/io.c
index 60b9238d38..3fc124589b 100644
--- a/erts/emulator/beam/io.c
+++ b/erts/emulator/beam/io.c
@@ -43,6 +43,8 @@
 #include "erl_version.h"
 #include "error.h"
 #include "erl_async.h"
+#define ERTS_WANT_EXTERNAL_TAGS
+#include "external.h"
 #include "dtrace-wrapper.h"
 
 extern ErlDrvEntry fd_driver_entry;
@@ -51,25 +53,29 @@ extern ErlDrvEntry spawn_driver_entry;
 extern ErlDrvEntry *driver_tab[]; /* table of static drivers, only used during initialization */
 
 erts_driver_t *driver_list; /* List of all drivers, static and dynamic. */
-erts_smp_mtx_t erts_driver_list_lock; /* Mutex for driver list */
+erts_smp_rwmtx_t erts_driver_list_lock; /* Mutex for driver list */
 static erts_smp_tsd_key_t driver_list_lock_status_key; /*stop recursive locks when calling 
 							 driver init */
 static erts_smp_tsd_key_t driver_list_last_error_key;  /* Save last DDLL error on a 
 							  per thread basis (for BC interfaces) */
 
-Port*      erts_port; /* The port table */
+ErtsPTab erts_port erts_align_attribute(ERTS_CACHE_LINE_SIZE); /* The port table */
 erts_smp_atomic_t erts_bytes_out;	/* No bytes sent out of the system */
 erts_smp_atomic_t erts_bytes_in;	/* No bytes gotten into the system */
 
-Uint erts_max_ports;
-Uint erts_port_tab_index_mask;
-
 const ErlDrvTermData driver_term_nil = (ErlDrvTermData)NIL;
 
+const Port erts_invalid_port = {{ERTS_INVALID_PORT}};
+
 erts_driver_t vanilla_driver;
 erts_driver_t spawn_driver;
 erts_driver_t fd_driver;
 
+int erts_port_synchronous_ops = 0;
+int erts_port_schedule_all_ops = 0;
+int erts_port_parallelism = 0;
+
+static void deliver_result(Eterm sender, Eterm pid, Eterm res);
 static int init_driver(erts_driver_t *, ErlDrvEntry *, DE_Handle *);
 static void terminate_port(Port *p);
 static void pdl_init(void);
@@ -89,36 +95,12 @@ static void driver_monitor_unlock_pdl(Port *p);
 static ERTS_INLINE ErlIOQueue*
 drvport2ioq(ErlDrvPort drvport)
 {
-    int ix = (int) drvport;
-    Uint32 status;
-
-    if (ix < 0 || erts_max_ports <= ix)
+    Port *prt = erts_thr_drvport2port_raw(drvport);
+    erts_aint32_t state = erts_atomic32_read_nob(&prt->state);
+    if (state & ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP)
 	return NULL;
-
-    if (erts_get_scheduler_data()) {
-	ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(&erts_port[ix]));
-	ERTS_LC_ASSERT(!erts_port[ix].port_data_lock
-		       || erts_lc_mtx_is_locked(
-			   &erts_port[ix].port_data_lock->mtx));
-
-	status = erts_port[ix].status;
-    }
-    else {
-	erts_smp_port_state_lock(&erts_port[ix]);
-	status = erts_port[ix].status;
-	erts_smp_port_state_unlock(&erts_port[ix]);
-
-	ERTS_LC_ASSERT((status & ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP)
-		       || erts_port[ix].port_data_lock);
-	ERTS_LC_ASSERT(!erts_port[ix].port_data_lock
-		       || erts_lc_mtx_is_locked(
-			   &erts_port[ix].port_data_lock->mtx));
-
-    }
-
-    return ((status & ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP)
-	    ? NULL
-	    : &erts_port[ix].ioq);
+    else
+	return &prt->ioq;
 }
 
 static ERTS_INLINE int
@@ -196,27 +178,13 @@ typedef struct line_buf_context {
     dtrace_port_str((PORT), port_str);
 #endif
 
-/* The 'number' field in a port now has two parts: the lowest bits
-   contain the index in the port table, and the higher bits are a counter
-   which is incremented each time we look for a free port and start from
-   the beginning of the table. erts_max_ports is the number of file descriptors,
-   rounded up to a power of 2.
-   To get the index from a port, use the macro 'internal_port_index';
-   'port_number' returns the whole number field.
-*/
-
-static erts_smp_spinlock_t get_free_port_lck;
-static Uint last_port_num;
-static Uint port_num_mask;
-erts_smp_atomic32_t erts_ports_snapshot; /* Identifies the _next_ snapshot (not the ongoing) */
-
-
 static ERTS_INLINE void
 kill_port(Port *pp)
 {
     ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(pp));
+    erts_ptab_delete_element(&erts_port, &pp->common); /* Time of death */
     erts_port_task_free_port(pp);
-    ASSERT(pp->status & ERTS_PORT_SFLGS_DEAD);
+    /* In non-smp case the port structure may have been deallocated now */
 }
 
 #ifdef ERTS_SMP
@@ -227,146 +195,280 @@ erts_lc_is_port_locked(Port *prt)
 {
     if (!prt)
 	return 0;
+    ERTS_SMP_LC_ASSERT(prt->lock);
     return erts_smp_lc_mtx_is_locked(prt->lock);
 }
 #endif
 
 #endif /* #ifdef ERTS_SMP */
 
-static int
-get_free_port(void)
-{
-    Uint num;
-    Uint tries = erts_max_ports;
-    Port* port;    
+static void initq(Port* prt);
 
-    erts_smp_spin_lock(&get_free_port_lck);
-    num = last_port_num + 1;
-    for (;; ++num) {	
-	port = &erts_port[num & erts_port_tab_index_mask];
+#if defined(ERTS_ENABLE_LOCK_CHECK) || defined(ERTS_ENABLE_LOCK_COUNT)
+#define ERTS_PORT_INIT_INSTR_NEED_ID 1
+#else
+#define ERTS_PORT_INIT_INSTR_NEED_ID 0
+#endif
 
-	erts_smp_port_state_lock(port);
-	if (port->status & ERTS_PORT_SFLG_FREE) {
-	    last_port_num = num;
-	    erts_smp_spin_unlock(&get_free_port_lck);
-	    break;
-	}
-	erts_smp_port_state_unlock(port);
+static ERTS_INLINE void port_init_instr(Port *prt
+#if ERTS_PORT_INIT_INSTR_NEED_ID
+				   , Eterm id
+#endif
+    )
+{
+#if !ERTS_PORT_INIT_INSTR_NEED_ID
+    Eterm id = NIL; /* Not used */
+#endif
 
-	if (--tries == 0) {
-	    erts_smp_spin_unlock(&get_free_port_lck);
-	    return -1;
-	}
+    /*
+     * Stuff that need to be initialized with the port id
+     * in the instrumented case, but not in the normal case.
+     */
+#ifdef ERTS_SMP
+    ASSERT(prt->drv_ptr && prt->lock);
+    if (!prt->drv_ptr->lock) {
+	char *lock_str = "port_lock";
+#ifdef ERTS_ENABLE_LOCK_COUNT
+	if (!(erts_lcnt_rt_options & ERTS_LCNT_OPT_PORTLOCK))
+	    lock_str = NULL;
+#endif
+	erts_mtx_init_locked_x(prt->lock, lock_str, id);
     }
-    port->status = ERTS_PORT_SFLG_INITIALIZING;
-    ERTS_LC_ASSERT(erts_smp_atomic_read_nob(&port->refc) == 0);
-    erts_smp_atomic_set_nob(&port->refc, 2); /* Port alive + lock */
-    erts_smp_port_state_unlock(port);
-    return num & port_num_mask;
+#endif
+    erts_port_task_init_sched(&prt->sched, id);
 }
 
-/*
- * erts_test_next_port() is only used for testing.
- */
-Sint
-erts_test_next_port(int set, Uint next)
+#if !ERTS_PORT_INIT_INSTR_NEED_ID
+static ERTS_INLINE void port_init_instr_abort(Port *prt)
 {
-    Uint i, num;
-    Sint res = -1;
-
-    erts_smp_spin_lock(&get_free_port_lck);
-    if (set) {
-	last_port_num = (next - 1) & port_num_mask;
+#ifdef ERTS_SMP
+    ASSERT(prt->drv_ptr && prt->lock);
+    if (!prt->drv_ptr->lock) {
+	erts_mtx_unlock(prt->lock);
+	erts_mtx_destroy(prt->lock);
     }
-    num = last_port_num + 1;
+#endif
+    erts_port_task_fini_sched(&prt->sched);
+}
+#endif
 
-    for (i=0; i < erts_max_ports && res<0; ++i, ++num) {	
-	
-	Port* port = &erts_port[num & erts_port_tab_index_mask];
+static void insert_port_struct(void *vprt, Eterm data)
+{
+    Port *prt = (Port *) vprt;
+    Eterm id = make_internal_port(data);
+#if ERTS_PORT_INIT_INSTR_NEED_ID
+    /*
+     * This cannot be done earlier in the instrumented
+     * case since we don't now 'id' until now.
+     */
+    port_init_instr(prt, id);
+#endif
+    prt->common.id = id;
+    erts_atomic32_init_relb(&prt->state, ERTS_PORT_SFLG_INITIALIZING);
+}
 
-	erts_smp_port_state_lock(port);
+#define ERTS_CREATE_PORT_FLAG_PARALLELISM		(1 << 0)
 
-	if (port->status & ERTS_PORT_SFLG_FREE) {	   
-	    last_port_num = num - 1;
-	    res = num & port_num_mask;
-	}
-	erts_smp_port_state_unlock(port);
+static Port *create_port(char *name,
+			 erts_driver_t *driver,
+			 erts_mtx_t *driver_lock,
+			 int create_flags,
+			 Eterm pid,
+			 int *enop)
+{
+    ErtsPortTaskBusyPortQ *busy_port_queue;
+    Port *prt;
+    char *p;
+    size_t port_size, busy_port_queue_size, size;
+    erts_aint32_t state = ERTS_PORT_SFLG_CONNECTED;
+    erts_aint32_t x_pts_flgs = 0;
+#ifdef DEBUG
+    /* Make sure the debug flags survives until port is freed */
+    state |= ERTS_PORT_SFLG_PORT_DEBUG;
+#endif
+
+#ifdef ERTS_SMP
+    if (!driver_lock) {
+	/* Align size for mutex following port struct */
+	port_size = size = ERTS_ALC_DATA_ALIGN_SIZE(sizeof(Port));
+	size += sizeof(erts_mtx_t);
     }
-    erts_smp_spin_unlock(&get_free_port_lck);
-    return res;
-}
+    else
+#endif
+	port_size = size = ERTS_ALC_DATA_ALIGN_SIZE(sizeof(Port));
 
+    busy_port_queue_size
+	= ((driver->flags & ERL_DRV_FLAG_NO_BUSY_MSGQ)
+	   ? 0
+	   : ERTS_ALC_DATA_ALIGN_SIZE(sizeof(ErtsPortTaskBusyPortQ)));
+    size += busy_port_queue_size;
 
-static void port_cleanup(Port *prt);
+    size += sys_strlen(name) + 1;
 
-#ifdef ERTS_SMP
+    p = erts_alloc_fnf(ERTS_ALC_T_PORT, size);
+    if (!p) {
+	if (enop)
+	    *enop = ENOMEM;
+	return NULL;
+    }
 
-static void
-sched_port_cleanup(void *vprt)
-{
-    Port *prt = (Port *) vprt;
-    erts_smp_mtx_lock(prt->lock);
-    port_cleanup(prt);
-}
+    prt = (Port *) p;
+    p += port_size;
 
-#endif
+    if (!busy_port_queue_size)
+	busy_port_queue = NULL;
+    else {
+	busy_port_queue = (ErtsPortTaskBusyPortQ *) p;
+	p += busy_port_queue_size;
+    }
 
-void
-erts_port_cleanup(Port *prt)
-{
 #ifdef ERTS_SMP
-    if (erts_smp_mtx_trylock(prt->lock) == EBUSY)
-	erts_schedule_misc_op(sched_port_cleanup, (void *) prt);
-    else
+    if (driver_lock) {
+	prt->lock = driver_lock;
+	erts_mtx_lock(driver_lock);
+    }
+    else {
+	prt->lock = (erts_mtx_t *) p;
+	p += sizeof(erts_mtx_t);
+	state |= ERTS_PORT_SFLG_PORT_SPECIFIC_LOCK;
+    }
+    erts_smp_atomic_set_nob(&prt->run_queue,
+			    (erts_aint_t) erts_get_runq_current(NULL));
+    prt->xports = NULL;
+#else
+    erts_atomic32_init_nob(&prt->refc, 1);
+    prt->cleanup = 0;
 #endif
-	port_cleanup(prt);
-}
+    
+    erts_port_task_pre_init_sched(&prt->sched, busy_port_queue);
 
-void
-port_cleanup(Port *prt)
-{
+    prt->name = p;
+    sys_strcpy(p, name);
+    prt->drv_ptr = driver;
+    ERTS_P_LINKS(prt) = NULL;
+    ERTS_P_MONITORS(prt) = NULL;
+    prt->linebuf = NULL;
+    prt->bp = NULL;
+    prt->suspended = NULL;
+    prt->data = am_undefined;
+    prt->port_data_lock = NULL;
+    prt->control_flags = 0;
+    prt->bytes_in = 0;
+    prt->bytes_out = 0;
+    prt->dist_entry = NULL;
+    ERTS_PORT_INIT_CONNECTED(prt, pid);
+    prt->common.u.alive.reg = NULL;
 #ifdef ERTS_SMP
-    Uint32 port_specific;
-    erts_smp_mtx_t *mtx;
+    prt->common.u.alive.ptimer = NULL;
+#else
+    sys_memset(&prt->common.u.alive.tm, 0, sizeof(ErlTimer));
 #endif
-    erts_driver_t *driver;
+    erts_port_task_handle_init(&prt->timeout_task);
+    prt->psd = NULL;
+    prt->drv_data = (SWord) 0;
+    prt->os_pid = -1;
 
-    erts_smp_port_state_lock(prt);
+    /* Set default tracing */
+    erts_get_default_tracing(&ERTS_TRACE_FLAGS(prt), &ERTS_TRACER_PROC(prt));
 
-    ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
-    driver = prt->drv_ptr;
-    prt->drv_ptr = NULL;
-    ASSERT(driver);
+    ASSERT(((char *) prt) == ((char *) &prt->common));
 
-    ASSERT(prt->status & ERTS_PORT_SFLG_FREE_SCHEDULED);
-    ERTS_LC_ASSERT(erts_smp_atomic_read_nob(&prt->refc) == 0);
+#if !ERTS_PORT_INIT_INSTR_NEED_ID
+    /*
+     * When 'id' isn't needed (the normal case), it is better to
+     * do the initialization here avoiding unnecessary contention
+     * on table...
+     */
+    port_init_instr(prt);
+#endif
 
-    ASSERT(prt->status & ERTS_PORT_SFLG_PORT_DEBUG);
-    ASSERT(!(prt->status & ERTS_PORT_SFLG_FREE));
-    prt->status = ERTS_PORT_SFLG_FREE;
+    if (!erts_ptab_new_element(&erts_port,
+			       &prt->common,
+			       (void *) prt,
+			       insert_port_struct)) {
 
+#if !ERTS_PORT_INIT_INSTR_NEED_ID
+	port_init_instr_abort(prt);
+#endif
 #ifdef ERTS_SMP
+	if (driver_lock)
+	    erts_mtx_unlock(driver_lock);
+#endif
+	if (enop)
+	    *enop = 0;
+	return NULL;
+    }
 
-    port_specific = (prt->status & ERTS_PORT_SFLG_PORT_SPECIFIC_LOCK);
+    ASSERT(prt == (Port *) (erts_ptab_pix2intptr_nob(
+				&erts_port,
+				internal_port_index(prt->common.id))));
 
-    mtx = prt->lock;
-    ASSERT(mtx);
+    initq(prt);
 
-    prt->lock = NULL;
+    ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
 
-    erts_smp_port_state_unlock(prt);    
-    erts_smp_mtx_unlock(mtx);
+    if (erts_port_schedule_all_ops)
+	x_pts_flgs |= ERTS_PTS_FLG_FORCE_SCHED;
 
-    if (port_specific) {
-	erts_smp_mtx_destroy(mtx);
-	erts_free(ERTS_ALC_T_PORT_LOCK, mtx);
-    }
-#endif
+    if (create_flags & ERTS_CREATE_PORT_FLAG_PARALLELISM)
+	x_pts_flgs |= ERTS_PTS_FLG_PARALLELISM;
 
-    if (driver->handle)
-	erts_ddll_dereference_driver(driver->handle);
+    if (x_pts_flgs)
+	erts_smp_atomic32_read_bor_nob(&prt->sched.flags, x_pts_flgs);
+
+    erts_atomic32_set_relb(&prt->state, state);
+    return prt;
+}
+
+#ifndef ERTS_SMP
+void
+erts_port_cleanup(Port *prt)
+{
+    if (prt->drv_ptr && prt->drv_ptr->handle)
+	erts_ddll_dereference_driver(prt->drv_ptr->handle);
+    prt->drv_ptr = NULL;
+    erts_port_dec_refc(prt);
 }
+#endif
 
+void
+erts_port_free(Port *prt)
+{
+#if defined(ERTS_SMP) || defined(ERTS_ENABLE_LOCK_CHECK)
+    erts_aint32_t state = erts_atomic32_read_nob(&prt->state);
+#endif
+    ERTS_LC_ASSERT(state & (ERTS_PORT_SFLG_INITIALIZING
+			    | ERTS_PORT_SFLG_FREE));
+    ASSERT(state & ERTS_PORT_SFLG_PORT_DEBUG);
+
+#ifdef ERTS_SMP
+    ERTS_LC_ASSERT(erts_atomic32_read_nob(&prt->common.refc) == 0);
+#else
+    ERTS_LC_ASSERT(erts_atomic32_read_nob(&prt->refc) == 0);
+#endif
+
+    erts_port_task_fini_sched(&prt->sched);
+
+#ifdef ERTS_SMP
+    ASSERT(prt->lock);
+    if (state & ERTS_PORT_SFLG_PORT_SPECIFIC_LOCK)
+	erts_mtx_destroy(prt->lock);
+
+    /*
+     * We cannot dereference a driver using driver
+     * locking until here in smp case. Otherwise,
+     * the driver lock may still be in use by others.
+     *
+     * In the non-smp case we cannot do it here since
+     * this function may be called by non-scheduler
+     * threads. This is done in erts_port_cleanup()
+     * in the non-smp case.
+     */
+    if (prt->drv_ptr->handle)
+	erts_ddll_dereference_driver(prt->drv_ptr->handle);
+#endif
+    erts_free(ERTS_ALC_T_PORT, prt);
+}
 
 /*
 ** Initialize v_start to point to the small fixed vector.
@@ -414,94 +516,21 @@ static void stopq(Port* prt)
     if (prt->port_data_lock) {
 	driver_pdl_unlock(prt->port_data_lock);
 	driver_pdl_dec_refc(prt->port_data_lock);
-	prt->port_data_lock = NULL;
-    }
-}
-
-
-
-static void
-setup_port(Port* prt, Eterm pid, erts_driver_t *driver, 
-	   ErlDrvData drv_data, char *name, Uint32 xstatus)
-{
-    ErtsRunQueue *runq = erts_get_runq_current(NULL);
-    char *new_name, *old_name;
-#ifdef DEBUG
-    /* Make sure the debug flags survives until port is freed */
-    xstatus |= ERTS_PORT_SFLG_PORT_DEBUG;
-#endif
-    ASSERT(runq);
-    ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
-
-    
-    new_name = (char*) erts_alloc(ERTS_ALC_T_PORT_NAME, sys_strlen(name)+1);
-    sys_strcpy(new_name, name);
-    erts_smp_runq_lock(runq);
-    erts_smp_port_state_lock(prt);    
-    prt->os_pid = -1;
-    prt->status = ERTS_PORT_SFLG_CONNECTED | xstatus;
-    prt->snapshot = erts_smp_atomic32_read_nob(&erts_ports_snapshot);    
-    old_name = prt->name;
-    prt->name = new_name;
-#ifdef ERTS_SMP
-    erts_smp_atomic_set_nob(&prt->run_queue, (erts_aint_t) runq);
-#endif
-    ASSERT(!prt->drv_ptr);
-    prt->drv_ptr = driver;
-    erts_smp_port_state_unlock(prt);
-    erts_smp_runq_unlock(runq);
-#ifdef ERTS_SMP
-    ASSERT(!prt->xports);
-#endif
-    if (old_name) {
-	erts_free(ERTS_ALC_T_PORT_NAME, (void *) old_name);
     }
-
-    prt->control_flags = 0;
-    prt->connected = pid;
-    prt->drv_data = (SWord) drv_data;
-    prt->bytes_in = 0;
-    prt->bytes_out = 0;
-    prt->dist_entry = NULL;
-    prt->reg = NULL;
-#ifdef ERTS_SMP
-    prt->ptimer = NULL;
-#else
-    sys_memset(&prt->tm, 0, sizeof(ErlTimer));
-#endif
-    erts_port_task_handle_init(&prt->timeout_task);
-    prt->suspended  = NULL;
-    sys_strcpy(prt->name, name);
-    prt->nlinks = NULL;
-    prt->monitors = NULL;
-    prt->linebuf = NULL;
-    prt->bp = NULL;
-    prt->data = am_undefined;
-    /* Set default tracing */
-    erts_get_default_tracing(&(prt->trace_flags), &(prt->tracer_proc));
-
-    prt->psd = NULL;
-
-    initq(prt);
 }
 
-void
-erts_wake_process_later(Port *prt, Process *process)
+int
+erts_save_suspend_process_on_port(Port *prt, Process *process)
 {
-    ErtsProcList** p;
-    ErtsProcList* new_p;
-
-    ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
-
-    if (prt->status & ERTS_PORT_SFLGS_DEAD)
-	return;
-
-    for (p = &(prt->suspended); *p != NULL; p = &((*p)->next))
-	/* Empty loop body */;
-
-    new_p = erts_proclist_create(process);
-    new_p->next = NULL;
-    *p = new_p;
+    int saved;
+    erts_aint32_t flags;
+    erts_port_task_sched_lock(&prt->sched);
+    flags = erts_smp_atomic32_read_nob(&prt->sched.flags);
+    saved = (flags & ERTS_PTS_FLGS_BUSY) && !(flags & ERTS_PTS_FLG_EXIT);
+    if (saved)
+	erts_proclist_store_last(&prt->suspended, erts_proclist_create(process));
+    erts_port_task_sched_unlock(&prt->sched);
+    return saved;
 }
 
 /*
@@ -513,47 +542,44 @@ erts_wake_process_later(Port *prt, Process *process)
    (*error_number_ptr must contain either BADARG or SYSTEM_LIMIT).
    The driver start function must obey the same conventions.
 */
-int
+Port *
 erts_open_driver(erts_driver_t* driver,	/* Pointer to driver. */
 		 Eterm pid,		/* Current process. */
 		 char* name,		/* Driver name. */
 		 SysDriverOpts* opts,	/* Options. */
-		 int *error_number_ptr)	/* errno in case -2 is returned */
+		 int *error_type_ptr,	/* error type */
+		 int *error_number_ptr)	/* errno in case of error type -2 */
 {
-    int port_num;
-    int port_ix;
+
+#undef ERTS_OPEN_DRIVER_RET
+#define ERTS_OPEN_DRIVER_RET(Prt, EType, ENo)	\
+    do {					\
+	if (error_type_ptr)			\
+	    *error_type_ptr = (EType);		\
+	if (error_number_ptr)			\
+	    *error_number_ptr = (ENo);		\
+	return (Prt);				\
+    } while (0)
+
     ErlDrvData drv_data = 0;
-    Uint32 xstatus = 0;
     Port *port;
     int fpe_was_unmasked;
-
-    if (error_number_ptr)
-	*error_number_ptr = 0;
+    int error_type, error_number;
+    int port_errno = 0;
+    erts_mtx_t *driver_lock = NULL;
+    int cprt_flgs = 0;
 
     ERTS_SMP_CHK_NO_PROC_LOCKS;
 
-    if ((port_num = get_free_port()) < 0) {
-	if (error_number_ptr) {
-	    *error_number_ptr = SYSTEM_LIMIT;
-	}
-	return -3;
-    }
-
-    port_ix = port_num & erts_port_tab_index_mask;
-    port = &erts_port[port_ix];
-    port->id = make_internal_port(port_num);
-
-    erts_smp_mtx_lock(&erts_driver_list_lock);
+    erts_smp_rwmtx_rlock(&erts_driver_list_lock);
     if (!driver) {
 	for (driver = driver_list; driver; driver = driver->next) {
 	    if (sys_strcmp(driver->name, name) == 0)
 		break;
 	}
 	if (!driver) { 
-	    erts_smp_mtx_unlock(&erts_driver_list_lock);
-	    if (error_number_ptr)
-		*error_number_ptr = BADARG;
-	    return -3;
+	    erts_smp_rwmtx_runlock(&erts_driver_list_lock);
+	    ERTS_OPEN_DRIVER_RET(NULL, -3, BADARG);
 	}
     }
     if (driver == &spawn_driver) {
@@ -597,59 +623,49 @@ erts_open_driver(erts_driver_t* driver,	/* Pointer to driver. */
     }
 
     if (driver == NULL || (driver != &spawn_driver && opts->exit_status)) {
-	erts_smp_mtx_unlock(&erts_driver_list_lock);
-	if (error_number_ptr) {
-	    *error_number_ptr = BADARG;
-	}
-	/* Need to mark the port as free again */
-	erts_smp_port_state_lock(port);
-	port->status = ERTS_PORT_SFLG_FREE;
-	ERTS_LC_ASSERT(erts_smp_atomic_read_nob(&port->refc) == 2);
-	erts_smp_atomic_set_nob(&port->refc, 0); 
-	erts_smp_port_state_unlock(port);
-	return -3;
+	erts_smp_rwmtx_runlock(&erts_driver_list_lock);
+	ERTS_OPEN_DRIVER_RET(NULL, -3, BADARG);
     }
 
-    /*
-     * We'll set up the port before calling the start function,
-     * to allow message sending and setting timers in the start function.
-     */
-
 #ifdef ERTS_SMP
-    ASSERT(!port->lock);
-    port->lock = driver->lock;
-    if (!port->lock) {
-	port->lock = erts_alloc(ERTS_ALC_T_PORT_LOCK,
-					      sizeof(erts_smp_mtx_t));
-	erts_smp_mtx_init_x(port->lock,
-#ifdef ERTS_ENABLE_LOCK_COUNT
-			    (erts_lcnt_rt_options & ERTS_LCNT_OPT_PORTLOCK) ? "port_lock" : NULL,
-#else
-			    "port_lock",
-#endif
-			    port->id);
-	xstatus |= ERTS_PORT_SFLG_PORT_SPECIFIC_LOCK;
-    }
+    driver_lock = driver->lock;
 #endif
 
     if (driver->handle != NULL) {
 	erts_ddll_increment_port_count(driver->handle);
 	erts_ddll_reference_driver(driver->handle);
     }
-    erts_smp_mtx_unlock(&erts_driver_list_lock);
+    erts_smp_rwmtx_runlock(&erts_driver_list_lock);
 
-#ifdef ERTS_SMP
-    erts_smp_mtx_lock(port->lock);
-#endif
+    /*
+     * We'll set up the port before calling the start function,
+     * to allow message sending and setting timers in the start function.
+     */
+
+    if (opts->parallelism)
+	cprt_flgs |= ERTS_CREATE_PORT_FLAG_PARALLELISM;
 
-    setup_port(port, pid, driver, drv_data, name, xstatus);
+    port = create_port(name, driver, driver_lock, cprt_flgs, pid, &port_errno);
+    if (!port) {
+	if (driver->handle) {
+	    erts_smp_rwmtx_rlock(&erts_driver_list_lock);
+	    erts_ddll_decrement_port_count(driver->handle);
+	    erts_smp_rwmtx_runlock(&erts_driver_list_lock);
+	    erts_ddll_dereference_driver(driver->handle);
+	}
+	if (port_errno)
+	    ERTS_OPEN_DRIVER_RET(NULL, -2, port_errno);
+	else
+	    ERTS_OPEN_DRIVER_RET(NULL, -3, SYSTEM_LIMIT);
+    }
     
     if (IS_TRACED_FL(port, F_TRACE_PORTS)) {
 	trace_port_open(port,
 		pid,		
 		am_atom_put(port->name, strlen(port->name)));
     }
-    
+
+    error_number = error_type = 0;
     if (driver->start) {
 	if (IS_TRACED_FL(port, F_TRACE_SCHED_PORTS)) {
 	    trace_sched_ports_where(port, am_in, am_start);
@@ -662,56 +678,63 @@ erts_open_driver(erts_driver_t* driver,	/* Pointer to driver. */
         }
 #endif
 	fpe_was_unmasked = erts_block_fpe();
-	drv_data = (*driver->start)((ErlDrvPort)(port_ix),
-				    name, opts);
+	drv_data = (*driver->start)((ErlDrvPort) port, name, opts);
+	if (((SWord) drv_data) == -1)
+	    error_type = -1;
+	else if (((SWord) drv_data) == -2) {
+	    /*
+	     * We need to save errno quickly after the
+	     * call to the 'start' callback before
+	     * something else modify it.
+	     */
+	    error_type = -2;
+	    error_number = errno;
+	}
+	else if (((SWord) drv_data) == -3) {
+	    error_type = -3;
+	    error_number = BADARG;
+	}
+
 	erts_unblock_fpe(fpe_was_unmasked);
 	port->caller = NIL;
 	if (IS_TRACED_FL(port, F_TRACE_SCHED_PORTS)) {
 	    trace_sched_ports_where(port, am_out, am_start);
 	}
-	if (error_number_ptr && ((SWord) drv_data) == (SWord) -2)
-	    *error_number_ptr = errno;
 #ifdef ERTS_SMP
 	if (port->xports)
-	    erts_smp_xports_unlock(port);
+	    erts_port_handle_xports(port);
 	ASSERT(!port->xports);
 #endif
     }
 
-    if (((SWord)drv_data) == -1 || 
-	((SWord)drv_data) == -2 || 
-	((SWord)drv_data) == -3) {
-	int res = (int) ((SWord) drv_data);
-
-	if (res == -3 && error_number_ptr) {
-	    *error_number_ptr = BADARG;
-	}
-
+    if (error_type) {
 	/*
 	 * Must clean up the port.
 	 */
 #ifdef ERTS_SMP
-	erts_cancel_smp_ptimer(port->ptimer);
+	erts_cancel_smp_ptimer(port->common.u.alive.ptimer);
 #else
-	erts_cancel_timer(&(port->tm));
+	erts_cancel_timer(&(port->common.u.alive.tm));
 #endif
 	stopq(port);
-	kill_port(port);
 	if (port->linebuf != NULL) {
 	    erts_free(ERTS_ALC_T_LINEBUF,
 		      (void *) port->linebuf);
 	    port->linebuf = NULL;
 	}
 	if (driver->handle != NULL) {
-	    erts_smp_mtx_lock(&erts_driver_list_lock);
+	    erts_smp_rwmtx_rlock(&erts_driver_list_lock);
 	    erts_ddll_decrement_port_count(driver->handle);
-	    erts_smp_mtx_unlock(&erts_driver_list_lock);
+	    erts_smp_rwmtx_runlock(&erts_driver_list_lock);
 	}
+	kill_port(port);
 	erts_port_release(port);
-	return res;
+	ERTS_OPEN_DRIVER_RET(NULL, error_type, error_number);
     }
-    port->drv_data = (SWord) drv_data;
-    return port_ix;
+    port->drv_data = (UWord) drv_data;
+    ERTS_OPEN_DRIVER_RET(port, 0, 0);
+
+#undef ERTS_OPEN_DRIVER_RET
 }
 
 #ifdef ERTS_SMP
@@ -736,102 +759,122 @@ driver_create_port(ErlDrvPort creator_port_ix, /* Creating port */
 		   char* name,            /* Driver name */
 		   ErlDrvData drv_data)   /* Driver data */
 {
+    int cprt_flgs = 0;
     Port *creator_port;
     Port* port;
     erts_driver_t *driver;
     Process *rp;
-    int port_num;
-    Eterm port_id;
-    Uint32 xstatus = 0;
+    erts_mtx_t *driver_lock = NULL;
 
     ERTS_SMP_CHK_NO_PROC_LOCKS;
 
-    creator_port = erts_drvport2port(creator_port_ix);
+    /* Need to be called from a scheduler thread */
+    if (!erts_get_scheduler_id())
+	return ERTS_INVALID_ERL_DRV_PORT;
+
+    creator_port = erts_drvport2port(creator_port_ix, NULL);
     if (!creator_port)
-	return (ErlDrvTermData) -1;
+	return ERTS_INVALID_ERL_DRV_PORT;
+
+    rp = erts_proc_lookup(pid);
+    if (!rp)
+	return ERTS_INVALID_ERL_DRV_PORT;
 
     ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(creator_port));
 
     driver = creator_port->drv_ptr;
-    erts_smp_mtx_lock(&erts_driver_list_lock);
+    erts_smp_rwmtx_rlock(&erts_driver_list_lock);
     if (!erts_ddll_driver_ok(driver->handle)) {
-	erts_smp_mtx_unlock(&erts_driver_list_lock);
-	return (ErlDrvTermData) -1;
+	erts_smp_rwmtx_runlock(&erts_driver_list_lock);
+	return ERTS_INVALID_ERL_DRV_PORT;
     }
 
-    rp = erts_pid2proc(NULL, 0, pid, ERTS_PROC_LOCK_LINK);
-    if (!rp) {
-	erts_smp_mtx_unlock(&erts_driver_list_lock);
-	return (ErlDrvTermData) -1;   /* pid does not exist */
+    if (driver->handle != NULL) {
+	erts_ddll_increment_port_count(driver->handle);
+	erts_ddll_reference_referenced_driver(driver->handle);
+    }
+
+#ifdef ERTS_SMP
+    driver_lock = driver->lock;
+#endif
+
+    erts_smp_rwmtx_runlock(&erts_driver_list_lock);
+
+    /* Inherit parallelism flag from parent */
+    if (ERTS_PTS_FLG_PARALLELISM &
+	erts_smp_atomic32_read_nob(&creator_port->sched.flags))
+	cprt_flgs |= ERTS_CREATE_PORT_FLAG_PARALLELISM;
+    port = create_port(name, driver, driver_lock, cprt_flgs, pid, NULL);
+    if (!port) {
+	if (driver->handle) {
+	    erts_smp_rwmtx_rlock(&erts_driver_list_lock);
+	    erts_ddll_decrement_port_count(driver->handle);
+	    erts_smp_rwmtx_runlock(&erts_driver_list_lock);
+	    erts_ddll_dereference_driver(driver->handle);
+	}
+	return ERTS_INVALID_ERL_DRV_PORT;
     }
-    if ((port_num = get_free_port()) < 0) {
-	errno = SYSTEM_LIMIT;
+    ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(port));
+
+    erts_smp_proc_lock(rp, ERTS_PROC_LOCK_LINK);
+    if (ERTS_PROC_IS_EXITING(rp)) {
 	erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_LINK);
-	erts_smp_mtx_unlock(&erts_driver_list_lock);
-	return (ErlDrvTermData) -1;
+	if (driver->handle) {
+	    erts_smp_rwmtx_rlock(&erts_driver_list_lock);
+	    erts_ddll_decrement_port_count(driver->handle);
+	    erts_smp_rwmtx_runlock(&erts_driver_list_lock);
+	}
+	kill_port(port);
+	erts_port_release(port);
+	return ERTS_INVALID_ERL_DRV_PORT;
     }
 
-    port_id = make_internal_port(port_num);
-    port = &erts_port[port_num & erts_port_tab_index_mask];
+    erts_add_link(&ERTS_P_LINKS(port), LINK_PID, pid);
+    erts_add_link(&ERTS_P_LINKS(rp), LINK_PID, port->common.id);
+    erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_LINK);
 
 #ifdef ERTS_SMP
-    ASSERT(!port->lock);
-    port->lock = driver->lock;
-    if (!port->lock) {
+    if (!driver_lock) {
 	ErtsXPortsList *xplp = xports_list_alloc();
 	xplp->port = port;
 	xplp->next = creator_port->xports;
 	creator_port->xports = xplp;
-	port->lock = erts_alloc(ERTS_ALC_T_PORT_LOCK,
-					      sizeof(erts_smp_mtx_t));
-	erts_smp_mtx_init_locked_x(port->lock,
-#ifdef ERTS_ENABLE_LOCK_COUNT
-				   (erts_lcnt_rt_options & ERTS_LCNT_OPT_PORTLOCK) ? "port_lock" : NULL,
-#else
-				   "port_lock",
-#endif
-				   port_id);
-	xstatus |= ERTS_PORT_SFLG_PORT_SPECIFIC_LOCK;
     }
-
 #endif
 
-    if (driver->handle != NULL) {
-	erts_ddll_increment_port_count(driver->handle);
-	erts_ddll_reference_referenced_driver(driver->handle);
-    }
-    erts_smp_mtx_unlock(&erts_driver_list_lock);
-
-    ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(port));
+    port->drv_data = (UWord) drv_data;
 
-    setup_port(port, pid, driver, drv_data, name, xstatus);
-    port->id = port_id;
-
-    erts_add_link(&(port->nlinks), LINK_PID, pid);
-    erts_add_link(&(rp->nlinks), LINK_PID, port_id);
-    erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_LINK);
-    return port_num & erts_port_tab_index_mask;
+    return (ErlDrvPort) port;
 }
 
 #ifdef ERTS_SMP
-void
-erts_smp_xports_unlock(Port *prt)
+int erts_port_handle_xports(Port *prt)
 {
+    int reds = 0;
     ErtsXPortsList *xplp;
 
     ASSERT(prt);
     xplp = prt->xports;
     ASSERT(xplp);
     while (xplp) {
+	Port *rprt = xplp->port;
 	ErtsXPortsList *free_xplp;
-	if (xplp->port->xports)
-	    erts_smp_xports_unlock(xplp->port);
-	erts_port_release(xplp->port);
+	erts_aint32_t state;
+	if (rprt->xports)
+	    reds += erts_port_handle_xports(rprt);
+	state = erts_atomic32_read_nob(&rprt->state);
+	if ((state & ERTS_PORT_SFLG_CLOSING) && erts_is_port_ioq_empty(rprt)) {
+	    terminate_port(rprt);
+	    reds += ERTS_PORT_REDS_TERMINATE;
+	}
+	erts_port_release(rprt);
 	free_xplp = xplp;
 	xplp = xplp->next;
 	xports_list_free(free_xplp);
+	reds++;
     }
     prt->xports = NULL;
+    return reds;
 }
 #endif
 
@@ -866,8 +909,8 @@ io_list_to_vec(Eterm obj,	/* io-list */
     DECLARE_ESTACK(s);
     Eterm* objp;
     char *buf  = cbin->orig_bytes;
-    ErlDrvSizeT len = cbin->orig_size;
-    ErlDrvSizeT csize  = 0;
+    Uint len = cbin->orig_size;
+    Uint csize  = 0;
     int vlen   = 0;
     char* cptr = buf;
 
@@ -982,7 +1025,7 @@ io_list_to_vec(Eterm obj,	/* io-list */
 
 #define IO_LIST_VEC_COUNT(obj)						\
 do {									\
-    ErlDrvSizeT _size = binary_size(obj);				\
+    Uint _size = binary_size(obj);					\
     Eterm _real;							\
     ERTS_DECLARE_DUMMY(Uint _offset);					\
     int _bitoffs;							\
@@ -1033,8 +1076,9 @@ do {									\
  */
 
 static int 
-io_list_vec_len(Eterm obj, Uint* vsize, Uint* csize,
-		Uint* pvsize, Uint* pcsize, Uint* total_size)
+io_list_vec_len(Eterm obj, int* vsize, Uint* csize,
+		Uint* pvsize, Uint* pcsize,
+		ErlDrvSizeT* total_size)
 {
     DECLARE_ESTACK(s);
     Eterm* objp;
@@ -1045,7 +1089,7 @@ io_list_vec_len(Eterm obj, Uint* vsize, Uint* csize,
     Uint p_v_size = 0;
     Uint p_c_size = 0;
     Uint p_in_clist = 0;
-    Uint total;
+    Uint total; /* Uint due to halfword emulator */
 
     goto L_jump_start;  /* avoid a push */
 
@@ -1105,7 +1149,7 @@ io_list_vec_len(Eterm obj, Uint* vsize, Uint* csize,
     if (total < c_size) {
 	goto L_overflow_error;
     }
-    *total_size = total;
+    *total_size = (ErlDrvSizeT) total;
 
     DESTROY_ESTACK(s);
     *vsize = v_size;
@@ -1120,56 +1164,724 @@ io_list_vec_len(Eterm obj, Uint* vsize, Uint* csize,
     return 1;
 }
 
-/* write data to a port */
-int erts_write_to_port(Eterm caller_id, Port *p, Eterm list)
-{
-    char *buf;
-    erts_driver_t *drv = p->drv_ptr;
-    Uint size;
+typedef enum {
+    ERTS_TRY_IMM_DRV_CALL_OK,
+    ERTS_TRY_IMM_DRV_CALL_BUSY_LOCK,
+    ERTS_TRY_IMM_DRV_CALL_INVALID_PORT,
+    ERTS_TRY_IMM_DRV_CALL_INVALID_SCHED_FLAGS
+} ErtsTryImmDrvCallResult;
+
+typedef struct {
+    Process *c_p; /* Currently executing process (unlocked) */
+    Port *port; /* Port to operate on */
+    Eterm port_op; /* port operation as an atom */
+    erts_aint32_t state; /* in: invalid state; out: read state (if read) */
+    erts_aint32_t sched_flags; /* in: invalid flags; out: read flags (if read) */
+    int async; /* Asynchronous operation */
+    int pre_chk_sched_flags; /* Check sched flags before lock? */
     int fpe_was_unmasked;
-    
-    ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(p) || ERTS_IS_CRASH_DUMPING);
+} ErtsTryImmDrvCallState;
+
+#define ERTS_INIT_TRY_IMM_DRV_CALL_STATE(C_P, PRT, SFLGS, PTS_FLGS, A, PRT_OP) \
+    {(C_P), (PRT), (PRT_OP), (SFLGS), (PTS_FLGS), (A), 1, 0}
+
+/*
+ * Try doing an immediate driver callback call from a process. If
+ * this fail, the operation should be scheduled in the normal case...
+ *
+ */
+static ERTS_INLINE ErtsTryImmDrvCallResult
+try_imm_drv_call(ErtsTryImmDrvCallState *sp)
+{
+    ErtsTryImmDrvCallResult res;
+    erts_aint32_t invalid_state, invalid_sched_flags;
+    Port *prt = sp->port;
+    Process *c_p = sp->c_p;
+
+    ASSERT(is_atom(sp->port_op));
+
+    invalid_sched_flags = ERTS_PTS_FLGS_FORCE_SCHEDULE_OP;
+    invalid_sched_flags |= sp->sched_flags;
+    if (sp->async)
+	invalid_sched_flags |= ERTS_PTS_FLG_PARALLELISM;
+
+    if (sp->pre_chk_sched_flags) {
+	sp->sched_flags = erts_smp_atomic32_read_nob(&prt->sched.flags);
+	if (sp->sched_flags & invalid_sched_flags)
+	    return ERTS_TRY_IMM_DRV_CALL_INVALID_SCHED_FLAGS;
+    }
+
+    if (erts_smp_port_trylock(prt) == EBUSY)
+	return ERTS_TRY_IMM_DRV_CALL_BUSY_LOCK;
+
+    invalid_state = sp->state;
+    sp->state = erts_atomic32_read_nob(&prt->state);
+    if (sp->state & invalid_state) {
+	res = ERTS_TRY_IMM_DRV_CALL_INVALID_PORT;
+	goto locked_fail;
+    }
+
+    sp->sched_flags = erts_smp_atomic32_read_nob(&prt->sched.flags);
+    if (sp->sched_flags & invalid_sched_flags) {
+	res = ERTS_TRY_IMM_DRV_CALL_INVALID_SCHED_FLAGS;
+	goto locked_fail;
+    }
+
+    if (c_p) {
+	if (IS_TRACED_FL(c_p, F_TRACE_SCHED_PROCS))
+	    trace_virtual_sched(c_p, am_out);
+	if (erts_system_profile_flags.runnable_procs
+	    && erts_system_profile_flags.exclusive)
+	    profile_runnable_proc(c_p, am_inactive);
+
+	erts_smp_proc_unlock(c_p, ERTS_PROC_LOCK_MAIN);
+    }
+
     ERTS_SMP_CHK_NO_PROC_LOCKS;
 
-    p->caller = caller_id;
-    if (drv->outputv != NULL) {
-	Uint vsize;
-	Uint csize;
-	Uint pvsize;
-	Uint pcsize;
-	ErlDrvSizeT blimit;
+    if (IS_TRACED_FL(prt, F_TRACE_SCHED_PORTS))
+	trace_sched_ports_where(prt, am_in, sp->port_op);
+    if (erts_system_profile_flags.runnable_ports
+	&& !erts_port_is_scheduled(prt))
+    	profile_runnable_port(prt, am_active);
+
+    sp->fpe_was_unmasked = erts_block_fpe();
+
+    return ERTS_TRY_IMM_DRV_CALL_OK;
+
+locked_fail:
+    erts_port_release(prt);
+    return res;
+}
+
+static ERTS_INLINE void
+finalize_imm_drv_call(ErtsTryImmDrvCallState *sp)
+{
+    Port *prt = sp->port;
+    Process *c_p = sp->c_p;
+
+    erts_port_driver_callback_epilogue(prt, NULL);
+
+    erts_unblock_fpe(sp->fpe_was_unmasked);
+
+    if (IS_TRACED_FL(prt, F_TRACE_SCHED_PORTS))
+	trace_sched_ports_where(prt, am_out, sp->port_op);
+    if (erts_system_profile_flags.runnable_ports
+	&& !erts_port_is_scheduled(prt))
+    	profile_runnable_port(prt, am_inactive);
+
+    erts_port_release(prt);
+
+    if (c_p) {
+	erts_smp_proc_lock(c_p, ERTS_PROC_LOCK_MAIN);
+
+	if (IS_TRACED_FL(c_p, F_TRACE_SCHED_PROCS))
+	    trace_virtual_sched(c_p, am_in);
+	if (erts_system_profile_flags.runnable_procs
+	    && erts_system_profile_flags.exclusive)
+	    profile_runnable_proc(c_p, am_active);
+    }
+}
+
+/*
+ * force_imm_drv_call()/finalize_force_imm_drv_call() should *only*
+ * be used while crash dumping...
+ */
+static ErtsTryImmDrvCallResult
+force_imm_drv_call(ErtsTryImmDrvCallState *sp)
+{
+    erts_aint32_t invalid_state;
+    Port *prt = sp->port;
+
+    ASSERT(ERTS_IS_CRASH_DUMPING)
+    ASSERT(is_atom(sp->port_op));
+
+    invalid_state = sp->state;
+    sp->state = erts_atomic32_read_nob(&prt->state);
+    if (sp->state & invalid_state)
+	return ERTS_TRY_IMM_DRV_CALL_INVALID_PORT;
+
+    sp->fpe_was_unmasked = erts_block_fpe();
+
+    return ERTS_TRY_IMM_DRV_CALL_OK;
+}
+
+static void
+finalize_force_imm_drv_call(ErtsTryImmDrvCallState *sp)
+{
+    erts_unblock_fpe(sp->fpe_was_unmasked);
+}
+
+#define ERTS_QUEUE_PORT_SCHED_OP_REPLY_SIZE (REF_THING_SIZE + 3)
+
+static ERTS_INLINE void
+queue_port_sched_op_reply(Process *rp,
+			  ErtsProcLocks *rp_locksp,
+			  Eterm *hp_start,
+			  Eterm *hp,
+			  Uint h_size,
+			  ErlHeapFragment* bp,
+			  Uint32 *ref_num,
+			  Eterm msg)
+{
+    Eterm ref = make_internal_ref(hp);
+    write_ref_thing(hp, ref_num[0], ref_num[1], ref_num[2]);
+    hp += REF_THING_SIZE;
+
+    msg = TUPLE2(hp, ref, msg);
+    hp += 3;
+
+    if (!bp) {
+	HRelease(rp, hp_start + h_size, hp);
+    }
+    else {
+	Uint used_h_size = hp - hp_start;
+	ASSERT(h_size >= used_h_size);
+	if (h_size > used_h_size)
+	    bp = erts_resize_message_buffer(bp, used_h_size, &msg, 1);
+    }
+
+    erts_queue_message(rp,
+		       rp_locksp,
+		       bp,
+		       msg,
+		       NIL
+#ifdef USE_VM_PROBES
+		       , NIL
+#endif
+	);
+}
+
+static void
+port_sched_op_reply(Eterm to, Uint32 *ref_num, Eterm msg)
+{
+    Process *rp = erts_proc_lookup_raw(to);
+    if (rp) {
+	ErlOffHeap *ohp;
+	ErlHeapFragment* bp;
+	Eterm msg_copy;
+	Uint hsz, msg_sz;
+	Eterm *hp, *hp_start;
+	ErtsProcLocks rp_locks = 0;
+
+	hsz = ERTS_QUEUE_PORT_SCHED_OP_REPLY_SIZE;
+	if (is_immed(msg))
+	    msg_sz = 0;
+	else {
+	    msg_sz = size_object(msg);
+	    hsz += msg_sz;
+	}
+
+	hp_start = hp = erts_alloc_message_heap(hsz,
+						&bp,
+						&ohp,
+						rp,
+						&rp_locks);
+	if (is_immed(msg))
+	    msg_copy = msg;
+	else
+	    msg_copy = copy_struct(msg, msg_sz, &hp, ohp);
+
+	queue_port_sched_op_reply(rp,
+				  &rp_locks,
+				  hp_start,
+				  hp,
+				  hsz,
+				  bp,
+				  ref_num,
+				  msg_copy);
+
+	if (rp_locks)
+	    erts_smp_proc_unlock(rp, rp_locks);
+    }
+}
+
+
+ErtsPortOpResult
+erts_schedule_proc2port_signal(Process *c_p,
+			       Port *prt,
+			       Eterm caller,
+			       Eterm *refp,
+			       ErtsProc2PortSigData *sigdp,
+			       int task_flags,
+			       ErtsProc2PortSigCallback callback)
+{
+    int sched_res;
+    if (!refp) {
+	if (c_p)
+	    erts_smp_proc_unlock(c_p, ERTS_PROC_LOCK_MAIN);
+    }
+    else {
+	ASSERT(c_p);
+	sigdp->flags |= ERTS_P2P_SIG_DATA_FLG_REPLY;
+	erts_make_ref_in_array(sigdp->ref);
+	*refp = erts_proc_store_ref(c_p, sigdp->ref);
+
+	/*
+	 * Caller needs to wait for a message containing
+	 * the ref that we just created. No such message
+	 * can exist in callers message queue at this time.
+	 * We therefore move the save pointer of the
+	 * callers message queue to the end of the queue.
+	 *
+	 * NOTE: It is of vital importance that the caller
+	 *       immediately do a receive unconditionaly
+	 *       waiting for the message with the reference;
+	 *       otherwise, next receive will *not* work
+	 *       as expected!
+	 */
+	erts_smp_proc_lock(c_p, ERTS_PROC_LOCKS_MSG_RECEIVE);
+
+	if (ERTS_PROC_PENDING_EXIT(c_p)) {
+	    /* need to exit caller instead */
+	    erts_smp_proc_unlock(c_p, ERTS_PROC_LOCKS_MSG_RECEIVE);
+	    KILL_CATCHES(c_p);
+	    c_p->freason = EXC_EXIT;
+	    return ERTS_PORT_OP_CALLER_EXIT;
+	}
+
+	ERTS_SMP_MSGQ_MV_INQ2PRIVQ(c_p);
+	c_p->msg.save = c_p->msg.last;
+
+	erts_smp_proc_unlock(c_p,
+			     (ERTS_PROC_LOCK_MAIN
+			      | ERTS_PROC_LOCKS_MSG_RECEIVE));
+    }
+
+
+    sigdp->caller = caller;
+
+    /* Schedule port close call for later execution... */
+    sched_res = erts_port_task_schedule(prt->common.id,
+					NULL,
+					ERTS_PORT_TASK_PROC_SIG,
+					sigdp,
+					callback,
+					task_flags);
+
+    if (c_p)
+	erts_smp_proc_lock(c_p, ERTS_PROC_LOCK_MAIN);
+
+    if (sched_res != 0) {
+	if (refp)
+	    *refp = NIL;
+	return ERTS_PORT_OP_DROPPED;
+    }
+    return ERTS_PORT_OP_SCHEDULED;
+}
+
+static ERTS_INLINE void
+send_badsig(Port *prt)
+{
+    ErtsProcLocks rp_locks = ERTS_PROC_LOCKS_XSIG_SEND;
+    Process* rp;
+    Eterm connected = ERTS_PORT_GET_CONNECTED(prt);
+
+    ERTS_SMP_CHK_NO_PROC_LOCKS;
+    ERTS_LC_ASSERT(erts_get_scheduler_id());
+
+    ASSERT(is_internal_pid(connected));
+
+    rp = erts_proc_lookup_raw(connected);
+    if (rp) {
+	erts_smp_proc_lock(rp, rp_locks);
+	if (!ERTS_PROC_IS_EXITING(rp))
+	    (void) erts_send_exit_signal(NULL,
+					 prt->common.id,
+					 rp,
+					 &rp_locks, 
+					 am_badsig,
+					 NIL,
+					 NULL,
+					 0);
+	if (rp_locks)
+	    erts_smp_proc_unlock(rp, rp_locks);
+    }
+}
+
+static void
+badsig_received(int bang_op,
+		Port *prt,
+		erts_aint32_t state,
+		int bad_output_value)
+{
+    /*
+     * if (bang_op)
+     *   we are part of a "Prt ! Something" operation
+     * else
+     *   we are part of a call to a port BIF
+     * behave accordingly...
+     */
+    if (!(state & ERTS_PORT_SFLGS_INVALID_LOOKUP)) {
+	if (bad_output_value) {
+	    erts_dsprintf_buf_t *dsbufp = erts_create_logger_dsbuf();
+	    erts_dsprintf(dsbufp, "Bad value on output port '%s'\n", prt->name);
+	    erts_send_error_to_logger_nogl(dsbufp);
+	}
+	if (bang_op)
+	    send_badsig(prt);
+    }
+}
+
+static int
+port_badsig(Port *prt, erts_aint32_t state, int op, ErtsProc2PortSigData *sigdp)
+{
+    if (op == ERTS_PROC2PORT_SIG_EXEC)
+	badsig_received(sigdp->flags & ERTS_P2P_SIG_DATA_FLG_BANG_OP,
+			prt,
+			state,
+			sigdp->flags & ERTS_P2P_SIG_DATA_FLG_BAD_OUTPUT);
+    if (sigdp->flags & ERTS_P2P_SIG_DATA_FLG_REPLY)
+	port_sched_op_reply(sigdp->caller, sigdp->ref, am_badarg);
+    return ERTS_PORT_REDS_BADSIG;
+}
+
+
+/*
+ * bad_port_signal() will
+ * - preserve signal order of signals.
+ * - send a 'badsig' exit signal to connected process if 'from' is an
+ *   internal pid and the port is alive when the bad signal reaches
+ *   it.
+ */
+static ErtsPortOpResult
+bad_port_signal(Process *c_p,
+		int flags,
+		Port *prt,
+		Eterm from,
+		Eterm *refp,
+		Eterm port_op)
+{
+    ErtsProc2PortSigData *sigdp;
+    ErtsTryImmDrvCallResult try_call_res;
+    ErtsTryImmDrvCallState try_call_state
+	= ERTS_INIT_TRY_IMM_DRV_CALL_STATE(
+	    c_p,
+	    prt,
+	    ERTS_PORT_SFLGS_INVALID_LOOKUP,
+	    0,
+	    !refp,
+	    port_op);
+
+    try_call_res = try_imm_drv_call(&try_call_state);
+    switch (try_call_res) {
+    case ERTS_TRY_IMM_DRV_CALL_OK:
+	badsig_received(flags & ERTS_PORT_SIG_FLG_BANG_OP,
+			prt,
+			try_call_state.state,
+			flags & ERTS_PORT_SIG_FLG_BAD_OUTPUT);
+	finalize_imm_drv_call(&try_call_state);
+	return ERTS_PORT_OP_BADARG;
+    case ERTS_TRY_IMM_DRV_CALL_INVALID_PORT:
+	return ERTS_PORT_OP_DROPPED;
+    case ERTS_TRY_IMM_DRV_CALL_INVALID_SCHED_FLAGS:
+    case ERTS_TRY_IMM_DRV_CALL_BUSY_LOCK:
+	/* Schedule badsig() call instead... */
+	break;
+    }
+
+    sigdp = erts_port_task_alloc_p2p_sig_data();
+    sigdp->flags = (flags & ~ERTS_P2P_SIG_TYPE_MASK) | ERTS_P2P_SIG_TYPE_BAD;
+
+    return erts_schedule_proc2port_signal(c_p,
+					  prt,
+					  c_p->common.id,
+					  refp,
+					  sigdp,
+					  0,
+					  port_badsig);
+}
+
+
+/*
+ * Driver outputv() callback
+ */
+
+static ERTS_INLINE void
+call_driver_outputv(int bang_op,
+		    Eterm caller,
+		    Eterm from,
+		    Port *prt,
+		    erts_driver_t *drv,
+		    ErlIOVec *evp)
+{
+    /*
+     * if (bang_op)
+     *   we are part of a "Prt ! {From, {command, Data}}" operation
+     * else
+     *   we are part of a call to port_command/[2,3]
+     * behave accordingly...
+     */
+    if (bang_op && from != ERTS_PORT_GET_CONNECTED(prt))
+	send_badsig(prt);
+    else {
+	ErlDrvSizeT size = evp->size;
+
+	ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt)	
+			   || ERTS_IS_CRASH_DUMPING);
+
+#ifdef USE_VM_PROBES
+	if (DTRACE_ENABLED(driver_outputv)) {
+	    DTRACE_FORMAT_COMMON_PID_AND_PORT(caller, prt);
+	    DTRACE4(driver_outputv, process_str, port_str, prt->name, size);
+	}
+#endif
+
+	prt->caller = caller;
+	(*drv->outputv)((ErlDrvData) prt->drv_data, evp);
+	prt->caller = NIL;
+
+	prt->bytes_out += size;
+	erts_smp_atomic_add_nob(&erts_bytes_out, size);
+    }
+}
+
+static ERTS_INLINE void
+cleanup_scheduled_outputv(ErlIOVec *ev, ErlDrvBinary *cbinp)
+{
+    int i;
+    /* Need to free all binaries */
+    for (i = 1; i < ev->vsize; i++)
+	if (ev->binv[i])
+	    driver_free_binary(ev->binv[i]);
+    if (cbinp)
+	driver_free_binary(cbinp);
+    erts_free(ERTS_ALC_T_DRV_CMD_DATA, ev);
+}
+
+static int
+port_sig_outputv(Port *prt, erts_aint32_t state, int op, ErtsProc2PortSigData *sigdp)
+{
+    Eterm reply;
+
+    switch (op) {
+    case ERTS_PROC2PORT_SIG_EXEC:
+	/* Execution of a scheduled outputv() call */
+
+	ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
+
+	if (state & ERTS_PORT_SFLGS_INVALID_LOOKUP)
+	    reply = am_badarg;
+	else {
+	    call_driver_outputv(sigdp->flags & ERTS_P2P_SIG_DATA_FLG_BANG_OP,
+				sigdp->caller,
+				sigdp->u.outputv.from,
+				prt,
+				prt->drv_ptr,
+				sigdp->u.outputv.evp);
+	    reply = am_true;
+	}
+	break;
+    case ERTS_PROC2PORT_SIG_ABORT_NOSUSPEND:
+	reply = am_false;
+	break;
+    default:
+	reply = am_badarg;
+	break;
+    }
+
+    if (sigdp->flags & ERTS_P2P_SIG_DATA_FLG_REPLY)
+	port_sched_op_reply(sigdp->caller, sigdp->ref, reply);
+
+    cleanup_scheduled_outputv(sigdp->u.outputv.evp,
+			      sigdp->u.outputv.cbinp);
+
+    return ERTS_PORT_REDS_CMD_OUTPUTV;
+}
+
+/*
+ * Driver output() callback
+ */
+
+static ERTS_INLINE void
+call_driver_output(int bang_op,
+		   Eterm caller,
+		   Eterm from,
+		   Port *prt,
+		   erts_driver_t *drv,
+		   char *bufp,
+		   ErlDrvSizeT size)
+{
+    /*
+     * if (bang_op)
+     *   we are part of a "Prt ! {From, {command, Data}}" operation
+     * else
+     *   we are part of a call to port_command/[2,3]
+     * behave accordingly...
+     */
+    if (bang_op && from != ERTS_PORT_GET_CONNECTED(prt))
+	send_badsig(prt);
+    else {
+
+	ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt)	
+			   || ERTS_IS_CRASH_DUMPING);
+
+#ifdef USE_VM_PROBES
+	if (DTRACE_ENABLED(driver_output)) {
+	    DTRACE_FORMAT_COMMON_PID_AND_PORT(caller, prt);
+	    DTRACE4(driver_output, process_str, port_str, prt->name, size);
+	}
+#endif
+
+	prt->caller = caller;
+	(*drv->output)((ErlDrvData) prt->drv_data, bufp, size);
+	prt->caller = NIL;
+
+	prt->bytes_out += size;
+	erts_smp_atomic_add_nob(&erts_bytes_out, size);
+    }
+}
+
+static ERTS_INLINE void
+cleanup_scheduled_output(char *bufp)
+{
+    erts_free(ERTS_ALC_T_DRV_CMD_DATA, bufp);
+}
+
+static int
+port_sig_output(Port *prt, erts_aint32_t state, int op, ErtsProc2PortSigData *sigdp)
+{
+    Eterm reply;
+
+    switch (op) {
+    case ERTS_PROC2PORT_SIG_EXEC:
+	/* Execution of a scheduled output() call */
+
+	ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
+
+	if (state & ERTS_PORT_SFLGS_INVALID_LOOKUP)
+	    reply = am_badarg;
+	else {
+	    call_driver_output(sigdp->flags & ERTS_P2P_SIG_DATA_FLG_BANG_OP,
+			       sigdp->caller,
+			       sigdp->u.output.from,
+			       prt,
+			       prt->drv_ptr,
+			       sigdp->u.output.bufp,
+			       sigdp->u.output.size);
+	    reply = am_true;
+	}
+	break;
+    case ERTS_PROC2PORT_SIG_ABORT_NOSUSPEND:
+	reply = am_false;
+	break;
+    default:
+	reply = am_badarg;
+	break;
+    }
+
+    if (sigdp->flags & ERTS_P2P_SIG_DATA_FLG_REPLY)
+	port_sched_op_reply(sigdp->caller, sigdp->ref, reply);
+
+    cleanup_scheduled_output(sigdp->u.output.bufp);
+
+    return ERTS_PORT_REDS_CMD_OUTPUT;
+}
+
+ErtsPortOpResult
+erts_port_output(Process *c_p,
+		 int flags,
+		 Port *prt,
+		 Eterm from,
+		 Eterm list,
+		 Eterm *refp)
+{
+    ErtsPortOpResult res;
+    ErtsProc2PortSigData *sigdp;
+    erts_driver_t *drv = prt->drv_ptr;
+    size_t size;
+    int try_call;
+    erts_aint32_t sched_flags, busy_flgs, invalid_flags;
+    int task_flags;
+    ErtsProc2PortSigCallback port_sig_callback;
+    ErlDrvBinary *cbin = NULL;
+    ErlIOVec *evp = NULL;
+    char *buf = NULL;
+    int force_immediate_call = (flags & ERTS_PORT_SIG_FLG_FORCE_IMM_CALL);
+
+    ASSERT((flags & ~(ERTS_PORT_SIG_FLG_BANG_OP
+		      | ERTS_PORT_SIG_FLG_NOSUSPEND
+		      | ERTS_PORT_SIG_FLG_FORCE
+		      | ERTS_PORT_SIG_FLG_FORCE_IMM_CALL)) == 0);
+
+    busy_flgs = ((flags & ERTS_PORT_SIG_FLG_FORCE)
+		 ? ((erts_aint32_t) 0)
+		 : ERTS_PTS_FLGS_BUSY);
+    invalid_flags = busy_flgs;
+    if (!refp)
+	invalid_flags |= ERTS_PTS_FLG_PARALLELISM;
+
+    /*
+     * Assumes caller have checked that port is valid...
+     */
+
+    sched_flags = erts_smp_atomic32_read_nob(&prt->sched.flags);
+    if (sched_flags & (busy_flgs|ERTS_PTS_FLG_EXIT))
+	return ((sched_flags & ERTS_PTS_FLG_EXIT)
+		? ERTS_PORT_OP_DROPPED
+		: ERTS_PORT_OP_BUSY);
+
+    try_call = (force_immediate_call /* crash dumping */
+		|| !(sched_flags & (invalid_flags
+				    | ERTS_PTS_FLGS_FORCE_SCHEDULE_OP)));
+
+#ifdef USE_VM_PROBES
+    if(DTRACE_ENABLED(port_command)) {
+	DTRACE_FORMAT_COMMON_PID_AND_PORT(c_p ? c_p->common.id : ERTS_INVALID_PID, prt);
+	DTRACE4(port_command, process_str, port_str, prt->name, "command");
+    }
+#endif
+
+    if (drv->outputv) {
+	ErlIOVec ev;
 	SysIOVec iv[SMALL_WRITE_VEC];
 	ErlDrvBinary* bv[SMALL_WRITE_VEC];
 	SysIOVec* ivp;
 	ErlDrvBinary**  bvp;
-	ErlDrvBinary* cbin;
-	ErlIOVec ev;
+	int vsize;
+	Uint csize;
+	Uint pvsize;
+	Uint pcsize;
+	Uint blimit;
+	size_t iov_offset, binv_offset, alloc_size;
 
-	if (io_list_vec_len(list, &vsize, &csize,
-			    &pvsize, &pcsize, &size)) {
+	if (io_list_vec_len(list, &vsize, &csize, &pvsize, &pcsize, &size))
 	    goto bad_value;
+
+	iov_offset = ERTS_ALC_DATA_ALIGN_SIZE(sizeof(ErlIOVec));
+	binv_offset = iov_offset;
+	binv_offset += ERTS_ALC_DATA_ALIGN_SIZE((vsize+1)*sizeof(SysIOVec));
+	alloc_size = binv_offset;
+	alloc_size += (vsize+1)*sizeof(ErlDrvBinary *);
+
+	if (try_call && vsize < SMALL_WRITE_VEC) {
+	    ivp = ev.iov = iv;
+	    bvp = ev.binv = bv;
+	    evp = &ev;
+	}
+	else {
+	    char *ptr = erts_alloc((try_call
+				    ? ERTS_ALC_T_TMP
+				    : ERTS_ALC_T_DRV_CMD_DATA), alloc_size);
+
+	    evp = (ErlIOVec *) ptr;
+	    ivp = evp->iov = (SysIOVec *) (ptr + iov_offset);
+	    bvp = evp->binv = (ErlDrvBinary **) (ptr + binv_offset);
 	}
+
 	/* To pack or not to pack (small binaries) ...? */
-	vsize++;
-	if (vsize <= SMALL_WRITE_VEC) {
+	if (vsize < SMALL_WRITE_VEC) {
 	    /* Do NOT pack */
 	    blimit = 0;
-	} else {
+	}
+	else {
 	    /* Do pack */
 	    vsize = pvsize + 1;
 	    csize = pcsize;
 	    blimit = ERL_SMALL_IO_BIN_LIMIT;
 	}
 	/* Use vsize and csize from now on */
-	if (vsize <= SMALL_WRITE_VEC) {
-	    ivp = iv;
-	    bvp = bv;
-	} else {
-	    ivp = (SysIOVec *) erts_alloc(ERTS_ALC_T_TMP,
-					  vsize * sizeof(SysIOVec));
-	    bvp = (ErlDrvBinary**) erts_alloc(ERTS_ALC_T_TMP,
-					      vsize * sizeof(ErlDrvBinary*));
-	}
+
 	cbin = driver_alloc_binary(csize);
 	if (!cbin)
 	    erts_alloc_enomem(ERTS_ALC_T_DRV_BINARY, ERTS_SIZEOF_Binary(csize));
@@ -1178,210 +1890,759 @@ int erts_write_to_port(Eterm caller_id, Port *p, Eterm list)
 	ivp[0].iov_base = NULL;
 	ivp[0].iov_len = 0;
 	bvp[0] = NULL;
-	ev.vsize = io_list_to_vec(list, ivp+1, bvp+1, cbin, blimit);
-	if (ev.vsize < 0) {
-	    if (ivp != iv) {
-		erts_free(ERTS_ALC_T_TMP, (void *) ivp);
-	    }
-	    if (bvp != bv) {
-		erts_free(ERTS_ALC_T_TMP, (void *) bvp);
-	    }
+	evp->vsize = io_list_to_vec(list, ivp+1, bvp+1, cbin, blimit);
+	if (evp->vsize < 0) {
+	    if (evp != &ev)
+		erts_free(try_call ? ERTS_ALC_T_TMP : ERTS_ALC_T_DRV_CMD_DATA,
+			  evp);
 	    driver_free_binary(cbin);
 	    goto bad_value;
 	}
-	ev.vsize++;
 #if 0
 	/* This assertion may say something useful, but it can
 	   be falsified during the emulator test suites. */
-	ASSERT(ev.vsize == vsize);
+	ASSERT(evp->vsize == vsize);
 #endif
-	ev.size = size;  /* total size */
-	ev.iov = ivp;
-	ev.binv = bvp;
-#ifdef USE_VM_PROBES
-        if (DTRACE_ENABLED(driver_outputv)) {
-            DTRACE_FORMAT_COMMON_PID_AND_PORT(caller_id, p)
-            DTRACE4(driver_outputv, process_str, port_str, p->name, size);
-        }
-#endif
-	fpe_was_unmasked = erts_block_fpe();
-	(*drv->outputv)((ErlDrvData)p->drv_data, &ev);
-	erts_unblock_fpe(fpe_was_unmasked);
-	if (ivp != iv) {
-	    erts_free(ERTS_ALC_T_TMP, (void *) ivp);
-	}
-	if (bvp != bv) {
-	    erts_free(ERTS_ALC_T_TMP, (void *) bvp);
+	evp->vsize++;
+	evp->size = size;  /* total size */
+
+	if (!try_call) {
+	    int i;
+	    /* Need to increase refc on all binaries */
+	    for (i = 1; i < evp->vsize; i++)
+		if (bvp[i])
+		    driver_binary_inc_refc(bvp[i]);
 	}
-	driver_free_binary(cbin);
-    } else {
-	int r;
-	
-	/* Try with an 8KB buffer first (will often be enough I guess). */
-	size = 8*1024;
-	/* See below why the extra byte is added. */
-	buf = erts_alloc(ERTS_ALC_T_TMP, size+1);
-	r = io_list_to_buf(list, buf, size);
+	else {
+	    int i;
+	    ErlIOVec *new_evp;
+	    ErtsTryImmDrvCallResult try_call_res;
+	    ErtsTryImmDrvCallState try_call_state
+		= ERTS_INIT_TRY_IMM_DRV_CALL_STATE(
+		    c_p,
+		    prt,
+		    ERTS_PORT_SFLGS_INVALID_LOOKUP,
+		    invalid_flags,
+		    !refp,
+		    am_command);
+
+	    try_call_state.pre_chk_sched_flags = 0; /* already checked */
+	    if (force_immediate_call)
+		try_call_res = force_imm_drv_call(&try_call_state);
+	    else
+		try_call_res = try_imm_drv_call(&try_call_state);
+	    switch (try_call_res) {
+	    case ERTS_TRY_IMM_DRV_CALL_OK:
+		call_driver_outputv(flags & ERTS_PORT_SIG_FLG_BANG_OP,
+				    c_p ? c_p->common.id : ERTS_INVALID_PID,
+				    from,
+				    prt,
+				    drv,
+				    evp);
+		if (force_immediate_call)
+		    finalize_force_imm_drv_call(&try_call_state);
+		else
+		    finalize_imm_drv_call(&try_call_state);
+		/* Fall through... */
+	    case ERTS_TRY_IMM_DRV_CALL_INVALID_PORT:
+		driver_free_binary(cbin);
+		if (evp != &ev)
+		    erts_free(ERTS_ALC_T_TMP, evp);
+		if (try_call_res == ERTS_TRY_IMM_DRV_CALL_OK)
+		    return ERTS_PORT_OP_DONE;
+		else
+		    return ERTS_PORT_OP_DROPPED;
+	    case ERTS_TRY_IMM_DRV_CALL_INVALID_SCHED_FLAGS:
+		sched_flags = try_call_state.sched_flags;
+	    case ERTS_TRY_IMM_DRV_CALL_BUSY_LOCK:
+		/* Schedule outputv() call instead... */
+		break;
+	    }
 
-#ifdef USE_VM_PROBES
-	if(DTRACE_ENABLED(port_command)) {
-            DTRACE_FORMAT_COMMON_PID_AND_PORT(caller_id, p)
-	    DTRACE4(port_command, process_str, port_str, p->name, "command");
-	}
+	    /* Need to increase refc on all binaries */
+	    for (i = 1; i < evp->vsize; i++)
+		if (bvp[i])
+		    driver_binary_inc_refc(bvp[i]);
+
+	    new_evp = erts_alloc(ERTS_ALC_T_DRV_CMD_DATA, alloc_size);
+
+	    if (evp != &ev) {
+		sys_memcpy((void *) new_evp, (void *) evp, alloc_size);
+		new_evp->iov = (SysIOVec *) (((char *) new_evp)
+					     + iov_offset);
+		bvp = new_evp->binv = (ErlDrvBinary **) (((char *) new_evp)
+							 + binv_offset);
+
+#ifdef DEBUG
+		ASSERT(new_evp->vsize == evp->vsize);
+		ASSERT(new_evp->size == evp->size);
+		for (i = 0; i < evp->vsize; i++) {
+		    ASSERT(new_evp->iov[i].iov_len == evp->iov[i].iov_len);
+		    ASSERT(new_evp->iov[i].iov_base == evp->iov[i].iov_base);
+		    ASSERT(new_evp->binv[i] == evp->binv[i]);
+		}
 #endif
 
-	if (r >= 0) {
-	    size -= r;
-#ifdef USE_VM_PROBES
-            if (DTRACE_ENABLED(driver_output)) {
-                DTRACE_FORMAT_COMMON_PID_AND_PORT(caller_id, p)
-                DTRACE4(driver_output, process_str, port_str, p->name, size);
-            }
+		erts_free(ERTS_ALC_T_TMP, evp);
+	    }
+	    else { /* from stack allocated structure; offsets may differ */
+
+		sys_memcpy((void *) new_evp, (void *) evp, sizeof(ErlIOVec));
+		new_evp->iov = (SysIOVec *) (((char *) new_evp)
+					     + iov_offset);
+		sys_memcpy((void *) new_evp->iov,
+			   (void *) evp->iov,
+			   evp->vsize * sizeof(SysIOVec));
+		new_evp->binv = (ErlDrvBinary **) (((char *) new_evp)
+						   + binv_offset);
+		sys_memcpy((void *) new_evp->binv,
+			   (void *) evp->binv,
+			   evp->vsize * sizeof(ErlDrvBinary *));
+
+#ifdef DEBUG
+		ASSERT(new_evp->vsize == evp->vsize);
+		ASSERT(new_evp->size == evp->size);
+		for (i = 0; i < evp->vsize; i++) {
+		    ASSERT(new_evp->iov[i].iov_len == evp->iov[i].iov_len);
+		    ASSERT(new_evp->iov[i].iov_base == evp->iov[i].iov_base);
+		    ASSERT(new_evp->binv[i] == evp->binv[i]);
+		}
 #endif
-	    fpe_was_unmasked = erts_block_fpe();
-	    (*drv->output)((ErlDrvData)p->drv_data, buf, size);
-	    erts_unblock_fpe(fpe_was_unmasked);
-	    erts_free(ERTS_ALC_T_TMP, buf);
+
+	    }
+
+	    evp = new_evp;
 	}
-	else if (r == -2) {
-	    erts_free(ERTS_ALC_T_TMP, buf);
-	    goto bad_value;
+
+	sigdp = erts_port_task_alloc_p2p_sig_data();
+	sigdp->flags = ERTS_P2P_SIG_TYPE_OUTPUTV;
+	sigdp->u.outputv.from = from;
+	sigdp->u.outputv.evp = evp;
+	sigdp->u.outputv.cbinp = cbin;
+	port_sig_callback = port_sig_outputv;
+    }
+    else {
+	ErlDrvSizeT r;
+
+	/*
+	 * Apperently there exist code that write 1 byte to
+	 * much in buffer. Where it resides I don't know, but
+	 * we can live with one byte extra allocated...
+	 */
+
+	if (!try_call) {
+	    if (erts_iolist_size(list, &size))
+		goto bad_value;
+
+	    buf = erts_alloc(ERTS_ALC_T_DRV_CMD_DATA, size + 1);
+
+	    r = erts_iolist_to_buf(list, buf, size);
+	    ASSERT(ERTS_IOLIST_TO_BUF_SUCCEEDED(r));
 	}
 	else {
-	    ASSERT(r == -1); /* Overflow */
-	    erts_free(ERTS_ALC_T_TMP, buf);
-	    if (erts_iolist_size(list, &size)) {
-		goto bad_value;
+	    char *new_buf;
+	    ErtsTryImmDrvCallResult try_call_res;
+	    ErtsTryImmDrvCallState try_call_state
+		= ERTS_INIT_TRY_IMM_DRV_CALL_STATE(
+		    c_p,
+		    prt,
+		    ERTS_PORT_SFLGS_INVALID_LOOKUP,
+		    invalid_flags,
+		    !refp,
+		    am_command);
+
+	    /* Try with an 8KB buffer first (will often be enough I guess). */
+	    size = 8*1024;
+
+	    buf = erts_alloc(ERTS_ALC_T_TMP, size + 1);
+	    r = erts_iolist_to_buf(list, buf, size);
+
+	    if (ERTS_IOLIST_TO_BUF_SUCCEEDED(r)) {
+		ASSERT(r <= size);
+		size -= r;
+	    }
+	    else {
+		erts_free(ERTS_ALC_T_TMP, buf);
+		if (r == ERTS_IOLIST_TO_BUF_TYPE_ERROR)
+		    goto bad_value;
+		ASSERT(r == ERTS_IOLIST_TO_BUF_OVERFLOW);
+		if (erts_iolist_size(list, &size))
+		    goto bad_value;
+		buf = erts_alloc(ERTS_ALC_T_TMP, size + 1); 
+		r = erts_iolist_to_buf(list, buf, size);
+		ASSERT(ERTS_IOLIST_TO_BUF_SUCCEEDED(r));
 	    }
 
-	    /*
-	     * I know drivers that pad space with '\0' this is clearly
-	     * incorrect but I don't feel like fixing them now, insted
-	     * add ONE extra byte.
-	     */
-	    buf = erts_alloc(ERTS_ALC_T_TMP, size+1); 
-	    r = io_list_to_buf(list, buf, size);
-#ifdef USE_VM_PROBES
-            if (DTRACE_ENABLED(driver_output)) {
-                DTRACE_FORMAT_COMMON_PID_AND_PORT(caller_id, p)
-                DTRACE4(driver_output, process_str, port_str, p->name, size);
-            }
-#endif
-	    fpe_was_unmasked = erts_block_fpe();
-	    (*drv->output)((ErlDrvData)p->drv_data, buf, size);
-	    erts_unblock_fpe(fpe_was_unmasked);
+	    try_call_state.pre_chk_sched_flags = 0; /* already checked */
+	    if (force_immediate_call)
+		try_call_res = force_imm_drv_call(&try_call_state);
+	    else
+		try_call_res = try_imm_drv_call(&try_call_state);
+	    switch (try_call_res) {
+	    case ERTS_TRY_IMM_DRV_CALL_OK:
+		call_driver_output(flags & ERTS_PORT_SIG_FLG_BANG_OP,
+				   c_p ? c_p->common.id : ERTS_INVALID_PID,
+				   from,
+				   prt,
+				   drv,
+				   buf,
+				   size);
+		if (force_immediate_call)
+		    finalize_force_imm_drv_call(&try_call_state);
+		else
+		    finalize_imm_drv_call(&try_call_state);
+		/* Fall through... */
+	    case ERTS_TRY_IMM_DRV_CALL_INVALID_PORT:
+		erts_free(ERTS_ALC_T_TMP, buf);
+		if (try_call_res == ERTS_TRY_IMM_DRV_CALL_OK)
+		    return ERTS_PORT_OP_DONE;
+		else
+		    return ERTS_PORT_OP_DROPPED;
+	    case ERTS_TRY_IMM_DRV_CALL_INVALID_SCHED_FLAGS:
+		sched_flags = try_call_state.sched_flags;
+	    case ERTS_TRY_IMM_DRV_CALL_BUSY_LOCK:
+		/* Schedule outputv() call instead... */
+		break;
+	    }
+
+	    new_buf = erts_alloc(ERTS_ALC_T_DRV_CMD_DATA, size + 1);
+	    sys_memcpy(new_buf, buf, size);
 	    erts_free(ERTS_ALC_T_TMP, buf);
+	    buf = new_buf;
 	}
+
+	sigdp = erts_port_task_alloc_p2p_sig_data();
+	sigdp->flags = ERTS_P2P_SIG_TYPE_OUTPUT;
+	sigdp->u.output.from = from;
+	sigdp->u.output.bufp = buf;
+	sigdp->u.output.size = size;
+	port_sig_callback = port_sig_output;
+    }
+
+    task_flags = ERTS_PT_FLG_WAIT_BUSY;
+    sigdp->flags |= flags;
+    if (flags & (ERTS_P2P_SIG_DATA_FLG_FORCE|ERTS_P2P_SIG_DATA_FLG_NOSUSPEND)) {
+	task_flags = 0;
+	if (flags & ERTS_P2P_SIG_DATA_FLG_FORCE)
+	    sigdp->flags &= ~ERTS_P2P_SIG_DATA_FLG_NOSUSPEND;
+	else if (flags & ERTS_P2P_SIG_DATA_FLG_NOSUSPEND)
+	    task_flags = ERTS_PT_FLG_NOSUSPEND;
+    }
+
+    res = erts_schedule_proc2port_signal(c_p,
+					 prt,
+					 c_p ? c_p->common.id : ERTS_INVALID_PID,
+					 refp,
+					 sigdp,
+					 task_flags,
+					 port_sig_callback);
+
+    if (res != ERTS_PORT_OP_SCHEDULED) {
+	if (drv->outputv)
+	    cleanup_scheduled_outputv(evp, cbin);
+	else
+	    cleanup_scheduled_output(buf);
+	return res;
     }
-    p->bytes_out += size;
-    erts_smp_atomic_add_nob(&erts_bytes_out, size);
 
-#ifdef ERTS_SMP
-    if (p->xports)
-	erts_smp_xports_unlock(p);
-    ASSERT(!p->xports);
+    if (!(sched_flags & ERTS_PTS_FLG_EXIT) && (sched_flags & busy_flgs))
+	return ERTS_PORT_OP_BUSY_SCHEDULED;
+
+    return res;
+
+bad_value:
+
+    flags |= ERTS_PORT_SIG_FLG_BAD_OUTPUT;
+    return bad_port_signal(c_p, flags, prt, from, refp, am_command);
+}
+
+static ERTS_INLINE ErtsPortOpResult
+call_deliver_port_exit(int bang_op,
+		       Eterm from,
+		       Port *prt,
+		       erts_aint32_t state,
+		       Eterm reason,
+		       int broken_link)
+{
+    /*
+     * if (bang_op)
+     *   we are part of a "Prt ! {From, close}" operation
+     * else
+     *   we are part of a call to port_close(Port)
+     * behave accordingly...
+     */
+
+    if (state & ERTS_PORT_SFLGS_INVALID_LOOKUP)
+	return ERTS_PORT_OP_DROPPED;
+
+    if (bang_op && from != ERTS_PORT_GET_CONNECTED(prt)) {
+	send_badsig(prt);
+	return ERTS_PORT_OP_DROPPED;
+    }
+
+    if (broken_link) {
+	ErtsLink *lnk = erts_remove_link(&ERTS_P_LINKS(prt), from);
+	if (lnk)
+	    erts_destroy_link(lnk);
+	else
+	    return ERTS_PORT_OP_DROPPED;
+    }
+
+    if (!erts_deliver_port_exit(prt, from, reason, bang_op))
+	return ERTS_PORT_OP_DROPPED;
+
+#ifdef USE_VM_PROBES
+    if(DTRACE_ENABLED(port_command) && bang_op) {
+	DTRACE_FORMAT_COMMON_PID_AND_PORT(from, prt);
+	DTRACE4(port_command, process_str, port_str, prt->name, "close");
+    }
 #endif
-    p->caller = NIL;
-    return 0;
 
- bad_value: 
-    p->caller = NIL;
-    {
-	erts_dsprintf_buf_t *dsbufp = erts_create_logger_dsbuf();
-	erts_dsprintf(dsbufp, "Bad value on output port '%s'\n", p->name);
-	erts_send_error_to_logger_nogl(dsbufp);
-	return 1;
+    return ERTS_PORT_OP_DONE;
+}
+
+static int
+port_sig_exit(Port *prt,
+	      erts_aint32_t state,
+	      int op,
+	      ErtsProc2PortSigData *sigdp)
+{
+    Eterm msg = am_badarg;
+    if (op == ERTS_PROC2PORT_SIG_EXEC) {
+	ErtsPortOpResult res;
+	int bang_op = sigdp->flags & ERTS_P2P_SIG_DATA_FLG_BANG_OP;
+	int broken_link = sigdp->flags & ERTS_P2P_SIG_DATA_FLG_BROKEN_LINK;
+	res = call_deliver_port_exit(bang_op,
+				     sigdp->u.exit.from,
+				     prt,
+				     state,
+				     sigdp->u.exit.reason,
+				     broken_link);
+
+	if (res == ERTS_PORT_OP_DONE)
+	    msg = am_true;
+    }
+    if (sigdp->u.exit.bp)
+	free_message_buffer(sigdp->u.exit.bp);
+    if (sigdp->flags & ERTS_P2P_SIG_DATA_FLG_REPLY)
+	port_sched_op_reply(sigdp->caller, sigdp->ref, msg);
+
+    return ERTS_PORT_REDS_EXIT;
+}
+
+ErtsPortOpResult
+erts_port_exit(Process *c_p,
+	       int flags,
+	       Port *prt,
+	       Eterm from,
+	       Eterm reason,
+	       Eterm *refp)
+{
+    ErtsPortOpResult res;
+    ErtsProc2PortSigData *sigdp;
+    ErlHeapFragment *bp = NULL;
+
+    ASSERT((flags & ~(ERTS_PORT_SIG_FLG_BANG_OP
+		      | ERTS_PORT_SIG_FLG_BROKEN_LINK
+		      | ERTS_PORT_SIG_FLG_FORCE_SCHED)) == 0);
+
+    if (!(flags & ERTS_PORT_SIG_FLG_FORCE_SCHED)) {
+	ErtsTryImmDrvCallState try_call_state
+	    = ERTS_INIT_TRY_IMM_DRV_CALL_STATE(c_p,
+					       prt,
+					       ERTS_PORT_SFLGS_INVALID_LOOKUP,
+					       0,
+					       !refp,
+					       am_exit);
+
+
+	switch (try_imm_drv_call(&try_call_state)) {
+	case ERTS_TRY_IMM_DRV_CALL_OK: {
+	    res = call_deliver_port_exit(flags & ERTS_PORT_SIG_FLG_BANG_OP,
+					 from,
+					 prt,
+					 try_call_state.state,
+					 reason,
+					 flags & ERTS_PORT_SIG_FLG_BROKEN_LINK);
+	    finalize_imm_drv_call(&try_call_state);
+	    return res;
+	}
+	case ERTS_TRY_IMM_DRV_CALL_INVALID_PORT:
+	    return ERTS_PORT_OP_DROPPED;
+	default:
+	    /* Schedule call instead... */
+	    break;
+	}
     }
+
+    sigdp = erts_port_task_alloc_p2p_sig_data();
+    sigdp->flags = ERTS_P2P_SIG_TYPE_EXIT | flags;
+    sigdp->u.exit.from = from;
+
+    if (is_immed(reason)) {
+	sigdp->u.exit.reason = reason;
+	sigdp->u.exit.bp = NULL;
+    }
+    else {
+	Eterm *hp;
+	Uint hsz = size_object(reason);
+	bp = new_message_buffer(hsz);
+	sigdp->u.exit.bp = bp;
+	hp = bp->mem;
+	sigdp->u.exit.reason = copy_struct(reason,
+					   hsz,
+					   &hp,
+					   &bp->off_heap);
+    }
+
+    res = erts_schedule_proc2port_signal(c_p,
+					 prt,
+					 c_p ? c_p->common.id : from,
+					 refp,
+					 sigdp,
+					 0,
+					 port_sig_exit);
+
+    if (res == ERTS_PORT_OP_DROPPED) {
+	if (bp)
+	    free_message_buffer(bp);
+    }
+
+    return res;
 }
 
-/* initialize the port array */
-void init_io(void)
+static ErtsPortOpResult
+set_port_connected(int bang_op,
+		   Eterm from,
+		   Port *prt,
+		   erts_aint32_t state,
+		   Eterm connect)
 {
-    int i;
-    ErlDrvEntry** dp;
-    char maxports[21]; /* enough for any 64-bit integer */
-    size_t maxportssize = sizeof(maxports);
-    Uint ports_bits = ERTS_PORTS_BITS;
-    Sint port_extra_shift;
+    /*
+     * if (bang_op)
+     *   we are part of a "Prt ! {From, {connect, Connect}}" operation
+     * else
+     *   we are part of a call to port_connect(Port, Connect)
+     * behave accordingly...
+     */
 
-#ifdef ERTS_SMP
-    init_xports_list_alloc();
+    if (state & ERTS_PORT_SFLGS_INVALID_LOOKUP)
+	return ERTS_PORT_OP_DROPPED;
+
+    if (bang_op) { /* Bang operation */
+	if (is_not_internal_pid(connect) || ERTS_PORT_GET_CONNECTED(prt) != from) {
+	    send_badsig(prt);
+	    return ERTS_PORT_OP_DROPPED;
+	}
+
+	ERTS_PORT_SET_CONNECTED(prt, connect);
+	deliver_result(prt->common.id, from, am_connected);
+
+#ifdef USE_VM_PROBES
+	if(DTRACE_ENABLED(port_command)) {
+	    DTRACE_FORMAT_COMMON_PID_AND_PORT(from, prt);
+	    DTRACE4(port_command, process_str, port_str, prt->name, "connect");
+	}
 #endif
+    }
+    else { /* Port BIF operation */
+	Process *rp = erts_proc_lookup_raw(connect);
+	if (!rp)
+	    return ERTS_PORT_OP_DROPPED;
+	erts_smp_proc_lock(rp, ERTS_PROC_LOCK_LINK);
+	if (ERTS_PROC_IS_EXITING(rp)) {
+	    erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_LINK);
+	    return ERTS_PORT_OP_DROPPED;
+	}
 
-    pdl_init();
+	erts_add_link(&ERTS_P_LINKS(rp), LINK_PID, prt->common.id);
+	erts_add_link(&ERTS_P_LINKS(prt), LINK_PID, connect);
+
+	ERTS_PORT_SET_CONNECTED(prt, connect);
+
+	erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_LINK);
+
+#ifdef USE_VM_PROBES
+	if (DTRACE_ENABLED(port_connect)) {
+	    DTRACE_CHARBUF(process_str, DTRACE_TERM_BUF_SIZE);
+	    DTRACE_CHARBUF(port_str, DTRACE_TERM_BUF_SIZE);
+	    DTRACE_CHARBUF(newprocess_str, DTRACE_TERM_BUF_SIZE);
+
+	    dtrace_pid_str(connect, process_str);
+	    erts_snprintf(port_str, sizeof(port_str), "%T", prt->common.id);
+	    dtrace_proc_str(rp, newprocess_str);
+	    DTRACE4(port_connect, process_str, port_str, prt->name, newprocess_str);
+	}
+#endif
+    }
+
+    return ERTS_PORT_OP_DONE;
+}
 
-    if (erts_sys_getenv_raw("ERL_MAX_PORTS", maxports, &maxportssize) == 0) 
-	erts_max_ports = atoi(maxports);
+static int
+port_sig_connect(Port *prt, erts_aint32_t state, int op, ErtsProc2PortSigData *sigdp)
+{
+    Eterm msg = am_badarg;
+    if (op == ERTS_PROC2PORT_SIG_EXEC) {
+	ErtsPortOpResult res;
+	res = set_port_connected(sigdp->flags & ERTS_P2P_SIG_DATA_FLG_BANG_OP,
+				 sigdp->u.connect.from,
+				 prt,
+				 state,
+				 sigdp->u.connect.connected);
+	if (res == ERTS_PORT_OP_DONE)
+	    msg = am_true;
+    }
+    if (sigdp->flags & ERTS_P2P_SIG_DATA_FLG_REPLY)
+	port_sched_op_reply(sigdp->caller, sigdp->ref, msg);
+    return ERTS_PORT_REDS_CONNECT;
+}
+
+ErtsPortOpResult
+erts_port_connect(Process *c_p,
+		  int flags,
+		  Port *prt,
+		  Eterm from,
+		  Eterm connect,
+		  Eterm *refp)
+{
+    ErtsProc2PortSigData *sigdp;
+    Eterm connect_id;
+    ErtsTryImmDrvCallState try_call_state
+	= ERTS_INIT_TRY_IMM_DRV_CALL_STATE(c_p,
+					   prt,
+					   ERTS_PORT_SFLGS_INVALID_LOOKUP,
+					   0,
+					   !refp,
+					   am_connect);
+
+    ASSERT((flags & ~ERTS_PORT_SIG_FLG_BANG_OP) == 0);
+
+    if (is_not_internal_pid(connect))
+	connect_id = NIL; /* Fail in op (for signal order) */
     else
-	erts_max_ports = sys_max_files();
+	connect_id = connect;
+
+    switch (try_imm_drv_call(&try_call_state)) {
+    case ERTS_TRY_IMM_DRV_CALL_OK: {
+	ErtsPortOpResult res;
+	res = set_port_connected(flags & ERTS_PORT_SIG_FLG_BANG_OP,
+				 from,
+				 prt,
+				 try_call_state.state,
+				 connect_id);
+	finalize_imm_drv_call(&try_call_state);
+	return res;
+    }
+    case ERTS_TRY_IMM_DRV_CALL_INVALID_PORT:
+	return ERTS_PORT_OP_DROPPED;
+    default:
+	/* Schedule call instead... */
+	break;
+    }
+
+    sigdp = erts_port_task_alloc_p2p_sig_data();
+    sigdp->flags = ERTS_P2P_SIG_TYPE_CONNECT | flags;
+
+    sigdp->u.connect.from = from;
+    sigdp->u.connect.connected = connect_id;
+    
+    return erts_schedule_proc2port_signal(c_p,
+					  prt,
+					  c_p->common.id,
+					  refp,
+					  sigdp,
+					  0,
+					  port_sig_connect);
+}
 
-    if (erts_max_ports > ERTS_MAX_PORTS)
-	erts_max_ports = ERTS_MAX_PORTS;
-    if (erts_max_ports < 1024)
-	erts_max_ports = 1024;
+static void
+port_unlink(Port *prt, Eterm from)
+{
+    ErtsLink *lnk = erts_remove_link(&ERTS_P_LINKS(prt), from);
+    if (lnk)
+	erts_destroy_link(lnk);
+}
 
-    if (erts_use_r9_pids_ports) {
-	ports_bits = ERTS_R9_PORTS_BITS;
-	if (erts_max_ports > ERTS_MAX_R9_PORTS)
-	    erts_max_ports = ERTS_MAX_R9_PORTS;
+static int
+port_sig_unlink(Port *prt, erts_aint32_t state, int op, ErtsProc2PortSigData *sigdp)
+{
+    if (op == ERTS_PROC2PORT_SIG_EXEC)
+	port_unlink(prt, sigdp->u.unlink.from);
+    if (sigdp->flags & ERTS_P2P_SIG_DATA_FLG_REPLY)
+	port_sched_op_reply(sigdp->caller, sigdp->ref, am_true);
+    return ERTS_PORT_REDS_UNLINK;
+}
+
+ErtsPortOpResult
+erts_port_unlink(Process *c_p, Port *prt, Eterm from, Eterm *refp)
+{
+    ErtsProc2PortSigData *sigdp;
+    ErtsTryImmDrvCallState try_call_state
+	= ERTS_INIT_TRY_IMM_DRV_CALL_STATE(c_p,
+					   prt,
+					   ERTS_PORT_SFLGS_DEAD,
+					   0,
+					   !refp,
+					   am_unlink);
+
+    switch (try_imm_drv_call(&try_call_state)) {
+    case ERTS_TRY_IMM_DRV_CALL_OK:
+	port_unlink(prt, from);
+	finalize_imm_drv_call(&try_call_state);
+	return ERTS_PORT_OP_DONE;
+    case ERTS_TRY_IMM_DRV_CALL_INVALID_PORT:
+	return ERTS_PORT_OP_DROPPED;
+    default:
+	/* Schedule call instead... */
+	break;
     }
 
-    port_extra_shift = erts_fit_in_bits_int32(erts_max_ports - 1);
-    port_num_mask = (1 << ports_bits) - 1;
+    sigdp = erts_port_task_alloc_p2p_sig_data();
+    sigdp->flags = ERTS_P2P_SIG_TYPE_UNLINK;
+    sigdp->u.unlink.from = from;
+    
+    return erts_schedule_proc2port_signal(c_p,
+					  prt,
+					  c_p ? c_p->common.id : from,
+					  refp,
+					  sigdp,
+					  0,
+					  port_sig_unlink);
+}
 
-    erts_port_tab_index_mask = ~(~((Uint) 0) << port_extra_shift);
-    erts_max_ports = 1 << port_extra_shift;
+static void
+port_link_failure(Eterm port_id, Eterm linker)
+{
+    Process *rp;
+    ErtsProcLocks rp_locks = ERTS_PROC_LOCK_LINK|ERTS_PROC_LOCKS_XSIG_SEND;
+    ASSERT(is_internal_pid(linker));
+    rp = erts_pid2proc(NULL, 0, linker, rp_locks);
+    if (rp) {
+	ErtsLink *rlnk = erts_remove_link(&ERTS_P_LINKS(rp), port_id);
+	if (rlnk) {
+	    int xres = erts_send_exit_signal(NULL,
+					     port_id,
+					     rp,
+					     &rp_locks, 
+					     am_noproc,
+					     NIL,
+					     NULL,
+					     0);
+	    if (xres >= 0 && IS_TRACED_FL(rp, F_TRACE_PROCS)) {
+		/* We didn't exit the process and it is traced */
+		if (IS_TRACED_FL(rp, F_TRACE_PROCS))
+		    trace_proc(NULL, rp, am_getting_unlinked, port_id);
+	    }
+	}
+    }
+}
 
-    erts_smp_mtx_init(&erts_driver_list_lock,"driver_list");
-    driver_list = NULL;
-    erts_smp_tsd_key_create(&driver_list_lock_status_key);
-    erts_smp_tsd_key_create(&driver_list_last_error_key);
+static void
+port_link(Port *prt, erts_aint32_t state, Eterm to)
+{
+    if (!(state & ERTS_PORT_SFLGS_INVALID_LOOKUP))
+	erts_add_link(&ERTS_P_LINKS(prt), LINK_PID, to);
+    else
+	port_link_failure(prt->common.id, to);
+}
 
-    if (erts_max_ports * sizeof(Port) <= erts_max_ports) {
-	/* More memory needed than the whole address space. */
-	erts_alloc_enomem(ERTS_ALC_T_PORT_TABLE, ~((Uint) 0));
+static int
+port_sig_link(Port *prt, erts_aint32_t state, int op, ErtsProc2PortSigData *sigdp)
+{
+    if (op == ERTS_PROC2PORT_SIG_EXEC)
+	port_link(prt, state, sigdp->u.link.to);
+    else
+	port_link_failure(sigdp->u.link.port, sigdp->u.link.to);
+    if (sigdp->flags & ERTS_P2P_SIG_DATA_FLG_REPLY)
+	port_sched_op_reply(sigdp->caller, sigdp->ref, am_true);
+    return ERTS_PORT_REDS_LINK;
+}
+
+ErtsPortOpResult
+erts_port_link(Process *c_p, Port *prt, Eterm to, Eterm *refp)
+{
+    ErtsProc2PortSigData *sigdp;
+    ErtsTryImmDrvCallState try_call_state
+	= ERTS_INIT_TRY_IMM_DRV_CALL_STATE(c_p,
+					   prt,
+					   ERTS_PORT_SFLGS_INVALID_LOOKUP,
+					   0,
+					   !refp,
+					   am_link);
+
+    switch (try_imm_drv_call(&try_call_state)) {
+    case ERTS_TRY_IMM_DRV_CALL_OK:
+	port_link(prt, try_call_state.state, to);
+	finalize_imm_drv_call(&try_call_state);
+	return ERTS_PORT_OP_DONE;
+    case ERTS_TRY_IMM_DRV_CALL_INVALID_PORT:
+	return ERTS_PORT_OP_BADARG;
+    default:
+	/* Schedule call instead... */
+	break;
     }
 
-    erts_port = (Port *) erts_alloc(ERTS_ALC_T_PORT_TABLE,
-				    erts_max_ports * sizeof(Port));
+    sigdp = erts_port_task_alloc_p2p_sig_data();
+    sigdp->flags = ERTS_P2P_SIG_TYPE_LINK;
+    sigdp->u.link.port = prt->common.id;
+    sigdp->u.link.to = to;
+    
+    return erts_schedule_proc2port_signal(c_p,
+					  prt,
+					  c_p ? c_p->common.id : to,
+					  refp,
+					  sigdp,
+					  0,
+					  port_sig_link);
+}
 
-    erts_smp_atomic_init_nob(&erts_bytes_out, 0);
-    erts_smp_atomic_init_nob(&erts_bytes_in, 0);
+void erts_init_io(int port_tab_size,
+		  int port_tab_size_ignore_files)
+{
+    ErlDrvEntry** dp;
+    erts_smp_rwmtx_opt_t drv_list_rwmtx_opts = ERTS_SMP_RWMTX_OPT_DEFAULT_INITER;
+    drv_list_rwmtx_opts.type = ERTS_SMP_RWMTX_TYPE_EXTREMELY_FREQUENT_READ;
+    drv_list_rwmtx_opts.lived = ERTS_SMP_RWMTX_LONG_LIVED;
 
-    for (i = 0; i < erts_max_ports; i++) {
-	erts_port_task_init_sched(&erts_port[i].sched);
-	erts_smp_atomic_init_nob(&erts_port[i].refc, 0);
 #ifdef ERTS_SMP
-	erts_port[i].lock = NULL;
-	erts_port[i].xports = NULL;
-	erts_smp_spinlock_init_x(&erts_port[i].state_lck,
-#ifdef ERTS_ENABLE_LOCK_COUNT
-				 (erts_lcnt_rt_options & ERTS_LCNT_OPT_PORTLOCK) ? "port_state" : NULL,
-#else
-				 "port_state",
-#endif
-				 make_small(0));
+    init_xports_list_alloc();
 #endif
-	erts_port[i].tracer_proc = NIL;
-	erts_port[i].trace_flags = 0;
 
-	erts_port[i].drv_ptr = NULL;
-	erts_port[i].status = ERTS_PORT_SFLG_FREE;
-	erts_port[i].name = NULL;
-	erts_port[i].nlinks = NULL;
-	erts_port[i].monitors = NULL;
-	erts_port[i].linebuf = NULL;
-	erts_port[i].port_data_lock = NULL;
+    pdl_init();
+
+    if (!port_tab_size_ignore_files) {
+	int max_files = sys_max_files();
+	if (port_tab_size < max_files)
+	    port_tab_size = max_files;
     }
 
-    erts_smp_atomic32_init_nob(&erts_ports_snapshot, (erts_aint32_t) 0);
-    last_port_num = 0;
-    erts_smp_spinlock_init(&get_free_port_lck, "get_free_port");
+    if (port_tab_size > ERTS_MAX_PORTS)
+	port_tab_size = ERTS_MAX_PORTS;
+    else if (port_tab_size < ERTS_MIN_PORTS)
+	port_tab_size = ERTS_MIN_PORTS;
+
+    erts_smp_rwmtx_init_opt(&erts_driver_list_lock,
+			    &drv_list_rwmtx_opts,
+			    "driver_list");
+    driver_list = NULL;
+    erts_smp_tsd_key_create(&driver_list_lock_status_key);
+    erts_smp_tsd_key_create(&driver_list_last_error_key);
+
+    erts_ptab_init_table(&erts_port,
+			 ERTS_ALC_T_PORT_TABLE,
+			 NULL,
+			 (ErtsPTabElementCommon *) &erts_invalid_port.common,
+			 port_tab_size,
+			 "port_table");
+
+    erts_smp_atomic_init_nob(&erts_bytes_out, 0);
+    erts_smp_atomic_init_nob(&erts_bytes_in, 0);
 
     sys_init_io();
 
     erts_smp_tsd_set(driver_list_lock_status_key, (void *) 1);
-    erts_smp_mtx_lock(&erts_driver_list_lock);
+    erts_smp_rwmtx_rwlock(&erts_driver_list_lock);
 
     init_driver(&fd_driver, &fd_driver_entry, NULL);
     init_driver(&vanilla_driver, &vanilla_driver_entry, NULL);
@@ -1390,27 +2651,63 @@ void init_io(void)
 	erts_add_driver_entry(*dp, NULL, 1);
 
     erts_smp_tsd_set(driver_list_lock_status_key, NULL);
-    erts_smp_mtx_unlock(&erts_driver_list_lock);
+    erts_smp_rwmtx_rwunlock(&erts_driver_list_lock);
 }
 
 #if defined(ERTS_ENABLE_LOCK_COUNT) && defined(ERTS_SMP)
-void erts_lcnt_enable_io_lock_count(int enable) {
-    int i;
 
-    for (i = 0; i < erts_max_ports; i++) {
-	Port* p = &erts_port[i];
-	if (enable) {
-	    erts_lcnt_init_lock_x(&p->state_lck.lcnt, "port_state", ERTS_LCNT_LT_SPINLOCK, make_small(i));
-	    if (p->lock) {
-		erts_lcnt_init_lock_x(&p->lock->lcnt, "port_lock", ERTS_LCNT_LT_MUTEX, make_small(i));
-	    }
-	} else {
-	    erts_lcnt_destroy_lock(&p->state_lck.lcnt);
-	    if (p->lock) {
-		erts_lcnt_destroy_lock(&p->lock->lcnt);
-	    }
-	}
+static ERTS_INLINE void lcnt_enable_drv_lock_count(erts_driver_t *dp, int enable)
+{
+    if (dp->lock) {
+	if (enable)
+	    erts_lcnt_init_lock_x(&dp->lock->lcnt,
+				  "driver_lock",
+				  ERTS_LCNT_LT_MUTEX,
+				  am_atom_put(dp->name,
+					      sys_strlen(dp->name)));
+	else
+	    erts_lcnt_destroy_lock(&dp->lock->lcnt);
+
+    }
+}
+
+static ERTS_INLINE void lcnt_enable_port_lock_count(Port *prt, int enable)
+{
+    erts_aint32_t state = erts_atomic32_read_nob(&prt->state);
+    if (!enable) {
+	erts_lcnt_destroy_lock(&prt->sched.mtx.lcnt);
+	if (state & ERTS_PORT_SFLG_PORT_SPECIFIC_LOCK)
+	    erts_lcnt_destroy_lock(&prt->lock->lcnt);
     }
+    else {
+	erts_lcnt_init_lock_x(&prt->sched.mtx.lcnt,
+			      "port_sched_lock",
+			      ERTS_LCNT_LT_MUTEX,
+			      prt->common.id);
+	if (state & ERTS_PORT_SFLG_PORT_SPECIFIC_LOCK)
+	    erts_lcnt_init_lock_x(&prt->lock->lcnt,
+				  "port_lock",
+				  ERTS_LCNT_LT_MUTEX,
+				  prt->common.id);
+    }
+}
+
+void erts_lcnt_enable_io_lock_count(int enable)
+{
+    erts_driver_t *dp;
+    int i, max = erts_ptab_max(&erts_port);
+
+    for (i = 0; i < max; i++) {
+	Port *prt = erts_pix2port(i);
+	if (prt)
+	    lcnt_enable_port_lock_count(prt, enable);
+    }
+
+    lcnt_enable_drv_lock_count(&vanilla_driver, enable);
+    lcnt_enable_drv_lock_count(&spawn_driver, enable);
+    lcnt_enable_drv_lock_count(&fd_driver, enable);
+    for (dp = driver_list; dp; dp = dp->next)
+	lcnt_enable_drv_lock_count(dp, enable);
 }
 #endif
 
@@ -1594,9 +2891,7 @@ deliver_result(Eterm sender, Eterm pid, Eterm res)
 
     ERTS_SMP_CHK_NO_PROC_LOCKS;
 
-    ASSERT(is_internal_port(sender)
-	   && is_internal_pid(pid)
-	   && internal_pid_index(pid) < erts_max_processes);
+    ASSERT(is_internal_port(sender) && is_internal_pid(pid));
 
     rp = (scheduler
 	  ? erts_proc_lookup(pid)
@@ -1608,16 +2903,19 @@ deliver_result(Eterm sender, Eterm pid, Eterm res)
 	ErlOffHeap *ohp;
 	Eterm* hp;
 	Uint sz_res;
-	    sz_res = size_object(res);
-	    hp = erts_alloc_message_heap(sz_res + 3, &bp, &ohp, rp, &rp_locks);
-	    res = copy_struct(res, sz_res, &hp, ohp);
-	    tuple = TUPLE2(hp, sender, res);
+
+	sz_res = size_object(res);
+	hp = erts_alloc_message_heap(sz_res + 3, &bp, &ohp, rp, &rp_locks);
+	res = copy_struct(res, sz_res, &hp, ohp);
+	tuple = TUPLE2(hp, sender, res);
 	erts_queue_message(rp, &rp_locks, bp, tuple, NIL
 #ifdef USE_VM_PROBES
 			   , NIL
 #endif
 			   );
-	erts_smp_proc_unlock(rp, rp_locks);
+
+	if (rp_locks)
+	    erts_smp_proc_unlock(rp, rp_locks);
 	if (!scheduler)
 	    erts_smp_proc_dec_refc(rp);
 
@@ -1633,7 +2931,7 @@ deliver_result(Eterm sender, Eterm pid, Eterm res)
  * len  -- length of data
  */
 
-static void deliver_read_message(Port* prt, Eterm to,
+static void deliver_read_message(Port* prt, erts_aint32_t state, Eterm to,
 				 char *hbuf, ErlDrvSizeT hlen,
 				 char *buf, ErlDrvSizeT len, int eol)
 {
@@ -1651,10 +2949,11 @@ static void deliver_read_message(Port* prt, Eterm to,
     ERTS_SMP_CHK_NO_PROC_LOCKS;
 
     need = 3 + 3 + 2*hlen;
-    if (prt->status & ERTS_PORT_SFLG_LINEBUF_IO) {
+
+    if (state & ERTS_PORT_SFLG_LINEBUF_IO) {
 	need += 3;
     }
-    if (prt->status & ERTS_PORT_SFLG_BINARY_IO && buf != NULL) {
+    if ((state & ERTS_PORT_SFLG_BINARY_IO) && buf != NULL) {
 	need += PROC_BIN_SIZE;
     } else {
 	need += 2*len;
@@ -1670,7 +2969,7 @@ static void deliver_read_message(Port* prt, Eterm to,
     hp = erts_alloc_message_heap(need, &bp, &ohp, rp, &rp_locks);
 
     listp = NIL;
-    if ((prt->status & ERTS_PORT_SFLG_BINARY_IO) == 0) {
+    if ((state & ERTS_PORT_SFLG_BINARY_IO) == 0) {
 	listp = buf_to_intlist(&hp, buf, len, listp);
     } else if (buf != NULL) {
 	ProcBin* pb;
@@ -1701,14 +3000,14 @@ static void deliver_read_message(Port* prt, Eterm to,
 	listp = buf_to_intlist(&hp, hbuf, hlen, listp);
     }
 
-    if (prt->status & ERTS_PORT_SFLG_LINEBUF_IO){
+    if (state & ERTS_PORT_SFLG_LINEBUF_IO){
 	listp = TUPLE2(hp, (eol) ? am_eol : am_noeol, listp); 
 	hp += 3;
     }
     tuple = TUPLE2(hp, am_data, listp);
     hp += 3;
 
-    tuple = TUPLE2(hp, prt->id, tuple);
+    tuple = TUPLE2(hp, prt->common.id, tuple);
     hp += 3;
 
     erts_queue_message(rp, &rp_locks, bp, tuple, am_undefined
@@ -1726,7 +3025,8 @@ static void deliver_read_message(Port* prt, Eterm to,
  * Deliver all lines in a line buffer, repeats calls to
  * deliver_read_message, and takes the same parameters.
  */
-static void deliver_linebuf_message(Port* prt, Eterm to, 
+static void deliver_linebuf_message(Port* prt, erts_aint_t state,
+				    Eterm to, 
 				    char* hbuf, ErlDrvSizeT hlen,
 				    char *buf, ErlDrvSizeT len)
 {
@@ -1735,7 +3035,7 @@ static void deliver_linebuf_message(Port* prt, Eterm to,
     if(init_linebuf_context(&lc,&(prt->linebuf), buf, len) < 0)
 	return;
     while((ret = read_linebuf(&lc)) > LINEBUF_EMPTY)
-	deliver_read_message(prt, to, hbuf, hlen, LINEBUF_DATA(lc), 
+	deliver_read_message(prt, state, to, hbuf, hlen, LINEBUF_DATA(lc), 
 			     LINEBUF_DATALEN(lc), (ret == LINEBUF_EOL));
 }
 
@@ -1746,20 +3046,25 @@ static void deliver_linebuf_message(Port* prt, Eterm to,
  * Parameters:
  * prt -  Pointer to a Port structure for this port.
  */
-static void flush_linebuf_messages(Port *prt)
+static void flush_linebuf_messages(Port *prt, erts_aint32_t state)
 {
     LineBufContext lc;
     int ret;
 
     ERTS_SMP_LC_ASSERT(!prt || erts_lc_is_port_locked(prt));
-    if(prt == NULL || !(prt->status & ERTS_PORT_SFLG_LINEBUF_IO))
+
+    if (!prt)
+	return;
+
+    if (!(state & ERTS_PORT_SFLG_LINEBUF_IO))
 	return;
 
     if(init_linebuf_context(&lc,&(prt->linebuf), NULL, 0) < 0)
 	return;
     while((ret = flush_linebuf(&lc)) > LINEBUF_EMPTY)
 	deliver_read_message(prt,
-			     prt->connected,
+			     state,
+			     ERTS_PORT_GET_CONNECTED(prt),
 			     NULL,
 			     0,
 			     LINEBUF_DATA(lc), 
@@ -1787,6 +3092,7 @@ deliver_vec_message(Port* prt,			/* Port */
     ErlOffHeap *ohp;
     ErtsProcLocks rp_locks = 0;
     int scheduler = erts_get_scheduler_id() != 0;
+    erts_aint32_t state;
 
     ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
     ERTS_SMP_CHK_NO_PROC_LOCKS;
@@ -1802,12 +3108,13 @@ deliver_vec_message(Port* prt,			/* Port */
     if (!rp)
 	return;
 
+    state = erts_atomic32_read_nob(&prt->state);
     /*
      * Calculate the exact number of heap words needed.
      */
 
     need = 3 + 3;		/* Heap space for two tuples */
-    if (prt->status & ERTS_PORT_SFLG_BINARY_IO) {
+    if (state & ERTS_PORT_SFLG_BINARY_IO) {
 	need += (2+PROC_BIN_SIZE)*vsize - 2 + hlen*2;
     } else {
 	need += (hlen+csize)*2;
@@ -1818,7 +3125,7 @@ deliver_vec_message(Port* prt,			/* Port */
     listp = NIL;
     iov += vsize;
 
-    if ((prt->status & ERTS_PORT_SFLG_BINARY_IO) == 0) {
+    if ((state & ERTS_PORT_SFLG_BINARY_IO) == 0) {
 	Eterm* thp = hp;
 	while (vsize--) {
 	    iov--;
@@ -1871,7 +3178,7 @@ deliver_vec_message(Port* prt,			/* Port */
 
     tuple = TUPLE2(hp, am_data, listp);
     hp += 3;
-    tuple = TUPLE2(hp, prt->id, tuple);
+    tuple = TUPLE2(hp, prt->common.id, tuple);
     hp += 3;
 
     erts_queue_message(rp, &rp_locks, bp, tuple, am_undefined
@@ -1904,7 +3211,7 @@ static void deliver_bin_message(Port*  prt,         /* port */
 /* 
  * Note. 
  *
- * The test for (p->status & ERTS_PORT_SFLGS_DEAD) == 0 is important since the
+ * The test for ERTS_PORT_SFLGS_DEAD is important since the
  * driver's  flush function might call driver_async, which when using no
  * threads and being short circuited will notice that the io queue is empty
  * (after calling the driver's async_ready) and recursively call 
@@ -1920,7 +3227,7 @@ static void flush_port(Port *p)
     if (p->drv_ptr->flush != NULL) {
 #ifdef USE_VM_PROBES
         if (DTRACE_ENABLED(driver_flush)) {
-            DTRACE_FORMAT_COMMON_PID_AND_PORT(p->connected, p)
+            DTRACE_FORMAT_COMMON_PID_AND_PORT(ERTS_PORT_GET_CONNECTED(p), p)
             DTRACE3(driver_flush, process_str, port_str, p->name);
         }
 #endif
@@ -1935,11 +3242,12 @@ static void flush_port(Port *p)
 	}
 #ifdef ERTS_SMP
 	if (p->xports)
-	    erts_smp_xports_unlock(p);
+	    erts_port_handle_xports(p);
 	ASSERT(!p->xports);
 #endif
     }
-    if ((p->status & ERTS_PORT_SFLGS_DEAD) == 0 && is_port_ioq_empty(p)) {
+    if ((erts_atomic32_read_nob(&p->state) & ERTS_PORT_SFLGS_DEAD) == 0
+	&& is_port_ioq_empty(p)) {
 	terminate_port(p);
     }
 }
@@ -1951,29 +3259,29 @@ terminate_port(Port *prt)
     Eterm send_closed_port_id;
     Eterm connected_id = NIL /* Initialize to silence compiler */;
     erts_driver_t *drv;
-    int halt;
+    erts_aint32_t state;
 
     ERTS_SMP_CHK_NO_PROC_LOCKS;
     ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
 
-    ASSERT(!prt->nlinks);
-    ASSERT(!prt->monitors);
+    ASSERT(!ERTS_P_LINKS(prt));
+    ASSERT(!ERTS_P_MONITORS(prt));
 
-    /* prt->status may be altered by kill_port()below */
-    halt = (prt->status & ERTS_PORT_SFLG_HALT) != 0;
-    if (prt->status & ERTS_PORT_SFLG_SEND_CLOSED) {
-	erts_port_status_band_set(prt, ~ERTS_PORT_SFLG_SEND_CLOSED);
-	send_closed_port_id = prt->id;
-	connected_id = prt->connected;
+    /* state may be altered by kill_port() below */
+    state = erts_atomic32_read_band_nob(&prt->state,
+					~ERTS_PORT_SFLG_SEND_CLOSED);
+    if (state & ERTS_PORT_SFLG_SEND_CLOSED) {
+	send_closed_port_id = prt->common.id;
+	connected_id = ERTS_PORT_GET_CONNECTED(prt);
     }
     else {
 	send_closed_port_id = NIL;
     }
 
 #ifdef ERTS_SMP
-    erts_cancel_smp_ptimer(prt->ptimer);
+    erts_cancel_smp_ptimer(prt->common.u.alive.ptimer);
 #else
-    erts_cancel_timer(&prt->tm);
+    erts_cancel_timer(&prt->common.u.alive.tm);
 #endif
 
     drv = prt->drv_ptr;
@@ -1981,7 +3289,7 @@ terminate_port(Port *prt)
 	int fpe_was_unmasked = erts_block_fpe();
 #ifdef USE_VM_PROBES
         if (DTRACE_ENABLED(driver_stop)) {
-            DTRACE_FORMAT_COMMON_PID_AND_PORT(prt->connected, prt)
+            DTRACE_FORMAT_COMMON_PID_AND_PORT(connected_id, prt)
             DTRACE3(driver_stop, process_str, drv->name, port_str);
         }
 #endif
@@ -1989,14 +3297,14 @@ terminate_port(Port *prt)
 	erts_unblock_fpe(fpe_was_unmasked);
 #ifdef ERTS_SMP
 	if (prt->xports)
-	    erts_smp_xports_unlock(prt);
+	    erts_port_handle_xports(prt);
 	ASSERT(!prt->xports);
 #endif
     }
     if(drv->handle != NULL) {
-	erts_smp_mtx_lock(&erts_driver_list_lock);
+	erts_smp_rwmtx_rlock(&erts_driver_list_lock);
 	erts_ddll_decrement_port_count(drv->handle); 
-	erts_smp_mtx_unlock(&erts_driver_list_lock);
+	erts_smp_rwmtx_runlock(&erts_driver_list_lock);
     }
     stopq(prt);        /* clear queue memory */
     if(prt->linebuf != NULL){
@@ -2012,20 +3320,21 @@ terminate_port(Port *prt)
     if (prt->psd)
 	erts_free(ERTS_ALC_T_PRTSD, prt->psd);
 
+    ASSERT(prt->dist_entry == NULL);
+
     kill_port(prt);
 
     /*
      * We don't want to send the closed message until after the
      * port has been removed from the port table (in kill_port()).
      */
-    if (halt && (erts_smp_atomic32_dec_read_nob(&erts_halt_progress) == 0)) {
-	erts_smp_port_unlock(prt); /* We will exit and never return */
+    if ((state & ERTS_PORT_SFLG_HALT)
+	&& (erts_smp_atomic32_dec_read_nob(&erts_halt_progress) == 0)) {
+	erts_port_release(prt); /* We will exit and never return */
 	erl_exit_flush_async(erts_halt_code, "");
     }
     if (is_internal_port(send_closed_port_id))
 	deliver_result(send_closed_port_id, connected_id, am_closed);
-
-    ASSERT(prt->dist_entry == NULL);
 }
 
 void
@@ -2045,7 +3354,7 @@ static void sweep_one_monitor(ErtsMonitor *mon, void *vpsc)
     if (!rp) {
 	goto done;
     }
-    rmon = erts_remove_monitor(&(rp->monitors),mon->ref);
+    rmon = erts_remove_monitor(&ERTS_P_MONITORS(rp), mon->ref);
     erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_LINK);
     if (rmon == NULL) {
 	goto done;
@@ -2099,7 +3408,7 @@ static void sweep_one_link(ErtsLink *lnk, void *vpsc)
 	ASSERT(is_internal_pid(lnk->pid));
 	rp = erts_pid2proc(NULL, 0, lnk->pid, rp_locks);
 	if (rp) {
-	    ErtsLink *rlnk = erts_remove_link(&(rp->nlinks), psc->port);
+	    ErtsLink *rlnk = erts_remove_link(&ERTS_P_LINKS(rp), psc->port);
 
 	    if (rlnk) {
 		int xres = erts_send_exit_signal(NULL,
@@ -2135,11 +3444,13 @@ static void sweep_one_link(ErtsLink *lnk, void *vpsc)
  * that is to kill a port till reason kill. Then the port is stopped.
  * 
  */
-void
-erts_do_exit_port(Port *p, Eterm from, Eterm reason)
+
+int
+erts_deliver_port_exit(Port *p, Eterm from, Eterm reason, int send_closed)
 {
    ErtsLink *lnk;
    Eterm rreason;
+   erts_aint32_t state;
 
    ERTS_SMP_CHK_NO_PROC_LOCKS;
    ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(p));
@@ -2159,66 +3470,76 @@ erts_do_exit_port(Port *p, Eterm from, Eterm reason)
    }
 #endif
 
-   if ((p->status & (ERTS_PORT_SFLGS_DEAD
-		     | ERTS_PORT_SFLG_EXITING
-		     | ERTS_PORT_SFLG_IMMORTAL))
-       || ((reason == am_normal) &&
-	   ((from != p->connected) && (from != p->id)))) {
-      return;
-   }
+   state = erts_atomic32_read_nob(&p->state);
+   if (state & (ERTS_PORT_SFLGS_DEAD
+		| ERTS_PORT_SFLG_EXITING
+		| ERTS_PORT_SFLG_CLOSING))
+       return 0;
+
+   if (reason == am_normal && from != ERTS_PORT_GET_CONNECTED(p) && from != p->common.id)
+       return 0;
+
+   if (send_closed)
+       erts_atomic32_read_bor_relb(&p->state,
+				   ERTS_PORT_SFLG_SEND_CLOSED);
 
    if (IS_TRACED_FL(p, F_TRACE_PORTS)) {
    	trace_port(p, am_closed, reason);
    }
 
-   erts_trace_check_exiting(p->id);
+   erts_trace_check_exiting(p->common.id);
 
    /*
     * Setting the port to not busy here, frees the list of pending
     * processes and makes them runnable.
     */
-   set_busy_port((ErlDrvPort)internal_port_index(p->id), 0);
+   set_busy_port((ErlDrvPort) p, 0);
 
-   if (p->reg != NULL)
-       (void) erts_unregister_name(NULL, 0, p, p->reg->name);
+   if (p->common.u.alive.reg != NULL)
+       (void) erts_unregister_name(NULL, 0, p, p->common.u.alive.reg->name);
 
-   erts_port_status_bor_set(p, ERTS_PORT_SFLG_EXITING);
+   state = erts_atomic32_read_bor_relb(&p->state, ERTS_PORT_SFLG_EXITING);
 
    {
-       SweepContext sc = {p->id, rreason};
-       lnk = p->nlinks;
-       p->nlinks = NULL;
+       SweepContext sc = {p->common.id, rreason};
+       lnk = ERTS_P_LINKS(p);
+       ERTS_P_LINKS(p) = NULL;
        erts_sweep_links(lnk, &sweep_one_link, &sc);
    }
    DRV_MONITOR_LOCK_PDL(p);
    {
-       ErtsMonitor *moni = p->monitors;
-       p->monitors = NULL;
+       ErtsMonitor *moni = ERTS_P_MONITORS(p);
+       ERTS_P_MONITORS(p) = NULL;
        erts_sweep_monitors(moni, &sweep_one_monitor, NULL);
    } 
    DRV_MONITOR_UNLOCK_PDL(p);
 
-   if ((p->status & ERTS_PORT_SFLG_DISTRIBUTION) && p->dist_entry) {
+   if ((state & ERTS_PORT_SFLG_DISTRIBUTION) && p->dist_entry) {
        erts_do_net_exits(p->dist_entry, rreason);
        erts_deref_dist_entry(p->dist_entry); 
-       p->dist_entry = NULL; 
-       erts_port_status_band_set(p, ~ERTS_PORT_SFLG_DISTRIBUTION);
+       p->dist_entry = NULL;
+       erts_atomic32_read_band_relb(&p->state,
+				    ~ERTS_PORT_SFLG_DISTRIBUTION);
    }
        
    if ((reason != am_kill) && !is_port_ioq_empty(p)) {
-       erts_port_status_bandor_set(p,
-				   ~ERTS_PORT_SFLG_EXITING, /* must turn it off */
-				   ERTS_PORT_SFLG_CLOSING);
+       /* must turn exiting flag off */
+       erts_atomic32_read_bset_relb(&p->state,
+				    (ERTS_PORT_SFLG_EXITING
+				     | ERTS_PORT_SFLG_CLOSING),
+				    ERTS_PORT_SFLG_CLOSING);
       flush_port(p);
    }
    else {
        terminate_port(p);
    }
+
+   return 1;
 }
 
 /* About the states ERTS_PORT_SFLG_EXITING and ERTS_PORT_SFLG_CLOSING used above.
 **
-** ERTS_PORT_SFLG_EXITING is a recursion protection for erts_do_exit_port().
+** ERTS_PORT_SFLG_EXITING is a recursion protection for erts_deliver_port_exit().
 ** It is unclear  whether this state is necessary or not, it might be possible
 ** to merge it with ERTS_PORT_SFLG_CLOSING. ERTS_PORT_SFLG_EXITING only persists
 ** over a section of sequential (but highly recursive) code.
@@ -2234,232 +3555,1108 @@ erts_do_exit_port(Port *p, Eterm from, Eterm reason)
 **   {PID, close}
 **   {PID, {command, io-list}}
 **   {PID, {connect, New_PID}}
-**
-**
 */
-void erts_port_command(Process *proc,
-		       Eterm caller_id,
-		       Port *port,
-		       Eterm command)
+ErtsPortOpResult
+erts_port_command(Process *c_p,
+		  int flags,
+		  Port *port,
+		  Eterm command,
+		  Eterm *refp)
 {
     Eterm *tp;
-    Eterm pid;
 
-    if (!port)
-	return;
+    ASSERT(port);
 
-    erts_smp_proc_unlock(proc, ERTS_PROC_LOCK_MAIN);
-    ERTS_SMP_CHK_NO_PROC_LOCKS;
-    ASSERT(!INVALID_PORT(port, port->id));
+    flags |= ERTS_PORT_SIG_FLG_BANG_OP;
 
     if (is_tuple_arity(command, 2)) {
+	Eterm cntd;
 	tp = tuple_val(command);
-	if ((pid = port->connected) == tp[1]) {
-	    /* PID must be connected */
+	cntd = tp[1];
+	if (is_internal_pid(cntd)) {
 	    if (tp[2] == am_close) {
-		erts_port_status_bor_set(port, ERTS_PORT_SFLG_SEND_CLOSED);
-		erts_do_exit_port(port, pid, am_normal);
-
-#ifdef USE_VM_PROBES
-		if(DTRACE_ENABLED(port_command)) {
-                    DTRACE_FORMAT_COMMON_PROC_AND_PORT(proc, port)
-		    DTRACE4(port_command, process_str, port_str, port->name, "close");
-		}
-#endif
-		goto done;
+		if (!erts_port_synchronous_ops)
+		    refp = NULL;
+		flags &= ~ERTS_PORT_SIG_FLG_NOSUSPEND;
+		return erts_port_exit(c_p, flags, port, cntd, am_normal, refp);
 	    } else if (is_tuple_arity(tp[2], 2)) {
 		tp = tuple_val(tp[2]);
 		if (tp[1] == am_command) {
-		    if (erts_write_to_port(caller_id, port, tp[2]) == 0)
-			goto done;
-		} else if ((tp[1] == am_connect) && is_internal_pid(tp[2])) {
-#ifdef USE_VM_PROBES
-		    if(DTRACE_ENABLED(port_command)) {
-                        DTRACE_FORMAT_COMMON_PROC_AND_PORT(proc, port)
-			DTRACE4(port_command, process_str, port_str, port->name, "connect");
-		    }
-#endif
-		    port->connected = tp[2];
-		    deliver_result(port->id, pid, am_connected);
-		    goto done;
+		    if (!(flags & ERTS_PORT_SIG_FLG_NOSUSPEND)
+			&& !erts_port_synchronous_ops)
+			refp = NULL;
+		    return erts_port_output(c_p, flags, port, cntd, tp[2], refp);
+		}
+		else if (tp[1] == am_connect) {
+		    if (!erts_port_synchronous_ops)
+			refp = NULL;
+		    flags &= ~ERTS_PORT_SIG_FLG_NOSUSPEND;
+		    return erts_port_connect(c_p, flags, port, cntd, tp[2], refp);
 		}
 	    }
 	}
     }
 
-    {
-	ErtsProcLocks rp_locks = ERTS_PROC_LOCKS_XSIG_SEND;
-	Process* rp = erts_pid2proc(NULL, 0,
-				    port->connected, rp_locks);
-	if (rp) {
-	    (void) erts_send_exit_signal(NULL,
-					 port->id,
-					 rp,
-					 &rp_locks, 
-					 am_badsig,
-					 NIL,
-					 NULL,
-					 0);
-	    erts_smp_proc_unlock(rp, rp_locks);
-	}
+    /* badsig */
+    if (!erts_port_synchronous_ops)
+	refp = NULL;
+    flags &= ~ERTS_PORT_SIG_FLG_NOSUSPEND;
+    return bad_port_signal(c_p, flags, port, c_p->common.id, refp, am_command);
+}
+
+static ERTS_INLINE ErtsPortOpResult
+call_driver_control(Eterm caller,
+		    Port *prt,
+		    unsigned int command,
+		    char *bufp,
+		    ErlDrvSizeT size,
+		    char **resp_bufp,
+		    ErlDrvSizeT *from_size)
+{
+    ErlDrvSSizeT cres;
+
+    if (!prt->drv_ptr->control)
+	return ERTS_PORT_OP_BADARG;
 
+
+#ifdef USE_VM_PROBES
+    if (DTRACE_ENABLED(port_control) || DTRACE_ENABLED(driver_control)) {
+        DTRACE_FORMAT_COMMON_PID_AND_PORT(caller, prt);
+        DTRACE4(port_control, process_str, port_str, prt->name, command);
+        DTRACE5(driver_control, process_str, port_str, prt->name,
+                command, size);
     }
- done:
-    erts_smp_proc_lock(proc, ERTS_PROC_LOCK_MAIN);
+#endif
+
+    prt->caller = caller;
+    cres = prt->drv_ptr->control((ErlDrvData) prt->drv_data,
+				 command,
+				 bufp,
+				 size,
+				 resp_bufp,
+				 *from_size);
+    prt->caller = NIL;
+
+    if (cres < 0)
+	return ERTS_PORT_OP_BADARG;
+
+    *from_size = (ErlDrvSizeT) cres;
+
+    return ERTS_PORT_OP_DONE;
 }
 
-/*
- * Control a port synchronously. 
- * Returns either a list or a binary.
- */
-Eterm
-erts_port_control(Process* p, Port* prt, Uint command, Eterm iolist)
-{
-    byte* to_port = NULL;	/* Buffer to write to port. */
-				/* Initialization is for shutting up
-				   warning about use before set. */
-    Uint to_len = 0;		/* Length of buffer. */
-    int must_free = 0;		/* True if the buffer should be freed. */
-    char port_result[ERL_ONHEAP_BIN_LIMIT];  /* Default buffer for result from port. */
-    char* port_resp;		/* Pointer to result buffer. */
-    ErlDrvSSizeT n;
-    ErlDrvSSizeT (*control)
-	(ErlDrvData, unsigned, char*, ErlDrvSizeT, char**, ErlDrvSizeT);
-    int fpe_was_unmasked;
+static void
+cleanup_scheduled_control(Binary *binp, char *bufp)
+{
+    if (binp) {
+	if (erts_refc_dectest(&binp->refc, 0) == 0)
+	    erts_bin_free(binp);
+    }
+    else {
+	if (bufp)
+	    erts_free(ERTS_ALC_T_DRV_CTRL_DATA, bufp);
+    }
+}
 
-    ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
 
-    if ((control = prt->drv_ptr->control) == NULL) {
-	return THE_NON_VALUE;
+static ERTS_INLINE Uint
+port_control_result_size(int control_flags,
+			 char *resp_bufp,
+			 ErlDrvSizeT *resp_size,
+			 char *pre_alloc_buf)
+{
+    if (!resp_bufp)
+	return (Uint) 0;
+
+    if (control_flags & PORT_CONTROL_FLAG_BINARY) {
+	if (resp_bufp != pre_alloc_buf) {
+	    ErlDrvBinary *dbin = (ErlDrvBinary *) resp_bufp;
+	    *resp_size = dbin->orig_size;
+	    if (*resp_size > ERL_ONHEAP_BIN_LIMIT)
+		return PROC_BIN_SIZE;
+	}
+	ASSERT(*resp_size <= ERL_ONHEAP_BIN_LIMIT);
+	return (Uint) heap_bin_size((*resp_size));
     }
 
-    /*
-     * Convert the iolist to a buffer, pointed to by to_port,
-     * and with its length in to_len.
-     */
-    if (is_binary(iolist) && binary_bitoffset(iolist) == 0) {
+    return (Uint) 2*(*resp_size);
+}
+
+static ERTS_INLINE Eterm
+write_port_control_result(int control_flags,
+			  char *resp_bufp,
+			  ErlDrvSizeT resp_size,
+			  char *pre_alloc_buf,
+			  Eterm **hpp,
+			  ErlHeapFragment *bp,
+			  ErlOffHeap *ohp)
+{
+    Eterm res;
+    if (!resp_bufp)
+	return NIL;
+    if (control_flags & PORT_CONTROL_FLAG_BINARY) {
+	/* Binary result */
+	ErlDrvBinary *dbin;
+	ErlHeapBin *hbin;
+
+	if (resp_bufp == pre_alloc_buf)
+	    dbin = NULL;
+	else {
+	    dbin = (ErlDrvBinary *) resp_bufp;
+	    if (dbin->orig_size > ERL_ONHEAP_BIN_LIMIT) {
+		ProcBin* pb = (ProcBin *) *hpp;
+		*hpp += PROC_BIN_SIZE;
+		pb->thing_word = HEADER_PROC_BIN;
+		pb->size = dbin->orig_size;
+		pb->next = ohp->first;
+		ohp->first = (struct erl_off_heap_header *) pb;
+		pb->val = ErlDrvBinary2Binary(dbin);
+		pb->bytes = (byte*) dbin->orig_bytes;
+		pb->flags = 0;
+		OH_OVERHEAD(ohp, dbin->orig_size / sizeof(Eterm));
+		return make_binary(pb);
+	    }
+	    resp_bufp = dbin->orig_bytes;
+	    resp_size = dbin->orig_size;
+	}
+
+	hbin = (ErlHeapBin *) *hpp;
+	*hpp += heap_bin_size(resp_size);
+	ASSERT(resp_size <= ERL_ONHEAP_BIN_LIMIT);
+	hbin->thing_word = header_heap_bin(resp_size);
+	hbin->size = resp_size;
+	sys_memcpy(hbin->data, resp_bufp, resp_size);
+	if (dbin)
+	    driver_free_binary(dbin);
+	return make_binary(hbin);
+    }
+
+    /* List result */
+    res = buf_to_intlist(hpp, resp_bufp, resp_size, NIL);
+    if (resp_bufp != pre_alloc_buf)
+	driver_free(resp_bufp);
+    return res;
+}
+
+static int
+port_sig_control(Port *prt,
+		 erts_aint32_t state,
+		 int op,
+		 ErtsProc2PortSigData *sigdp)
+{
+    ASSERT(sigdp->flags & ERTS_P2P_SIG_DATA_FLG_REPLY);
+
+    if (op == ERTS_PROC2PORT_SIG_EXEC) {
+	char resp_buf[ERL_ONHEAP_BIN_LIMIT];
+	ErlDrvSizeT resp_size = sizeof(resp_buf);
+	char *resp_bufp = &resp_buf[0];
+	ErtsPortOpResult res;
+
+	res = call_driver_control(sigdp->caller,
+				  prt,
+				  sigdp->u.control.command,
+				  sigdp->u.control.bufp,
+				  sigdp->u.control.size,
+				  &resp_bufp,
+				  &resp_size);
+
+	if (res == ERTS_PORT_OP_DONE) {
+	    Eterm msg;
+	    Eterm *hp, *hp_start;
+	    ErlHeapFragment *bp;
+	    ErlOffHeap *ohp;
+	    Process *rp;
+	    ErtsProcLocks rp_locks = 0;
+	    Uint hsz;
+	    int control_flags;
+
+	    rp = erts_proc_lookup_raw(sigdp->caller);
+	    if (!rp)
+		goto done;
+
+	    control_flags = prt->control_flags;
+
+	    hsz = ERTS_QUEUE_PORT_SCHED_OP_REPLY_SIZE;
+	    hsz += port_control_result_size(control_flags,
+					    resp_bufp,
+					    &resp_size,
+					    &resp_buf[0]);
+
+	    hp_start = hp = erts_alloc_message_heap(hsz,
+						    &bp,
+						    &ohp,
+						    rp,
+						    &rp_locks);
+
+	    msg = write_port_control_result(control_flags,
+					    resp_bufp,
+					    resp_size,
+					    &resp_buf[0],
+					    &hp,
+					    bp,
+					    ohp);
+
+	    queue_port_sched_op_reply(rp,
+				      &rp_locks,
+				      hp_start,
+				      hp,
+				      hsz,
+				      bp,
+				      sigdp->ref,
+				      msg);
+
+	    if (rp_locks)
+		erts_smp_proc_unlock(rp, rp_locks);
+	    goto done;
+	}
+    }
+
+    /* failure */
+
+    port_sched_op_reply(sigdp->caller, sigdp->ref, am_badarg);
+
+done:
+
+    cleanup_scheduled_control(sigdp->u.control.binp,
+			      sigdp->u.control.bufp);
+
+    return ERTS_PORT_REDS_CONTROL;
+}
+
+
+ErtsPortOpResult
+erts_port_control(Process* c_p,
+		  Port *prt,
+		  unsigned int command,
+		  Eterm data,
+		  Eterm *retvalp)
+{
+    ErtsPortOpResult res;
+    char *bufp = NULL;
+    ErlDrvSizeT size = 0;
+    int try_call;
+    int tmp_alloced = 0;
+    erts_aint32_t sched_flags;
+    Binary *binp;
+    int copy;
+    ErtsProc2PortSigData *sigdp;
+
+    sched_flags = erts_smp_atomic32_read_nob(&prt->sched.flags);
+    if (sched_flags & ERTS_PTS_FLG_EXIT)
+	return ERTS_PORT_OP_BADARG;
+
+    try_call = !(sched_flags & ERTS_PTS_FLGS_FORCE_SCHEDULE_OP);
+
+    if (is_binary(data) && binary_bitoffset(data) == 0) {
+	byte *bytep;
 	ERTS_DECLARE_DUMMY(Uint bitoffs);
 	ERTS_DECLARE_DUMMY(Uint bitsize);
-	ERTS_GET_BINARY_BYTES(iolist, to_port, bitoffs, bitsize);
-	to_len = binary_size(iolist);
+	ERTS_GET_BINARY_BYTES(data, bytep, bitoffs, bitsize);
+	bufp = (char *) bytep;
+	size = binary_size(data);
     } else {
 	int r;
 
-	/* Try with an 8KB buffer first (will often be enough I guess). */
-	to_len = 8*1024;
-	to_port = erts_alloc(ERTS_ALC_T_TMP, to_len);
-	must_free = 1;
+	if (!try_call) {
+	    if (erts_iolist_size(data, &size))
+		return ERTS_PORT_OP_BADARG;
+	    bufp = erts_alloc(ERTS_ALC_T_DRV_CTRL_DATA, size);
+	    r = erts_iolist_to_buf(data, bufp, size);
+	    ASSERT(r == 0);
+	}
+	else {
+	    /* Try with an 8KB buffer first (will often be enough I guess). */
+	    size = 8*1024;
+	    bufp = erts_alloc(ERTS_ALC_T_TMP, size);
+	    tmp_alloced = 1;
+
+	    r = erts_iolist_to_buf(data, bufp, size);
+	    if (ERTS_IOLIST_TO_BUF_SUCCEEDED(r)) {
+		size -= r;
+	    } else {
+		if (r == ERTS_IOLIST_TO_BUF_TYPE_ERROR) { /* Type error */
+		    erts_free(ERTS_ALC_T_TMP, bufp);
+		    return ERTS_PORT_OP_BADARG;
+		}
+		else {
+		    ASSERT(r == ERTS_IOLIST_TO_BUF_OVERFLOW); /* Overflow */
+		    erts_free(ERTS_ALC_T_TMP, bufp);
+		    if (erts_iolist_size(data, &size))
+			return ERTS_PORT_OP_BADARG; /* Type error */
+		}
+		bufp = erts_alloc(ERTS_ALC_T_TMP, size);
+		r = erts_iolist_to_buf(data, bufp, size);
+		ASSERT(r == 0);
+	    }
+	}
+    }
 
-	/*
-	 * In versions before R10B, we used to reserve random
-	 * amounts of extra memory. From R10B, we allocate the
-	 * exact amount.
-	 */
-	r = io_list_to_buf(iolist, (char*) to_port, to_len);
-	if (r >= 0) {
-	    to_len -= r;
-	} else if (r == -2) {	/* Type error */
-	    erts_free(ERTS_ALC_T_TMP, (void *) to_port);
-	    return THE_NON_VALUE;
-	} else {
-	    ASSERT(r == -1);	/* Overflow */
-	    erts_free(ERTS_ALC_T_TMP, (void *) to_port);
-	    if (erts_iolist_size(iolist, &to_len)) { /* Type error */
-		return THE_NON_VALUE;
+    if (try_call) {
+	char resp_buf[ERL_ONHEAP_BIN_LIMIT];
+	char* resp_bufp = &resp_buf[0];
+	ErlDrvSizeT resp_size = sizeof(resp_buf);
+	ErtsTryImmDrvCallResult try_call_res;
+	ErtsTryImmDrvCallState try_call_state
+	    = ERTS_INIT_TRY_IMM_DRV_CALL_STATE(
+		c_p,
+		prt,
+		ERTS_PORT_SFLGS_INVALID_LOOKUP,
+		0,
+		0,
+		am_control);
+
+	try_call_res = try_imm_drv_call(&try_call_state);
+	switch (try_call_res) {
+	case ERTS_TRY_IMM_DRV_CALL_OK: {
+	    Eterm *hp;
+	    Uint hsz;
+	    int control_flags;
+
+	    res = call_driver_control(c_p->common.id,
+				      prt,
+				      command,
+				      bufp,
+				      size,
+				      &resp_bufp,
+				      &resp_size);
+	    finalize_imm_drv_call(&try_call_state);
+	    if (tmp_alloced)
+		erts_free(ERTS_ALC_T_TMP, bufp);
+	    if (res == ERTS_PORT_OP_BADARG) {
+		return ERTS_PORT_OP_BADARG;
 	    }
-	    must_free = 1;
-	    to_port = erts_alloc(ERTS_ALC_T_TMP, to_len);
-	    r = io_list_to_buf(iolist, (char*) to_port, to_len);
-	    ASSERT(r == 0);
+
+	    control_flags = prt->control_flags;
+
+	    hsz = port_control_result_size(control_flags,
+					   resp_bufp,
+					   &resp_size,
+					   &resp_buf[0]);
+	    hp = HAlloc(c_p, hsz);
+	    *retvalp = write_port_control_result(control_flags,
+						 resp_bufp,
+						 resp_size,
+						 &resp_buf[0],
+						 &hp,
+						 NULL,
+						 &c_p->off_heap);
+	    return ERTS_PORT_OP_DONE;
+	}
+	case ERTS_TRY_IMM_DRV_CALL_INVALID_PORT:
+	    if (tmp_alloced)
+		erts_free(ERTS_ALC_T_TMP, bufp);
+	    return ERTS_PORT_OP_BADARG;
+	default:
+	    /* Schedule control() call instead... */
+	    break;
 	}
     }
 
-    prt->caller = p->id;	/* Internal pid */
+    /* Convert data into something that can be scheduled */
 
-    erts_smp_proc_unlock(p, ERTS_PROC_LOCK_MAIN);
-    ERTS_SMP_CHK_NO_PROC_LOCKS;
+    copy = tmp_alloced;
+
+    binp = NULL;
+
+    if (is_binary(data) && binary_bitoffset(data) == 0) {
+	Eterm *ebinp = binary_val_rel(data, NULL);
+	ASSERT(!tmp_alloced);
+	if (*ebinp == HEADER_SUB_BIN)
+	    ebinp = binary_val_rel(((ErlSubBin *) ebinp)->orig, NULL);
+	if (*ebinp != HEADER_PROC_BIN)
+	    copy = 1;
+	else {
+	    binp = ((ProcBin *) ebinp)->val;
+	    ASSERT(bufp < bufp + size);
+	    ASSERT(binp->orig_bytes <= bufp
+		   && bufp + size <= binp->orig_bytes + binp->orig_size);
+	    erts_refc_inc(&binp->refc, 1);
+	}
+    }
+
+    if (copy) {
+	char *old_bufp = bufp;
+	bufp = erts_alloc(ERTS_ALC_T_DRV_CTRL_DATA, size);
+	sys_memcpy(bufp, old_bufp, size);
+	if (tmp_alloced)
+	    erts_free(ERTS_ALC_T_TMP, old_bufp);
+    }
+
+    sigdp = erts_port_task_alloc_p2p_sig_data();
+    sigdp->flags = ERTS_P2P_SIG_TYPE_CONTROL;
+    sigdp->u.control.binp = binp;
+    sigdp->u.control.command = command;
+    sigdp->u.control.bufp = bufp;
+    sigdp->u.control.size = size;
+    
+    res = erts_schedule_proc2port_signal(c_p,
+					 prt,
+					 c_p->common.id,
+					 retvalp,
+					 sigdp,
+					 0,
+					 port_sig_control);
+    if (res != ERTS_PORT_OP_SCHEDULED) {
+	cleanup_scheduled_control(binp, bufp);
+	return ERTS_PORT_OP_BADARG;
+    }
+    return res;
+}
+
+static ERTS_INLINE ErtsPortOpResult
+call_driver_call(Eterm caller,
+		 Port *prt,
+		 unsigned int command,
+		 char *bufp,
+		 ErlDrvSizeT size,
+		 char **resp_bufp,
+		 ErlDrvSizeT *from_size,
+		 unsigned *ret_flagsp)
+{
+    ErlDrvSSizeT cres;
+
+    if (!prt->drv_ptr->call)
+	return ERTS_PORT_OP_BADARG;
 
 #ifdef USE_VM_PROBES
-    if (DTRACE_ENABLED(port_control) || DTRACE_ENABLED(driver_control)) {
-        DTRACE_FORMAT_COMMON_PROC_AND_PORT(p, prt);
-        DTRACE4(port_control, process_str, port_str, prt->name, command);
-        DTRACE5(driver_control, process_str, port_str, prt->name,
-                command, to_len);
+    if (DTRACE_ENABLED(driver_call)) {
+        DTRACE_CHARBUF(process_str, DTRACE_TERM_BUF_SIZE);
+        DTRACE_CHARBUF(port_str, DTRACE_TERM_BUF_SIZE);
+
+        dtrace_pid_str(caller, process_str);
+        dtrace_port_str(prt, port_str);
+        DTRACE5(driver_call, process_str, port_str, prt->name, command, size);
     }
 #endif
 
-    /*
-     * Call the port's control routine.
-     */
+    prt->caller = caller;
+    cres = prt->drv_ptr->call((ErlDrvData) prt->drv_data,
+			      command,
+			      bufp,
+			      size,
+			      resp_bufp,
+			      *from_size,
+			      ret_flagsp);
+    prt->caller = NIL;
 
-    port_resp = port_result;
-    fpe_was_unmasked = erts_block_fpe();
-    n = control((ErlDrvData)prt->drv_data, command, (char*)to_port, to_len,
-		&port_resp, sizeof(port_result));
-    erts_unblock_fpe(fpe_was_unmasked);
-    if (must_free) {
-	erts_free(ERTS_ALC_T_TMP, (void *) to_port);
+    if (cres <= 0
+	|| ((byte) (*resp_bufp)[0]) != VERSION_MAGIC)
+	return ERTS_PORT_OP_BADARG;
+
+    *from_size = (ErlDrvSizeT) cres;
+
+    return ERTS_PORT_OP_DONE;
+}
+
+
+static
+void cleanup_scheduled_call(char *bufp)
+{
+    if (bufp)
+	erts_free(ERTS_ALC_T_DRV_CALL_DATA, bufp);
+}
+
+static int
+port_sig_call(Port *prt,
+	      erts_aint32_t state,
+	      int op,
+	      ErtsProc2PortSigData *sigdp)
+{
+    char resp_buf[256];
+    ErlDrvSizeT resp_size = sizeof(resp_buf);
+    char *resp_bufp = &resp_buf[0];
+    unsigned ret_flags = 0U;
+
+
+    ASSERT(sigdp->flags & ERTS_P2P_SIG_DATA_FLG_REPLY);
+
+    if (op == ERTS_PROC2PORT_SIG_EXEC) {
+	ErtsPortOpResult res;
+
+	res = call_driver_call(sigdp->caller,
+			       prt,
+			       sigdp->u.call.command,
+			       sigdp->u.call.bufp,
+			       sigdp->u.call.size,
+			       &resp_bufp,
+			       &resp_size,
+			       &ret_flags);
+
+	if (res == ERTS_PORT_OP_DONE) {
+	    Eterm msg;
+	    Eterm *hp;
+	    ErlHeapFragment *bp;
+	    ErlOffHeap *ohp;
+	    Process *rp;
+	    ErtsProcLocks rp_locks = 0;
+	    Uint hsz;
+
+	    rp = erts_proc_lookup_raw(sigdp->caller);
+	    if (!rp)
+		goto done;
+
+	    hsz = erts_decode_ext_size((byte *) resp_bufp, resp_size);
+	    if (hsz >= 0) {
+		Eterm *hp_start;
+		byte *endp;
+
+		hsz += 3; /* ok tuple */
+		hsz += ERTS_QUEUE_PORT_SCHED_OP_REPLY_SIZE;
+
+		hp_start = hp = erts_alloc_message_heap(hsz,
+							&bp,
+							&ohp,
+							rp,
+							&rp_locks);
+		endp = (byte *) resp_bufp;
+		msg = erts_decode_ext(&hp, ohp, &endp);
+		if (is_value(msg)) {
+		    msg = TUPLE2(hp, am_ok, msg);
+		    hp += 3;
+
+		    queue_port_sched_op_reply(rp,
+					      &rp_locks,
+					      hp_start,
+					      hp,
+					      hsz,
+					      bp,
+					      sigdp->ref,
+					      msg);
+
+		    if (rp_locks)
+			erts_smp_proc_unlock(rp, rp_locks);
+		    goto done;
+		}
+		if (bp)
+		    free_message_buffer(bp);
+		if (rp_locks)
+		    erts_smp_proc_unlock(rp, rp_locks);
+	    }
+	}
     }
-    prt->caller = NIL;
-#ifdef ERTS_SMP
-    if (prt->xports)
-	erts_smp_xports_unlock(prt);
-    ASSERT(!prt->xports);
-#endif
 
-    erts_smp_proc_lock(p, ERTS_PROC_LOCK_MAIN);
-    /*
-     * Handle the result.
-     */
+    port_sched_op_reply(sigdp->caller, sigdp->ref, am_badarg);
+
+done:
 
-    if (n < 0) {
-	return THE_NON_VALUE;
+    if (resp_bufp != &resp_buf[0] && !(ret_flags & DRIVER_CALL_KEEP_BUFFER))
+	driver_free(resp_bufp);
+
+    cleanup_scheduled_call(sigdp->u.call.bufp);
+
+    return ERTS_PORT_REDS_CALL;
+}
+
+
+ErtsPortOpResult
+erts_port_call(Process* c_p,
+	       Port *prt,
+	       unsigned int command,
+	       Eterm data,
+	       Eterm *retvalp)
+{
+    ErtsPortOpResult res;
+    char input_buf[256];
+    char *bufp;
+    byte *endp;
+    ErlDrvSizeT size;
+    int try_call;
+    erts_aint32_t sched_flags;
+    ErtsProc2PortSigData *sigdp;
+
+    sched_flags = erts_smp_atomic32_read_nob(&prt->sched.flags);
+    if (sched_flags & ERTS_PTS_FLG_EXIT) {
+	return ERTS_PORT_OP_BADARG;
     }
 
-    if ((prt->control_flags & PORT_CONTROL_FLAG_BINARY) == 0) {	/* List result */
-	Eterm ret;	
-	Eterm* hp = HAlloc(p, 2*n);
-	ret = buf_to_intlist(&hp, port_resp, n, NIL);
-	if (port_resp != port_result) {
-	    driver_free(port_resp);
+    try_call = !(sched_flags & ERTS_PTS_FLGS_FORCE_SCHEDULE_OP);
+
+    size = erts_encode_ext_size(data);
+
+    if (!try_call)
+	bufp = erts_alloc(ERTS_ALC_T_DRV_CALL_DATA, size);
+    else if (size <= sizeof(input_buf))
+	bufp = &input_buf[0];
+    else
+	bufp = erts_alloc(ERTS_ALC_T_TMP, size);
+
+    endp = (byte *) bufp;
+    erts_encode_ext(data, &endp);
+
+    if (endp - (byte *) bufp > size)
+	ERTS_INTERNAL_ERROR("erts_internal:port_call() - Buffer overflow");
+
+    size = endp - (byte *) bufp;
+
+    if (try_call) {
+	char resp_buf[255];
+	char* resp_bufp = &resp_buf[0];
+	ErlDrvSizeT resp_size = sizeof(resp_buf);
+	ErtsTryImmDrvCallResult try_call_res;
+	ErtsTryImmDrvCallState try_call_state
+	    = ERTS_INIT_TRY_IMM_DRV_CALL_STATE(
+		c_p,
+		prt,
+		ERTS_PORT_SFLGS_INVALID_LOOKUP,
+		0,
+		0,
+		am_call);
+
+	try_call_res = try_imm_drv_call(&try_call_state);
+	switch (try_call_res) {
+	case ERTS_TRY_IMM_DRV_CALL_OK: {
+	    Eterm *hp, *hp_end;
+	    Uint hsz;
+	    unsigned ret_flags = 0U;
+	    Eterm term;
+
+	    res = call_driver_call(c_p->common.id,
+				   prt,
+				   command,
+				   bufp,
+				   size,
+				   &resp_bufp,
+				   &resp_size,
+				   &ret_flags);
+
+	    finalize_imm_drv_call(&try_call_state);
+	    if (bufp != &input_buf[0])
+		erts_free(ERTS_ALC_T_TMP, bufp);
+	    if (res == ERTS_PORT_OP_BADARG)
+		return ERTS_PORT_OP_BADARG;
+	    hsz = erts_decode_ext_size((byte *) resp_bufp, resp_size);
+	    if (hsz < 0)
+		return ERTS_PORT_OP_BADARG;
+	    hsz += 3;
+	    hp = HAlloc(c_p, hsz);
+	    hp_end = hp + hsz;
+	    endp = (byte *) resp_bufp;
+	    term = erts_decode_ext(&hp, &MSO(c_p), &endp);
+	    if (term == THE_NON_VALUE)
+		return ERTS_PORT_OP_BADARG;
+	    *retvalp = TUPLE2(hp, am_ok, term);
+	    hp += 3;
+	    HRelease(c_p, hp_end, hp);
+	    if (resp_buf != &resp_buf[0]
+		&& !(ret_flags & DRIVER_CALL_KEEP_BUFFER))
+		driver_free(resp_buf);
+	    return ERTS_PORT_OP_DONE;
 	}
-	return ret;
-    } 
-    else if (port_resp == NULL) {
-	return NIL;
-    } 
-    else {                   /* Binary result */
-	ErlDrvBinary *dbin;
-	ErlHeapBin *hbin;
-	if (port_resp != port_result) {
-	    dbin = (ErlDrvBinary *) port_resp;
-	    if (dbin->orig_size > ERL_ONHEAP_BIN_LIMIT) {
-		ProcBin* pb = (ProcBin *) HAlloc(p, PROC_BIN_SIZE);
-		pb->thing_word = HEADER_PROC_BIN;
-		pb->size = dbin->orig_size;
-		pb->next = MSO(p).first;
-		MSO(p).first = (struct erl_off_heap_header*)pb;
-		pb->val = ErlDrvBinary2Binary(dbin);
-		pb->bytes = (byte*) dbin->orig_bytes;
-		pb->flags = 0;
-		OH_OVERHEAD(&(MSO(p)), dbin->orig_size / sizeof(Eterm));
-		return make_binary(pb);
-	    }
-	    port_resp = dbin->orig_bytes;
-	    n = dbin->orig_size;
-	} else {
-	    dbin = NULL;
+	case ERTS_TRY_IMM_DRV_CALL_INVALID_PORT:
+	    if (bufp != &input_buf[0])
+		erts_free(ERTS_ALC_T_TMP, bufp);
+	    return ERTS_PORT_OP_BADARG;
+	default:
+	    /* Schedule call() call instead... */
+	    break;
 	}
-	hbin = (ErlHeapBin*) HAlloc(p, heap_bin_size(n));
-	ASSERT(n <= ERL_ONHEAP_BIN_LIMIT);
-	hbin->thing_word = header_heap_bin(n);
-	hbin->size = n;
-	sys_memcpy(hbin->data, port_resp, n);
-	if (dbin != NULL) {
-	    driver_free_binary(dbin);
+    }
+
+    /* Convert data into something that can be scheduled */
+
+    if (bufp == &input_buf[0] || try_call) {
+	char *new_bufp = erts_alloc(ERTS_ALC_T_DRV_CALL_DATA, size);
+	sys_memcpy(new_bufp, bufp, size);
+	if (bufp != &input_buf[0])
+	    erts_free(ERTS_ALC_T_TMP, bufp);
+	bufp = new_bufp;
+    }
+
+    sigdp = erts_port_task_alloc_p2p_sig_data();
+    sigdp->flags = ERTS_P2P_SIG_TYPE_CALL;
+    sigdp->u.call.command = command;
+    sigdp->u.call.bufp = bufp;
+    sigdp->u.call.size = size;
+    
+    res = erts_schedule_proc2port_signal(c_p,
+					 prt,
+					 c_p->common.id,
+					 retvalp,
+					 sigdp,
+					 0,
+					 port_sig_call);
+    if (res != ERTS_PORT_OP_SCHEDULED) {
+	cleanup_scheduled_call(bufp);
+	return ERTS_PORT_OP_BADARG;
+    }
+    return res;
+}
+
+static Eterm
+make_port_info_term(Eterm **hpp_start,
+		    Eterm **hpp,
+		    Uint *hszp,
+		    ErlHeapFragment **bpp,
+		    Port *prt,
+		    Eterm item)
+{
+    ErlOffHeap *ohp;
+
+    if (is_value(item)) {
+	if (erts_bld_port_info(NULL, NULL, hszp, prt, item) == am_false)
+	    return THE_NON_VALUE;
+	if (*hszp) {
+	    *bpp = new_message_buffer(*hszp);
+	    *hpp_start = *hpp = (*bpp)->mem;
+	    ohp = &(*bpp)->off_heap;
 	}
-	return make_binary(hbin);
+	else {
+	    *bpp = NULL;
+	    *hpp_start = *hpp = NULL;
+	    ohp = NULL;
+	}
+	return erts_bld_port_info(hpp, ohp, NULL, prt, item);
+    }
+    else {
+	int i;
+	int len;
+	int start;
+	static Eterm item[] = ERTS_PORT_INFO_1_ITEMS;
+	static Eterm value[sizeof(item)/sizeof(item[0])];
+
+	start = 0;
+	len = sizeof(item)/sizeof(item[0]);
+
+	for (i = start; i < sizeof(item)/sizeof(item[0]); i++) {
+	    ASSERT(is_atom(item[i]));
+	    value[i] = erts_bld_port_info(NULL, NULL, hszp, prt, item[i]);
+	}
+
+	if (value[0] == am_undefined) {
+	    start++;
+	    len--;
+	}
+
+	erts_bld_list(NULL, hszp, len, &value[start]);
+
+	*bpp = new_message_buffer(*hszp);
+	*hpp_start = *hpp = (*bpp)->mem;
+	ohp = &(*bpp)->off_heap;
+
+	for (i = start; i < sizeof(item)/sizeof(item[0]); i++)
+	    value[i] = erts_bld_port_info(hpp, ohp, NULL, prt, item[i]);
+
+	return erts_bld_list(hpp, NULL, len, &value[start]);
+    }
+}
+
+static int
+port_sig_info(Port *prt,
+	      erts_aint32_t state,
+	      int op,
+	      ErtsProc2PortSigData *sigdp)
+{
+    ASSERT(sigdp->flags & ERTS_P2P_SIG_DATA_FLG_REPLY);
+    if (op != ERTS_PROC2PORT_SIG_EXEC)
+	port_sched_op_reply(sigdp->caller, sigdp->ref, am_undefined);
+    else {
+	Eterm *hp, *hp_start;
+	Uint hsz;
+	ErlHeapFragment *bp;
+	Eterm value;
+	Process *rp;
+	ErtsProcLocks rp_locks = 0;
+
+	rp = erts_proc_lookup_raw(sigdp->caller);
+	if (!rp)
+	    return ERTS_PORT_REDS_INFO;
+
+	hsz = ERTS_QUEUE_PORT_SCHED_OP_REPLY_SIZE;
+	value = make_port_info_term(&hp_start,
+				    &hp,
+				    &hsz,
+				    &bp,
+				    prt,
+				    sigdp->u.info.item);
+	if (is_value(value)) {
+	    queue_port_sched_op_reply(rp,
+				      &rp_locks,
+				      hp_start,
+				      hp,
+				      hsz,
+				      bp,
+				      sigdp->ref,
+				      value);
+	}
+	if (rp_locks)
+	    erts_smp_proc_unlock(rp, rp_locks);
+    }
+    return ERTS_PORT_REDS_INFO;
+}
+
+ErtsPortOpResult
+erts_port_info(Process* c_p,
+	       Port *prt,
+	       Eterm item,
+	       Eterm *retvalp)
+{
+    ErtsProc2PortSigData *sigdp;
+    ErtsTryImmDrvCallResult try_call_res;
+    ErtsTryImmDrvCallState try_call_state
+	= ERTS_INIT_TRY_IMM_DRV_CALL_STATE(
+	    c_p,
+	    prt,
+	    ERTS_PORT_SFLGS_INVALID_LOOKUP,
+	    0,
+	    0,
+	    am_info);
+
+    try_call_res = try_imm_drv_call(&try_call_state);
+    switch (try_call_res) {
+    case ERTS_TRY_IMM_DRV_CALL_OK: {
+	Eterm *hp, *hp_start;
+	ErlHeapFragment *bp;
+	Uint hsz = 0;
+	Eterm value = make_port_info_term(&hp_start, &hp, &hsz, &bp, prt, item);
+	finalize_imm_drv_call(&try_call_state);
+	if (is_non_value(value))
+	    return ERTS_PORT_OP_BADARG;
+	else if (is_immed(value))
+	    *retvalp = value;
+	else {
+	    Uint used_h_size = hp - hp_start;
+	    hp = HAlloc(c_p, used_h_size);
+	    *retvalp = copy_struct(value, used_h_size, &hp, &MSO(c_p));
+	    free_message_buffer(bp);
+	}
+	return ERTS_PORT_OP_DONE;
+    }
+    case ERTS_TRY_IMM_DRV_CALL_INVALID_PORT:
+	return ERTS_PORT_OP_DROPPED;
+    case ERTS_TRY_IMM_DRV_CALL_INVALID_SCHED_FLAGS:
+    case ERTS_TRY_IMM_DRV_CALL_BUSY_LOCK:
+	/* Schedule call instead... */
+	break;
+    }
+
+    sigdp = erts_port_task_alloc_p2p_sig_data();
+    sigdp->flags = ERTS_P2P_SIG_TYPE_INFO;
+    sigdp->u.info.item = item;
+
+    return erts_schedule_proc2port_signal(c_p,
+					  prt,
+					  c_p->common.id,
+					  retvalp,
+					  sigdp,
+					  0,
+					  port_sig_info);
+}
+
+static int
+port_sig_set_data(Port *prt,
+		  erts_aint32_t state,
+		  int op,
+		  ErtsProc2PortSigData *sigdp)
+{
+    ASSERT(sigdp->flags & ERTS_P2P_SIG_DATA_FLG_REPLY);
+
+    if (op == ERTS_PROC2PORT_SIG_EXEC) {
+	if (prt->bp)
+	    free_message_buffer(prt->bp);
+	prt->bp = sigdp->u.set_data.bp;
+	prt->data = sigdp->u.set_data.data;
+	port_sched_op_reply(sigdp->caller, sigdp->ref, am_true);
+    }
+    else {
+	if (sigdp->u.set_data.bp)
+	    free_message_buffer(sigdp->u.set_data.bp);
+	port_sched_op_reply(sigdp->caller, sigdp->ref, am_badarg);
+    }
+    return ERTS_PORT_REDS_SET_DATA;
+}
+
+ErtsPortOpResult
+erts_port_set_data(Process* c_p,
+		   Port *prt,
+		   Eterm data,
+		   Eterm *refp)
+{
+    ErtsPortOpResult res;
+    Eterm set_data;
+    ErlHeapFragment *bp;
+    ErtsProc2PortSigData *sigdp;
+    ErtsTryImmDrvCallResult try_call_res;
+    ErtsTryImmDrvCallState try_call_state
+	= ERTS_INIT_TRY_IMM_DRV_CALL_STATE(
+	    c_p,
+	    prt,
+	    ERTS_PORT_SFLGS_INVALID_LOOKUP,
+	    0,
+	    !refp,
+	    am_set_data);
+
+    if (is_immed(data)) {
+	set_data = data;
+	bp = NULL;
+    }
+    else {
+	Eterm *hp;
+	Uint sz = size_object(data);
+	bp = new_message_buffer(sz);
+	hp = bp->mem;
+	set_data = copy_struct(data, sz, &hp, &bp->off_heap);
+    }
+
+    try_call_res = try_imm_drv_call(&try_call_state);
+    switch (try_call_res) {
+    case ERTS_TRY_IMM_DRV_CALL_OK:
+	if (prt->bp)
+	    free_message_buffer(prt->bp);
+	prt->bp = bp;
+	prt->data = set_data;
+	finalize_imm_drv_call(&try_call_state);
+	return ERTS_PORT_OP_DONE;
+    case ERTS_TRY_IMM_DRV_CALL_INVALID_PORT:
+	return ERTS_PORT_OP_DROPPED;
+    case ERTS_TRY_IMM_DRV_CALL_INVALID_SCHED_FLAGS:
+    case ERTS_TRY_IMM_DRV_CALL_BUSY_LOCK:
+	/* Schedule call instead... */
+	break;
+    }
+
+    sigdp = erts_port_task_alloc_p2p_sig_data();
+    sigdp->flags = ERTS_P2P_SIG_TYPE_SET_DATA;
+    sigdp->u.set_data.data = set_data;
+    sigdp->u.set_data.bp = bp;
+
+    res = erts_schedule_proc2port_signal(c_p,
+					 prt,
+					 c_p->common.id,
+					 refp,
+					 sigdp,
+					 0,
+					 port_sig_set_data);
+    if (res != ERTS_PORT_OP_SCHEDULED && bp)
+	free_message_buffer(bp);
+    return res;
+}
+
+static int
+port_sig_get_data(Port *prt,
+		  erts_aint32_t state,
+		  int op,
+		  ErtsProc2PortSigData *sigdp)
+{
+    ASSERT(sigdp->flags & ERTS_P2P_SIG_DATA_FLG_REPLY);
+    if (op != ERTS_PROC2PORT_SIG_EXEC)
+	port_sched_op_reply(sigdp->caller, sigdp->ref, am_badarg);
+    else {
+	Process *rp;
+	ErtsProcLocks rp_locks = 0;
+
+	rp = erts_proc_lookup_raw(sigdp->caller);
+	if (rp) {
+	    Uint hsz;
+	    Eterm *hp, *hp_start;
+	    Eterm data, msg;
+	    ErlHeapFragment *bp;
+	    ErlOffHeap *ohp;
+
+	    hsz = ERTS_QUEUE_PORT_SCHED_OP_REPLY_SIZE;
+	    hsz += 3;
+	    if (prt->bp)
+		hsz += prt->bp->used_size;
+
+	    hp_start = hp = erts_alloc_message_heap(hsz,
+						    &bp,
+						    &ohp,
+						    rp,
+						    &rp_locks);
+
+	    if (is_immed(prt->data))
+		data = prt->data;
+	    else
+		data = copy_struct(prt->data,
+				   prt->bp->used_size,
+				   &hp,
+				   &bp->off_heap);
+
+
+
+	    msg = TUPLE2(hp, am_ok, data);
+	    hp += 3;
+
+	    queue_port_sched_op_reply(rp,
+				      &rp_locks,
+				      hp_start,
+				      hp,
+				      hsz,
+				      bp,
+				      sigdp->ref,
+				      msg);
+	    if (rp_locks)
+		erts_smp_proc_unlock(rp, rp_locks);
+	}
+    }
+    return ERTS_PORT_REDS_GET_DATA;
+}
+
+ErtsPortOpResult
+erts_port_get_data(Process* c_p,
+		   Port *prt,
+		   Eterm *retvalp)
+{
+    ErtsProc2PortSigData *sigdp;
+    ErtsTryImmDrvCallResult try_call_res;
+    ErtsTryImmDrvCallState try_call_state
+	= ERTS_INIT_TRY_IMM_DRV_CALL_STATE(
+	    c_p,
+	    prt,
+	    ERTS_PORT_SFLGS_INVALID_LOOKUP,
+	    0,
+	    0,
+	    am_get_data);
+
+    try_call_res = try_imm_drv_call(&try_call_state);
+    switch (try_call_res) {
+    case ERTS_TRY_IMM_DRV_CALL_OK: {
+	Eterm *hp;
+	Eterm data;
+	ErlHeapFragment *bp;
+	Uint sz;
+	if (is_immed(prt->data)) {
+	    bp = NULL;
+	    data = prt->data;
+	}
+	else {
+	    bp = new_message_buffer(prt->bp->used_size);
+	    data = copy_struct(prt->data,
+			       prt->bp->used_size,
+			       &hp,
+			       &bp->off_heap);
+	}	    
+	finalize_imm_drv_call(&try_call_state);
+	if (is_immed(data))
+	    sz = 0;
+	else 
+	    sz = bp->used_size;
+
+	hp = HAlloc(c_p,  sz + 3);
+	if (is_not_immed(data)) {
+	    data = copy_struct(data, bp->used_size, &hp, &MSO(c_p));
+	    free_message_buffer(bp);
+	}
+	*retvalp = TUPLE2(hp, am_ok, data);
+	return ERTS_PORT_OP_DONE;
+    }
+    case ERTS_TRY_IMM_DRV_CALL_INVALID_PORT:
+	return ERTS_PORT_OP_DROPPED;
+    case ERTS_TRY_IMM_DRV_CALL_INVALID_SCHED_FLAGS:
+    case ERTS_TRY_IMM_DRV_CALL_BUSY_LOCK:
+	/* Schedule call instead... */
+	break;
     }
+
+    sigdp = erts_port_task_alloc_p2p_sig_data();
+    sigdp->flags = ERTS_P2P_SIG_TYPE_GET_DATA;
+
+    return erts_schedule_proc2port_signal(c_p,
+					  prt,
+					  c_p->common.id,
+					  retvalp,
+					  sigdp,
+					  0,
+					  port_sig_get_data);
 }
 
 typedef struct {
@@ -2480,39 +4677,39 @@ static void prt_one_lnk(ErtsLink *lnk, void *vprtd)
 }
 
 void
-print_port_info(int to, void *arg, int i)
+print_port_info(Port *p, int to, void *arg)
 {
-    Port* p = &erts_port[i];
+    erts_aint32_t state = erts_atomic32_read_nob(&p->state);
 
-    if (p->status & ERTS_PORT_SFLGS_DEAD)
+    if (state & ERTS_PORT_SFLGS_DEAD)
 	return;
 
-    erts_print(to, arg, "=port:%T\n", p->id);
-    erts_print(to, arg, "Slot: %d\n", i);
-    if (p->status & ERTS_PORT_SFLG_CONNECTED) {
-	erts_print(to, arg, "Connected: %T", p->connected);
+    erts_print(to, arg, "=port:%T\n", p->common.id);
+    erts_print(to, arg, "Slot: %d\n", internal_port_index(p->common.id));
+    if (state & ERTS_PORT_SFLG_CONNECTED) {
+	erts_print(to, arg, "Connected: %T", ERTS_PORT_GET_CONNECTED(p));
 	erts_print(to, arg, "\n");
     }
 
-    if (p->nlinks != NULL) {
+    if (ERTS_P_LINKS(p)) {
 	prt_one_lnk_data prtd;
 	prtd.to = to;
 	prtd.arg = arg;
 	erts_print(to, arg, "Links: ");
-	erts_doforall_links(p->nlinks, &prt_one_lnk, &prtd);
+	erts_doforall_links(ERTS_P_LINKS(p), &prt_one_lnk, &prtd);
 	erts_print(to, arg, "\n");
     }
-    if (p->monitors != NULL) {
+    if (ERTS_P_MONITORS(p)) {
 	prt_one_lnk_data prtd;
 	prtd.to = to;
 	prtd.arg = arg;
 	erts_print(to, arg, "Monitors: ");
-	erts_doforall_monitors(p->monitors, &prt_one_monitor, &prtd);
+	erts_doforall_monitors(ERTS_P_MONITORS(p), &prt_one_monitor, &prtd);
 	erts_print(to, arg, "\n");
     }
 
-    if (p->reg != NULL)
-	erts_print(to, arg, "Registered as: %T\n", p->reg->name);
+    if (p->common.u.alive.reg != NULL)
+	erts_print(to, arg, "Registered as: %T\n", p->common.u.alive.reg->name);
 
     if (p->drv_ptr == &fd_driver) {
 	erts_print(to, arg, "Port is UNIX fd not opened by emulator: %s\n", p->name);
@@ -2526,109 +4723,143 @@ print_port_info(int to, void *arg, int i)
 }
 
 void
-set_busy_port(ErlDrvPort port_num, int on)
+set_busy_port(ErlDrvPort dprt, int on)
 {
+    Port *prt;
+    erts_aint32_t flags;
+
 #ifdef USE_VM_PROBES
     DTRACE_CHARBUF(port_str, 16);
 #endif
 
     ERTS_SMP_CHK_NO_PROC_LOCKS;
 
-    ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(&erts_port[port_num]));
+    prt = erts_drvport2port_raw(dprt);
+    if (!prt)
+	return;
 
     if (on) {
-        erts_port_status_bor_set(&erts_port[port_num],
-				 ERTS_PORT_SFLG_PORT_BUSY);
+	flags = erts_smp_atomic32_read_bor_acqb(&prt->sched.flags,
+						ERTS_PTS_FLG_BUSY_PORT);
+	if (flags & ERTS_PTS_FLG_BUSY_PORT)
+	    return; /* Already busy */
+
+	if (flags & ERTS_PTS_FLG_HAVE_NS_TASKS)
+	    erts_port_task_abort_nosuspend_tasks(prt);
+
 #ifdef USE_VM_PROBES
         if (DTRACE_ENABLED(port_busy)) {
             erts_snprintf(port_str, sizeof(port_str),
-                          "%T", erts_port[port_num].id);
+                          "%T", prt->common.id);
             DTRACE1(port_busy, port_str);
         }
 #endif
     } else {
-        ErtsProcList* plp = erts_port[port_num].suspended;
-        erts_port_status_band_set(&erts_port[port_num],
-				  ~ERTS_PORT_SFLG_PORT_BUSY);
-        erts_port[port_num].suspended = NULL;
+	flags = erts_smp_atomic32_read_band_acqb(&prt->sched.flags,
+						 ~ERTS_PTS_FLG_BUSY_PORT);
+	if (!(flags & ERTS_PTS_FLG_BUSY_PORT))
+	    return; /* Already non-busy */
 
 #ifdef USE_VM_PROBES
         if (DTRACE_ENABLED(port_not_busy)) {
             erts_snprintf(port_str, sizeof(port_str),
-                          "%T", erts_port[port_num].id);
+                          "%T", prt->common.id);
             DTRACE1(port_not_busy, port_str);
         }
 #endif
-	if (erts_port[port_num].dist_entry) {
+	if (prt->dist_entry) {
 	    /*
 	     * Processes suspended on distribution ports are
 	     * normally queued on the dist entry.
 	     */
-	    erts_dist_port_not_busy(&erts_port[port_num]);
+	    erts_dist_port_not_busy(prt);
 	}
 
-	/*
-	 * Resume, in a round-robin fashion, all processes waiting on the port.
-	 * 
-	 * This version submitted by Tony Rogvall. The earlier version used
-	 * to resume the processes in order, which caused starvation of all but
-	 * the first process.
-	 */
+	if (!(flags & ERTS_PTS_FLG_BUSY_PORT_Q))
+	    erts_port_resume_procs(prt);
+    }
+}
+
+void
+erts_port_resume_procs(Port *prt)
+{
+    /*
+     * Resume, in a round-robin fashion, all processes waiting on the port.
+     * 
+     * This version submitted by Tony Rogvall. The earlier version used
+     * to resume the processes in order, which caused starvation of all but
+     * the first process.
+     */
+    ErtsProcList *plp;
+
+    erts_port_task_sched_lock(&prt->sched);
+    plp = prt->suspended;
+    prt->suspended = NULL;
+    erts_port_task_sched_unlock(&prt->sched);
+
+    if (erts_proclist_fetch(&plp, NULL)) {
 
-        if (plp) {
 #ifdef USE_VM_PROBES
-            /*
-             * Hrm, for blocked dist ports, plp always seems to be NULL.
-             * That's not so fun.
-             * Well, another way to get the same info is using a D
-             * script to correlate an earlier process-port_blocked+pid
-             * event with a later process-scheduled event.  That's
-             * subject to the multi-CPU races with how events are
-             * handled, but hey, that way works most of the time.
-             */
-            if (DTRACE_ENABLED(process_port_unblocked)) {
-                DTRACE_CHARBUF(pid_str, 16);
-                ErtsProcList* plp2 = plp;
-
-                erts_snprintf(port_str, sizeof(port_str),
-                             "%T", erts_port[port_num]);
-                while (plp2 != NULL) {
-                    erts_snprintf(pid_str, sizeof(pid_str), "%T", plp2->pid);
-                    DTRACE2(process_port_unblocked, pid_str, port_str);
-                }
-            }
-#endif
-            /* First proc should be resumed last */
-	    if (plp->next) {
-		erts_resume_processes(plp->next);
-		plp->next = NULL;
+	/*
+	 * Hrm, for blocked dist ports, plp always seems to be NULL.
+	 * That's not so fun.
+	 * Well, another way to get the same info is using a D
+	 * script to correlate an earlier process-port_blocked+pid
+	 * event with a later process-scheduled event.  That's
+	 * subject to the multi-CPU races with how events are
+	 * handled, but hey, that way works most of the time.
+	 */
+	if (DTRACE_ENABLED(process_port_unblocked)) {
+	    DTRACE_CHARBUF(port_str, 16);
+	    DTRACE_CHARBUF(pid_str, 16);
+	    ErtsProcList* plp2 = plp;
+
+	    erts_snprintf(port_str, sizeof(port_str), "%T", prt->common.id);
+	    while (plp2 != NULL) {
+		erts_snprintf(pid_str, sizeof(pid_str), "%T", plp2->pid);
+		DTRACE2(process_port_unblocked, pid_str, port_str);
 	    }
-	    erts_resume_processes(plp);
-        }
+	}
+#endif
+
+	/* First proc should be resumed last */
+	if (plp->next) {
+	    plp->next->prev = NULL;
+	    erts_resume_processes(plp->next);
+	    plp->next = NULL;
+	}
+	erts_resume_processes(plp);
     }
 }
 
 void set_port_control_flags(ErlDrvPort port_num, int flags)
 {
-
-    ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(&erts_port[port_num]));
-
-    erts_port[port_num].control_flags = flags;
+    Port *prt = erts_drvport2port_raw(port_num);
+    if (prt)
+	prt->control_flags = flags;
 }
 
-int get_port_flags(ErlDrvPort ix) { 
-    Port* prt = erts_drvport2port(ix);
+int get_port_flags(ErlDrvPort ix)
+{
+    int flags;
+    Port *prt;
+    erts_aint32_t state;
+
+    prt = erts_drvport2port(ix, &state);
+    if (!prt)
+	return 0;
 
     ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
 
-    if (prt == NULL)
-	return 0;
+    flags = 0;
+    if (state & ERTS_PORT_SFLG_BINARY_IO)
+	flags |= PORT_FLAG_BINARY;
+    if (state & ERTS_PORT_SFLG_LINEBUF_IO)
+	flags |= PORT_FLAG_LINE;
 
-    return (prt->status & ERTS_PORT_SFLG_BINARY_IO ? PORT_FLAG_BINARY : 0) 
-	| (prt->status & ERTS_PORT_SFLG_LINEBUF_IO ? PORT_FLAG_LINE : 0);
+    return flags;
 }
 
-
 void erts_raw_port_command(Port* p, byte* buf, Uint len)
 {
     int fpe_was_unmasked;
@@ -2665,25 +4896,18 @@ int async_ready(Port *p, void* data)
 
     if (p) {
 	ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(p));
-	ASSERT(!(p->status & ERTS_PORT_SFLGS_DEAD));
 	if (p->drv_ptr->ready_async != NULL) {
 #ifdef USE_VM_PROBES
             if (DTRACE_ENABLED(driver_ready_async)) {
-                DTRACE_FORMAT_COMMON_PID_AND_PORT(p->connected, p)
+                DTRACE_FORMAT_COMMON_PID_AND_PORT(ERTS_PORT_GET_CONNECTED(p), p)
                 DTRACE3(driver_ready_async, process_str, port_str, p->name);
             }
 #endif
 	    (*p->drv_ptr->ready_async)((ErlDrvData)p->drv_data, data);
 	    need_free = 0;
-#ifdef ERTS_SMP
-	    if (p->xports)
-		erts_smp_xports_unlock(p);
-	    ASSERT(!p->xports);
-#endif
-	}
-	if ((p->status & ERTS_PORT_SFLG_CLOSING) && is_port_ioq_empty(p)) {
-	    terminate_port(p);
+
 	}
+	erts_port_driver_callback_epilogue(p, NULL);
     }
     return need_free;
 }
@@ -2691,12 +4915,12 @@ int async_ready(Port *p, void* data)
 static void
 report_missing_drv_callback(Port *p, char *drv_type, char *callback)
 {
-    ErtsPortNames *pnp = erts_get_port_names(p->id);
+    ErtsPortNames *pnp = erts_get_port_names(p->common.id);
     char *unknown = "<unknown>";
     char *drv_name = pnp->driver_name ? pnp->driver_name : unknown;
     char *prt_name = pnp->name ? pnp->name : unknown;
     erts_dsprintf_buf_t *dsbufp = erts_create_logger_dsbuf();    
-    erts_dsprintf(dsbufp, "%T: %s driver '%s' ", p->id, drv_type, drv_name);
+    erts_dsprintf(dsbufp, "%T: %s driver '%s' ", p->common.id, drv_type, drv_name);
     if (sys_strcmp(drv_name, prt_name) != 0)
 	erts_dsprintf(dsbufp, "(%s) ", prt_name);
     erts_dsprintf(dsbufp, "does not implement the %s callback!\n", callback);
@@ -2711,7 +4935,7 @@ erts_stale_drv_select(Eterm port,
 		      int deselect)
 {
     char *type;
-    ErlDrvPort drv_port = internal_port_index(port);
+    ErlDrvPort drv_port = (ErlDrvPort) erts_port_lookup_raw(port);
     ErtsPortNames *pnp = erts_get_port_names(port);
     erts_dsprintf_buf_t *dsbufp;
 
@@ -2751,16 +4975,16 @@ erts_stale_drv_select(Eterm port,
 ErtsPortNames *
 erts_get_port_names(Eterm id)
 {
+    Port *prt = erts_port_lookup_raw(id);
     ErtsPortNames *pnp;
     ASSERT(is_nil(id) || is_internal_port(id));
-    
-    if (is_not_internal_port(id)) {
+
+    if (!prt) {
 	pnp = erts_alloc(ERTS_ALC_T_PORT_NAMES, sizeof(ErtsPortNames));
 	pnp->name = NULL;
 	pnp->driver_name = NULL;
     }
     else {
-	Port* prt = &erts_port[internal_port_index(id)];
 	int do_realloc = 1;
 	int len = -1;
 	size_t pnp_len = sizeof(ErtsPortNames);
@@ -2776,17 +5000,10 @@ erts_get_port_names(Eterm id)
 		pnp_len = sizeof(ErtsPortNames) + len;
 		pnp = erts_alloc(ERTS_ALC_T_PORT_NAMES, pnp_len);
 	    }
-	    erts_smp_port_state_lock(prt);
-	    if (id != prt->id) {
-		len = nlen = 0;
-		name = driver_name = NULL;
-	    }
-	    else {
-		name = prt->name;
-		len = nlen = name ? sys_strlen(name) + 1 : 0;
-		driver_name = (prt->drv_ptr ? prt->drv_ptr->name : NULL);
-		len += driver_name ? sys_strlen(driver_name) + 1 : 0;
-	    }
+	    name = prt->name;
+	    len = nlen = name ? sys_strlen(name) + 1 : 0;
+	    driver_name = (prt->drv_ptr ? prt->drv_ptr->name : NULL);
+	    len += driver_name ? sys_strlen(driver_name) + 1 : 0;
 	    if (len <= pnp_len - sizeof(ErtsPortNames)) {
 		if (!name)
 		    pnp->name = NULL;
@@ -2804,7 +5021,6 @@ erts_get_port_names(Eterm id)
 		}
 		do_realloc = 0;
 	    }
-	    erts_smp_port_state_unlock(prt);
 	} while (do_realloc);
     }
     return pnp;
@@ -2829,11 +5045,9 @@ static void schedule_port_timeout(Port *p)
      * /Rickard
      */
     ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(p));
-    (void) erts_port_task_schedule(p->id,
-				   &p->timeout_task,
-				   ERTS_PORT_TASK_TIMEOUT,
-				   (ErlDrvEvent) -1,
-				   NULL);
+    erts_port_task_schedule(p->common.id,
+			    &p->timeout_task,
+			    ERTS_PORT_TASK_TIMEOUT);
 }
 
 ErlDrvTermData driver_mk_term_nil(void)
@@ -2841,9 +5055,9 @@ ErlDrvTermData driver_mk_term_nil(void)
     return driver_term_nil;
 }
 
-void driver_report_exit(int ix, int status)
+void driver_report_exit(ErlDrvPort ix, int status)
 {
-   Port* prt = erts_drvport2port(ix);
+    Port* prt = erts_drvport2port(ix, NULL);
    Eterm* hp;
    Eterm tuple;
    Process *rp;
@@ -2856,7 +5070,7 @@ void driver_report_exit(int ix, int status)
    ERTS_SMP_CHK_NO_PROC_LOCKS;
    ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
 
-   pid = prt->connected;
+   pid = ERTS_PORT_GET_CONNECTED(prt);
    ASSERT(is_internal_pid(pid));
 
    rp = (scheduler
@@ -2869,7 +5083,7 @@ void driver_report_exit(int ix, int status)
 
    tuple = TUPLE2(hp, am_exit_status, make_small(status));
    hp += 3;
-   tuple = TUPLE2(hp, prt->id, tuple);
+   tuple = TUPLE2(hp, prt->common.id, tuple);
 
    erts_queue_message(rp, &rp_locks, bp, tuple, am_undefined
 #ifdef USE_VM_PROBES
@@ -2882,28 +5096,6 @@ void driver_report_exit(int ix, int status)
        erts_smp_proc_dec_refc(rp);
 }
 
-
-static ERTS_INLINE int
-deliver_term_check_port(ErlDrvPort drvport)
-{
-    int res;
-    int ix = (int) drvport;
-    if (ix < 0 || erts_max_ports <= ix)
-	res = -1; /* invalid */
-    else {
-	Port* prt = &erts_port[ix];
-	erts_smp_port_state_lock(prt);
-	if (!(prt->status & ERTS_PORT_SFLGS_INVALID_LOOKUP))
-	    res = 1; /* ok */
-	else if (prt->status & ERTS_PORT_SFLG_CLOSING)
-	    res = 0; /* closing */
-	else
-	    res = -1; /* invalid (dead) */
-	erts_smp_port_state_unlock(prt);
-    }
-    return res;
-}
-
 #define ERTS_B2T_STATES_DEF_STATES_SZ 5
 #define ERTS_B2T_STATES_DEF_STATES_INC 100
 
@@ -2991,10 +5183,7 @@ cleanup_b2t_states(struct b2t_states__ *b2tsp)
  */
 
 static int
-driver_deliver_term(ErlDrvPort port,
-		    Eterm to,
-		    ErlDrvTermData* data,
-		    int len)
+driver_deliver_term(Eterm to, ErlDrvTermData* data, int len)
 {
 #define ERTS_DDT_FAIL do { res = -1; goto done; } while (0)
     Uint need = 0;
@@ -3196,11 +5385,8 @@ driver_deliver_term(ErlDrvPort port,
     b2t.ix = 0;
 
     /*
-     * The term is OK. Go ahead and validate the port and process.
+     * The term is OK. Go ahead and validate the process.
      */
-    res = deliver_term_check_port(port);
-    if (res <= 0)
-	goto done;
 
     /*
      * Increase refc on proc if done from a non-scheduler thread.
@@ -3470,25 +5656,115 @@ driver_deliver_term(ErlDrvPort port,
 #undef ERTS_DDT_FAIL
 }
 
+static ERTS_INLINE int
+deliver_term_check_port(ErlDrvTermData port_id, Eterm *connected_p)
+{
+#ifdef ERTS_SMP
+    ErtsThrPrgrDelayHandle dhndl = erts_thr_progress_unmanaged_delay();
+#endif
+    Port *prt = erts_port_lookup_raw((Eterm) port_id);
+    erts_aint32_t state = erts_atomic32_read_nob(&prt->state);
+    if (connected_p) {
+#ifdef ERTS_SMP
+	if (dhndl != ERTS_THR_PRGR_DHANDLE_MANAGED)
+	    ETHR_MEMBAR(ETHR_LoadLoad);
+#endif
+	*connected_p = ERTS_PORT_GET_CONNECTED(prt);
+    }
+#ifdef ERTS_SMP
+    if (dhndl != ERTS_THR_PRGR_DHANDLE_MANAGED) {
+	erts_thr_progress_unmanaged_continue(dhndl);
+	ETHR_MEMBAR(ETHR_LoadLoad|ETHR_LoadStore);
+    }
+#endif
+    ERTS_SMP_LC_ASSERT(dhndl == ERTS_THR_PRGR_DHANDLE_MANAGED
+		       ? erts_lc_is_port_locked(prt)
+		       : !erts_lc_is_port_locked(prt));
+    return ((state & ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP)
+	    ? -1
+	    : ((state & ERTS_PORT_SFLG_CLOSING) ? 0 : 1));
+}
+
+int erl_drv_output_term(ErlDrvTermData port_id, ErlDrvTermData* data, int len)
+{
+    /* May be called from arbitrary thread */
+    Eterm connected;
+    int res = deliver_term_check_port(port_id, &connected);
+    if (res <= 0)
+	return res;
+    return driver_deliver_term(connected, data, len);
+}
 
+/*
+ * driver_output_term() is deprecated, and has been scheduled for
+ * removal in OTP-R17. It is replaced by erl_drv_output_term()
+ * above.
+ */
 int 
-driver_output_term(ErlDrvPort ix, ErlDrvTermData* data, int len)
+driver_output_term(ErlDrvPort drvport, ErlDrvTermData* data, int len)
 {
-    Port* prt = erts_drvport2port(ix);
+    erts_aint32_t state;
+    Port* prt;
 
     ERTS_SMP_CHK_NO_PROC_LOCKS;
+    /* NOTE! It *not* safe to access 'drvport' from unmanaged threads. */
+    prt = erts_drvport2port(drvport, &state);
+    if (!prt)
+	return -1; /* invalid (dead) */
+    ERTS_SMP_CHK_NO_PROC_LOCKS;
     ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
-
-    if (prt == NULL)
+    if (state & ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP)
 	return -1;
-    return driver_deliver_term(ix, prt->connected, data, len);
+    else if (state & ERTS_PORT_SFLG_CLOSING)
+	return 0;
+
+    return driver_deliver_term(ERTS_PORT_GET_CONNECTED(prt), data, len);
 }
 
+int erl_drv_send_term(ErlDrvTermData port_id,
+		      ErlDrvTermData to,
+		      ErlDrvTermData* data,
+		      int len)
+{
+    /* May be called from arbitrary thread */
+    int res = deliver_term_check_port(port_id, NULL);
+    if (res <= 0)
+	return res;
+    return driver_deliver_term(to, data, len);
+}
 
+/*
+ * driver_send_term() is deprecated, and has been scheduled for
+ * removal in OTP-R17. It is replaced by erl_drv_send_term() above.
+ */
 int
-driver_send_term(ErlDrvPort ix, ErlDrvTermData to, ErlDrvTermData* data, int len)
+driver_send_term(ErlDrvPort drvport,
+		 ErlDrvTermData to,
+		 ErlDrvTermData* data,
+		 int len)
 {
-    return driver_deliver_term(ix, to, data, len);
+    /*
+     * NOTE! It is *not* safe to access the 'drvport' parameter
+     * from unmanaged threads. Also note that it is impossible
+     * to make this access safe without using a less efficient
+     * internal data representation for ErlDrvPort.
+     */
+    ERTS_SMP_CHK_NO_PROC_LOCKS;
+#ifdef ERTS_SMP
+    if (erts_thr_progress_is_managed_thread())
+#endif
+    {
+	erts_aint32_t state;
+	Port* prt = erts_drvport2port(drvport, &state);
+	if (!prt)
+	    return -1; /* invalid (dead) */
+	ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
+	if (state & ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP)
+	    return -1;
+	else if (state & ERTS_PORT_SFLG_CLOSING)
+	    return 0;
+    }
+    return driver_deliver_term(to, data, len);
 }
 
 
@@ -3500,26 +5776,27 @@ driver_send_term(ErlDrvPort ix, ErlDrvTermData to, ErlDrvTermData* data, int len
 int driver_output_binary(ErlDrvPort ix, char* hbuf, ErlDrvSizeT hlen,
 			 ErlDrvBinary* bin, ErlDrvSizeT offs, ErlDrvSizeT len)
 {
-    Port* prt = erts_drvport2port(ix);
+    erts_aint32_t state;
+    Port* prt = erts_drvport2port(ix, &state);
 
     ERTS_SMP_CHK_NO_PROC_LOCKS;
 
     if (prt == NULL)
 	return -1;
     ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
-    if (prt->status & ERTS_PORT_SFLG_CLOSING)
+    if (state & ERTS_PORT_SFLG_CLOSING)
 	return 0;
 
     prt->bytes_in += (hlen + len);
     erts_smp_atomic_add_nob(&erts_bytes_in, (erts_aint_t) (hlen + len));
-    if (prt->status & ERTS_PORT_SFLG_DISTRIBUTION) {
+    if (state & ERTS_PORT_SFLG_DISTRIBUTION) {
 	return erts_net_message(prt,
 				prt->dist_entry,
 				(byte*) hbuf, hlen,
 				(byte*) (bin->orig_bytes+offs), len);
     }
     else
-	deliver_bin_message(prt, prt->connected, 
+	deliver_bin_message(prt, ERTS_PORT_GET_CONNECTED(prt), 
 			    hbuf, hlen, bin, offs, len);
     return 0;
 }
@@ -3534,7 +5811,8 @@ int driver_output_binary(ErlDrvPort ix, char* hbuf, ErlDrvSizeT hlen,
 int driver_output2(ErlDrvPort ix, char* hbuf, ErlDrvSizeT hlen,
 		   char* buf, ErlDrvSizeT len)
 {
-    Port* prt = erts_drvport2port(ix);
+    erts_aint32_t state;
+    Port* prt = erts_drvport2port(ix, &state);
 
     ERTS_SMP_CHK_NO_PROC_LOCKS;
 
@@ -3543,12 +5821,12 @@ int driver_output2(ErlDrvPort ix, char* hbuf, ErlDrvSizeT hlen,
 
     ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
 
-    if (prt->status & ERTS_PORT_SFLG_CLOSING)
+    if (state & ERTS_PORT_SFLG_CLOSING)
 	return 0;
     
     prt->bytes_in += (hlen + len);
     erts_smp_atomic_add_nob(&erts_bytes_in, (erts_aint_t) (hlen + len));
-    if (prt->status & ERTS_PORT_SFLG_DISTRIBUTION) {
+    if (state & ERTS_PORT_SFLG_DISTRIBUTION) {
 	if (len == 0)
 	    return erts_net_message(prt,
 				    prt->dist_entry,
@@ -3560,10 +5838,12 @@ int driver_output2(ErlDrvPort ix, char* hbuf, ErlDrvSizeT hlen,
 				    (byte*) hbuf, hlen,
 				    (byte*) buf, len);
     }
-    else if(prt->status & ERTS_PORT_SFLG_LINEBUF_IO)
-	deliver_linebuf_message(prt, prt->connected, hbuf, hlen, buf, len);
+    else if (state & ERTS_PORT_SFLG_LINEBUF_IO)
+	deliver_linebuf_message(prt, state, ERTS_PORT_GET_CONNECTED(prt),
+				hbuf, hlen, buf, len);
     else
-	deliver_read_message(prt, prt->connected, hbuf, hlen, buf, len, 0);
+	deliver_read_message(prt, state, ERTS_PORT_GET_CONNECTED(prt),
+			     hbuf, hlen, buf, len, 0);
     return 0;
 }
 
@@ -3584,6 +5864,7 @@ int driver_outputv(ErlDrvPort ix, char* hbuf, ErlDrvSizeT hlen,
     SysIOVec* iov;
     ErlDrvBinary** binv;
     Port* prt;
+    erts_aint32_t state;
 
     ERTS_SMP_CHK_NO_PROC_LOCKS;
 
@@ -3596,13 +5877,13 @@ int driver_outputv(ErlDrvPort ix, char* hbuf, ErlDrvSizeT hlen,
     if (hlen < 0)
 	hlen = 0;
 
-    prt = erts_drvport2port(ix);
+    prt = erts_drvport2port(ix, &state);
     if (prt == NULL)
 	return -1;
 
     ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
 
-    if (prt->status & ERTS_PORT_SFLG_CLOSING)
+    if (state & ERTS_PORT_SFLG_CLOSING)
 	return 0;
 
     /* size > 0 ! */
@@ -3627,7 +5908,8 @@ int driver_outputv(ErlDrvPort ix, char* hbuf, ErlDrvSizeT hlen,
     /* XXX handle distribution !!! */
     prt->bytes_in += (hlen + size);
     erts_smp_atomic_add_nob(&erts_bytes_in, (erts_aint_t) (hlen + size));
-    deliver_vec_message(prt, prt->connected, hbuf, hlen, binv, iov, n, size);
+    deliver_vec_message(prt, ERTS_PORT_GET_CONNECTED(prt), hbuf, hlen,
+			binv, iov, n, size);
     return 0;
 }
 
@@ -3738,8 +6020,7 @@ ErlDrvBinary* driver_realloc_binary(ErlDrvBinary* bin, ErlDrvSizeT size)
 }
 
 
-void driver_free_binary(dbin)
-ErlDrvBinary* dbin;
+void driver_free_binary(ErlDrvBinary* dbin)
 {
     Binary *bin;
     if (!dbin) {
@@ -3835,6 +6116,7 @@ static ERTS_INLINE void pdl_destroy(ErlDrvPDL pdl)
 {
     ERTS_LC_ASSERT(driver_pdl_get_refc(pdl) == 0);
     erts_mtx_destroy(&pdl->mtx);
+    erts_port_dec_refc(pdl->prt);
     erts_free(ERTS_ALC_T_PORT_DATA_LOCK, pdl);
 }
 
@@ -3872,16 +6154,18 @@ ErlDrvPDL
 driver_pdl_create(ErlDrvPort dp)
 {
     ErlDrvPDL pdl;
-    Port *pp = erts_drvport2port(dp);
+    Port *pp = erts_drvport2port(dp, NULL);
     if (!pp || pp->port_data_lock)
 	return NULL;
     pdl = erts_alloc(ERTS_ALC_T_PORT_DATA_LOCK,
 		     sizeof(struct erl_drv_port_data_lock));
     erts_mtx_init(&pdl->mtx, "port_data_lock");
     pdl_init_refc(pdl);
+    erts_port_inc_refc(pp);
+    pdl->prt = pp;
     pp->port_data_lock = pdl;
 #ifdef HARDDEBUG
-    erts_fprintf(stderr, "driver_pdl_create(%T) -> 0x%08X\r\n",pp->id,(unsigned) pdl);
+    erts_fprintf(stderr, "driver_pdl_create(%T) -> 0x%08X\r\n",pp->common.id,(unsigned) pdl);
 #endif
     return pdl;
 }
@@ -4319,33 +6603,33 @@ static ERTS_INLINE void
 drv_cancel_timer(Port *prt)
 {
 #ifdef ERTS_SMP
-    erts_cancel_smp_ptimer(prt->ptimer);
+    erts_cancel_smp_ptimer(prt->common.u.alive.ptimer);
 #else
-    erts_cancel_timer(&prt->tm);
+    erts_cancel_timer(&prt->common.u.alive.tm);
 #endif
     if (erts_port_task_is_scheduled(&prt->timeout_task))
-	erts_port_task_abort(prt->id, &prt->timeout_task);
+	erts_port_task_abort(&prt->timeout_task);
 }
 
 int driver_set_timer(ErlDrvPort ix, unsigned long t)
 {
-    Port* prt = erts_drvport2port(ix);
+    Port* prt = erts_drvport2port(ix, NULL);
 
     ERTS_SMP_CHK_NO_PROC_LOCKS;
 
     if (prt == NULL)
 	return -1;
-    ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
+
     if (prt->drv_ptr->timeout == NULL)
 	return -1;
     drv_cancel_timer(prt);
 #ifdef ERTS_SMP
-    erts_create_smp_ptimer(&prt->ptimer,
-			   prt->id,
+    erts_create_smp_ptimer(&prt->common.u.alive.ptimer,
+			   prt->common.id,
 			   (ErlTimeoutProc) schedule_port_timeout,
 			   t);
 #else
-    erts_set_timer(&prt->tm,
+    erts_set_timer(&prt->common.u.alive.tm,
 		  (ErlTimeoutProc) schedule_port_timeout,
 		  NULL,
 		  prt,
@@ -4356,7 +6640,7 @@ int driver_set_timer(ErlDrvPort ix, unsigned long t)
 
 int driver_cancel_timer(ErlDrvPort ix)
 {
-    Port* prt = erts_drvport2port(ix);
+    Port* prt = erts_drvport2port(ix, NULL);
     if (prt == NULL)
 	return -1;
     ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
@@ -4368,7 +6652,7 @@ int driver_cancel_timer(ErlDrvPort ix)
 int
 driver_read_timer(ErlDrvPort ix, unsigned long* t)
 {
-    Port* prt = erts_drvport2port(ix);
+    Port* prt = erts_drvport2port(ix, NULL);
 
     ERTS_SMP_CHK_NO_PROC_LOCKS;
 
@@ -4376,9 +6660,11 @@ driver_read_timer(ErlDrvPort ix, unsigned long* t)
 	return -1;
     ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
 #ifdef ERTS_SMP
-    *t = prt->ptimer ? erts_time_left(&prt->ptimer->timer.tm) : 0;
+    *t = (prt->common.u.alive.ptimer
+	  ? erts_time_left(&prt->common.u.alive.ptimer->timer.tm)
+	  : 0);
 #else
-    *t = erts_time_left(&prt->tm);
+    *t = erts_time_left(&prt->common.u.alive.tm);
 #endif
     return 0;
 }
@@ -4429,8 +6715,8 @@ static int do_driver_monitor_process(Port *prt,
     }
 
     ref = erts_make_ref_in_buffer(buf);
-    erts_add_monitor(&(prt->monitors), MON_ORIGIN, ref, rp->id, NIL);
-    erts_add_monitor(&(rp->monitors), MON_TARGET, ref, prt->id, NIL);
+    erts_add_monitor(&ERTS_P_MONITORS(prt), MON_ORIGIN, ref, rp->common.id, NIL);
+    erts_add_monitor(&ERTS_P_MONITORS(rp), MON_TARGET, ref, prt->common.id, NIL);
 
     erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_LINK);
     ref_to_driver_monitor(ref,monitor);
@@ -4440,31 +6726,24 @@ static int do_driver_monitor_process(Port *prt,
 /*
  * This can be called from a non scheduler thread iff a port_data_lock exists
  */
-int driver_monitor_process(ErlDrvPort port,
+int driver_monitor_process(ErlDrvPort drvport,
 			   ErlDrvTermData process,
 			   ErlDrvMonitor *monitor)
 {
     Port *prt;
     int ret;
-    Uint32 status;
+    erts_aint32_t state;
+#if !HEAP_ON_C_STACK || (defined(ERTS_SMP) && defined(ERTS_ENABLE_LOCK_CHECK))
     ErtsSchedulerData *sched = erts_get_scheduler_data();
-    int ix = (int) port;
-    if (ix < 0 || erts_max_ports <= ix) {
-	return -1;
-    }
-    prt = &erts_port[ix];
+#endif
+
+    prt = erts_thr_drvport2port_raw(drvport);
 
     DRV_MONITOR_LOCK_PDL(prt);
 
-    if (sched) {
-	status = erts_port[ix].status;
-    } else {
-	erts_smp_port_state_lock(prt);
-	status = erts_port[ix].status;
-	erts_smp_port_state_unlock(prt);
-    }
+    state = erts_atomic32_read_nob(&prt->state);
 
-    if (status & ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP) {
+    if (state & ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP) {
 	DRV_MONITOR_UNLOCK_PDL(prt);
 	return -1;
     }
@@ -4502,7 +6781,7 @@ static int do_driver_demonitor_process(Port *prt, Eterm *buf,
 
     memcpy(buf,monitor,sizeof(Eterm)*REF_THING_SIZE);
     ref = make_internal_ref(buf);
-    mon = erts_lookup_monitor(prt->monitors, ref);
+    mon = erts_lookup_monitor(ERTS_P_MONITORS(prt), ref);
     if (mon == NULL) {
 	return 1;
     }
@@ -4514,13 +6793,13 @@ static int do_driver_demonitor_process(Port *prt, Eterm *buf,
 			   to,
 			   ERTS_PROC_LOCK_LINK,
 			   ERTS_P2P_FLG_ALLOW_OTHER_X);
-    mon = erts_remove_monitor(&(prt->monitors), ref);
+    mon = erts_remove_monitor(&ERTS_P_MONITORS(prt), ref);
     if (mon) {
 	erts_destroy_monitor(mon);
     }
     if (rp) {
 	ErtsMonitor *rmon;
-	rmon = erts_remove_monitor(&(rp->monitors), ref);
+	rmon = erts_remove_monitor(&ERTS_P_MONITORS(rp), ref);
 	erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_LINK);
 	if (rmon != NULL) {
 	    erts_destroy_monitor(rmon);
@@ -4529,30 +6808,23 @@ static int do_driver_demonitor_process(Port *prt, Eterm *buf,
     return 0;
 }
 
-int driver_demonitor_process(ErlDrvPort port,
+int driver_demonitor_process(ErlDrvPort drvport,
 			     const ErlDrvMonitor *monitor)
 {
     Port *prt;
     int ret;
-    Uint32 status;
+    erts_aint32_t state;
+#if !HEAP_ON_C_STACK || (defined(ERTS_SMP) && defined(ERTS_ENABLE_LOCK_CHECK))
     ErtsSchedulerData *sched = erts_get_scheduler_data();
-    int ix = (int) port;
-    if (ix < 0 || erts_max_ports <= ix) {
-	return -1;
-    }
-    prt = &erts_port[ix];
+#endif
+
+    prt = erts_thr_drvport2port_raw(drvport);
 
     DRV_MONITOR_LOCK_PDL(prt);
 
-    if (sched) {
-	status = erts_port[ix].status;
-    } else {
-	erts_smp_port_state_lock(prt);
-	status = erts_port[ix].status;
-	erts_smp_port_state_unlock(prt);
-    }
+    state = erts_atomic32_read_nob(&prt->state);
 
-    if (status & ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP) {
+    if (state & ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP) {
 	DRV_MONITOR_UNLOCK_PDL(prt);
 	return -1;
     }
@@ -4588,7 +6860,7 @@ static ErlDrvTermData do_driver_get_monitored_process(Port *prt, Eterm *buf,
 
     memcpy(buf,monitor,sizeof(Eterm)*REF_THING_SIZE);
     ref = make_internal_ref(buf);
-    mon = erts_lookup_monitor(prt->monitors, ref);
+    mon = erts_lookup_monitor(ERTS_P_MONITORS(prt), ref);
     if (mon == NULL) {
 	return driver_term_nil;
     }
@@ -4599,30 +6871,22 @@ static ErlDrvTermData do_driver_get_monitored_process(Port *prt, Eterm *buf,
 }
 
 
-ErlDrvTermData driver_get_monitored_process(ErlDrvPort port,
+ErlDrvTermData driver_get_monitored_process(ErlDrvPort drvport,
 					    const ErlDrvMonitor *monitor)
 {
     Port *prt;
     ErlDrvTermData ret;
-    Uint32 status;
+    erts_aint32_t state;
+#if !HEAP_ON_C_STACK || (defined(ERTS_SMP) && defined(ERTS_ENABLE_LOCK_CHECK))
     ErtsSchedulerData *sched = erts_get_scheduler_data();
-    int ix = (int) port;
-    if (ix < 0 || erts_max_ports <= ix) {
-	return driver_term_nil;
-    }
-    prt = &erts_port[ix];
+#endif
 
-    DRV_MONITOR_LOCK_PDL(prt);
+    prt = erts_thr_drvport2port_raw(drvport);
 
-    if (sched) {
-	status = erts_port[ix].status;
-    } else {
-	erts_smp_port_state_lock(prt);
-	status = erts_port[ix].status;
-	erts_smp_port_state_unlock(prt);
-    }
+    DRV_MONITOR_LOCK_PDL(prt);
 
-    if (status & ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP) {
+    state = erts_atomic32_read_nob(&prt->state);
+    if (state & ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP) {
 	DRV_MONITOR_UNLOCK_PDL(prt);
 	return driver_term_nil;
     }
@@ -4667,7 +6931,7 @@ void erts_fire_port_monitor(Port *prt, Eterm ref)
     ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
     ASSERT(prt->drv_ptr != NULL);    
     DRV_MONITOR_LOCK_PDL(prt);
-    if (erts_lookup_monitor(prt->monitors,ref) == NULL) {
+    if (erts_lookup_monitor(ERTS_P_MONITORS(prt), ref) == NULL) {
 	DRV_MONITOR_UNLOCK_PDL(prt);
 	return;
     }
@@ -4677,7 +6941,7 @@ void erts_fire_port_monitor(Port *prt, Eterm ref)
     DRV_MONITOR_UNLOCK_PDL(prt);
 #ifdef USE_VM_PROBES
     if (DTRACE_ENABLED(driver_process_exit)) {
-        DTRACE_FORMAT_COMMON_PID_AND_PORT(prt->connected, prt)
+        DTRACE_FORMAT_COMMON_PID_AND_PORT(ERTS_PORT_GET_CONNECTED(prt), prt)
         DTRACE3(driver_process_exit, process_str, port_str, prt->name);
     }
 #endif
@@ -4686,7 +6950,7 @@ void erts_fire_port_monitor(Port *prt, Eterm ref)
     erts_unblock_fpe(fpe_was_unmasked);
     DRV_MONITOR_LOCK_PDL(prt);
     /* remove monitor *after* callback */
-    rmon = erts_remove_monitor(&(prt->monitors),ref);
+    rmon = erts_remove_monitor(&ERTS_P_MONITORS(prt), ref);
     DRV_MONITOR_UNLOCK_PDL(prt);
     if (rmon) {
 	erts_destroy_monitor(rmon);
@@ -4697,7 +6961,8 @@ void erts_fire_port_monitor(Port *prt, Eterm ref)
 static int
 driver_failure_term(ErlDrvPort ix, Eterm term, int eof)
 {
-    Port* prt = erts_drvport2port(ix);
+    erts_aint32_t state;
+    Port* prt = erts_drvport2port(ix, &state);
 
     ERTS_SMP_CHK_NO_PROC_LOCKS;
 
@@ -4705,19 +6970,19 @@ driver_failure_term(ErlDrvPort ix, Eterm term, int eof)
 	return -1;
     ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
     if (eof)
-	flush_linebuf_messages(prt);
-    if (prt->status & ERTS_PORT_SFLG_CLOSING) {
+	flush_linebuf_messages(prt, state);
+    if (state & ERTS_PORT_SFLG_CLOSING) {
 	terminate_port(prt);
-    } else if (eof && (prt->status & ERTS_PORT_SFLG_SOFT_EOF)) {
-	deliver_result(prt->id, prt->connected, am_eof);
+    } else if (eof && (state & ERTS_PORT_SFLG_SOFT_EOF)) {
+	deliver_result(prt->common.id, ERTS_PORT_GET_CONNECTED(prt), am_eof);
     } else {
-	/* XXX UGLY WORK AROUND, Let do_exit_port terminate the port */
+	/* XXX UGLY WORK AROUND, Let erts_deliver_port_exit() terminate the port */
 	if (prt->port_data_lock)
 	    driver_pdl_lock(prt->port_data_lock);
 	prt->ioq.size = 0;
 	if (prt->port_data_lock)
 	    driver_pdl_unlock(prt->port_data_lock);
-	erts_do_exit_port(prt, prt->id, eof ? am_normal : term);
+	erts_deliver_port_exit(prt, prt->common.id, eof ? am_normal : term, 0);
     }
     return 0;
 }
@@ -4730,23 +6995,23 @@ driver_failure_term(ErlDrvPort ix, Eterm term, int eof)
 */
 int driver_exit(ErlDrvPort ix, int err)
 {
-    Port* prt = erts_drvport2port(ix);
+    Port* prt = erts_drvport2port(ix, NULL);
     Process* rp;
     ErtsLink *lnk, *rlnk = NULL;
+    Eterm connected;
 
     ERTS_SMP_CHK_NO_PROC_LOCKS;
   
     if (prt == NULL)
         return -1;
 
-    ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
-
-    rp = erts_pid2proc(NULL, 0, prt->connected, ERTS_PROC_LOCK_LINK);
+    connected = ERTS_PORT_GET_CONNECTED(prt);
+    rp = erts_pid2proc(NULL, 0, connected, ERTS_PROC_LOCK_LINK);
     if (rp) {
-	rlnk = erts_remove_link(&(rp->nlinks),prt->id);
+	rlnk = erts_remove_link(&ERTS_P_LINKS(rp),prt->common.id);
     }
 
-    lnk = erts_remove_link(&(prt->nlinks),prt->connected);
+    lnk = erts_remove_link(&ERTS_P_LINKS(prt), connected);
 
 #ifdef ERTS_SMP
     if (rp)
@@ -4803,24 +7068,24 @@ ErlDrvTermData driver_mk_atom(char* string)
 
 ErlDrvTermData driver_mk_port(ErlDrvPort ix)
 {
-    Port* prt = erts_drvport2port(ix);
+    Port* prt = erts_drvport2port(ix, NULL);
     ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
-    return (ErlDrvTermData) prt->id;
+    return (ErlDrvTermData) prt->common.id;
 }
 
 ErlDrvTermData driver_connected(ErlDrvPort ix)
 {
-    Port* prt = erts_drvport2port(ix);
+    Port* prt = erts_drvport2port(ix, NULL);
     ERTS_SMP_CHK_NO_PROC_LOCKS;
     if (prt == NULL)
 	return NIL;
     ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
-    return prt->connected;
+    return ERTS_PORT_GET_CONNECTED(prt);
 }
 
 ErlDrvTermData driver_caller(ErlDrvPort ix)
 {
-    Port* prt = erts_drvport2port(ix);
+    Port* prt = erts_drvport2port(ix, NULL);
     ERTS_SMP_CHK_NO_PROC_LOCKS;
     if (prt == NULL)
 	return NIL;
@@ -4830,25 +7095,25 @@ ErlDrvTermData driver_caller(ErlDrvPort ix)
 
 int driver_lock_driver(ErlDrvPort ix)
 {
-    Port* prt = erts_drvport2port(ix);
+    Port* prt = erts_drvport2port(ix, NULL);
     DE_Handle* dh;
 
     ERTS_SMP_CHK_NO_PROC_LOCKS;
 
-    erts_smp_mtx_lock(&erts_driver_list_lock);
+    erts_smp_rwmtx_rwlock(&erts_driver_list_lock);
 
     if (prt == NULL) {
-	erts_smp_mtx_unlock(&erts_driver_list_lock);
+	erts_smp_rwmtx_rwunlock(&erts_driver_list_lock);
 	return -1;
     }
 
     ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(prt));
     if ((dh = (DE_Handle*)prt->drv_ptr->handle ) == NULL) {
-	erts_smp_mtx_unlock(&erts_driver_list_lock);
+	erts_smp_rwmtx_rwunlock(&erts_driver_list_lock);
 	return -1;
     }
     erts_ddll_lock_driver(dh, prt->drv_ptr->name);
-    erts_smp_mtx_unlock(&erts_driver_list_lock);
+    erts_smp_rwmtx_rwunlock(&erts_driver_list_lock);
     return 0;
 }
 
@@ -4858,7 +7123,7 @@ static int maybe_lock_driver_list(void)
     void *rec_lock;
     rec_lock = erts_smp_tsd_get(driver_list_lock_status_key);
     if (rec_lock == 0) {
-	erts_smp_mtx_lock(&erts_driver_list_lock);
+	erts_smp_rwmtx_rwlock(&erts_driver_list_lock);
 	return 1;
     }
     return 0;
@@ -4866,7 +7131,7 @@ static int maybe_lock_driver_list(void)
 static void maybe_unlock_driver_list(int doit)
 {
     if (doit) {
-	erts_smp_mtx_unlock(&erts_driver_list_lock);
+	erts_smp_rwmtx_rwunlock(&erts_driver_list_lock);
     }
 }
 /* 
@@ -5035,7 +7300,7 @@ no_event_callback(ErlDrvData drv_data, ErlDrvEvent event, ErlDrvEventData event_
 {
     Port *prt = get_current_port();
     report_missing_drv_callback(prt, "Event", "event()");
-    driver_event((ErlDrvPort) internal_port_index(prt->id), event, NULL);
+    driver_event((ErlDrvPort) prt, event, NULL);
 }
 
 static void
@@ -5043,7 +7308,7 @@ no_ready_input_callback(ErlDrvData drv_data, ErlDrvEvent event)
 {
     Port *prt = get_current_port();
     report_missing_drv_callback(prt, "Input", "ready_input()");
-    driver_select((ErlDrvPort) internal_port_index(prt->id), event, 
+    driver_select((ErlDrvPort) prt, event, 
 		  (ERL_DRV_READ | ERL_DRV_USE_NO_CALLBACK), 0);
 }
 
@@ -5052,7 +7317,7 @@ no_ready_output_callback(ErlDrvData drv_data, ErlDrvEvent event)
 {
     Port *prt = get_current_port();
     report_missing_drv_callback(prt, "Output", "ready_output()");
-    driver_select((ErlDrvPort) internal_port_index(prt->id), event,
+    driver_select((ErlDrvPort) prt, event,
 		  (ERL_DRV_WRITE | ERL_DRV_USE_NO_CALLBACK), 0);
 }
 
@@ -5087,13 +7352,13 @@ init_driver(erts_driver_t *drv, ErlDrvEntry *de, DE_Handle *handle)
 	drv->lock = NULL;
     else {
 	drv->lock = erts_alloc(ERTS_ALC_T_DRIVER_LOCK,
-			       sizeof(erts_smp_mtx_t));
-	erts_smp_mtx_init_x(drv->lock,
-			    "driver_lock",
+			       sizeof(erts_mtx_t));
+	erts_mtx_init_x(drv->lock,
+			"driver_lock",
 #if defined(ERTS_ENABLE_LOCK_CHECK) || defined(ERTS_ENABLE_LOCK_COUNT)
-			    am_atom_put(drv->name, sys_strlen(drv->name))
+			am_atom_put(drv->name, sys_strlen(drv->name))
 #else
-			    NIL
+			NIL
 #endif
 	    );
     }
@@ -5165,7 +7430,7 @@ int erts_add_driver_entry(ErlDrvEntry *de, DE_Handle *handle, int driver_list_lo
     int res;
 
     if (!driver_list_locked) {
-	erts_smp_mtx_lock(&erts_driver_list_lock);
+	erts_smp_rwmtx_rwlock(&erts_driver_list_lock);
     }
 
     dp->next = driver_list;
@@ -5194,7 +7459,7 @@ int erts_add_driver_entry(ErlDrvEntry *de, DE_Handle *handle, int driver_list_lo
 	
     if (!driver_list_locked) {
 	erts_smp_tsd_set(driver_list_lock_status_key, NULL);
-	erts_smp_mtx_unlock(&erts_driver_list_lock);
+	erts_smp_rwmtx_rwunlock(&erts_driver_list_lock);
     }
     return res;
 }
@@ -5207,7 +7472,7 @@ int remove_driver_entry(ErlDrvEntry *drv)
     
     rec_lock = erts_smp_tsd_get(driver_list_lock_status_key);
     if (rec_lock == NULL) {
-	erts_smp_mtx_lock(&erts_driver_list_lock);
+	erts_smp_rwmtx_rwlock(&erts_driver_list_lock);
     }
     dp = driver_list;
     while (dp && dp->entry != drv)
@@ -5215,7 +7480,7 @@ int remove_driver_entry(ErlDrvEntry *drv)
     if (dp) {
 	if (dp->handle) {
 	    if (rec_lock == NULL) {
-		erts_smp_mtx_unlock(&erts_driver_list_lock);
+		erts_smp_rwmtx_rwunlock(&erts_driver_list_lock);
 	    }
 	    return -1;
 	}
@@ -5229,12 +7494,12 @@ int remove_driver_entry(ErlDrvEntry *drv)
 	}
 	erts_destroy_driver(dp);
 	if (rec_lock == NULL) {
-	    erts_smp_mtx_unlock(&erts_driver_list_lock);
+	    erts_smp_rwmtx_rwunlock(&erts_driver_list_lock);
 	}
 	return 1;
     }
     if (rec_lock == NULL) {
-	erts_smp_mtx_unlock(&erts_driver_list_lock);
+	erts_smp_rwmtx_rwunlock(&erts_driver_list_lock);
     }
     return 0;
 }
@@ -5264,18 +7529,22 @@ erl_drv_getenv(char *key, char *value, size_t *value_size)
  * - uses the fact that heart_port is registered when starting heart
  */
 
-Port *erts_get_heart_port() {
+Port *erts_get_heart_port(void)
+{
+    int ix, max = erts_ptab_max(&erts_port);
 
-    Port* port;
-    Uint  ix;
+    for (ix = 0; ix < max; ix++) {
+	struct reg_proc *reg;
+	Port *port = erts_pix2port(ix);
 
-    for(ix = 0; ix < erts_max_ports; ix++) {
-	port = &erts_port[ix];
+	if (!port)
+	    continue;
 	/* only examine undead or alive ports */
-	if (port->status & ERTS_PORT_SFLGS_DEAD)
+	if (erts_atomic32_read_nob(&port->state) & ERTS_PORT_SFLGS_DEAD)
 	    continue;
 	/* immediate atom compare */
-	if (port->reg && port->reg->name == am_heart_port) {
+	reg = port->common.u.alive.reg;
+	if (reg && reg->name == am_heart_port) {
 	    return port;
 	}
     }
diff --git a/erts/emulator/beam/register.c b/erts/emulator/beam/register.c
index c02872ef80..757e2800e6 100644
--- a/erts/emulator/beam/register.c
+++ b/erts/emulator/beam/register.c
@@ -175,14 +175,14 @@ int erts_register_name(Process *c_p, Eterm name, Eterm id)
     if (is_not_atom(name) || name == am_undefined)
 	return res;
 
-    if (c_p->id == id) /* A very common case I think... */
+    if (c_p->common.id == id) /* A very common case I think... */
 	proc = c_p;
     else {
 	if (is_not_internal_pid(id) && is_not_internal_port(id))
 	    return res;
 	erts_smp_proc_unlock(c_p, ERTS_PROC_LOCK_MAIN);
 	if (is_internal_port(id)) {
-	    port = erts_id2port(id, NULL, 0);
+	    port = erts_id2port(id);
 	    if (!port)
 		goto done;
 	}
@@ -204,7 +204,7 @@ int erts_register_name(Process *c_p, Eterm name, Eterm id)
 	r.p = proc;
 	if (!proc)
 	    goto done;
-	if (proc->reg)
+	if (proc->common.u.alive.reg)
 	    goto done;
 	r.pt = NULL;
     }
@@ -212,7 +212,7 @@ int erts_register_name(Process *c_p, Eterm name, Eterm id)
 	ASSERT(!INVALID_PORT(port, id));
 	ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(port));
 	r.pt = port;
-	if (r.pt->reg)
+	if (r.pt->common.u.alive.reg)
 	    goto done;
 	r.p = NULL;
     }
@@ -224,23 +224,24 @@ int erts_register_name(Process *c_p, Eterm name, Eterm id)
 	if (IS_TRACED_FL(proc, F_TRACE_PROCS)) {
 	    trace_proc(c_p, proc, am_register, name);
 	}
-	proc->reg = rp;
+	proc->common.u.alive.reg = rp;
     }
     else if (port && rp->pt == port) {
     	if (IS_TRACED_FL(port, F_TRACE_PORTS)) {
 		trace_port(port, am_register, name);
 	}
-	port->reg = rp;
+	port->common.u.alive.reg = rp;
     }
 
-    if ((rp->p && rp->p->id == id) || (rp->pt && rp->pt->id == id)) {
+    if ((rp->p && rp->p->common.id == id)
+	|| (rp->pt && rp->pt->common.id == id)) {
 	res = 1;
     }
 
  done:
     reg_write_unlock();
     if (port)
-	erts_smp_port_unlock(port);
+	erts_port_release(port);
     if (c_p != proc) {
 	if (proc)
 	    erts_smp_proc_unlock(proc, ERTS_PROC_LOCK_MAIN);
@@ -291,9 +292,9 @@ erts_whereis_name_to_id(Process *c_p, Eterm name)
 	     * is read only.
 	     */
 	    if (rp->p)
-		res = rp->p->id;
+		res = rp->p->common.id;
 	    else if (rp->pt)
-		res = rp->pt->id;
+		res = rp->pt->common.id;
 	    break;
 	}
 	b = b->next;
@@ -396,28 +397,26 @@ erts_whereis_name(Process *c_p,
 	if (!rp || !rp->pt)
 	    *port = NULL;
 	else {
-#ifndef ERTS_SMP
-	    erts_smp_atomic_inc_nob(&rp->pt->refc);
-#else
+#ifdef ERTS_SMP
 	    if (pending_port == rp->pt)
 		pending_port = NULL;
 	    else {
 		if (pending_port) {
 		    /* Ahh! Registered port changed while reg lock
 		       was unlocked... */
-		    erts_smp_port_unlock(pending_port);
+		    erts_port_release(pending_port);
 		    pending_port = NULL;
 		}
 		    
 		if (erts_smp_port_trylock(rp->pt) == EBUSY) {
-		    Eterm id = rp->pt->id; /* id read only... */
+		    Eterm id = rp->pt->common.id; /* id read only... */
 		    /* Unlock all locks, acquire port lock, and restart... */
 		    if (current_c_p_locks) {
 			erts_smp_proc_unlock(c_p, current_c_p_locks);
 			current_c_p_locks = 0;
 		    }
 		    reg_read_unlock();
-		    pending_port = erts_id2port(id, NULL, 0);
+		    pending_port = erts_id2port(id);
 		    goto restart;
 		}
 	    }
@@ -431,7 +430,7 @@ erts_whereis_name(Process *c_p,
     if (c_p && !current_c_p_locks)
 	erts_smp_proc_lock(c_p, c_p_locks);
     if (pending_port)
-	erts_smp_port_unlock(pending_port);
+	erts_port_release(pending_port);
 #endif
 
     reg_read_unlock();
@@ -493,8 +492,8 @@ int erts_unregister_name(Process *c_p,
 	    current_c_p_locks = c_p_locks;
 	}
 #endif
-	if (c_p->reg) {
-	    r.name = c_p->reg->name;
+	if (c_p->common.u.alive.reg) {
+	    r.name = c_p->common.u.alive.reg->name;
 	} else {
 	    /* Name got unregistered while main lock was released */
 	    res = 0;
@@ -505,24 +504,22 @@ int erts_unregister_name(Process *c_p,
     if ((rp = (RegProc*) hash_get(&process_reg, (void*) &r)) != NULL) {
 	if (rp->pt) {
 	    if (port != rp->pt) {
-#ifndef ERTS_SMP
-		erts_smp_atomic_inc_nob(&rp->pt->refc);
-#else
+#ifdef ERTS_SMP
 		if (port) {
 		    ASSERT(port != c_prt);
-		    erts_smp_port_unlock(port);
+		    erts_port_release(port);
 		    port = NULL;
 		}
 
 		if (erts_smp_port_trylock(rp->pt) == EBUSY) {
-		    Eterm id = rp->pt->id; /* id read only... */
+		    Eterm id = rp->pt->common.id; /* id read only... */
 		    /* Unlock all locks, acquire port lock, and restart... */
 		    if (current_c_p_locks) {
 			erts_smp_proc_unlock(c_p, current_c_p_locks);
 			current_c_p_locks = 0;
 		    }
 		    reg_write_unlock();
-		    port = erts_id2port(id, NULL, 0);
+		    port = erts_id2port(id);
 		    goto restart;
 		}
 #endif
@@ -532,7 +529,7 @@ int erts_unregister_name(Process *c_p,
 	    ASSERT(rp->pt == port);
 	    ERTS_SMP_LC_ASSERT(erts_lc_is_port_locked(port));
 
-	    rp->pt->reg = NULL;
+	    rp->pt->common.u.alive.reg = NULL;
 	    
 	    if (IS_TRACED_FL(port, F_TRACE_PORTS)) {
 		trace_port(port, am_unregister, r.name);
@@ -549,7 +546,7 @@ int erts_unregister_name(Process *c_p,
 			       ERTS_PROC_LOCK_MAIN);
 	    current_c_p_locks = c_p_locks;
 #endif
-	    rp->p->reg = NULL;
+	    rp->p->common.u.alive.reg = NULL;
 	    if (IS_TRACED_FL(rp->p, F_TRACE_PROCS)) {
 		trace_proc(c_p, rp->p, am_unregister, r.name);
 	    }
@@ -568,7 +565,7 @@ int erts_unregister_name(Process *c_p,
     reg_write_unlock();
     if (c_prt != port) {
 	if (port) {
-	    erts_smp_port_unlock(port);
+	    erts_port_release(port);
 	}
 	if (c_prt) {
 	    erts_smp_port_lock(c_prt);
diff --git a/erts/emulator/beam/register.h b/erts/emulator/beam/register.h
index 38e8cfbf28..7170463375 100644
--- a/erts/emulator/beam/register.h
+++ b/erts/emulator/beam/register.h
@@ -24,26 +24,19 @@
 #ifndef __REGPROC_H__
 #define __REGPROC_H__
 
-#ifndef __SYS_H__
 #include "sys.h"
-#endif
-
-#ifndef __HASH_H__
 #include "hash.h"
-#endif
-
-#ifndef __PROCESS_H__
 #include "erl_process.h"
-#endif
-
-struct port;
+#define ERL_PORT_GET_PORT_TYPE_ONLY__
+#include "erl_port.h"
+#undef ERL_PORT_GET_PORT_TYPE_ONLY__
 
 typedef struct reg_proc
 {
     HashBucket bucket;  /* MUST BE LOCATED AT TOP OF STRUCT!!! */
     Process *p;         /* The process registered (only one of this and
 			   'pt' is non-NULL */
-    struct port *pt;    /* The port registered */
+    Port *pt;		/* The port registered */
     Eterm name;         /* Atom name */
 } RegProc;
 
@@ -55,12 +48,12 @@ int erts_register_name(Process *, Eterm, Eterm);
 Eterm erts_whereis_name_to_id(Process *, Eterm);
 void erts_whereis_name(Process *, ErtsProcLocks,
 		       Eterm, Process**, ErtsProcLocks, int,
-		       struct port**);
+		       Port**);
 Process *erts_whereis_process(Process *,
 			      ErtsProcLocks,
 			      Eterm,
 			      ErtsProcLocks,
 			      int);
-int erts_unregister_name(Process *, ErtsProcLocks, struct port *, Eterm);
+int erts_unregister_name(Process *, ErtsProcLocks, Port *, Eterm);
 
 #endif
diff --git a/erts/emulator/beam/sys.h b/erts/emulator/beam/sys.h
index f5f10bb616..898a30b010 100644
--- a/erts/emulator/beam/sys.h
+++ b/erts/emulator/beam/sys.h
@@ -116,6 +116,16 @@ typedef ERTS_SYS_FD_TYPE ErtsSysFdType;
 #  define ERTS_DECLARE_DUMMY(X) X
 #endif
 
+#if !defined(__func__)
+#  if !defined(__STDC_VERSION__) || __STDC_VERSION__ < 199901L
+#    if !defined(__GNUC__) ||  __GNUC__ < 2
+#      define __func__ "[unknown_function]"
+#    else
+#      define __func__ __FUNCTION__
+#    endif
+#  endif
+#endif
+
 #if defined(DEBUG) || defined(ERTS_ENABLE_LOCK_CHECK)
 #  undef ERTS_CAN_INLINE
 #  define ERTS_CAN_INLINE 0
@@ -231,9 +241,11 @@ void erl_assert_error(char* expr, char* file, int line);
 #if SIZEOF_VOID_P == 8
 #undef  ARCH_32
 #define ARCH_64
+#define ERTS_SIZEOF_TERM 8
 #elif SIZEOF_VOID_P == 4
 #define ARCH_32
 #undef  ARCH_64
+#define ERTS_SIZEOF_TERM 4
 #else
 #error Neither 32 nor 64 bit architecture
 #endif
@@ -241,6 +253,8 @@ void erl_assert_error(char* expr, char* file, int line);
 #    define HALFWORD_HEAP 1
 #    define HALFWORD_ASSERT 0
 #    define ASSERT_HALFWORD(COND) ASSERT(COND)
+#    undef ERTS_SIZEOF_TERM
+#    define ERTS_SIZEOF_TERM 4
 #else
 #    define HALFWORD_HEAP 0
 #    define HALFWORD_ASSERT 0
@@ -367,6 +381,27 @@ typedef unsigned char byte;
 #error 64-bit architecture, but no appropriate type to use for Uint64 and Sint64 found 
 #endif
 
+#ifdef WORDS_BIGENDIAN
+#  define ERTS_HUINT_HVAL_HIGH 0
+#  define ERTS_HUINT_HVAL_LOW 1
+#else
+#  define ERTS_HUINT_HVAL_HIGH 1
+#  define ERTS_HUINT_HVAL_LOW 0
+#endif
+#if ERTS_SIZEOF_TERM == 8
+typedef union {
+    Uint val;
+    Uint32 hval[2];
+} HUint;
+#elif ERTS_SIZEOF_TERM == 4
+typedef union {
+    Uint val;
+    Uint16 hval[2];
+} HUint;
+#else
+#error "Unsupported size of term"
+#endif
+
 #  define ERTS_EXTRA_DATA_ALIGN_SZ(X) \
     (((size_t) 8) - (((size_t) (X)) & ((size_t) 7)))
 
@@ -505,6 +540,10 @@ __decl_noreturn void __noreturn erl_exit(int n, char*, ...);
 #define ERTS_ABORT_EXIT	(INT_MIN + 1)	/* no crash dump; only abort() */
 #define ERTS_DUMP_EXIT	(INT_MIN + 2)	/* crash dump; then exit() */
 
+#define ERTS_INTERNAL_ERROR(What) \
+    erl_exit(ERTS_ABORT_EXIT, "%s:%d:%s(): Internal error: %s\n", \
+	     __FILE__, __LINE__, __func__, What)
+
 Eterm erts_check_io_info(void *p);
 
 /* Size of misc memory allocated from system dependent code */
@@ -579,6 +618,7 @@ typedef struct _SysDriverOpts {
     char *wd;			/* Working directory. */
     unsigned spawn_type;        /* Bitfield of ERTS_SPAWN_DRIVER | 
 				   ERTS_SPAWN_EXTERNAL | both*/ 
+    int parallelism;            /* Optimize for parallelism */
 } SysDriverOpts;
 
 extern char *erts_default_arg0;
diff --git a/erts/emulator/beam/utils.c b/erts/emulator/beam/utils.c
index 1969fc762c..5261effef9 100644
--- a/erts/emulator/beam/utils.c
+++ b/erts/emulator/beam/utils.c
@@ -46,6 +46,7 @@
 #include "erl_thr_queue.h"
 #include "erl_sched_spec_pre_alloc.h"
 #include "beam_bp.h"
+#include "erl_ptab.h"
 
 #undef M_TRIM_THRESHOLD
 #undef M_TOP_PAD
@@ -3016,12 +3017,13 @@ buf_to_intlist(Eterm** hpp, char *buf, size_t len, Eterm tail)
 **        ;
 ** 
 ** Return remaining bytes in buffer on success
-**        -1 on overflow
-**        -2 on type error (including that result would not be a whole number of bytes)
+**        ERTS_IOLIST_TO_BUF_OVERFLOW on overflow
+**        ERTS_IOLIST_TO_BUF_TYPE_ERROR on type error (including that result would not be a whole number of bytes)
 */
 
-int io_list_to_buf(Eterm obj, char* buf, int len)
+ErlDrvSizeT erts_iolist_to_buf(Eterm obj, char* buf, ErlDrvSizeT alloced_len)
 {
+    ErlDrvSizeT len = (ErlDrvSizeT) alloced_len;
     Eterm* objp;
     DECLARE_ESTACK(s);
     goto L_again;
@@ -3114,20 +3116,20 @@ int io_list_to_buf(Eterm obj, char* buf, int len)
 
  L_type_error:
     DESTROY_ESTACK(s);
-    return -2;
+    return ERTS_IOLIST_TO_BUF_TYPE_ERROR;
 
  L_overflow:
     DESTROY_ESTACK(s);
-    return -1;
+    return ERTS_IOLIST_TO_BUF_OVERFLOW;
 }
 
 /*
  * Return 0 if successful, and non-zero if unsuccessful.
  */
-int erts_iolist_size(Eterm obj, Uint* sizep)
+int erts_iolist_size(Eterm obj, ErlDrvSizeT* sizep)
 {
     Eterm* objp;
-    Uint size = 0;
+    Uint size = 0; /* Intentionally Uint due to halfword heap */
     DECLARE_ESTACK(s);
     goto L_again;
 
@@ -3179,7 +3181,7 @@ int erts_iolist_size(Eterm obj, Uint* sizep)
 #undef SAFE_ADD
 
     DESTROY_ESTACK(s);
-    *sizep = size;
+    *sizep = (ErlDrvSizeT) size;
     return ERTS_IOLIST_OK;
 
  L_overflow_error:
diff --git a/erts/emulator/drivers/common/inet_drv.c b/erts/emulator/drivers/common/inet_drv.c
index 3210ffa92a..236b8710fb 100644
--- a/erts/emulator/drivers/common/inet_drv.c
+++ b/erts/emulator/drivers/common/inet_drv.c
@@ -678,6 +678,8 @@ static int my_strncasecmp(const char *s1, const char *s2, size_t n)
 #define INET_LOPT_UDP_READ_PACKETS 33  /* Number of packets to read */
 #define INET_OPT_RAW               34  /* Raw socket options */
 #define INET_LOPT_TCP_SEND_TIMEOUT_CLOSE 35  /* auto-close on send timeout or not */
+#define INET_LOPT_TCP_MSGQ_HIWTRMRK     36  /* set local high watermark */
+#define INET_LOPT_TCP_MSGQ_LOWTRMRK     37  /* set local low watermark */
 /* SCTP options: a separate range, from 100: */
 #define SCTP_OPT_RTOINFO		100
 #define SCTP_OPT_ASSOCINFO		101
@@ -788,6 +790,8 @@ static int my_strncasecmp(const char *s1, const char *s2, size_t n)
 
 #define INET_HIGH_WATERMARK (1024*8) /* 8k pending high => busy  */
 #define INET_LOW_WATERMARK  (1024*4) /* 4k pending => allow more */
+#define INET_HIGH_MSGQ_WATERMARK (1024*8) /* 8k pending high => busy  */
+#define INET_LOW_MSGQ_WATERMARK  (1024*4) /* 4k pending => allow more */
 
 #define INET_INFINITY  0xffffffff  /* infinity value */
 
@@ -879,7 +883,7 @@ typedef struct subs_list_ {
 
 #define NO_PROCESS 0
 #define NO_SUBSCRIBERS(SLP) ((SLP)->subscriber == NO_PROCESS)
-static void send_to_subscribers(ErlDrvPort, subs_list *, int,
+static void send_to_subscribers(ErlDrvTermData, subs_list *, int,
 				ErlDrvTermData [], int);
 static void free_subscribers(subs_list*);
 static int save_subscriber(subs_list *, ErlDrvTermData);
@@ -1873,8 +1877,7 @@ static int deq_async(inet_descriptor* desc, int* ap, ErlDrvTermData* cp, int* rp
 **     {inet_async, Port, Ref, ok} 
 */
 static int 
-send_async_ok(ErlDrvPort port, ErlDrvTermData Port, int Ref, 
-	      ErlDrvTermData recipient)
+send_async_ok(ErlDrvTermData Port, int Ref,ErlDrvTermData recipient)
 {
     ErlDrvTermData spec[2*LOAD_ATOM_CNT + LOAD_PORT_CNT + 
 			LOAD_INT_CNT + LOAD_TUPLE_CNT];
@@ -1888,14 +1891,14 @@ send_async_ok(ErlDrvPort port, ErlDrvTermData Port, int Ref,
     
     ASSERT(i == sizeof(spec)/sizeof(*spec));
     
-    return driver_send_term(port, recipient, spec, i);
+    return erl_drv_send_term(Port, recipient, spec, i);
 }
 
 /* send message:
 **     {inet_async, Port, Ref, {ok,Port2}} 
 */
 static int 
-send_async_ok_port(ErlDrvPort port, ErlDrvTermData Port, int Ref, 
+send_async_ok_port(ErlDrvTermData Port, int Ref, 
 		   ErlDrvTermData recipient, ErlDrvTermData Port2)
 {
     ErlDrvTermData spec[2*LOAD_ATOM_CNT + 2*LOAD_PORT_CNT + 
@@ -1914,14 +1917,14 @@ send_async_ok_port(ErlDrvPort port, ErlDrvTermData Port, int Ref,
     
     ASSERT(i == sizeof(spec)/sizeof(*spec));
     
-    return driver_send_term(port, recipient, spec, i);
+    return erl_drv_send_term(Port, recipient, spec, i);
 }
 
 /* send message:
 **      {inet_async, Port, Ref, {error,Reason}}
 */
 static int
-send_async_error(ErlDrvPort port, ErlDrvTermData Port, int Ref,
+send_async_error(ErlDrvTermData Port, int Ref,
 		 ErlDrvTermData recipient, ErlDrvTermData Reason)
 {
     ErlDrvTermData spec[3*LOAD_ATOM_CNT + LOAD_PORT_CNT + 
@@ -1939,7 +1942,7 @@ send_async_error(ErlDrvPort port, ErlDrvTermData Port, int Ref,
     i = LOAD_TUPLE(spec, i, 4);
     ASSERT(i == sizeof(spec)/sizeof(*spec));
     DEBUGF(("send_async_error %ld %ld\r\n", recipient, Reason));
-    return driver_send_term(port, recipient, spec, i);
+    return erl_drv_send_term(Port, recipient, spec, i);
 }
 
 
@@ -1951,7 +1954,7 @@ static int async_ok(inet_descriptor* desc)
 
     if (deq_async(desc, &aid, &caller, &req) < 0)
 	return -1;
-    return send_async_ok(desc->port, desc->dport, aid, caller);
+    return send_async_ok(desc->dport, aid, caller);
 }
 
 static int async_ok_port(inet_descriptor* desc, ErlDrvTermData Port2)
@@ -1962,7 +1965,7 @@ static int async_ok_port(inet_descriptor* desc, ErlDrvTermData Port2)
 
     if (deq_async(desc, &aid, &caller, &req) < 0)
 	return -1;
-    return send_async_ok_port(desc->port, desc->dport, aid, caller, Port2);
+    return send_async_ok_port(desc->dport, aid, caller, Port2);
 }
 
 static int async_error_am(inet_descriptor* desc, ErlDrvTermData reason)
@@ -1973,8 +1976,7 @@ static int async_error_am(inet_descriptor* desc, ErlDrvTermData reason)
 
     if (deq_async(desc, &aid, &caller, &req) < 0)
 	return -1;
-    return send_async_error(desc->port, desc->dport, aid, caller,
-			    reason);
+    return send_async_error(desc->dport, aid, caller, reason);
 }
 
 /* dequeue all operations */
@@ -1985,8 +1987,7 @@ static int async_error_am_all(inet_descriptor* desc, ErlDrvTermData reason)
     ErlDrvTermData caller;
 
     while (deq_async(desc, &aid, &caller, &req) == 0) {
-	send_async_error(desc->port, desc->dport, aid, caller,
-			 reason);
+	send_async_error(desc->dport, aid, caller, reason);
     }
     return 0;
 }
@@ -2014,7 +2015,7 @@ static int inet_reply_ok(inet_descriptor* desc)
     ASSERT(i == sizeof(spec)/sizeof(*spec));
     
     desc->caller = 0;
-    return driver_send_term(desc->port, caller, spec, i);    
+    return erl_drv_send_term(desc->dport, caller, spec, i);    
 }
 
 #ifdef HAVE_SCTP
@@ -2033,7 +2034,7 @@ static int inet_reply_ok_port(inet_descriptor* desc, ErlDrvTermData dport)
     ASSERT(i == sizeof(spec)/sizeof(*spec));
 
     desc->caller = 0;
-    return driver_send_term(desc->port, caller, spec, i);
+    return erl_drv_send_term(desc->dport, caller, spec, i);
 }
 #endif
 
@@ -2056,7 +2057,7 @@ static int inet_reply_error_am(inet_descriptor* desc, ErlDrvTermData reason)
     desc->caller = 0;
     
     DEBUGF(("inet_reply_error_am %ld %ld\r\n", caller, reason));
-    return driver_send_term(desc->port, caller, spec, i);
+    return erl_drv_send_term(desc->dport, caller, spec, i);
 }
 
 /* send:
@@ -2165,12 +2166,12 @@ static int http_response_inetdrv(void *arg, int major, int minor,
         i = LOAD_TUPLE(spec, i, 2);
         i = LOAD_TUPLE(spec, i, 4);
         ASSERT(i<=27);
-        return driver_send_term(desc->inet.port, caller, spec, i);
+        return erl_drv_send_term(desc->inet.dport, caller, spec, i);
     }
     else {
         i = LOAD_TUPLE(spec, i, 3);
         ASSERT(i<=27);
-        return driver_output_term(desc->inet.port, spec, i);
+        return erl_drv_output_term(desc->inet.dport, spec, i);
     }
 }
 
@@ -2262,12 +2263,12 @@ http_request_inetdrv(void* arg, const http_atom_t* meth, const char* meth_ptr,
         i = LOAD_TUPLE(spec, i, 2);
         i = LOAD_TUPLE(spec, i, 4);
         ASSERT(i <= 43);
-        return driver_send_term(desc->inet.port, caller, spec, i);
+        return erl_drv_send_term(desc->inet.dport, caller, spec, i);
     }
     else {
         i = LOAD_TUPLE(spec, i, 3);
         ASSERT(i <= 43);
-        return driver_output_term(desc->inet.port, spec, i);
+        return erl_drv_output_term(desc->inet.dport, spec, i);
     }
 }
 
@@ -2316,12 +2317,12 @@ http_header_inetdrv(void* arg, const http_atom_t* name, const char* name_ptr,
         i = LOAD_TUPLE(spec, i, 2);
         i = LOAD_TUPLE(spec, i, 4);
         ASSERT(i <= 26);
-        return driver_send_term(desc->inet.port, caller, spec, i);
+        return erl_drv_send_term(desc->inet.dport, caller, spec, i);
     }
     else {
         i = LOAD_TUPLE(spec, i, 3);
         ASSERT(i <= 26);
-        return driver_output_term(desc->inet.port, spec, i);
+        return erl_drv_output_term(desc->inet.dport, spec, i);
     }
 }
 
@@ -2347,7 +2348,7 @@ static int http_eoh_inetdrv(void* arg)
     i = LOAD_TUPLE(spec, i, 2);
     i = LOAD_TUPLE(spec, i, 4);
     ASSERT(i <= 14);
-    return driver_send_term(desc->inet.port, caller, spec, i);
+    return erl_drv_send_term(desc->inet.dport, caller, spec, i);
   }
   else {
       /* {http, S, http_eoh} */
@@ -2356,7 +2357,7 @@ static int http_eoh_inetdrv(void* arg)
       i = LOAD_ATOM(spec, i,  am_http_eoh);
       i = LOAD_TUPLE(spec, i, 3);
       ASSERT(i <= 14);
-      return driver_output_term(desc->inet.port, spec, i);
+      return erl_drv_output_term(desc->inet.dport, spec, i);
   }
 }
 
@@ -2384,7 +2385,7 @@ static int http_error_inetdrv(void* arg, const char* buf, int len)
     i = LOAD_TUPLE(spec, i, 2);
     i = LOAD_TUPLE(spec, i, 4);
     ASSERT(i <= 19);
-    return driver_send_term(desc->inet.port, caller, spec, i);
+    return erl_drv_send_term(desc->inet.dport, caller, spec, i);
   }
   else {
       /* {http, S, {http_error,Line} */
@@ -2395,7 +2396,7 @@ static int http_error_inetdrv(void* arg, const char* buf, int len)
       i = LOAD_TUPLE(spec, i, 2);
       i = LOAD_TUPLE(spec, i, 3);
       ASSERT(i <= 19);
-      return driver_output_term(desc->inet.port, spec, i);
+      return erl_drv_output_term(desc->inet.dport, spec, i);
   }
 }
 
@@ -2448,11 +2449,11 @@ int ssl_tls_inetdrv(void* arg, unsigned type, unsigned major, unsigned minor,
         i = LOAD_TUPLE(spec, i, 2);
         i = LOAD_TUPLE(spec, i, 4);
         ASSERT(i <= 28);
-        ret = driver_send_term(desc->inet.port, caller, spec, i);
+        ret = erl_drv_send_term(desc->inet.dport, caller, spec, i);
     }
     else {
         ASSERT(i <= 28);
-        ret = driver_output_term(desc->inet.port, spec, i);
+        ret = erl_drv_output_term(desc->inet.dport, spec, i);
     }
 done:
     driver_free_binary(bin);
@@ -2502,7 +2503,7 @@ static int inet_async_data(inet_descriptor* desc, const char* buf, int len)
 	i = LOAD_TUPLE(spec, i, 4);
 	ASSERT(i == 15);
 	desc->caller = 0;
-	return driver_send_term(desc->port, caller, spec, i);
+	return erl_drv_send_term(desc->dport, caller, spec, i);
     }
     else {
 	/* INET_MODE_BINARY => [H1,H2,...HSz | Binary] */
@@ -2516,7 +2517,7 @@ static int inet_async_data(inet_descriptor* desc, const char* buf, int len)
 	i = LOAD_TUPLE(spec, i, 4);
 	ASSERT(i <= 20);
 	desc->caller = 0;
-	code = driver_send_term(desc->port, caller, spec, i);
+	code = erl_drv_send_term(desc->dport, caller, spec, i);
 	return code;
     }
 }
@@ -3109,7 +3110,7 @@ inet_async_binary_data
 
     ASSERT(i <= PACKET_ERL_DRV_TERM_DATA_LEN);    
     desc->caller = 0;
-    return driver_send_term(desc->port, caller, spec, i);
+    return erl_drv_send_term(desc->dport, caller, spec, i);
 }
 
 /* 
@@ -3132,7 +3133,7 @@ static int tcp_message(inet_descriptor* desc, const char* buf, int len)
 	i = LOAD_STRING(spec, i, buf, len); /* => [H1,H2,...Hn] */ 
 	i = LOAD_TUPLE(spec, i, 3);
 	ASSERT(i <= 20);
-	return driver_output_term(desc->port, spec, i);
+	return erl_drv_output_term(desc->dport, spec, i);
     }
     else {
 	/* INET_MODE_BINARY => [H1,H2,...HSz | Binary] */
@@ -3144,7 +3145,7 @@ static int tcp_message(inet_descriptor* desc, const char* buf, int len)
 	    i = LOAD_STRING_CONS(spec, i, buf, hsz);
 	i = LOAD_TUPLE(spec, i, 3);
 	ASSERT(i <= 20);
-	code = driver_output_term(desc->port, spec, i);
+	code = erl_drv_output_term(desc->dport, spec, i);
 	return code;
     }
 }
@@ -3179,7 +3180,7 @@ tcp_binary_message(inet_descriptor* desc, ErlDrvBinary* bin, int offs, int len)
     }
     i = LOAD_TUPLE(spec, i, 3);
     ASSERT(i <= 20);
-    return driver_output_term(desc->port, spec, i);
+    return erl_drv_output_term(desc->dport, spec, i);
 }
 
 /*
@@ -3198,7 +3199,7 @@ static int tcp_closed_message(tcp_descriptor* desc)
 	i = LOAD_PORT(spec, i, desc->inet.dport);
 	i = LOAD_TUPLE(spec, i, 2);
 	ASSERT(i <= 6);
-	return driver_output_term(desc->inet.port, spec, i);
+	return erl_drv_output_term(desc->inet.dport, spec, i);
     } 
     return 0;
 }
@@ -3219,7 +3220,7 @@ static int tcp_error_message(tcp_descriptor* desc, int err)
     i = LOAD_ATOM(spec, i, am_err);
     i = LOAD_TUPLE(spec, i, 3);
     ASSERT(i <= 8);
-    return driver_output_term(desc->inet.port, spec, i);
+    return erl_drv_output_term(desc->inet.dport, spec, i);
 }
 
 /* 
@@ -3310,7 +3311,7 @@ static int packet_binary_message
     /* Close up the outer 5-tuple: */
     i = LOAD_TUPLE(spec, i, 5);
     ASSERT(i <= PACKET_ERL_DRV_TERM_DATA_LEN);
-    return driver_output_term(desc->port, spec, i);
+    return erl_drv_output_term(desc->dport, spec, i);
 }
 
 /*
@@ -3337,7 +3338,7 @@ static int packet_error_message(udp_descriptor* udesc, int err)
     i = LOAD_ATOM(spec, i, am_err);
     i = LOAD_TUPLE(spec, i, 3);
     ASSERT(i == sizeof(spec)/sizeof(*spec));
-    return driver_output_term(desc->port, spec, i);
+    return erl_drv_output_term(desc->dport, spec, i);
 }
 
 
@@ -5465,6 +5466,28 @@ static int inet_set_opts(inet_descriptor* desc, char* ptr, int len)
 	    }
 	    continue;
 
+	case INET_LOPT_TCP_MSGQ_HIWTRMRK:
+	    if (desc->stype == SOCK_STREAM) {
+		ErlDrvSizeT high;
+		if (ival < ERL_DRV_BUSY_MSGQ_LIM_MIN
+		    || ERL_DRV_BUSY_MSGQ_LIM_MAX < ival)
+		    return -1;
+		high = (ErlDrvSizeT) ival;
+		erl_drv_busy_msgq_limits(desc->port, NULL, &high);
+	    }
+	    continue;
+
+	case INET_LOPT_TCP_MSGQ_LOWTRMRK:
+	    if (desc->stype == SOCK_STREAM) {
+		ErlDrvSizeT low;
+		if (ival < ERL_DRV_BUSY_MSGQ_LIM_MIN
+		    || ERL_DRV_BUSY_MSGQ_LIM_MAX < ival)
+		    return -1;
+		low = (ErlDrvSizeT) ival;
+		erl_drv_busy_msgq_limits(desc->port, &low, NULL);
+	    }
+	    continue;
+
 	case INET_LOPT_TCP_SEND_TIMEOUT:
 	    if (desc->stype == SOCK_STREAM) {
 		tcp_descriptor* tdesc = (tcp_descriptor*) desc;
@@ -6365,6 +6388,32 @@ static ErlDrvSSizeT inet_fill_opts(inet_descriptor* desc,
 	    }
 	    continue;
 
+	case INET_LOPT_TCP_MSGQ_HIWTRMRK:
+	    if (desc->stype == SOCK_STREAM) {
+		ErlDrvSizeT high = ERL_DRV_BUSY_MSGQ_READ_ONLY;
+		*ptr++ = opt;
+		erl_drv_busy_msgq_limits(desc->port, NULL, &high);
+		ival = high > INT_MAX ? INT_MAX : (int) high;
+		put_int32(ival, ptr);
+	    }
+	    else {
+		TRUNCATE_TO(0,ptr);
+	    }
+	    continue;
+
+	case INET_LOPT_TCP_MSGQ_LOWTRMRK:
+	    if (desc->stype == SOCK_STREAM) {
+		ErlDrvSizeT low = ERL_DRV_BUSY_MSGQ_READ_ONLY;
+		*ptr++ = opt;
+		erl_drv_busy_msgq_limits(desc->port, &low, NULL);
+		ival = low > INT_MAX ? INT_MAX : (int) low;
+		put_int32(ival, ptr);
+	    }
+	    else {
+		TRUNCATE_TO(0,ptr);
+	    }
+	    continue;
+
 	case INET_LOPT_TCP_SEND_TIMEOUT:
 	    if (desc->stype == SOCK_STREAM) {
 		*ptr++ = opt;
@@ -7278,7 +7327,7 @@ static ErlDrvSSizeT sctp_fill_opts(inet_descriptor* desc,
     i = LOAD_TUPLE(spec, i, 3);
 
     /* Now, convert "spec" into the returnable term: */
-    driver_send_term(desc->port, driver_caller(desc->port), spec, i);
+    erl_drv_send_term(desc->dport, driver_caller(desc->port), spec, i);
     FREE(spec);
 
     (*dest)[0] = INET_REP;
@@ -7360,7 +7409,7 @@ send_empty_out_q_msgs(inet_descriptor* desc)
 
   ASSERT(msg_len == sizeof(msg)/sizeof(*msg));
 
-  send_to_subscribers(desc->port,
+  send_to_subscribers(desc->dport,
 		      &desc->empty_out_q_subs,
 		      1,
 		      msg,
@@ -8007,6 +8056,7 @@ static int tcp_inet_init(void)
 
 static ErlDrvData tcp_inet_start(ErlDrvPort port, char* args)
 {
+    ErlDrvSizeT q_low, q_high;
     tcp_descriptor* desc;
     DEBUGF(("tcp_inet_start(%ld) {\r\n", (long)port));
 
@@ -8016,6 +8066,17 @@ static ErlDrvData tcp_inet_start(ErlDrvPort port, char* args)
 	return ERL_DRV_ERROR_ERRNO;
     desc->high = INET_HIGH_WATERMARK;
     desc->low  = INET_LOW_WATERMARK;
+    q_high = INET_HIGH_MSGQ_WATERMARK;
+    q_low = INET_LOW_MSGQ_WATERMARK;
+    if (q_low < ERL_DRV_BUSY_MSGQ_LIM_MIN)
+	q_low = ERL_DRV_BUSY_MSGQ_LIM_MIN;
+    else if (q_low > ERL_DRV_BUSY_MSGQ_LIM_MAX)
+	q_low = ERL_DRV_BUSY_MSGQ_LIM_MAX;
+    if (q_high < ERL_DRV_BUSY_MSGQ_LIM_MIN)
+	q_high = ERL_DRV_BUSY_MSGQ_LIM_MIN;
+    else if (q_high > ERL_DRV_BUSY_MSGQ_LIM_MAX)
+	q_high = ERL_DRV_BUSY_MSGQ_LIM_MAX;
+    erl_drv_busy_msgq_limits(port, &q_low, &q_high);
     desc->send_timeout = INET_INFINITY;
     desc->send_timeout_close = 0;
     desc->busy_on_send = 0;
@@ -8039,6 +8100,7 @@ static ErlDrvData tcp_inet_start(ErlDrvPort port, char* args)
 static tcp_descriptor* tcp_inet_copy(tcp_descriptor* desc,SOCKET s,
 				     ErlDrvTermData owner, int* err)
 {
+    ErlDrvSizeT q_low, q_high;
     ErlDrvPort port = desc->inet.port;
     tcp_descriptor* copy_desc;
 
@@ -8076,6 +8138,13 @@ static tcp_descriptor* tcp_inet_copy(tcp_descriptor* desc,SOCKET s,
 	FREE(copy_desc);
 	return NULL;
     }
+
+    /* Read busy msgq limits of parent */
+    q_low = q_high = ERL_DRV_BUSY_MSGQ_READ_ONLY;
+    erl_drv_busy_msgq_limits(desc->inet.port, &q_low, &q_high);
+    /* Write same busy msgq limits to child */
+    erl_drv_busy_msgq_limits(port, &q_low, &q_high);
+
     copy_desc->inet.port = port;
     copy_desc->inet.dport = driver_mk_port(port);
     *err = 0;
@@ -8108,7 +8177,7 @@ static void tcp_close_check(tcp_descriptor* desc)
 	desc->inet.state = INET_STATE_LISTENING;
 	while (deq_multi_op(desc,&id,&req,&caller,NULL,&monitor) == 0) {
 	    driver_demonitor_process(desc->inet.port, &monitor);
-	    send_async_error(desc->inet.port, desc->inet.dport, id, caller, am_closed);
+	    send_async_error(desc->inet.dport, id, caller, am_closed);
 	}
 	clean_multi_timers(&(desc->mtd), desc->inet.port);
     }
@@ -8532,7 +8601,7 @@ static void tcp_inet_multi_timeout(ErlDrvData e, ErlDrvTermData caller)
 	sock_select(INETP(desc),FD_ACCEPT,0);
 	desc->inet.state = INET_STATE_LISTENING; /* restore state */
     }
-    send_async_error(desc->inet.port, desc->inet.dport, id, caller, am_timeout);
+    send_async_error(desc->inet.dport, id, caller, am_timeout);
 }
     
 
@@ -9273,7 +9342,7 @@ static int tcp_inet_input(tcp_descriptor* desc, HANDLE event)
 	    
 	    
 	    if (s == INVALID_SOCKET) { /* Not ERRNO_BLOCK, that's handled right away */
-		ret = send_async_error(desc->inet.port, desc->inet.dport, 
+		ret = send_async_error(desc->inet.dport, 
 				       id, caller, error_atom(sock_errno()));
 		goto done;
 	    }
@@ -9283,7 +9352,7 @@ static int tcp_inet_input(tcp_descriptor* desc, HANDLE event)
 		
 		if ((accept_desc = tcp_inet_copy(desc,s,caller,&err)) == NULL) {
 		    sock_close(s);
-		    ret = send_async_error(desc->inet.port, desc->inet.dport, 
+		    ret = send_async_error(desc->inet.dport, 
 					   id, caller, error_atom(err));
 		    goto done;
 		}
@@ -9294,7 +9363,7 @@ static int tcp_inet_input(tcp_descriptor* desc, HANDLE event)
 			      ERL_DRV_READ, 1);
 #endif
 		accept_desc->inet.state = INET_STATE_CONNECTED;
-		ret =  send_async_ok_port(desc->inet.port, desc->inet.dport, 
+		ret =  send_async_ok_port(desc->inet.dport, 
 					  id, caller, accept_desc->inet.dport);
 	    }
 	}
@@ -10936,7 +11005,7 @@ subs_list *subs;
 
 static void send_to_subscribers
 (
-    ErlDrvPort	   port,
+    ErlDrvTermData port,
     subs_list	   *subs,
     int		   free_subs,
     ErlDrvTermData msg[],
@@ -10953,7 +11022,7 @@ static void send_to_subscribers
   this = subs;
   while(this) {
     
-    (void) driver_send_term(port, this->subscriber, msg, msg_len);
+    (void) erl_drv_send_term(port, this->subscriber, msg, msg_len);
 
     if(free_subs && !first) {
       next = this->next;
diff --git a/erts/emulator/hipe/hipe_bif_list.m4 b/erts/emulator/hipe/hipe_bif_list.m4
index ab078b9583..764b8d180c 100644
--- a/erts/emulator/hipe/hipe_bif_list.m4
+++ b/erts/emulator/hipe/hipe_bif_list.m4
@@ -145,6 +145,7 @@
  * Zero-arity BIFs that can fail.
  */
 standard_bif_interface_0(nbif_processes_0, processes_0)
+standard_bif_interface_0(nbif_ports_0, ports_0)
 
 /*
  * BIFs and primops that may do a GC (change heap limit and walk the native stack).
diff --git a/erts/emulator/hipe/hipe_debug.c b/erts/emulator/hipe/hipe_debug.c
index 37615bf718..f2e9d03607 100644
--- a/erts/emulator/hipe/hipe_debug.c
+++ b/erts/emulator/hipe/hipe_debug.c
@@ -189,11 +189,10 @@ void hipe_print_pcb(Process *p)
     U("old_head   ", old_heap);
     U("min_heap_..", min_heap_size);
     U("rcount     ", rcount);
-    U("id         ", id);
-    U("prio       ", prio);
+    U("id         ", common.id);
     U("reds       ", reds);
-    U("tracer_pr..", tracer_proc);
-    U("trace_fla..", trace_flags);
+    U("tracer_pr..", common.tracer_proc);
+    U("trace_fla..", common.trace_flags);
     U("group_lea..", group_leader);
     U("flags      ", flags);
     U("fvalue     ", fvalue);
@@ -202,8 +201,8 @@ void hipe_print_pcb(Process *p)
     /*XXX: ErlTimer tm; */
     U("next       ", next);
     /*XXX: ErlOffHeap off_heap; */
-    U("reg        ", reg);
-    U("nlinks     ", nlinks);
+    U("reg        ", common.u.alive.reg);
+    U("nlinks     ", common.u.alive.links);
     /*XXX: ErlMessageQueue msg; */
     U("mbuf       ", mbuf);
     U("mbuf_sz    ", mbuf_sz);
diff --git a/erts/emulator/hipe/hipe_mkliterals.c b/erts/emulator/hipe/hipe_mkliterals.c
index cbbf1db2e5..5911d76ad9 100644
--- a/erts/emulator/hipe/hipe_mkliterals.c
+++ b/erts/emulator/hipe/hipe_mkliterals.c
@@ -267,7 +267,7 @@ static const struct literal {
     { "P_HP_LIMIT", offsetof(struct process, stop) },
     { "P_OFF_HEAP_FIRST", offsetof(struct process, off_heap.first) },
     { "P_MBUF", offsetof(struct process, mbuf) },
-    { "P_ID", offsetof(struct process, id) },
+    { "P_ID", offsetof(struct process, common.id) },
     { "P_FLAGS", offsetof(struct process, flags) },
     { "P_FVALUE", offsetof(struct process, fvalue) },
     { "P_FREASON", offsetof(struct process, freason) },
diff --git a/erts/emulator/sys/common/erl_check_io.c b/erts/emulator/sys/common/erl_check_io.c
index ce014c19c2..474408ae7c 100644
--- a/erts/emulator/sys/common/erl_check_io.c
+++ b/erts/emulator/sys/common/erl_check_io.c
@@ -200,17 +200,6 @@ static void event_large_fd_error(ErlDrvPort, ErtsSysFdType, ErlDrvEventData);
 #endif
 static void steal_pending_stop_select(erts_dsprintf_buf_t*, ErlDrvPort,
 				      ErtsDrvEventState*, int mode, int on);
-static ERTS_INLINE Eterm
-drvport2id(ErlDrvPort dp)
-{
-    Port *pp = erts_drvport2port(dp);
-    if (pp)
-	return pp->id;
-    else {
-	ASSERT(0);
-	return am_undefined;
-    }
-}
 
 #ifdef ERTS_SMP
 ERTS_SCHED_PREF_QUICK_ALLOC_IMPL(removed_fd, struct removed_fd, 64, ERTS_ALC_T_FD_LIST)
@@ -378,7 +367,7 @@ abort_task(Eterm id, ErtsPortTaskHandle *pthp, EventStateType type)
 	       || !erts_port_task_is_scheduled(pthp));
     }
     else if (erts_port_task_is_scheduled(pthp)) {
-	erts_port_task_abort(id, pthp);
+	erts_port_task_abort(pthp);
 	ASSERT(erts_is_port_alive(id));
     }
 }
@@ -492,7 +481,7 @@ ERTS_CIO_EXPORT(driver_select)(ErlDrvPort ix,
 			       int on)
 {
     void (*stop_select_fn)(ErlDrvEvent, void*) = NULL;
-    Eterm id = drvport2id(ix);
+    Eterm id = erts_drvport2id(ix);
     ErtsSysFdType fd = (ErtsSysFdType) e;
     ErtsPollEvents ctl_events = (ErtsPollEvents) 0;
     ErtsPollEvents new_events, old_events;
@@ -503,8 +492,8 @@ ERTS_CIO_EXPORT(driver_select)(ErlDrvPort ix,
     DTRACE_CHARBUF(name, 64);
 #endif
     
-    ERTS_SMP_LC_ASSERT(erts_drvport2port(ix)
-		       && erts_lc_is_port_locked(erts_drvport2port(ix)));
+    ERTS_SMP_LC_ASSERT(erts_drvport2port(ix, NULL)
+		       && erts_lc_is_port_locked(erts_drvport2port(ix, NULL)));
 
 #ifdef ERTS_SYS_CONTINOUS_FD_NUMBERS
     if ((unsigned)fd >= (unsigned)erts_smp_atomic_read_nob(&drv_ev_state_len)) {
@@ -530,9 +519,9 @@ ERTS_CIO_EXPORT(driver_select)(ErlDrvPort ix,
     if (!on && (mode&ERL_DRV_USE_NO_CALLBACK) == ERL_DRV_USE) {
 	if (IS_FD_UNKNOWN(state)) {
 	    /* fast track to stop_select callback */
-	    stop_select_fn = erts_drvport2port(ix)->drv_ptr->stop_select;
+	    stop_select_fn = erts_drvport2port(ix, NULL)->drv_ptr->stop_select;
 #ifdef USE_VM_PROBES
-	    strncpy(name, erts_drvport2port(ix)->drv_ptr->name, sizeof(name)-1);
+	    strncpy(name, erts_drvport2port(ix, NULL)->drv_ptr->name, sizeof(name)-1);
 	    name[sizeof(name)-1] = '\0';
 #endif
 	    ret = 0;
@@ -665,14 +654,14 @@ ERTS_CIO_EXPORT(driver_select)(ErlDrvPort ix,
 		}
 	    }
 	    if ((mode & ERL_DRV_USE_NO_CALLBACK) == ERL_DRV_USE) {
-		erts_driver_t* drv_ptr = erts_drvport2port(ix)->drv_ptr;
+		erts_driver_t* drv_ptr = erts_drvport2port(ix, NULL)->drv_ptr;
 		ASSERT(new_events==0);
 		if (state->remove_cnt == 0 || !wake_poller) {
 		    /* Safe to close fd now as it is not in pollset
 		       or there was no need to eject fd (kernel poll) */
 		    stop_select_fn = drv_ptr->stop_select;
 #ifdef USE_VM_PROBES
-		    strncpy(name, erts_drvport2port(ix)->drv_ptr->name, sizeof(name)-1);
+		    strncpy(name, erts_drvport2port(ix, NULL)->drv_ptr->name, sizeof(name)-1);
 		    name[sizeof(name)-1] = '\0';
 #endif
 		}
@@ -719,13 +708,13 @@ ERTS_CIO_EXPORT(driver_event)(ErlDrvPort ix,
     ErtsPollEvents events;
     ErtsPollEvents add_events;
     ErtsPollEvents remove_events;
-    Eterm id = drvport2id(ix);
+    Eterm id = erts_drvport2id(ix);
     ErtsDrvEventState *state;
     int do_wake = 0;
     int ret;
 
-    ERTS_SMP_LC_ASSERT(erts_drvport2port(ix)
-		       && erts_lc_is_port_locked(erts_drvport2port(ix)));
+    ERTS_SMP_LC_ASSERT(erts_drvport2port(ix, NULL)
+		       && erts_lc_is_port_locked(erts_drvport2port(ix, NULL)));
 
 #ifdef ERTS_SYS_CONTINOUS_FD_NUMBERS
     if ((unsigned)fd >= (unsigned)erts_smp_atomic_read_nob(&drv_ev_state_len)) {
@@ -960,7 +949,7 @@ static void
 print_select_op(erts_dsprintf_buf_t *dsbufp,
 		ErlDrvPort ix, ErtsSysFdType fd, int mode, int on)
 {
-    Port *pp = erts_drvport2port(ix);
+    Port *pp = erts_drvport2port(ix, NULL);
     erts_dsprintf(dsbufp,
 		  "driver_select(%p, %d,%s%s%s%s, %d) "
 		  "by ",
@@ -971,8 +960,8 @@ print_select_op(erts_dsprintf_buf_t *dsbufp,
 		  mode & ERL_DRV_USE ? " ERL_DRV_USE" : "",
 		  mode & (ERL_DRV_USE_NO_CALLBACK & ~ERL_DRV_USE) ? "_NO_CALLBACK" : "",
 		  on);
-    print_driver_name(dsbufp, pp->id);
-    erts_dsprintf(dsbufp, "driver %T ", pp ? pp->id : NIL);
+    print_driver_name(dsbufp, pp->common.id);
+    erts_dsprintf(dsbufp, "driver %T ", pp ? pp->common.id : NIL);
 }
 
 static void
@@ -1031,7 +1020,7 @@ steal_pending_stop_select(erts_dsprintf_buf_t *dsbufp, ErlDrvPort ix,
 	state->driver.drv_ptr = NULL;
     }
     else if ((mode & ERL_DRV_USE_NO_CALLBACK) == ERL_DRV_USE) {
-	erts_driver_t* drv_ptr = erts_drvport2port(ix)->drv_ptr;
+	erts_driver_t* drv_ptr = erts_drvport2port(ix, NULL)->drv_ptr;
 	if (drv_ptr != state->driver.drv_ptr) {
 	    /* Some other driver wants the stop_select callback */
 	    if (state->driver.drv_ptr->handle) {
@@ -1053,7 +1042,7 @@ static void
 print_event_op(erts_dsprintf_buf_t *dsbufp,
 	       ErlDrvPort ix, ErtsSysFdType fd, ErlDrvEventData event_data)
 {
-    Port *pp = erts_drvport2port(ix);
+    Port *pp = erts_drvport2port(ix, NULL);
     erts_dsprintf(dsbufp, "driver_event(%p, %d, ", ix, (int) fd);
     if (!event_data)
 	erts_dsprintf(dsbufp, "NULL");
@@ -1062,8 +1051,8 @@ print_event_op(erts_dsprintf_buf_t *dsbufp,
 		      (unsigned int) event_data->events,
 		      (unsigned int) event_data->revents);
     erts_dsprintf(dsbufp, ") by ");
-    print_driver_name(dsbufp, pp->id);
-    erts_dsprintf(dsbufp, "driver %T ", pp ? pp->id : NIL);
+    print_driver_name(dsbufp, pp->common.id);
+    erts_dsprintf(dsbufp, "driver %T ", pp ? pp->common.id : NIL);
 }
 
 static void
@@ -1100,8 +1089,7 @@ iready(Eterm id, ErtsDrvEventState *state)
     if (erts_port_task_schedule(id,
 				&state->driver.select->intask,
 				ERTS_PORT_TASK_INPUT,
-				(ErlDrvEvent) state->fd,
-				NULL) != 0) {
+				(ErlDrvEvent) state->fd) != 0) {
 	stale_drv_select(id, state, ERL_DRV_READ);
     }
 }
@@ -1112,8 +1100,7 @@ oready(Eterm id, ErtsDrvEventState *state)
     if (erts_port_task_schedule(id,
 				&state->driver.select->outtask,
 				ERTS_PORT_TASK_OUTPUT,
-				(ErlDrvEvent) state->fd,
-				NULL) != 0) {
+				(ErlDrvEvent) state->fd) != 0) {
 	stale_drv_select(id, state, ERL_DRV_WRITE);
     }
 }
diff --git a/erts/emulator/sys/unix/sys.c b/erts/emulator/sys/unix/sys.c
index 9e7cbc017f..0b96eded76 100644
--- a/erts/emulator/sys/unix/sys.c
+++ b/erts/emulator/sys/unix/sys.c
@@ -123,7 +123,8 @@ struct ErtsSysReportExit_ {
 
 /* This data is shared by these drivers - initialized by spawn_init() */
 static struct driver_data {
-    int port_num, ofd, packet_bytes;
+    ErlDrvPort port_num;
+    int ofd, packet_bytes;
     ErtsSysReportExit *report_exit;
     int pid;
     int alive;
@@ -731,7 +732,8 @@ prepare_crash_dump(int secs)
 	list = CONS(hp, make_small(8), list); hp += 2;
 
 	/* send to heart port, CMD = 8, i.e. prepare crash dump =o */
-	erts_write_to_port(ERTS_INVALID_PID, heart_port, list);
+	erts_port_output(NULL, ERTS_PORT_SIG_FLG_FORCE_IMM_CALL, heart_port,
+			 heart_port->common.id, list, NULL);
     }
 
     /* Make sure we unregister at epmd (unknown fd) and get at least
@@ -1182,7 +1184,7 @@ static RETSIGTYPE onchld(int signum)
 #endif
 }
 
-static int set_driver_data(int port_num,
+static int set_driver_data(ErlDrvPort port_num,
 			   int ifd,
 			   int ofd,
 			   int packet_bytes,
@@ -1190,6 +1192,7 @@ static int set_driver_data(int port_num,
 			   int exit_status,
 			   int pid)
 {
+    Port *prt;
     ErtsSysReportExit *report_exit;
 
     if (!exit_status)
@@ -1198,7 +1201,7 @@ static int set_driver_data(int port_num,
 	report_exit = erts_alloc(ERTS_ALC_T_PRT_REP_EXIT,
 				 sizeof(ErtsSysReportExit));
 	report_exit->next = report_exit_list;
-	report_exit->port = erts_port[port_num].id;
+	report_exit->port = erts_drvport2id(port_num);
 	report_exit->pid = pid;
 	report_exit->ifd = read_write & DO_READ ? ifd : -1;
 	report_exit->ofd = read_write & DO_WRITE ? ofd : -1;
@@ -1208,7 +1211,9 @@ static int set_driver_data(int port_num,
 	report_exit_list = report_exit;
     }
 
-    erts_port[port_num].os_pid = pid;
+    prt = erts_drvport2port(port_num, NULL);
+    if (prt)
+	prt->os_pid = pid;
 
     if (read_write & DO_READ) {
 	driver_data[ifd].packet_bytes = packet_bytes;
@@ -1281,7 +1286,7 @@ static void close_pipes(int ifd[2], int ofd[2], int read_write)
     }
 }
 
-static void init_fd_data(int fd, int prt)
+static void init_fd_data(int fd, ErlDrvPort port_num)
 {
     fd_data[fd].buf = NULL;
     fd_data[fd].cpos = NULL;
@@ -1971,7 +1976,7 @@ static void clear_fd_data(int fd)
     fd_data[fd].psz = 0;
 }
 
-static void nbio_stop_fd(int prt, int fd)
+static void nbio_stop_fd(ErlDrvPort prt, int fd)
 {
     driver_select(prt,fd,DO_READ|DO_WRITE,0);
     clear_fd_data(fd);
@@ -2019,7 +2024,8 @@ static ErlDrvData vanilla_start(ErlDrvPort port_num, char* name,
 
 static void stop(ErlDrvData fd)
 {
-    int prt, ofd;
+    ErlDrvPort prt;
+    int ofd;
 
     prt = driver_data[(int)(long)fd].port_num;
     nbio_stop_fd(prt, (int)(long)fd);
@@ -2032,7 +2038,7 @@ static void stop(ErlDrvData fd)
 
     CHLD_STAT_LOCK;
 
-    /* Mark as unused. Maybe resetting the 'port_num' slot is better? */
+    /* Mark as unused. */
     driver_data[(int)(long)fd].pid = -1;
 
     CHLD_STAT_UNLOCK;
@@ -2048,7 +2054,7 @@ static void stop(ErlDrvData fd)
 static void outputv(ErlDrvData e, ErlIOVec* ev)
 {
     int fd = (int)(long)e;
-    int ix = driver_data[fd].port_num;
+    ErlDrvPort ix = driver_data[fd].port_num;
     int pb = driver_data[fd].packet_bytes;
     int ofd = driver_data[fd].ofd;
     ssize_t n;
@@ -2098,7 +2104,7 @@ static void outputv(ErlDrvData e, ErlIOVec* ev)
 static void output(ErlDrvData e, char* buf, ErlDrvSizeT len)
 {
     int fd = (int)(long)e;
-    int ix = driver_data[fd].port_num;
+    ErlDrvPort ix = driver_data[fd].port_num;
     int pb = driver_data[fd].packet_bytes;
     int ofd = driver_data[fd].ofd;
     ssize_t n;
@@ -2149,7 +2155,7 @@ static void output(ErlDrvData e, char* buf, ErlDrvSizeT len)
     return; /* 0; */
 }
 
-static int port_inp_failure(int port_num, int ready_fd, int res)
+static int port_inp_failure(ErlDrvPort port_num, int ready_fd, int res)
 				/* Result: 0 (eof) or -1 (error) */
 {
     int err = errno;
@@ -2199,7 +2205,7 @@ static int port_inp_failure(int port_num, int ready_fd, int res)
 static void ready_input(ErlDrvData e, ErlDrvEvent ready_fd)
 {
     int fd = (int)(long)e;
-    int port_num;
+    ErlDrvPort port_num;
     int packet_bytes;
     int res;
     Uint h;
@@ -2322,7 +2328,7 @@ static void ready_input(ErlDrvData e, ErlDrvEvent ready_fd)
 static void ready_output(ErlDrvData e, ErlDrvEvent ready_fd)
 {
     int fd = (int)(long)e;
-    int ix = driver_data[fd].port_num;
+    ErlDrvPort ix = driver_data[fd].port_num;
     int n;
     struct iovec* iv;
     int vsize;
@@ -2631,19 +2637,20 @@ report_exit_status(ErtsSysReportExit *rep, int status)
     Port *pp;
 #ifdef ERTS_SMP
     CHLD_STAT_UNLOCK;
-#endif
+    pp = erts_thr_id2port_sflgs(rep->port,
+				ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP);
+    CHLD_STAT_LOCK;
+#else
     pp = erts_id2port_sflgs(rep->port,
 			    NULL,
 			    0,
 			    ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP);
-#ifdef ERTS_SMP
-    CHLD_STAT_LOCK;
 #endif
     if (pp) {
 	if (rep->ifd >= 0) {
 	    driver_data[rep->ifd].alive = 0;
 	    driver_data[rep->ifd].status = status;
-	    (void) driver_select((ErlDrvPort) internal_port_index(pp->id),
+	    (void) driver_select((ErlDrvPort) pp,
 				 rep->ifd,
 				 (ERL_DRV_READ|ERL_DRV_USE),
 				 1);
@@ -2651,12 +2658,16 @@ report_exit_status(ErtsSysReportExit *rep, int status)
 	if (rep->ofd >= 0) {
 	    driver_data[rep->ofd].alive = 0;
 	    driver_data[rep->ofd].status = status;
-	    (void) driver_select((ErlDrvPort) internal_port_index(pp->id),
+	    (void) driver_select((ErlDrvPort) pp,
 				 rep->ofd,
 				 (ERL_DRV_WRITE|ERL_DRV_USE),
 				 1);
 	}
+#ifdef ERTS_SMP
+	erts_thr_port_release(pp);
+#else
 	erts_port_release(pp);
+#endif
     }
     erts_free(ERTS_ALC_T_PRT_REP_EXIT, rep);
 }
diff --git a/erts/emulator/sys/win32/erl_win_dyn_driver.h b/erts/emulator/sys/win32/erl_win_dyn_driver.h
index ec5141838a..8b6be2b2f1 100644
--- a/erts/emulator/sys/win32/erl_win_dyn_driver.h
+++ b/erts/emulator/sys/win32/erl_win_dyn_driver.h
@@ -74,7 +74,9 @@ WDD_TYPEDEF(ErlDrvTermData, driver_mk_port,(ErlDrvPort));
 WDD_TYPEDEF(ErlDrvTermData, driver_connected,(ErlDrvPort));
 WDD_TYPEDEF(ErlDrvTermData, driver_caller,(ErlDrvPort));
 WDD_TYPEDEF(ErlDrvTermData, driver_mk_term_nil,(void));
+WDD_TYPEDEF(int, erl_drv_output_term, (ErlDrvTermData, ErlDrvTermData*, int));
 WDD_TYPEDEF(int, driver_output_term, (ErlDrvPort, ErlDrvTermData*, int));
+WDD_TYPEDEF(int, erl_drv_send_term, (ErlDrvTermData, ErlDrvTermData, ErlDrvTermData*, int));
 WDD_TYPEDEF(int, driver_send_term, (ErlDrvPort, ErlDrvTermData, ErlDrvTermData*, int));
 WDD_TYPEDEF(long, driver_async, (ErlDrvPort,unsigned int*,void (*)(void*),void*,void (*)(void*)));
 WDD_TYPEDEF(int, driver_async_cancel, (unsigned int));
@@ -187,7 +189,9 @@ typedef struct {
     WDD_FTYPE(driver_connected) *driver_connected;
     WDD_FTYPE(driver_caller) *driver_caller;
     WDD_FTYPE(driver_mk_term_nil) *driver_mk_term_nil;
+    WDD_FTYPE(erl_drv_output_term) *erl_drv_output_term;
     WDD_FTYPE(driver_output_term) *driver_output_term;
+    WDD_FTYPE(erl_drv_send_term) *erl_drv_send_term;
     WDD_FTYPE(driver_send_term) *driver_send_term;
     WDD_FTYPE(driver_async) *driver_async;
     WDD_FTYPE(driver_async_cancel) *driver_async_cancel;
@@ -294,7 +298,9 @@ extern TWinDynDriverCallbacks WinDynDriverCallbacks;
 #define driver_connected (WinDynDriverCallbacks.driver_connected)
 #define driver_caller (WinDynDriverCallbacks.driver_caller)
 #define driver_mk_term_nil (WinDynDriverCallbacks.driver_mk_term_nil)
+#define erl_drv_output_term (WinDynDriverCallbacks.erl_drv_output_term)
 #define driver_output_term (WinDynDriverCallbacks.driver_output_term)
+#define erl_drv_send_term (WinDynDriverCallbacks.erl_drv_send_term)
 #define driver_send_term (WinDynDriverCallbacks.driver_send_term)
 #define driver_async (WinDynDriverCallbacks.driver_async)
 #define driver_async_cancel (WinDynDriverCallbacks.driver_async_cancel)
@@ -425,7 +431,9 @@ do {				                        \
 ((W).driver_connected) = driver_connected;		\
 ((W).driver_caller) = driver_caller;			\
 ((W).driver_mk_term_nil) = driver_mk_term_nil;		\
+((W).erl_drv_output_term) = erl_drv_output_term;	\
 ((W).driver_output_term) = driver_output_term;		\
+((W).erl_drv_send_term) = erl_drv_send_term;		\
 ((W).driver_send_term) = driver_send_term;		\
 ((W).driver_async) = driver_async;			\
 ((W).driver_async_cancel) = driver_async_cancel;	\
diff --git a/erts/emulator/sys/win32/sys.c b/erts/emulator/sys/win32/sys.c
index f19f4ebd8c..1cd9072cea 100755
--- a/erts/emulator/sys/win32/sys.c
+++ b/erts/emulator/sys/win32/sys.c
@@ -87,9 +87,6 @@ static erts_smp_tsd_key_t win32_errstr_key;
 
 static erts_smp_atomic_t pipe_creation_counter;
 
-static erts_smp_mtx_t sys_driver_data_lock;
-
-
 /* Results from application_type(_w) is one of */
 #define APPL_NONE 0
 #define APPL_DOS  1
@@ -97,7 +94,6 @@ static erts_smp_mtx_t sys_driver_data_lock;
 #define APPL_WIN32 3
 
 static int driver_write(long, HANDLE, byte*, int);
-static void common_stop(int);
 static int create_file_thread(struct async_io* aio, int mode);
 #ifdef ERTS_SMP
 static void close_active_handle(ErlDrvPort, HANDLE handle);
@@ -115,9 +111,6 @@ BOOL WINAPI ctrl_handler(DWORD dwCtrlType);
 
 #define PORT_BUFSIZ 4096
 
-#define PORT_FREE (-1)
-#define PORT_EXITING (-2)
-
 #define DRV_BUF_ALLOC(SZ) \
   erts_alloc_fnf(ERTS_ALC_T_DRV_DATA_BUF, (SZ))
 #define DRV_BUF_REALLOC(P, SZ) \
@@ -269,7 +262,8 @@ int erts_sys_prepare_crash_dump(int secs)
 	list = CONS(hp, make_small(8), list); hp += 2;
 
 	/* send to heart port, CMD = 8, i.e. prepare crash dump =o */
-	erts_write_to_port(NIL, heart_port, list);
+	erts_port_output(NULL, ERTS_PORT_SIG_FLG_FORCE_IMM_CALL, heart_port,
+			 heart_port->common.id, list, NULL);
 
 	return 1;
     }
@@ -474,7 +468,7 @@ typedef struct driver_data {
     byte *inbuf;		/* Buffer to use for overlapped read. */
     int outBufSize;		/* Size of output buffer. */
     byte *outbuf;		/* Buffer to use for overlapped write. */
-    ErlDrvPort port_num;		/* The port number. */
+    ErlDrvPort port_num;	/* The port handle. */
     int packet_bytes;		/* 0: continous stream, 1, 2, or 4: the number
 				 * of bytes in the packet header.
 				 */
@@ -484,8 +478,6 @@ typedef struct driver_data {
     int report_exit;            /* Do report exit status for the port */
 } DriverData;
 
-static DriverData* driver_data;	/* Pointer to array of driver data. */
-
 /* Driver interfaces */
 static ErlDrvData spawn_start(ErlDrvPort, char*, SysDriverOpts*);
 static ErlDrvData fd_start(ErlDrvPort, char*, SysDriverOpts*);
@@ -597,67 +589,53 @@ struct erl_drv_entry vanilla_driver_entry = {
  */
 
 static DriverData*
-new_driver_data(int port_num, int packet_bytes, int wait_objs_required, int use_threads)
+new_driver_data(ErlDrvPort port_num, int packet_bytes, int wait_objs_required, int use_threads)
 {
     DriverData* dp;
-    
-    erts_smp_mtx_lock(&sys_driver_data_lock);
 
-    DEBUGF(("new_driver_data(port_num %d, pb %d)\n",
-	    port_num, packet_bytes));
+    DEBUGF(("new_driver_data(%p, pb %d)\n", port_num, packet_bytes));
 
+    dp = driver_alloc(sizeof(DriverData));
+    if (!dp)
+	return NULL;
     /*
      * We used to test first at all that there is enough room in the
      * array used by WaitForMultipleObjects(), but that is not necessary
      * any more, since driver_select() can't fail.
      */
 
-    /*
-     * Search for a free slot.
-     */
+    dp->bytesInBuffer = 0;
+    dp->totalNeeded = packet_bytes;
+    dp->inBufSize = PORT_BUFSIZ;
+    dp->inbuf = DRV_BUF_ALLOC(dp->inBufSize);
+    if (dp->inbuf == NULL)
+	goto buf_alloc_error;
+    erts_smp_atomic_add_nob(&sys_misc_mem_sz, dp->inBufSize);
+    dp->outBufSize = 0;
+    dp->outbuf = NULL;
+    dp->port_num = port_num;
+    dp->packet_bytes = packet_bytes;
+    dp->port_pid = INVALID_HANDLE_VALUE;
+    if (init_async_io(&dp->in, use_threads) == -1)
+	goto async_io_error1;
+    if (init_async_io(&dp->out, use_threads) == -1)
+	goto async_io_error2;
 
-    for (dp = driver_data; dp < driver_data+max_files; dp++) {
-	if (dp->port_num == PORT_FREE) {
-	    dp->bytesInBuffer = 0;
-	    dp->totalNeeded = packet_bytes;
-	    dp->inBufSize = PORT_BUFSIZ;
-	    dp->inbuf = DRV_BUF_ALLOC(dp->inBufSize);
-	    if (dp->inbuf == NULL) {
-		erts_smp_mtx_unlock(&sys_driver_data_lock);
-		return NULL;
-	    }
-	    erts_smp_atomic_add_nob(&sys_misc_mem_sz, dp->inBufSize);
-	    dp->outBufSize = 0;
-	    dp->outbuf = NULL;
-	    dp->port_num = port_num;
-	    dp->packet_bytes = packet_bytes;
-	    dp->port_pid = INVALID_HANDLE_VALUE;
-	    if (init_async_io(&dp->in, use_threads) == -1)
-		break;
-	    if (init_async_io(&dp->out, use_threads) == -1)
-		break;
-	    erts_smp_mtx_unlock(&sys_driver_data_lock);
-	    return dp;
-	}
-    }
+    return dp;
 
-    /*
-     * Error or no free driver data.
-     */
+async_io_error2:
+    release_async_io(&dp->in, dp->port_num);
+async_io_error1:
+    release_async_io(&dp->out, dp->port_num);
 
-    if (dp < driver_data+max_files) {
-	release_async_io(&dp->in, dp->port_num);
-	release_async_io(&dp->out, dp->port_num);
-    }
-    erts_smp_mtx_unlock(&sys_driver_data_lock);
+buf_alloc_error:
+    driver_free(dp);
     return NULL;
 }
 
 static void
 release_driver_data(DriverData* dp)
 {
-    erts_smp_mtx_lock(&sys_driver_data_lock);
-
 #ifdef ERTS_SMP
 #ifdef USE_CANCELIOEX
     if (fpCancelIoEx != NULL) {
@@ -741,8 +719,7 @@ release_driver_data(DriverData* dp)
      * the exit thread.
      */
 
-    dp->port_num = PORT_FREE;
-    erts_smp_mtx_unlock(&sys_driver_data_lock);
+    driver_free(dp);
 }
 
 #ifdef ERTS_SMP
@@ -837,7 +814,6 @@ threaded_handle_closer(LPVOID param)
 static ErlDrvData
 set_driver_data(DriverData* dp, HANDLE ifd, HANDLE ofd, int read_write, int report_exit)
 {
-    int index = dp - driver_data;
     int result;
 
     dp->in.fd = ifd;
@@ -856,13 +832,12 @@ set_driver_data(DriverData* dp, HANDLE ifd, HANDLE ofd, int read_write, int repo
 			       ERL_DRV_WRITE|ERL_DRV_USE, 1);
 	ASSERT(result != -1);
     }
-    return (ErlDrvData)index;
+    return (ErlDrvData) dp;
 }
 
 static ErlDrvData
 reuse_driver_data(DriverData *dp, HANDLE ifd, HANDLE ofd, int read_write, ErlDrvPort port_num)
 {
-    int index = dp - driver_data;
     int result;
 
     dp->port_num = port_num;
@@ -881,7 +856,7 @@ reuse_driver_data(DriverData *dp, HANDLE ifd, HANDLE ofd, int read_write, ErlDrv
 			       ERL_DRV_WRITE|ERL_DRV_USE, 1);
 	ASSERT(result != -1);
     }
-    return (ErlDrvData)index;
+    return (ErlDrvData) dp;
 }
 
 /*
@@ -1154,12 +1129,6 @@ spawn_init(void)
 	((module != NULL) ? GetProcAddress(module,"CancelIoEx") : NULL);
     DEBUGF(("fpCancelIoEx = %p\r\n", fpCancelIoEx));
 #endif
-    driver_data = (struct driver_data *)
-	erts_alloc(ERTS_ALC_T_DRV_TAB, max_files * sizeof(struct driver_data));
-    erts_smp_atomic_add_nob(&sys_misc_mem_sz,
-			    max_files*sizeof(struct driver_data));
-    for (i = 0; i < max_files; i++)
-	driver_data[i].port_num = PORT_FREE;
 
     return 0;
 }
@@ -1290,9 +1259,12 @@ spawn_start(ErlDrvPort port_num, char* name, SysDriverOpts* opts)
 #endif
 	retval = set_driver_data(dp, hFromChild, hToChild, opts->read_write,
 				 opts->exit_status);
-	if (retval != ERL_DRV_ERROR_GENERAL && retval != ERL_DRV_ERROR_ERRNO)
-	    /* We assume that this cannot generate a negative number */
-	    erts_port[port_num].os_pid = (SWord) pid;
+	if (retval != ERL_DRV_ERROR_GENERAL && retval != ERL_DRV_ERROR_ERRNO) {
+	    Port *prt = erts_drvport2port_raw(port_num);
+		/* We assume that this cannot generate a negative number */
+	    ASSERT(prt);
+	    prt->os_pid = (SWord) pid;
+	}
     }
     
     if (retval != ERL_DRV_ERROR_GENERAL && retval != ERL_DRV_ERROR_ERRNO)
@@ -2281,12 +2253,10 @@ fd_start(ErlDrvPort port_num, char* name, SysDriverOpts* opts)
 	 **/
 
 	if (!create_file_thread(&dp->in, DO_READ)) {
-	    dp->port_num = PORT_FREE;
 	    return ERL_DRV_ERROR_GENERAL;
 	}
 	
 	if (!create_file_thread(&dp->out, DO_WRITE)) {
-	    dp->port_num = PORT_FREE;
 	    return ERL_DRV_ERROR_GENERAL;
 	}
 	
@@ -2306,10 +2276,9 @@ fd_start(ErlDrvPort port_num, char* name, SysDriverOpts* opts)
     }
 }
 
-static void fd_stop(ErlDrvData d)
+static void fd_stop(ErlDrvData data)
 {
-  int fd = (int)d;
-  DriverData* dp = driver_data+fd;
+  DriverData * dp = (DriverData *) data;
   /*
    * There's no way we can terminate an fd port in a consistent way.
    * Instead we let it live until it's opened again (which it is,
@@ -2372,16 +2341,10 @@ vanilla_start(ErlDrvPort port_num, char* name, SysDriverOpts* opts)
 }
 
 static void
-stop(ErlDrvData index)
-{
-    common_stop((int)index);
-}
-
-static void common_stop(int index)
+stop(ErlDrvData data)
 {
-    DriverData* dp = driver_data+index;
-
-    DEBUGF(("common_stop(%d)\n", index));
+    DriverData *dp = (DriverData *) data;
+    DEBUGF(("stop(%p)\n", dp));
 
     if (dp->in.ov.hEvent != NULL) {
 	(void) driver_select(dp->port_num,
@@ -2403,7 +2366,6 @@ static void common_stop(int index)
 	 */
 	HANDLE thread;
 	DWORD tid;
-	dp->port_num = PORT_EXITING;
 	thread = (HANDLE *) _beginthreadex(NULL, 0, threaded_exiter, dp, 0, &tid);
 	CloseHandle(thread);
     }
@@ -2528,22 +2490,17 @@ threaded_exiter(LPVOID param)
 
 static void
 output(ErlDrvData drv_data, char* buf, ErlDrvSizeT len)
-/*     long drv_data;		/* The slot to use in the driver data table.
+/*     ErlDrvData drv_data;	/* The slot to use in the driver data table.
 				 * For Windows NT, this is *NOT* a file handle.
 				 * The handle is found in the driver data.
 				 */
 /*     char *buf;		/* Pointer to data to write to the port program. */
 /*     ErlDrvSizeT len;		/* Number of bytes to write. */
 {
-    DriverData* dp;
+    DriverData* dp = (DriverData *) drv_data;
     int pb;			/* The header size for this port. */
-    int port_num;		/* The actual port number (for diagnostics). */
     char* current;
 
-    dp = driver_data + (int)drv_data;
-    if ((port_num = dp->port_num) == -1)
-	return ; /*-1;*/
-
     pb = dp->packet_bytes;
 
     if ((pb+len) == 0)
@@ -2554,7 +2511,7 @@ output(ErlDrvData drv_data, char* buf, ErlDrvSizeT len)
      */
 
     if ((pb == 2 && len > 65535) || (pb == 1 && len > 255)) {
-	driver_failure_posix(port_num, EINVAL);
+	driver_failure_posix(dp->port_num, EINVAL);
 	return ; /* -1; */
     }
 
@@ -2568,7 +2525,7 @@ output(ErlDrvData drv_data, char* buf, ErlDrvSizeT len)
     ASSERT(!dp->outbuf);
     dp->outbuf = DRV_BUF_ALLOC(pb+len);
     if (!dp->outbuf) {
-	driver_failure_posix(port_num, ENOMEM);
+	driver_failure_posix(dp->port_num, ENOMEM);
 	return ; /* -1; */
     }
 
@@ -2598,7 +2555,7 @@ output(ErlDrvData drv_data, char* buf, ErlDrvSizeT len)
 	memcpy(current, buf, len);
     
     if (!async_write_file(&dp->out, dp->outbuf, pb+len)) {
-	set_busy_port(port_num, 1);
+	set_busy_port(dp->port_num, 1);
     } else {
 	dp->out.ov.Offset += pb+len; /* For vanilla driver. */
 	/* XXX OffsetHigh should be changed too. */
@@ -2633,10 +2590,9 @@ ready_input(ErlDrvData drv_data, ErlDrvEvent ready_event)
 {
     int error = 0;		/* The error code (assume initially no errors). */
     DWORD bytesRead;		/* Number of bytes read. */
-    DriverData* dp;
+    DriverData* dp = (DriverData *) drv_data;
     int pb;
 
-    dp = driver_data+(int)drv_data;
     pb = dp->packet_bytes;
 #ifdef ERTS_SMP
     if(dp->in.thread == (HANDLE) -1) {
@@ -2804,7 +2760,7 @@ static void
 ready_output(ErlDrvData drv_data, ErlDrvEvent ready_event)
 {
     DWORD bytesWritten;
-    DriverData* dp = driver_data + (int)drv_data;
+    DriverData *dp = (DriverData *) drv_data;
     int error;
 
 #ifdef ERTS_SMP
@@ -2812,7 +2768,7 @@ ready_output(ErlDrvData drv_data, ErlDrvEvent ready_event)
 	dp->out.async_io_active = 0;
     }
 #endif
-    DEBUGF(("ready_output(%d, 0x%x)\n", drv_data, ready_event));
+    DEBUGF(("ready_output(%p, 0x%x)\n", drv_data, ready_event));
     set_busy_port(dp->port_num, 0);
     if (!(dp->outbuf)) {
 	/* Happens because event sometimes get signalled during a successful
@@ -2867,7 +2823,7 @@ sys_init_io(void)
        can change our view of the number of open files possible.
        We estimate the number to twice the amount of ports. 
        We really dont know on windows, do we? */
-    max_files = 2*erts_max_ports;
+    max_files = 2*erts_ptab_max(&erts_port);
 }
 
 #ifdef ERTS_SMP
@@ -3322,9 +3278,6 @@ void erl_sys_init(void)
     noinherit_std_handle(STD_INPUT_HANDLE);
     noinherit_std_handle(STD_ERROR_HANDLE);
 
-
-    erts_smp_mtx_init(&sys_driver_data_lock, "sys_driver_data_lock");
-
 #ifdef ERTS_SMP
     erts_smp_tsd_key_create(&win32_errstr_key);
     InitializeCriticalSection(&htbc_lock);
diff --git a/erts/emulator/test/busy_port_SUITE.erl b/erts/emulator/test/busy_port_SUITE.erl
index 3a29fd4d68..32e907ca69 100644
--- a/erts/emulator/test/busy_port_SUITE.erl
+++ b/erts/emulator/test/busy_port_SUITE.erl
@@ -148,9 +148,9 @@ message_order(Config) when is_list(Config) ->
 
 send_to_busy_1(Parent) ->
     {Owner, Slave} = get_slave(),
-    Slave ! {Owner, {command, "set_me_busy"}},
-    Slave ! {Owner, {command, "hello"}},
-    Slave ! {Owner, {command, "hello again"}},
+    (catch port_command(Slave, "set_me_busy")),
+    (catch port_command(Slave, "hello")),
+    (catch port_command(Slave, "hello again")),
     receive
 	Message ->
 	    Parent ! {self(), Message}
@@ -193,10 +193,10 @@ system_monitor(Config) when is_list(Config) ->
     ?line Busy = 
 	spawn_link(
 	  fun() ->
-		  Slave ! {Owner,{command,"set busy"}},
+		  (catch port_command(Slave, "set busy")),
 		  receive {Parent,alpha} -> ok end,
-		  Slave ! {Owner,{command,"busy"}},
-		  Slave ! {Owner,{command,"free"}},
+		  (catch port_command(Slave, "busy")),
+		  (catch port_command(Slave, "free")),
 		  Parent ! {self(),alpha},
 		  command(lock),
 		  receive {Parent,beta} -> ok end,
@@ -212,7 +212,7 @@ system_monitor(Config) when is_list(Config) ->
     ?line Void = rec(Void),
     ?line Busy ! {self(), beta},
     ?line {monitor,Owner,busy_port,Slave} = rec(Void),
-    ?line Master ! {Owner, {command, "u"}},
+    ?line port_command(Master, "u"),
     ?line {Busy,beta} = rec(Void),
     ?line Void = rec(Void),
     ?line _NewMonitor = erlang:system_monitor(OldMonitor),
@@ -296,9 +296,9 @@ no_trap_exit_process(ResultTo, Link, Config) ->
 	      linked -> ok;
 	      unlink -> unlink(Slave)
 	  end,
-    ?line Slave ! {self(), {command, "lock port"}},
+    ?line (catch port_command(Slave, "lock port")),
     ?line ResultTo ! {self(), port_created, Slave},
-    ?line Slave ! {self(), {command, "suspend me"}},
+    ?line (catch port_command(Slave, "suspend me")),
     ok.
 
 %% Assuming the following scenario,
@@ -339,9 +339,9 @@ busy_port_exit_process(ResultTo, Config) ->
     ?line load_busy_driver(Config),
     ?line _Master = open_port({spawn, "busy_drv master"}, [eof]),
     ?line Slave = open_port({spawn, "busy_drv slave"}, [eof]),
-    ?line Slave ! {self(), {command, "lock port"}},
+    ?line (catch port_command(Slave, "lock port")),
     ?line ResultTo ! {self(), port_created, Slave},
-    ?line Slave ! {self(), {command, "suspend me"}},
+    ?line (catch port_command(Slave, "suspend me")),
     receive
 	{'EXIT', Slave, die} ->
 	    ResultTo ! {self(), ok};
@@ -383,8 +383,8 @@ multiple_writers(Config) when is_list(Config) ->
 
 quick_writer() ->
     {Owner, Port} = get_slave(),
-    Port ! {Owner, {command, "port to busy"}},
-    Port ! {Owner, {command, "lock me"}},
+    (catch port_command(Port, "port to busy")),
+    (catch port_command(Port, "lock me")),
     ok.
 
 hard_busy_driver(Config) when is_list(Config) ->
@@ -644,11 +644,11 @@ loop(Master, Slave) ->
 	    Pid ! {busy_drv_reply, {self(), Slave}},
 	    loop(Master, Slave);
 	{Pid, unlock} ->
-	    Master ! {self(), {command, "u"}},
+	    port_command(Master, "u"),
 	    Pid ! {busy_drv_reply, ok},
 	    loop(Master, Slave);
 	{Pid, lock} ->
-	    Master ! {self(), {command, "l"}},
+	    port_command(Master, "l"),
 	    Pid ! {busy_drv_reply, ok},
 	    loop(Master, Slave);
 	{Pid, {port_command,Data}} ->
diff --git a/erts/emulator/test/ddll_SUITE.erl b/erts/emulator/test/ddll_SUITE.erl
index 6e15c228cd..4675cab15c 100644
--- a/erts/emulator/test/ddll_SUITE.erl
+++ b/erts/emulator/test/ddll_SUITE.erl
@@ -136,8 +136,8 @@ delayed_unload_with_ports(Config) when is_list(Config) ->
     ?line {ok,pending_driver,Ref} = erl_ddll:try_unload(echo_drv,[{monitor, pending_driver}]),
     ?line ok = receive _ -> false after 0 -> ok end,
     ?line Port ! {self(), close},
-    ?line 1 = erl_ddll:info(echo_drv, port_count),
     ?line ok = receive {Port,closed} -> ok after 1000 -> false end,
+    ?line 1 = erl_ddll:info(echo_drv, port_count),
     ?line Port2 ! {self(), close},
     ?line ok = receive {Port2,closed} -> ok after 1000 -> false end,
     ?line ok = receive {'DOWN', Ref, driver, echo_drv, unloaded} -> ok after 1000 -> false end,
diff --git a/erts/emulator/test/driver_SUITE.erl b/erts/emulator/test/driver_SUITE.erl
index 643357263c..13f18b4563 100644
--- a/erts/emulator/test/driver_SUITE.erl
+++ b/erts/emulator/test/driver_SUITE.erl
@@ -77,7 +77,8 @@
 	 thread_mseg_alloc_cache_clean/1,
 	 otp_9302/1,
 	 thr_free_drv/1,
-	 async_blast/1]).
+	 async_blast/1,
+	 thr_msg_blast/1]).
 
 -export([bin_prefix/2]).
 
@@ -147,7 +148,8 @@ all() ->
      thread_mseg_alloc_cache_clean,
      otp_9302,
      thr_free_drv,
-     async_blast].
+     async_blast,
+     thr_msg_blast].
 
 groups() -> 
     [{timer, [],
@@ -1136,7 +1138,9 @@ check_driver_system_info_result(Result) ->
 	      {{1, 1}, _} ->
 		  ?line ExpNs = lists:sort(?EXPECTED_SYSTEM_INFO_NAMES
 					   -- ?EXPECTED_SYSTEM_INFO_NAMES2),
-		  ?line ExpNs = lists:sort(Ns)
+		  ?line ExpNs = lists:sort(Ns);
+	      {{2, 0}, _} ->
+		  ?line [] = Ns
 	  end.
 
 chk_sis(SIs, Ns) ->
@@ -2010,7 +2014,64 @@ async_blast(Config) when is_list(Config) ->
     ?line erlang:display({async_blast_time, AsyncBlastTime}),
     ?line ok.
 
+thr_msg_blast_receiver(_Port, N, N) ->
+    ok;
+thr_msg_blast_receiver(Port, N, Max) ->
+    receive
+	{Port, hi} ->
+	    thr_msg_blast_receiver(Port, N+1, Max)
+    end.
+
+thr_msg_blast_receiver_proc(Port, Max, Parent, Done) ->
+    case port_control(Port, 0, "") of
+	"receiver" ->
+	    spawn(fun () ->
+			  thr_msg_blast_receiver_proc(Port, Max+1, Parent, Done)
+		  end),
+	    thr_msg_blast_receiver(Port, 0, Max);
+	"done" ->
+	    Parent ! Done
+    end.
 
+thr_msg_blast(Config) when is_list(Config) ->
+    case erlang:system_info(smp_support) of
+	false ->
+	    {skipped, "Non-SMP emulator; nothing to test..."};
+	true ->
+	    Path = ?config(data_dir, Config),
+	    erl_ddll:start(),
+	    ok = load_driver(Path, thr_msg_blast_drv),
+	    MemBefore = driver_alloc_size(),
+	    Start = os:timestamp(),
+	    Port = open_port({spawn, thr_msg_blast_drv}, []),
+	    true = is_port(Port),
+	    Done = make_ref(),
+	    Me = self(),
+	    spawn(fun () ->
+			  thr_msg_blast_receiver_proc(Port, 1, Me, Done)
+		  end),
+	    receive
+		Done -> ok
+	    end,
+	    ok = thr_msg_blast_receiver(Port, 0, 32*10000),
+	    port_close(Port),
+	    End = os:timestamp(),
+	    receive
+		Garbage ->
+		    ?t:fail({received_garbage, Port, Garbage})
+	    after 2000 ->
+		    ok
+	    end,
+	    MemAfter = driver_alloc_size(),
+	    io:format("MemBefore=~p, MemAfter=~p~n",
+		      [MemBefore, MemAfter]),
+	    ThrMsgBlastTime = timer:now_diff(End,Start)/1000000,
+	    io:format("ThrMsgBlastTime=~p~n", [ThrMsgBlastTime]),
+	    MemBefore = MemAfter,
+	    Res = {thr_msg_blast_time, ThrMsgBlastTime},
+	    erlang:display(Res),
+	    Res
+    end.
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %% 		Utilities
diff --git a/erts/emulator/test/driver_SUITE_data/Makefile.src b/erts/emulator/test/driver_SUITE_data/Makefile.src
index 9cc107cc66..b667dff6b6 100644
--- a/erts/emulator/test/driver_SUITE_data/Makefile.src
+++ b/erts/emulator/test/driver_SUITE_data/Makefile.src
@@ -14,7 +14,8 @@ MISC_DRVS =		outputv_drv@dll@ \
 			thr_alloc_drv@dll@ \
 			otp_9302_drv@dll@ \
 			thr_free_drv@dll@ \
-			async_blast_drv@dll@
+			async_blast_drv@dll@ \
+			thr_msg_blast_drv@dll@
 
 SYS_INFO_DRVS = 	sys_info_base_drv@dll@ \
 			sys_info_prev_drv@dll@ \
diff --git a/erts/emulator/test/driver_SUITE_data/thr_msg_blast_drv.c b/erts/emulator/test/driver_SUITE_data/thr_msg_blast_drv.c
new file mode 100644
index 0000000000..1070678d7b
--- /dev/null
+++ b/erts/emulator/test/driver_SUITE_data/thr_msg_blast_drv.c
@@ -0,0 +1,178 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2012. All Rights Reserved.
+ *
+ * The contents of this file are subject to the Erlang Public License,
+ * Version 1.1, (the "License"); you may not use this file except in
+ * compliance with the License. You should have received a copy of the
+ * Erlang Public License along with this software. If not, it can be
+ * retrieved online at http://www.erlang.org/.
+ *
+ * Software distributed under the License is distributed on an "AS IS"
+ * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+ * the License for the specific language governing rights and limitations
+ * under the License.
+ *
+ * %CopyrightEnd%
+ */
+
+#include "erl_driver.h"
+
+#define THR_MSG_BLAST_NO_PROCS 10
+#define THR_MSG_BLAST_NO_SENDS_PER_PROC 10000
+
+#define THR_MSG_BLAST_THREADS 32
+
+static void stop(ErlDrvData drv_data);
+static ErlDrvData start(ErlDrvPort port,
+			char *command);
+static ErlDrvSSizeT control(ErlDrvData drv_data,
+			    unsigned int command,
+			    char *buf, ErlDrvSizeT len,
+			    char **rbuf, ErlDrvSizeT rlen);
+
+static ErlDrvEntry thr_msg_blast_drv_entry = { 
+    NULL /* init */,
+    start,
+    stop,
+    NULL /* output */,
+    NULL /* ready_input */,
+    NULL /* ready_output */,
+    "thr_msg_blast_drv",
+    NULL /* finish */,
+    NULL /* handle */,
+    control,
+    NULL /* timeout */,
+    NULL /* outputv */,
+    NULL /* ready_async */,
+    NULL /* flush */,
+    NULL /* call */,
+    NULL /* event */,
+    ERL_DRV_EXTENDED_MARKER,
+    ERL_DRV_EXTENDED_MAJOR_VERSION,
+    ERL_DRV_EXTENDED_MINOR_VERSION,
+    ERL_DRV_FLAG_USE_PORT_LOCKING,
+    NULL /* handle2 */,
+    NULL /* handle_monitor */
+};
+
+typedef struct {
+    ErlDrvPort port;
+    ErlDrvTermData td_port;
+    ErlDrvTermData hi;
+    ErlDrvTid tid[THR_MSG_BLAST_THREADS];
+    int no_thrs;
+    ErlDrvTermData proc[THR_MSG_BLAST_NO_PROCS];
+    int no_procs;
+} thr_msg_blast_data_t;
+
+
+DRIVER_INIT(thr_msg_blast_drv)
+{
+    return &thr_msg_blast_drv_entry;
+}
+
+static void stop(ErlDrvData drv_data)
+{
+    int i;
+    thr_msg_blast_data_t *tmbd = (thr_msg_blast_data_t *) drv_data;
+    for (i = 0; i < tmbd->no_thrs; i++)
+	erl_drv_thread_join(tmbd->tid[i], NULL);
+    driver_free((void *) tmbd);
+}
+
+static ErlDrvData start(ErlDrvPort port,
+			char *command)
+{
+    thr_msg_blast_data_t *tmbd;
+
+    tmbd = driver_alloc(sizeof(thr_msg_blast_data_t));
+    if (!tmbd)
+	return ERL_DRV_ERROR_GENERAL;
+
+    tmbd->port = port;
+    tmbd->td_port = driver_mk_port(port);
+    tmbd->hi = driver_mk_atom("hi");
+    tmbd->no_thrs = 0;
+    tmbd->no_procs = 1;
+    tmbd->proc[0] = driver_caller(port);
+
+    return (ErlDrvData) tmbd;
+}
+
+static void *thread(void *);
+
+static ErlDrvSSizeT control(ErlDrvData drv_data,
+			    unsigned int command,
+			    char *buf, ErlDrvSizeT len,
+			    char **rbuf, ErlDrvSizeT rlen)
+{
+    thr_msg_blast_data_t *tmbd = (thr_msg_blast_data_t *) drv_data;
+    char *res_str = "error";
+
+    if (tmbd->no_procs >= THR_MSG_BLAST_NO_PROCS) {
+	int i;
+	for (i = 0; i < tmbd->no_thrs; i++)
+	    erl_drv_thread_join(tmbd->tid[i], NULL);
+	tmbd->no_thrs = 0;
+	res_str = "done";
+    }
+    else {
+
+	tmbd->proc[tmbd->no_procs++] = driver_caller(tmbd->port);
+
+	if (tmbd->no_procs == THR_MSG_BLAST_NO_PROCS) {
+	    for (tmbd->no_thrs = 0;
+		 tmbd->no_thrs < THR_MSG_BLAST_THREADS;
+		 tmbd->no_thrs++) {
+		int res = erl_drv_thread_create("test",
+						&tmbd->tid[tmbd->no_thrs],
+						thread,
+						tmbd,
+						NULL);
+		if (res != 0) {
+		    driver_failure_posix(tmbd->port, res);
+		    goto done;
+		}
+	    }
+	}
+
+	res_str = "receiver";
+    }
+
+ done: {
+	ErlDrvSSizeT res_len = strlen(res_str);
+	if (res_len > rlen) {
+	    char *abuf = driver_alloc(sizeof(char)*res_len);
+	    if (!abuf)
+		return 0;
+	    *rbuf = abuf;
+	}
+
+	memcpy((void *) *rbuf, (void *) res_str, res_len);
+
+	return res_len;
+    }
+}
+
+static void *thread(void *varg)
+{
+    int s, p;
+    thr_msg_blast_data_t *tmbd = (thr_msg_blast_data_t *) varg;
+    ErlDrvTermData spec[] = {
+	ERL_DRV_PORT, tmbd->td_port,
+	ERL_DRV_ATOM, tmbd->hi,
+	ERL_DRV_TUPLE, 2
+    };
+
+    for (s = 0; s < THR_MSG_BLAST_NO_SENDS_PER_PROC; s++) {
+	for (p = 0; p < THR_MSG_BLAST_NO_PROCS; p++) {
+	    int res = driver_send_term(tmbd->port, tmbd->proc[p],
+				       spec, sizeof(spec)/sizeof(spec[0]));
+	    if (p == 0 && res <= 0)
+		abort(); /* Could not send to creator */
+	}
+    }
+    return NULL;
+}
diff --git a/erts/emulator/test/port_SUITE.erl b/erts/emulator/test/port_SUITE.erl
index 873601ddd1..13aa0f4c00 100644
--- a/erts/emulator/test/port_SUITE.erl
+++ b/erts/emulator/test/port_SUITE.erl
@@ -90,7 +90,7 @@
 	 mix_up_ports/1, otp_5112/1, otp_5119/1, otp_6224/1,
 	 exit_status_multi_scheduling_block/1, ports/1,
 	 spawn_driver/1, spawn_executable/1, close_deaf_port/1,
-	 unregister_name/1]).
+	 unregister_name/1, parallelism_option/1]).
 
 -export([]).
 
@@ -114,7 +114,8 @@ all() ->
      stderr_to_stdout, otp_3906, otp_4389, win_massive,
      mix_up_ports, otp_5112, otp_5119,
      exit_status_multi_scheduling_block, ports, spawn_driver,
-     spawn_executable, close_deaf_port, unregister_name].
+     spawn_executable, close_deaf_port, unregister_name,
+     parallelism_option].
 
 groups() -> 
     [{stream, [], [stream_small, stream_big]},
@@ -159,11 +160,11 @@ win_massive(Config) when is_list(Config) ->
 do_win_massive() ->
     Dog = test_server:timetrap(test_server:seconds(360)),
     SuiteDir = filename:dirname(code:which(?MODULE)),
-    Env = " -env ERL_MAX_PORTS 8192",
+    Ports = " +Q 8192",
     {ok, Node} = 
 	test_server:start_node(win_massive,
 			       slave,
-			       [{args, " -pa " ++ SuiteDir ++ Env}]),
+			       [{args, " -pa " ++ SuiteDir ++ Ports}]),
     ok = rpc:call(Node,?MODULE,win_massive_client,[3000]),
     test_server:stop_node(Node),
     test_server:timetrap_cancel(Dog),
@@ -1298,6 +1299,43 @@ spawn_driver(Config) when is_list(Config) ->
     test_server:timetrap_cancel(Dog),
     ok.
 
+parallelism_option(suite) ->
+    [];
+parallelism_option(doc) ->
+    ["Test parallelism option of open_port"];
+parallelism_option(Config) when is_list(Config) ->
+    ?line Dog = test_server:timetrap(test_server:seconds(10)),
+    ?line Path = ?config(data_dir, Config),
+    ?line ok = load_driver(Path, "echo_drv"),
+    ?line Port = erlang:open_port({spawn_driver, "echo_drv"},
+				  [{parallelism, true}]),
+    ?line {parallelism, true} = erlang:port_info(Port, parallelism),
+    ?line Port ! {self(), {command, "Hello port!"}},
+    ?line receive 
+	      {Port, {data, "Hello port!"}} = Msg1 -> 
+		  io:format("~p~n", [Msg1]),
+		  ok; 
+	      Other ->
+		  test_server:fail({unexpected, Other})
+	  end,
+    ?line Port ! {self(), close},
+    ?line receive {Port, closed} -> ok end,
+
+    ?line Port2 = erlang:open_port({spawn_driver, "echo_drv -Hello port?"}, 
+				   [{parallelism, false}]),
+    ?line {parallelism, false} = erlang:port_info(Port2, parallelism),
+    ?line receive 
+	      {Port2, {data, "Hello port?"}} = Msg2 -> 
+		  io:format("~p~n", [Msg2]),
+		  ok; 
+	      Other2 ->
+		  test_server:fail({unexpected2, Other2})
+	  end,
+    ?line Port2 ! {self(), close},
+    ?line receive {Port2, closed} -> ok end,
+    ?line test_server:timetrap_cancel(Dog),
+    ok.
+
 spawn_executable(suite) ->
     [];
 spawn_executable(doc) ->
@@ -1566,6 +1604,7 @@ otp_5112(Config) when is_list(Config) ->
     ?t:format("Links1: ~p~n",[Links1]),
     true = lists:member(Port, Links1),
     Port ! {self(), {command, ""}},
+    ?line wait_until(fun () -> lists:member(Port, erlang:ports()) == false end),
     {links, Links2} = process_info(self(),links),
     ?t:format("Links2: ~p~n",[Links2]),
     false = lists:member(Port, Links2), %% This used to fail
@@ -1636,38 +1675,8 @@ otp_5119_fill_empty_port_tab(Ports) ->
 		  LastPort
 	  end.
 
--define(DEF_MAX_PORTS, 1024).
-
-max_ports_env() ->
-    case os:getenv("ERL_MAX_PORTS") of
-	      EMP when is_list(EMP) ->
-		  case catch list_to_integer(EMP) of
-		      Int when is_integer(Int) -> Int;
-		      _ -> false
-		  end;
-	      _ -> false
-	  end.
-
 max_ports() ->
-    PreMaxPorts
-	= case max_ports_env() of
-	      Env when is_integer(Env) -> Env;
-	      _ ->
-		  case os:type() of
-			    {unix, _} ->
-				UlimStr = string:strip(os:cmd("ulimit -n")
-							     -- "\n"),
-				case catch list_to_integer(UlimStr) of
-					  Ulim when is_integer(Ulim) -> Ulim;
-					  _ -> ?DEF_MAX_PORTS
-				      end;
-			    _ -> ?DEF_MAX_PORTS
-			end
-	  end,
-    case PreMaxPorts > ?DEF_MAX_PORTS of
-	      true -> PreMaxPorts;
-	      false -> ?DEF_MAX_PORTS
-	  end.
+    erlang:system_info(port_limit).
 
 port_ix(Port) when is_port(Port) ->
     ["#Port",_,PortIxStr] = string:tokens(erlang:port_to_list(Port),
@@ -2270,5 +2279,12 @@ close_deaf_port_1(N, Cmd) ->
     	_:eagain ->
 	    {comment, "Could not spawn more than " ++ integer_to_list(N) ++ " OS processes."}
     end.
-    
 
+wait_until(Fun) ->
+    case catch Fun() of
+	true ->
+	    ok;
+	_ ->
+	    receive after 100 -> ok end,
+	    wait_until(Fun)
+    end.
diff --git a/erts/emulator/test/process_SUITE.erl b/erts/emulator/test/process_SUITE.erl
index 6509871a7d..898535693f 100644
--- a/erts/emulator/test/process_SUITE.erl
+++ b/erts/emulator/test/process_SUITE.erl
@@ -1384,7 +1384,7 @@ otp_6237_select_loop() ->
 
 
 -define(NoTestProcs, 10000).
--record(processes_bif_info, {min_start_reds,
+-record(ptab_list_bif_info, {min_start_reds,
 			     tab_chunks,
 			     tab_chunks_size,
 			     tab_indices_per_red,
@@ -1419,11 +1419,11 @@ processes_large_tab(Config) when is_list(Config) ->
     %% the connection times out; therefore, shrink the test on
     %% high debug levels.
     ?line DbgLvl = case erts_debug:get_internal_state(processes_bif_info) of
-		       #processes_bif_info{debug_level = Lvl} when Lvl > MaxDbgLvl ->
+		       #ptab_list_bif_info{debug_level = Lvl} when Lvl > MaxDbgLvl ->
 			   20;
-		       #processes_bif_info{debug_level = Lvl} when Lvl < 0 ->
+		       #ptab_list_bif_info{debug_level = Lvl} when Lvl < 0 ->
 			   ?line ?t:fail({debug_level, Lvl});
-		       #processes_bif_info{debug_level = Lvl} ->
+		       #ptab_list_bif_info{debug_level = Lvl} ->
 			   Lvl
 		   end,
     ?line ProcTabSize3 = ProcTabSize2 - (1300000 * DbgLvl div MaxDbgLvl),
@@ -1438,7 +1438,7 @@ processes_large_tab(Config) when is_list(Config) ->
 			erts_debug,
 			get_internal_state,
 			[processes_bif_info]) of
-	      #processes_bif_info{tab_chunks = Chunks} when is_integer(Chunks),
+	      #ptab_list_bif_info{tab_chunks = Chunks} when is_integer(Chunks),
 							    Chunks > 1 -> ok;
 	      PBInfo -> ?t:fail(PBInfo)
 	  end,
@@ -1460,14 +1460,14 @@ processes_small_tab(doc) ->
 processes_small_tab(suite) ->
     [];
 processes_small_tab(Config) when is_list(Config) ->
-    ?line {ok, SmallNode} = start_node(Config, "+P 500"),
+    ?line {ok, SmallNode} = start_node(Config, "+P 1024"),
     ?line Res = rpc:call(SmallNode, ?MODULE, processes_bif_test, []),
     ?line PBInfo = rpc:call(SmallNode,
 			    erts_debug,
 			    get_internal_state,
 			    [processes_bif_info]),
     ?line stop_node(SmallNode),
-    ?line 1 = PBInfo#processes_bif_info.tab_chunks,
+    ?line true = PBInfo#ptab_list_bif_info.tab_chunks < 10,
     ?line chk_processes_bif_test_res(Res).
 
 processes_this_tab(doc) ->
@@ -1481,7 +1481,7 @@ chk_processes_bif_test_res(ok) -> ok;
 chk_processes_bif_test_res({comment, _} = Comment) -> Comment;
 chk_processes_bif_test_res(Failure) -> ?t:fail(Failure).
 
-print_processes_bif_info(#processes_bif_info{min_start_reds = MinStartReds,
+print_processes_bif_info(#ptab_list_bif_info{min_start_reds = MinStartReds,
 					     tab_chunks = TabChunks,
 					     tab_chunks_size = TabChunksSize,
 					     tab_indices_per_red = TabIndPerRed,
@@ -1579,11 +1579,11 @@ processes_bif_test() ->
     ?line enable_internal_state(),
     ?line PBInfo = erts_debug:get_internal_state(processes_bif_info),
     ?line print_processes_bif_info(PBInfo),
-    ?line WantReds = PBInfo#processes_bif_info.min_start_reds + 10,
+    ?line WantReds = PBInfo#ptab_list_bif_info.min_start_reds + 10,
     ?line WillTrap = case PBInfo of
-			#processes_bif_info{tab_chunks = 1} ->
-			    false;
-			#processes_bif_info{tab_chunks = Chunks,
+			#ptab_list_bif_info{tab_chunks = Chunks} when Chunks < 10 ->
+			    false; %% Skip for small tables
+			#ptab_list_bif_info{tab_chunks = Chunks,
 					    tab_chunks_size = ChunksSize,
 					    tab_indices_per_red = IndiciesPerRed
 					   } ->
@@ -1618,7 +1618,7 @@ processes_bif_test() ->
 	    ?line erlang:system_flag(multi_scheduling, unblock),
 	    
 	    ?line [{status,suspended},
-		   {current_function,{erlang,processes_trap,2}}]
+		   {current_function,{erlang,ptab_list_continue,2}}]
 		= process_info(Suspendee, [status, current_function]),
 
 	    ?line ok = do_processes_bif_test(WantReds, WillTrap, Processes),
@@ -1785,7 +1785,7 @@ do_processes_bif_die_test(N, Processes) ->
     catch
 	throw:{kill_in_trap, R} when N > 0 ->
 	    ?t:format("Failed to kill in trap: ~p~n", [R]),
-	    ?t:format("Trying again~p~n", []),
+	    ?t:format("Trying again~n", []),
 	    do_processes_bif_die_test(N-1, Processes)
     end.
 	    
@@ -1848,7 +1848,7 @@ processes_last_call_trap(Config) when is_list(Config) ->
     ?line Processes = fun () -> processes() end,
     ?line PBInfo = erts_debug:get_internal_state(processes_bif_info),
     ?line print_processes_bif_info(PBInfo),
-    ?line WantReds = case PBInfo#processes_bif_info.min_start_reds of
+    ?line WantReds = case PBInfo#ptab_list_bif_info.min_start_reds of
 			 R when R > 10 -> R - 1;
 			 _R -> 9
 		     end,
@@ -1873,7 +1873,7 @@ processes_apply_trap(Config) when is_list(Config) ->
     ?line enable_internal_state(),
     ?line PBInfo = erts_debug:get_internal_state(processes_bif_info),
     ?line print_processes_bif_info(PBInfo),
-    ?line WantReds = case PBInfo#processes_bif_info.min_start_reds of
+    ?line WantReds = case PBInfo#ptab_list_bif_info.min_start_reds of
 			 R when R > 10 -> R - 1;
 			 _R -> 9
 		     end,
@@ -1893,7 +1893,7 @@ processes_gc_trap(Config) when is_list(Config) ->
     ?line enable_internal_state(),
     ?line PBInfo = erts_debug:get_internal_state(processes_bif_info),
     ?line print_processes_bif_info(PBInfo),
-    ?line WantReds = PBInfo#processes_bif_info.min_start_reds + 10,
+    ?line WantReds = PBInfo#ptab_list_bif_info.min_start_reds + 10,
     ?line Processes = fun () ->
 			      erts_debug:set_internal_state(reds_left,WantReds),
 			      processes()
@@ -1911,7 +1911,7 @@ processes_gc_trap(Config) when is_list(Config) ->
     ?line erlang:suspend_process(Suspendee),
     ?line erlang:system_flag(multi_scheduling, unblock),
 	    
-    ?line [{status,suspended}, {current_function,{erlang,processes_trap,2}}]
+    ?line [{status,suspended}, {current_function,{erlang,ptab_list_continue,2}}]
 	= process_info(Suspendee, [status, current_function]),
 
     ?line erlang:garbage_collect(Suspendee),
@@ -1982,8 +1982,8 @@ chk_term_proc_list(Line, MustChk, ExpectBlks) ->
 	    not_enabled;
 	{_, MS} ->
 	    {value,
-	     {processes_term_proc_el,
-	      DL}} = lists:keysearch(processes_term_proc_el, 1, MS),
+	     {ptab_list_deleted_el,
+	      DL}} = lists:keysearch(ptab_list_deleted_el, 1, MS),
 	    case lists:keysearch(blocks, 1, DL) of
 		{value, {blocks, ExpectBlks, _, _}} ->
 		    ok;
@@ -2001,8 +2001,8 @@ processes_term_proc_list_test(MustChk) ->
     ?line enable_internal_state(),
     ?line PBInfo = erts_debug:get_internal_state(processes_bif_info),
     ?line print_processes_bif_info(PBInfo),
-    ?line WantReds = PBInfo#processes_bif_info.min_start_reds + 10,
-    ?line #processes_bif_info{tab_chunks = Chunks,
+    ?line WantReds = PBInfo#ptab_list_bif_info.min_start_reds + 10,
+    ?line #ptab_list_bif_info{tab_chunks = Chunks,
 			      tab_chunks_size = ChunksSize,
 			      tab_indices_per_red = IndiciesPerRed
 			     } = PBInfo,
@@ -2038,7 +2038,7 @@ processes_term_proc_list_test(MustChk) ->
 		  erlang:suspend_process(P),
 		  erlang:system_flag(multi_scheduling, unblock),
 		  [{status,suspended},
-		   {current_function,{erlang,processes_trap,2}}]
+		   {current_function,{erlang,ptab_list_continue,2}}]
 		      = process_info(P, [status, current_function]),
 		  P
 	  end,