Support for dirty BIFs

20 files changed, 1663 insertions, 608 deletions

diff --git a/erts/emulator/beam/atom.names b/erts/emulator/beam/atom.names
index b1aeed7889..7df350116a 100644
--- a/erts/emulator/beam/atom.names
+++ b/erts/emulator/beam/atom.names
@@ -76,6 +76,7 @@ atom ac
 atom accessor
 atom active
 atom active_tasks
+atom alive
 atom all
 atom all_but_first
 atom all_names
@@ -199,10 +200,15 @@ atom dexit
 atom depth
 atom dgroup_leader
 atom dictionary
+atom dirty_bif_exception
+atom dirty_bif_result
+atom dirty_bif_trap
 atom dirty_cpu
 atom dirty_cpu_schedulers_online
 atom dirty_execution
 atom dirty_io
+atom dirty_nif_exception
+atom dirty_nif_finalizer
 atom disable_trace
 atom disabled
 atom discard
@@ -243,6 +249,7 @@ atom ERROR='ERROR'
 atom error_handler
 atom error_logger
 atom erts_code_purger
+atom erts_debug
 atom erts_internal
 atom ets
 atom ETS_TRANSFER='ETS-TRANSFER'
@@ -573,6 +580,7 @@ atom scientific
 atom scope
 atom second
 atom seconds
+atom send
 atom send_to_non_existing_process
 atom sensitive
 atom sequential_tracer
@@ -665,6 +673,7 @@ atom value
 atom values
 atom version
 atom visible
+atom wait
 atom waiting
 atom wall_clock
 atom warning
diff --git a/erts/emulator/beam/beam_bif_load.c b/erts/emulator/beam/beam_bif_load.c
index 09331eb8ad..36bbe81ed5 100644
--- a/erts/emulator/beam/beam_bif_load.c
+++ b/erts/emulator/beam/beam_bif_load.c
@@ -36,6 +36,7 @@
 #include "erl_nif.h"
 #include "erl_bits.h"
 #include "erl_thr_progress.h"
+#include "erl_nfunc_sched.h"
 #ifdef HIPE
 #  include "hipe_bif0.h"
 #  define IF_HIPE(X) (X)
@@ -1105,6 +1106,11 @@ check_process_code(Process* rp, Module* modp, int *redsp, int fcalls)
     if (erts_check_nif_export_in_area(rp, mod_start, mod_size))
 	return am_true;
 
+    *redsp += 1;
+
+    if (erts_check_nif_export_in_area(rp, mod_start, mod_size))
+	return am_true;
+
     *redsp += (STACK_START(rp) - rp->stop) / 32;
 
     /*
diff --git a/erts/emulator/beam/beam_debug.c b/erts/emulator/beam/beam_debug.c
index e72d7f8de4..3ffbb0364c 100644
--- a/erts/emulator/beam/beam_debug.c
+++ b/erts/emulator/beam/beam_debug.c
@@ -39,6 +39,7 @@
 #include "beam_bp.h"
 #include "erl_binary.h"
 #include "erl_thr_progress.h"
+#include "erl_nfunc_sched.h"
 
 #ifdef ARCH_64
 # define HEXF "%016bpX"
@@ -764,3 +765,349 @@ static void print_bif_name(fmtfn_t to, void* to_arg, BifFunction bif)
 	erts_print(to, to_arg, "%T/%u", name, arity);
     }
 }
+
+/*
+ * Dirty BIF testing.
+ *
+ * The erts_debug:dirty_cpu/2, erts_debug:dirty_io/1, and
+ * erts_debug:dirty/3 BIFs are used by the dirty_bif_SUITE
+ * test suite.
+ */
+
+#ifdef ERTS_DIRTY_SCHEDULERS
+static int ms_wait(Process *c_p, Eterm etimeout, int busy);
+static int dirty_send_message(Process *c_p, Eterm to, Eterm tag);
+#endif
+static BIF_RETTYPE dirty_test(Process *c_p, Eterm type, Eterm arg1, Eterm arg2, UWord *I);
+
+/*
+ * erts_debug:dirty_cpu/2 is statically determined to execute on
+ * a dirty CPU scheduler (see erts_dirty_bif.tab).
+ */
+BIF_RETTYPE
+erts_debug_dirty_cpu_2(BIF_ALIST_2)
+{
+    return dirty_test(BIF_P, am_dirty_cpu, BIF_ARG_1, BIF_ARG_2, BIF_I);
+}
+
+/*
+ * erts_debug:dirty_io/2 is statically determined to execute on
+ * a dirty I/O scheduler (see erts_dirty_bif.tab).
+ */
+BIF_RETTYPE
+erts_debug_dirty_io_2(BIF_ALIST_2)
+{
+    return dirty_test(BIF_P, am_dirty_io, BIF_ARG_1, BIF_ARG_2, BIF_I);
+}
+
+/*
+ * erts_debug:dirty/3 executes on a normal scheduler.
+ */
+BIF_RETTYPE
+erts_debug_dirty_3(BIF_ALIST_3)
+{
+#ifdef ERTS_DIRTY_SCHEDULERS
+    Eterm argv[2];
+    switch (BIF_ARG_1) {
+    case am_normal:
+	return dirty_test(BIF_P, am_normal, BIF_ARG_2, BIF_ARG_3, BIF_I);
+    case am_dirty_cpu:
+	argv[0] = BIF_ARG_2;
+	argv[1] = BIF_ARG_3;
+	return erts_schedule_bif(BIF_P,
+				 argv,
+				 BIF_I,
+				 erts_debug_dirty_cpu_2,
+				 ERTS_SCHED_DIRTY_CPU,
+				 am_erts_debug,
+				 am_dirty_cpu,
+				 2);
+    case am_dirty_io:
+	argv[0] = BIF_ARG_2;
+	argv[1] = BIF_ARG_3;
+	return erts_schedule_bif(BIF_P,
+				 argv,
+				 BIF_I,
+				 erts_debug_dirty_io_2,
+				 ERTS_SCHED_DIRTY_IO,
+				 am_erts_debug,
+				 am_dirty_io,
+				 2);
+    default:
+	BIF_ERROR(BIF_P, EXC_BADARG);
+    }
+#else
+	BIF_ERROR(BIF_P, EXC_UNDEF);
+#endif
+}
+
+
+static BIF_RETTYPE
+dirty_test(Process *c_p, Eterm type, Eterm arg1, Eterm arg2, UWord *I)
+{
+    BIF_RETTYPE ret;
+#ifdef ERTS_DIRTY_SCHEDULERS
+    if (am_scheduler == arg1) {
+	ErtsSchedulerData *esdp;
+	if (arg2 != am_type) 
+	    goto badarg;
+	esdp = erts_proc_sched_data(c_p);
+	if (!esdp)
+	    ERTS_BIF_PREP_RET(ret, am_error);
+	else if (!ERTS_SCHEDULER_IS_DIRTY(esdp))
+	    ERTS_BIF_PREP_RET(ret, am_normal);
+	else if (ERTS_SCHEDULER_IS_DIRTY_CPU(esdp))
+	    ERTS_BIF_PREP_RET(ret, am_dirty_cpu);
+	else if (ERTS_SCHEDULER_IS_DIRTY_IO(esdp))
+	    ERTS_BIF_PREP_RET(ret, am_dirty_io);
+	else
+	    ERTS_BIF_PREP_RET(ret, am_error);
+    }
+    else if (am_error == arg1) {
+	switch (arg2) {
+	case am_notsup:
+	    ERTS_BIF_PREP_ERROR(ret, c_p, EXC_NOTSUP);
+	    break;
+	case am_undef:
+	    ERTS_BIF_PREP_ERROR(ret, c_p, EXC_UNDEF);
+	    break;
+	case am_badarith:
+	    ERTS_BIF_PREP_ERROR(ret, c_p, EXC_BADARITH);
+	    break;
+	case am_noproc:
+	    ERTS_BIF_PREP_ERROR(ret, c_p, EXC_NOPROC);
+	    break;
+	case am_system_limit:
+	    ERTS_BIF_PREP_ERROR(ret, c_p, SYSTEM_LIMIT);
+	    break;
+	case am_badarg:
+	default:
+	    goto badarg;
+	}
+    }
+    else if (am_copy == arg1) {
+	int i;
+	Eterm res;
+
+	for (res = NIL, i = 0; i < 1000; i++) {
+	    Eterm *hp, sz;
+	    Eterm cpy;
+	    /* We do not want this to be optimized,
+	       but rather the oposite... */
+	    sz = size_object(arg2);
+	    hp = HAlloc(c_p, sz);
+	    cpy = copy_struct(arg2, sz, &hp, &c_p->off_heap);
+	    hp = HAlloc(c_p, 2);
+	    res = CONS(hp, cpy, res);
+	}
+
+	ERTS_BIF_PREP_RET(ret, res);
+    }
+    else if (am_send == arg1) {
+	dirty_send_message(c_p, arg2, am_ok);
+	ERTS_BIF_PREP_RET(ret, am_ok);
+    }
+    else if (ERTS_IS_ATOM_STR("wait", arg1)) {
+	if (!ms_wait(c_p, arg2, type == am_dirty_cpu))
+	    goto badarg;
+	ERTS_BIF_PREP_RET(ret, am_ok);
+    }
+    else if (ERTS_IS_ATOM_STR("reschedule", arg1)) {
+	/*
+	 * Reschedule operation after decrement of two until we reach
+	 * zero. Switch between dirty scheduler types when 'n' is
+	 * evenly divided by 4. If the initial value wasn't evenly
+	 * dividable by 2, throw badarg exception.
+	 */
+	Eterm next_type;
+	Sint n;
+	if (!term_to_Sint(arg2, &n) || n < 0)
+	    goto badarg;
+	if (n == 0)
+	    ERTS_BIF_PREP_RET(ret, am_ok);
+	else {
+	    Eterm argv[3];
+	    Eterm eint = erts_make_integer((Uint) (n - 2), c_p);
+	    if (n % 4 != 0)
+		next_type = type;
+	    else {
+		switch (type) {
+		case am_dirty_cpu: next_type = am_dirty_io; break;
+		case am_dirty_io: next_type = am_normal; break;
+		case am_normal: next_type = am_dirty_cpu; break;
+		default: goto badarg;
+		}
+	    }
+	    switch (next_type) {
+	    case am_dirty_io:
+		argv[0] = arg1;
+		argv[1] = eint;
+		ret = erts_schedule_bif(c_p,
+					argv,
+					I,
+					erts_debug_dirty_io_2,
+					ERTS_SCHED_DIRTY_IO,
+					am_erts_debug,
+					am_dirty_io,
+					2);
+		break;
+	    case am_dirty_cpu:
+		argv[0] = arg1;
+		argv[1] = eint;
+		ret = erts_schedule_bif(c_p,
+					argv,
+					I,
+					erts_debug_dirty_cpu_2,
+					ERTS_SCHED_DIRTY_CPU,
+					am_erts_debug,
+					am_dirty_cpu,
+					2);
+		break;
+	    case am_normal:
+		argv[0] = am_normal;
+		argv[1] = arg1;
+		argv[2] = eint;
+		ret = erts_schedule_bif(c_p,
+					argv,
+					I,
+					erts_debug_dirty_3,
+					ERTS_SCHED_NORMAL,
+					am_erts_debug,
+					am_dirty,
+					3);
+		break;
+	    default:
+		goto badarg;
+	    }
+	}
+    }
+    else if (ERTS_IS_ATOM_STR("ready_wait6_done", arg1)) {
+	ERTS_DECL_AM(ready);
+	ERTS_DECL_AM(done);
+	dirty_send_message(c_p, arg2, AM_ready);
+	ms_wait(c_p, make_small(6000), 0);
+	dirty_send_message(c_p, arg2, AM_done);
+	ERTS_BIF_PREP_RET(ret, am_ok);
+    }
+    else if (ERTS_IS_ATOM_STR("alive_waitexiting", arg1)) {
+	Process *real_c_p = erts_proc_shadow2real(c_p);
+	Eterm *hp, *hp2;
+	Uint sz;
+	int i;
+	if (ERTS_PROC_IS_EXITING(real_c_p))
+	    goto badarg;
+	dirty_send_message(c_p, arg2, am_alive);
+	/* Wait until dead */
+
+	while (!ERTS_PROC_IS_EXITING(real_c_p))
+	    erts_thr_yield();
+
+	ms_wait(c_p, make_small(1000), 0);
+
+	/* Should still be able to allocate memory */
+	hp = HAlloc(c_p, 3); /* Likely on heap */
+	sz = 10000;
+	hp2 = HAlloc(c_p, sz); /* Likely in heap fragment */
+	*hp2 = make_pos_bignum_header(sz);
+	for (i = 1; i < sz; i++)
+	    hp2[i] = (Eterm) 4711;
+	ERTS_BIF_PREP_RET(ret, TUPLE2(hp, am_ok, make_big(hp2)));
+    }
+    else {
+    badarg:
+	ERTS_BIF_PREP_ERROR(ret, c_p, BADARG);
+    }
+#else
+    ERTS_BIF_PREP_ERROR(ret, c_p, EXC_UNDEF);
+#endif
+    return ret;
+}
+
+#ifdef ERTS_DIRTY_SCHEDULERS
+
+static int
+dirty_send_message(Process *c_p, Eterm to, Eterm tag)
+{
+    ErtsProcLocks c_p_locks, rp_locks;
+    Process *rp, *real_c_p;
+    Eterm msg, *hp;
+    ErlOffHeap *ohp;
+    ErtsMessage *mp;
+
+    ASSERT(is_immed(tag));
+
+    real_c_p = erts_proc_shadow2real(c_p);
+    if (real_c_p != c_p)
+	c_p_locks = 0;
+    else
+	c_p_locks = ERTS_PROC_LOCK_MAIN;
+
+    ASSERT(real_c_p->common.id == c_p->common.id);
+
+    rp = erts_pid2proc_opt(real_c_p, c_p_locks,
+			   to, 0,
+			   ERTS_P2P_FLG_INC_REFC);
+
+    if (!rp)
+	return 0;
+
+    rp_locks = 0;
+    mp = erts_alloc_message_heap(rp, &rp_locks, 3, &hp, &ohp);
+
+    msg = TUPLE2(hp, tag, c_p->common.id);
+    erts_queue_message(rp, rp_locks, mp, msg, c_p->common.id);
+
+    if (rp == real_c_p)
+	rp_locks &= ~c_p_locks;
+    if (rp_locks)
+	erts_smp_proc_unlock(rp, rp_locks);
+
+    erts_proc_dec_refc(rp);
+
+    return 1;
+}
+
+static int
+ms_wait(Process *c_p, Eterm etimeout, int busy)
+{
+    ErtsSchedulerData *esdp = erts_proc_sched_data(c_p);
+    ErtsMonotonicTime time, timeout_time;
+    Sint64 ms;
+
+    if (!term_to_Sint64(etimeout, &ms))
+	return 0;
+
+    time = erts_get_monotonic_time(esdp);
+
+    if (ms < 0)
+	timeout_time = time;
+    else
+	timeout_time = time + ERTS_MSEC_TO_MONOTONIC(ms);
+
+    while (time < timeout_time) {
+	if (busy)
+	    erts_thr_yield();
+	else {
+	    ErtsMonotonicTime timeout = timeout_time - time;
+
+#ifdef __WIN32__
+	    Sleep((DWORD) ERTS_MONOTONIC_TO_MSEC(timeout));
+#else
+	    {
+		ErtsMonotonicTime to = ERTS_MONOTONIC_TO_USEC(timeout);
+		struct timeval tv;
+
+		tv.tv_sec = (long) to / (1000*1000);
+		tv.tv_usec = (long) to % (1000*1000);
+
+		select(0, NULL, NULL, NULL, &tv);
+	    }
+#endif
+	}
+
+	time = erts_get_monotonic_time(esdp);
+    }
+    return 1;
+}
+
+#endif /* ERTS_DIRTY_SCHEDULERS */
diff --git a/erts/emulator/beam/beam_emu.c b/erts/emulator/beam/beam_emu.c
index bb77dbd955..befd2989f9 100644
--- a/erts/emulator/beam/beam_emu.c
+++ b/erts/emulator/beam/beam_emu.c
@@ -38,6 +38,7 @@
 #include "beam_bp.h"
 #include "beam_catches.h"
 #include "erl_thr_progress.h"
+#include "erl_nfunc_sched.h"
 #ifdef HIPE
 #include "hipe_mode_switch.h"
 #include "hipe_bif1.h"
@@ -214,6 +215,7 @@ BeamInstr beam_continue_exit[1];
 BeamInstr* em_call_error_handler;
 BeamInstr* em_apply_bif;
 BeamInstr* em_call_nif;
+BeamInstr* em_call_bif_e;
 
 
 /* NOTE These should be the only variables containing trace instructions.
@@ -2581,7 +2583,7 @@ do {						\
 
  OpCase(bif1_fbsd):
     {
-	Eterm (*bf)(Process*, Eterm*);
+	ErtsBifFunc bf;
 	Eterm tmp_reg[1];
 	Eterm result;
 
@@ -2592,7 +2594,7 @@ do {						\
 	PROCESS_MAIN_CHK_LOCKS(c_p);
 	ASSERT(!ERTS_PROC_IS_EXITING(c_p));
 	ERTS_CHK_MBUF_SZ(c_p);
-	result = (*bf)(c_p, tmp_reg);
+	result = (*bf)(c_p, tmp_reg, I);
 	ERTS_CHK_MBUF_SZ(c_p);
 	ASSERT(!ERTS_PROC_IS_EXITING(c_p) || is_non_value(result));
 	ERTS_VERIFY_UNUSED_TEMP_ALLOC(c_p);
@@ -2613,19 +2615,19 @@ do {						\
 
  OpCase(bif1_body_bsd):
     {
-	Eterm (*bf)(Process*, Eterm*);
+	ErtsBifFunc bf;
 
 	Eterm tmp_reg[1];
 	Eterm result;
 
 	GetArg1(1, tmp_reg[0]);
-	bf = (BifFunction) Arg(0);
+	bf = (ErtsBifFunc) Arg(0);
 	ERTS_DBG_CHK_REDS(c_p, FCALLS);
 	c_p->fcalls = FCALLS;
 	PROCESS_MAIN_CHK_LOCKS(c_p);
 	ASSERT(!ERTS_PROC_IS_EXITING(c_p));
 	ERTS_CHK_MBUF_SZ(c_p);
-	result = (*bf)(c_p, tmp_reg);
+	result = (*bf)(c_p, tmp_reg, I);
 	ERTS_CHK_MBUF_SZ(c_p);
 	ASSERT(!ERTS_PROC_IS_EXITING(c_p) || is_non_value(result));
 	ERTS_VERIFY_UNUSED_TEMP_ALLOC(c_p);
@@ -2775,17 +2777,17 @@ do {						\
  OpCase(i_bif2_fbssd):
     {
 	Eterm tmp_reg[2];
-	Eterm (*bf)(Process*, Eterm*);
+	ErtsBifFunc bf;
 	Eterm result;
 
 	GetArg2(2, tmp_reg[0], tmp_reg[1]);
-	bf = (BifFunction) Arg(1);
+	bf = (ErtsBifFunc) Arg(1);
 	ERTS_DBG_CHK_REDS(c_p, FCALLS);
 	c_p->fcalls = FCALLS;
 	PROCESS_MAIN_CHK_LOCKS(c_p);
 	ASSERT(!ERTS_PROC_IS_EXITING(c_p));
 	ERTS_CHK_MBUF_SZ(c_p);
-	result = (*bf)(c_p, tmp_reg);
+	result = (*bf)(c_p, tmp_reg, I);
 	ERTS_CHK_MBUF_SZ(c_p);
 	ASSERT(!ERTS_PROC_IS_EXITING(c_p) || is_non_value(result));
 	ERTS_VERIFY_UNUSED_TEMP_ALLOC(c_p);
@@ -2806,15 +2808,15 @@ do {						\
  OpCase(i_bif2_body_bssd):
     {
 	Eterm tmp_reg[2];
-	Eterm (*bf)(Process*, Eterm*);
+	ErtsBifFunc bf;
 	Eterm result;
 
 	GetArg2(1, tmp_reg[0], tmp_reg[1]);
-	bf = (BifFunction) Arg(0);
+	bf = (ErtsBifFunc) Arg(0);
 	PROCESS_MAIN_CHK_LOCKS(c_p);
 	ASSERT(!ERTS_PROC_IS_EXITING(c_p));
 	ERTS_CHK_MBUF_SZ(c_p);
-	result = (*bf)(c_p, tmp_reg);
+	result = (*bf)(c_p, tmp_reg, I);
 	ERTS_CHK_MBUF_SZ(c_p);
 	ASSERT(!ERTS_PROC_IS_EXITING(c_p) || is_non_value(result));
 	ERTS_VERIFY_UNUSED_TEMP_ALLOC(c_p);
@@ -2837,7 +2839,7 @@ do {						\
      */
  OpCase(call_bif_e):
     {
-        Eterm (*bf)(Process*, Eterm*, BeamInstr*);
+	ErtsBifFunc bf;
 	Eterm result;
 	BeamInstr *next;
 	ErlHeapFragment *live_hf_end;
@@ -3644,7 +3646,7 @@ do {						\
 	    ERTS_SMP_UNREQ_PROC_MAIN_LOCK(c_p);
 	    ERTS_VERIFY_UNUSED_TEMP_ALLOC(c_p);
 	    {
-		Eterm (*bf)(Process*, Eterm*, BeamInstr*) = vbf;
+		ErtsBifFunc bf = vbf;
 		ASSERT(!ERTS_PROC_IS_EXITING(c_p));
 		live_hf_end = c_p->mbuf;
 		ERTS_CHK_MBUF_SZ(c_p);
@@ -5137,6 +5139,7 @@ do {						\
      em_call_error_handler = OpCode(call_error_handler);
      em_apply_bif = OpCode(apply_bif);
      em_call_nif = OpCode(call_nif);
+     em_call_bif_e = OpCode(call_bif_e);
 
      beam_apply[0]             = (BeamInstr) OpCode(i_apply);
      beam_apply[1]             = (BeamInstr) OpCode(normal_exit);
@@ -5342,8 +5345,6 @@ void erts_dirty_process_main(ErtsSchedulerData *esdp)
 
 	I = c_p->i;
 
-	ASSERT(em_call_nif == (BeamInstr *) *I);
-
 	/*
 	 * Set fcalls even though we ignore it, so we don't
 	 * confuse code accessing it...
@@ -5379,10 +5380,7 @@ void erts_dirty_process_main(ErtsSchedulerData *esdp)
     }
 
     {
-#ifdef DEBUG
-	Eterm result;
-#endif
-	Eterm arity;
+	int exiting;
 
 	{
 	    /*
@@ -5398,7 +5396,6 @@ void erts_dirty_process_main(ErtsSchedulerData *esdp)
              *
              * This layout is determined by the NifExport struct
 	     */
-	    BifFunction vbf;
             ErtsCodeMFA *codemfa;
 
 	    ERTS_MSACC_SET_STATE_CACHED_M_X(ERTS_MSACC_STATE_NIF);
@@ -5406,44 +5403,29 @@ void erts_dirty_process_main(ErtsSchedulerData *esdp)
             codemfa = erts_code_to_codemfa(I);
 
 	    DTRACE_NIF_ENTRY(c_p, codemfa);
-            /* current and vbf set to please handle_error */
 	    c_p->current = codemfa;
 	    SWAPOUT;
 	    PROCESS_MAIN_CHK_LOCKS(c_p);
-	    arity = codemfa->arity;
 	    ERTS_SMP_UNREQ_PROC_MAIN_LOCK(c_p);
 
 	    ASSERT(!ERTS_PROC_IS_EXITING(c_p));
-	    {
-		typedef Eterm NifF(struct enif_environment_t*, int argc, Eterm argv[]);
-		NifF* fp = vbf = (NifF*) I[1];
-		struct enif_environment_t env;
-		ASSERT(!c_p->scheduler_data);
-
-		erts_pre_dirty_nif(esdp, &env, c_p,
-				   (struct erl_module_nif*)I[2]);
-
-#ifdef DEBUG
-		result =
-#else
-		(void)
-#endif
-		    (*fp)(&env, arity, reg);
-
-		erts_post_dirty_nif(&env);
+	    if (em_apply_bif == (BeamInstr *) *I) {
+		exiting = erts_call_dirty_bif(esdp, c_p, I, reg);
+	    }
+	    else {
+		ASSERT(em_call_nif == (BeamInstr *) *I);
+		exiting = erts_call_dirty_nif(esdp, c_p, I, reg);
+	    }
 
-		ASSERT(!is_value(result));
-		ASSERT(c_p->freason == TRAP);
-		ASSERT(!(c_p->flags & F_HIBERNATE_SCHED));
+	    ASSERT(!(c_p->flags & F_HIBERNATE_SCHED));
 
-		PROCESS_MAIN_CHK_LOCKS(c_p);
-		ERTS_SMP_REQ_PROC_MAIN_LOCK(c_p);
-		ERTS_VERIFY_UNUSED_TEMP_ALLOC(c_p);
-		ERTS_MSACC_SET_STATE_CACHED_M_X(ERTS_MSACC_STATE_EMULATOR);
-		if (env.exiting)
-		    goto do_dirty_schedule;
-		ASSERT(!ERTS_PROC_IS_EXITING(c_p));
-	    }
+	    PROCESS_MAIN_CHK_LOCKS(c_p);
+	    ERTS_SMP_REQ_PROC_MAIN_LOCK(c_p);
+	    ERTS_VERIFY_UNUSED_TEMP_ALLOC(c_p);
+	    ERTS_MSACC_SET_STATE_CACHED_M_X(ERTS_MSACC_STATE_EMULATOR);
+	    if (exiting)
+		goto do_dirty_schedule;
+	    ASSERT(!ERTS_PROC_IS_EXITING(c_p));
 
 	    DTRACE_NIF_RETURN(c_p, codemfa);
 	    ERTS_HOLE_CHECK(c_p);
@@ -5529,10 +5511,15 @@ handle_error(Process* c_p, BeamInstr* pc, Eterm* reg, BifFunction bf)
     Eterm* hp;
     Eterm Value = c_p->fvalue;
     Eterm Args = am_true;
-    c_p->i = pc;    /* In case we call erts_exit(). */
 
     ASSERT(c_p->freason != TRAP); /* Should have been handled earlier. */
 
+    if (c_p->freason & EXF_RESTORE_NIF) {
+	erts_nif_export_restore_error(c_p, &pc, reg, &bf);
+    }
+
+    c_p->i = pc;    /* In case we call erts_exit(). */
+
     /*
      * Check if we have an arglist for the top level call. If so, this
      * is encoded in Value, so we have to dig out the real Value as well
@@ -5830,6 +5817,18 @@ expand_error_value(Process* c_p, Uint freason, Eterm Value) {
  */
 
 static void
+save_stacktrace_current(struct StackTrace *s, Process *c_p, ErtsCodeMFA *mfa)
+{
+    NifExport *nep = (NifExport *) ERTS_PROC_GET_NIF_TRAP_EXPORT(c_p);
+    if (!nep || &nep->exp.info.mfa != mfa)
+	s->current = mfa;
+    else {
+	s->mfa = *mfa;
+	s->current = &s->mfa;
+    }
+}
+
+static void
 save_stacktrace(Process* c_p, BeamInstr* pc, Eterm* reg, BifFunction bf,
 		Eterm args) {
     struct StackTrace* s;
@@ -5858,12 +5857,10 @@ save_stacktrace(Process* c_p, BeamInstr* pc, Eterm* reg, BifFunction bf,
 	&& bf != throw_1 && bf != wrap_error_1 && bf != wrap_error_2
 	&& bf != wrap_exit_1 && bf != wrap_throw_1) {
         int i;
-	int a = 0;
+	int a;
 	for (i = 0; i < BIF_SIZE; i++) {
 	    if (bf == bif_table[i].f || bf == bif_table[i].traced) {
-		Export *ep = bif_export[i];
-		s->current = &ep->info.mfa;
-	        a = bif_table[i].arity;
+		save_stacktrace_current(s, c_p, &bif_export[i]->info.mfa);
 		break;
 	    }
 	}
@@ -5875,9 +5872,11 @@ save_stacktrace(Process* c_p, BeamInstr* pc, Eterm* reg, BifFunction bf,
 	     * OR it is a NIF called by call_nif where current is also set.
 	     */
 	    ASSERT(c_p->current);
-	    s->current = c_p->current;
-	    a = s->current->arity;
+	    save_stacktrace_current(s, c_p, c_p->current);
 	}
+
+	a = s->current->arity;
+
 	/* Save first stack entry */
 	ASSERT(pc);
 	if (depth > 0) {
@@ -5892,7 +5891,9 @@ save_stacktrace(Process* c_p, BeamInstr* pc, Eterm* reg, BifFunction bf,
 	s->pc = NULL;
 	args = make_arglist(c_p, reg, a); /* Overwrite CAR(c_p->ftrace) */
     } else {
-	s->current = c_p->current;
+
+	save_stacktrace_current(s, c_p, c_p->current);
+
         /* 
 	 * For a function_clause error, the arguments are in the beam
 	 * registers, c_p->cp is valid, and c_p->current is set.
diff --git a/erts/emulator/beam/bif.c b/erts/emulator/beam/bif.c
index d886c2985e..7bcb7c196d 100644
--- a/erts/emulator/beam/bif.c
+++ b/erts/emulator/beam/bif.c
@@ -4958,7 +4958,7 @@ erts_bif_prep_await_proc_exit_apply_trap(Process *c_p,
 Export bif_return_trap_export;
 
 void erts_init_trap_export(Export* ep, Eterm m, Eterm f, Uint a,
-			   Eterm (*bif)(BIF_ALIST_0))
+			   Eterm (*bif)(BIF_ALIST))
 {
     int i;
     sys_memset((void *) ep, 0, sizeof(Export));
@@ -5019,6 +5019,321 @@ void erts_init_bif(void)
     erts_smp_atomic32_init_nob(&msacc, ERTS_MSACC_IS_ENABLED());
 }
 
+/*
+ * Scheduling of BIFs via NifExport...
+ */
+#define ERTS_WANT_NFUNC_SCHED_INTERNALS__
+#include "erl_nfunc_sched.h"
+
+#define ERTS_SCHED_BIF_TRAP_MARKER ((void *) (UWord) 1)
+
+static void
+schedule(Process *c_p, Process *dirty_shadow_proc,
+	 ErtsCodeMFA *mfa, BifFunction *nif, BeamInstr *pc,
+	 ErtsBifFunc dfunc, void *ifunc,
+	 Eterm module, Eterm function,
+	 int argc, Eterm *argv)
+{
+    ERTS_SMP_LC_ASSERT(ERTS_PROC_LOCK_MAIN & erts_proc_lc_my_proc_locks(c_p));
+    (void) erts_nif_export_schedule(c_p, dirty_shadow_proc,
+				    mfa, nif, pc,
+				    (BeamInstr) em_apply_bif,
+				    dfunc, ifunc,
+				    module, function,
+				    argc, argv);
+}
+
+#ifdef ERTS_DIRTY_SCHEDULERS
+
+static BIF_RETTYPE dirty_bif_result(BIF_ALIST_1)
+{
+    NifExport *nep = (NifExport *) ERTS_PROC_GET_NIF_TRAP_EXPORT(BIF_P);
+    erts_nif_export_restore(BIF_P, nep);
+    BIF_RET(BIF_ARG_1);
+}
+
+static BIF_RETTYPE dirty_bif_trap(BIF_ALIST)
+{
+    NifExport *nep = (NifExport *) ERTS_PROC_GET_NIF_TRAP_EXPORT(BIF_P);
+
+    /*
+     * Arity and argument registers already set
+     * correct by call to dirty_bif_trap()...
+     */
+
+    ASSERT(BIF_P->arity == nep->exp.info.mfa.arity);
+
+    erts_nif_export_restore(BIF_P, nep);
+
+    BIF_P->i = (BeamInstr *) nep->func;
+    BIF_P->freason = TRAP;
+    return THE_NON_VALUE;
+}
+
+static BIF_RETTYPE dirty_bif_exception(BIF_ALIST_2)
+{
+    Eterm freason;
+
+    ASSERT(is_small(BIF_ARG_1));
+
+    freason = signed_val(BIF_ARG_1);
+
+    /* Restore orig info for error and clear nif export in handle_error() */
+    freason |= EXF_RESTORE_NIF;
+
+    BIF_P->fvalue = BIF_ARG_2;
+
+    BIF_ERROR(BIF_P, freason);
+}
+
+#endif /* ERTS_DIRTY_SCHEDULERS */
+
+extern BeamInstr* em_call_bif_e;
+static BIF_RETTYPE call_bif(Process *c_p, Eterm *reg, BeamInstr *I);
+
+BIF_RETTYPE
+erts_schedule_bif(Process *proc,
+		  Eterm *argv,
+		  BeamInstr *i,
+		  ErtsBifFunc bif,
+		  ErtsSchedType sched_type,
+		  Eterm mod,
+		  Eterm func,
+		  int argc)
+{
+    Process *c_p, *dirty_shadow_proc;
+    ErtsCodeMFA *mfa;
+
+#ifdef ERTS_DIRTY_SCHEDULERS
+    if (proc->static_flags & ERTS_STC_FLG_SHADOW_PROC) {
+	dirty_shadow_proc = proc;
+	c_p = proc->next;
+	ASSERT(c_p->common.id == dirty_shadow_proc->common.id);
+	erts_smp_proc_lock(c_p, ERTS_PROC_LOCK_MAIN);
+    }
+    else
+#endif
+    {
+	dirty_shadow_proc = NULL;
+	c_p = proc;
+    }
+
+    if (!ERTS_PROC_IS_EXITING(c_p)) {
+	Export *exp;
+	BifFunction obif, dbif, ibif;
+	BeamInstr *pc;
+
+	/*
+	 * obif - original bif
+	 * dbif - direct bif
+	 * ibif - indirect bif
+	 */
+
+#ifdef ERTS_DIRTY_SCHEDULERS
+	erts_aint32_t set, mask;
+	mask = (ERTS_PSFLG_DIRTY_CPU_PROC
+		| ERTS_PSFLG_DIRTY_IO_PROC);
+	switch (sched_type) {
+	case ERTS_SCHED_DIRTY_CPU:
+	    set = ERTS_PSFLG_DIRTY_CPU_PROC;
+	    dbif = bif;
+	    ibif = NULL;
+	    break;
+	case ERTS_SCHED_DIRTY_IO:
+	    set = ERTS_PSFLG_DIRTY_IO_PROC;
+	    dbif = bif;
+	    ibif = NULL;
+	    break;
+	case ERTS_SCHED_NORMAL:
+	default:
+	    set = 0;
+	    dbif = call_bif;
+	    ibif = bif;
+	    break;
+	}
+
+	(void) erts_smp_atomic32_read_bset_nob(&c_p->state, mask, set);
+#else
+	dbif = call_bif;
+	ibif = bif;
+#endif
+
+	if (i == NULL) {
+	    ERTS_INTERNAL_ERROR("Missing instruction pointer");
+	    obif = NULL;
+	}
+#ifdef HIPE
+	else if (proc->flags & F_HIPE_MODE) {
+	    /* Pointer to bif export in i */
+	    exp = (Export *) i;
+	    pc = c_p->cp;
+	    obif = (BifFunction) exp->beam[1];
+	    mfa = &exp->info.mfa;
+	}
+#endif
+	else if (em_call_bif_e == (BeamInstr *) *i) {
+	    /* Pointer to bif export in i+1 */
+	    exp = (Export *) i[1];
+	    pc = i;
+	    obif = (BifFunction) exp->beam[1];
+	    mfa = &exp->info.mfa;
+	}
+	else if (em_apply_bif == (BeamInstr *) *i) {
+	    /* Pointer to bif in i+1, and mfa in i-3 */	    
+	    obif = (BifFunction) i[1];
+	    pc = c_p->cp;
+	    mfa = erts_code_to_codemfa(i);
+	}
+	else {
+	    ERTS_INTERNAL_ERROR("erts_schedule_bif() called "
+				"from unexpected instruction");
+	    obif = NULL;
+	}
+	ASSERT(bif);
+
+	if (argc < 0) { /* reschedule original call */
+	    mod = mfa->module;
+	    func = mfa->function;
+	    argc = (int) mfa->arity;
+	}
+
+	schedule(c_p, dirty_shadow_proc, mfa, obif,
+		 pc, dbif, ibif, mod, func, argc, argv);
+    }
+
+    if (dirty_shadow_proc)
+	erts_smp_proc_unlock(c_p, ERTS_PROC_LOCK_MAIN);
+
+    return THE_NON_VALUE;
+}
+
+static BIF_RETTYPE
+call_bif(Process *c_p, Eterm *reg, BeamInstr *I)
+{
+    NifExport *nep = ERTS_I_BEAM_OP_TO_NIF_EXPORT(I);
+    ErtsBifFunc bif = (ErtsBifFunc) nep->func;
+    BIF_RETTYPE ret;
+
+    ASSERT(!ERTS_SCHEDULER_IS_DIRTY(erts_get_scheduler_data()));
+
+    nep->func = ERTS_SCHED_BIF_TRAP_MARKER;
+
+    ASSERT(bif);
+
+    ret = (*bif)(c_p, reg, I);
+
+    if (is_value(ret))
+	erts_nif_export_restore(c_p, nep);
+    else if (c_p->freason != TRAP)
+	c_p->freason |= EXF_RESTORE_NIF; /* restore in handle_error() */
+    else if (nep->func == ERTS_SCHED_BIF_TRAP_MARKER) {
+	/* BIF did an ordinary trap... */
+	erts_nif_export_restore(c_p, nep);
+    }
+    /* else:
+     *   BIF rescheduled itself using erts_schedule_bif().
+     */
+
+    return ret;
+}
+
+#ifdef ERTS_DIRTY_SCHEDULERS
+
+int
+erts_call_dirty_bif(ErtsSchedulerData *esdp, Process *c_p, BeamInstr *I, Eterm *reg)
+{
+    BIF_RETTYPE result;
+    int exiting;
+    Process *dirty_shadow_proc;
+    ErtsBifFunc bf;
+    NifExport *nep;
+#ifdef DEBUG
+    Eterm *c_p_htop;
+    erts_aint32_t state;
+
+    ASSERT(!c_p->scheduler_data);
+    state = erts_smp_atomic32_read_nob(&c_p->state);
+    ASSERT((state & ERTS_PSFLG_DIRTY_RUNNING)
+	   && !(state & (ERTS_PSFLG_RUNNING|ERTS_PSFLG_RUNNING_SYS)));
+    ASSERT(esdp);
+
+#endif
+
+    nep = ERTS_I_BEAM_OP_TO_NIF_EXPORT(I);
+    ASSERT(nep == ERTS_PROC_GET_NIF_TRAP_EXPORT(c_p));
+
+    nep->func = ERTS_SCHED_BIF_TRAP_MARKER;
+
+    bf = (ErtsBifFunc) I[1];
+
+    erts_smp_atomic32_read_band_mb(&c_p->state, ~(ERTS_PSFLG_DIRTY_CPU_PROC
+						  | ERTS_PSFLG_DIRTY_IO_PROC));
+
+    dirty_shadow_proc = erts_make_dirty_shadow_proc(esdp, c_p);
+
+    dirty_shadow_proc->freason = c_p->freason;
+    dirty_shadow_proc->fvalue = c_p->fvalue;
+    dirty_shadow_proc->ftrace = c_p->ftrace;
+    dirty_shadow_proc->cp = c_p->cp;
+    dirty_shadow_proc->i = c_p->i;
+
+#ifdef DEBUG
+    c_p_htop = c_p->htop;
+#endif
+
+    erts_smp_proc_unlock(c_p, ERTS_PROC_LOCK_MAIN);
+
+    result = (*bf)(dirty_shadow_proc, reg, I);
+
+    erts_smp_proc_lock(c_p, ERTS_PROC_LOCK_MAIN);
+
+    ASSERT(c_p_htop == c_p->htop);
+    ASSERT(dirty_shadow_proc->static_flags & ERTS_STC_FLG_SHADOW_PROC);
+    ASSERT(dirty_shadow_proc->next == c_p);
+
+    exiting = ERTS_PROC_IS_EXITING(c_p);
+
+    if (!exiting) {
+	if (is_value(result))
+	    schedule(c_p, dirty_shadow_proc, NULL, NULL, NULL, dirty_bif_result,
+		     NULL, am_erts_internal, am_dirty_bif_result, 1, &result);
+	else if (dirty_shadow_proc->freason != TRAP) {
+	    Eterm argv[2];
+	    ASSERT(dirty_shadow_proc->freason <= MAX_SMALL);
+	    argv[0] = make_small(dirty_shadow_proc->freason);
+	    argv[1] = dirty_shadow_proc->fvalue;
+	    schedule(c_p, dirty_shadow_proc, NULL, NULL, NULL,
+		     dirty_bif_exception, NULL, am_erts_internal,
+		     am_dirty_bif_exception, 2, argv);
+	}
+	else if (nep->func == ERTS_SCHED_BIF_TRAP_MARKER) {
+	    /* Dirty BIF did an ordinary trap... */
+	    ASSERT(!(erts_smp_atomic32_read_nob(&c_p->state)
+		     & (ERTS_PSFLG_DIRTY_CPU_PROC|ERTS_PSFLG_DIRTY_IO_PROC)));
+	    schedule(c_p, dirty_shadow_proc, NULL, NULL, NULL,
+		     dirty_bif_trap, (void *) dirty_shadow_proc->i,
+		     am_erts_internal, am_dirty_bif_trap,
+		     dirty_shadow_proc->arity, reg);
+	}
+	/* else:
+	 *   BIF rescheduled itself using erts_schedule_bif().
+	 */
+	c_p->freason = dirty_shadow_proc->freason;
+	c_p->fvalue = dirty_shadow_proc->fvalue;
+	c_p->ftrace = dirty_shadow_proc->ftrace;
+	c_p->cp = dirty_shadow_proc->cp;
+	c_p->i = dirty_shadow_proc->i;
+	c_p->arity = dirty_shadow_proc->arity;
+    }
+
+    erts_flush_dirty_shadow_proc(dirty_shadow_proc);
+
+    return exiting;
+}
+
+#endif /* ERTS_DIRTY_SCHEDULERS */
+
+
 #ifdef HARDDEBUG
 /*
 You'll need this line in bif.tab to be able to use this debug bif
diff --git a/erts/emulator/beam/bif.h b/erts/emulator/beam/bif.h
index 0c85e19ef0..ad55b19d0a 100644
--- a/erts/emulator/beam/bif.h
+++ b/erts/emulator/beam/bif.h
@@ -29,17 +29,35 @@ extern Export *erts_convert_time_unit_trap;
 
 #define BIF_P A__p
 
-#define BIF_ALIST_0 Process* A__p, Eterm* BIF__ARGS
-#define BIF_ALIST_1 Process* A__p, Eterm* BIF__ARGS
-#define BIF_ALIST_2 Process* A__p, Eterm* BIF__ARGS
-#define BIF_ALIST_3 Process* A__p, Eterm* BIF__ARGS
-#define BIF_ALIST_4 Process* A__p, Eterm* BIF__ARGS
+#define BIF_ALIST Process* A__p, Eterm* BIF__ARGS, BeamInstr *A__I
+#define BIF_CALL_ARGS A__p, BIF__ARGS, A__I
+
+#define BIF_ALIST_0 BIF_ALIST
+#define BIF_ALIST_1 BIF_ALIST
+#define BIF_ALIST_2 BIF_ALIST
+#define BIF_ALIST_3 BIF_ALIST
+#define BIF_ALIST_4 BIF_ALIST
 
 #define BIF_ARG_1  (BIF__ARGS[0])
 #define BIF_ARG_2  (BIF__ARGS[1])
 #define BIF_ARG_3  (BIF__ARGS[2])
 #define BIF_ARG_4  (BIF__ARGS[3])
 
+#define BIF_I A__I
+
+/* NBIF_* is for bif calls from native code... */
+
+#define NBIF_ALIST Process* A__p, Eterm* BIF__ARGS
+#define NBIF_CALL_ARGS A__p, BIF__ARGS
+
+#define NBIF_ALIST_0 NBIF_ALIST
+#define NBIF_ALIST_1 NBIF_ALIST
+#define NBIF_ALIST_2 NBIF_ALIST
+#define NBIF_ALIST_3 NBIF_ALIST
+#define NBIF_ALIST_4 NBIF_ALIST
+
+typedef BIF_RETTYPE (*ErtsBifFunc)(BIF_ALIST);
+
 #define ERTS_IS_PROC_OUT_OF_REDS(p)		\
     ((p)->fcalls > 0				\
      ? 0					\
@@ -480,6 +498,49 @@ erts_bif_prep_await_proc_exit_apply_trap(Process *c_p,
 					 Eterm args[],
 					 int nargs);
 
+typedef enum {
+    ERTS_SCHED_NORMAL,
+    ERTS_SCHED_DIRTY_CPU,
+    ERTS_SCHED_DIRTY_IO
+} ErtsSchedType;
+
+#ifdef ERTS_DIRTY_SCHEDULERS
+int erts_call_dirty_bif(ErtsSchedulerData *esdp, Process *c_p,
+			BeamInstr *I, Eterm *reg);
+#endif
+
+BIF_RETTYPE
+erts_schedule_bif(Process *proc,
+		  Eterm *argv,
+		  BeamInstr *i,
+		  ErtsBifFunc dbf,
+		  ErtsSchedType sched_type,
+		  Eterm mod,
+		  Eterm func,
+		  int argc);
+
+ERTS_GLB_INLINE BIF_RETTYPE
+erts_reschedule_bif(Process *proc,
+		    Eterm *argv,
+		    BeamInstr *i,
+		    ErtsBifFunc dbf,
+		    ErtsSchedType sched_type);
+
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+
+ERTS_GLB_INLINE BIF_RETTYPE
+erts_reschedule_bif(Process *proc,
+		    Eterm *argv,
+		    BeamInstr *i,
+		    ErtsBifFunc dbf,
+		    ErtsSchedType sched_type)
+{
+    return erts_schedule_bif(proc, argv, i, dbf, sched_type,
+			     THE_NON_VALUE, THE_NON_VALUE, -1);
+}
+
+#endif /* ERTS_GLB_INLINE_INCL_FUNC_DEF */
+
 #ifdef ERL_WANT_HIPE_BIF_WRAPPER__
 
 #ifndef HIPE
@@ -510,16 +571,16 @@ erts_bif_prep_await_proc_exit_apply_trap(Process *c_p,
 
 
 #define HIPE_WRAPPER_BIF_DISABLE_GC(BIF_NAME, ARITY)			\
-BIF_RETTYPE hipe_wrapper_ ## BIF_NAME ## _ ## ARITY (Process* c_p,	\
-						     Eterm* args);	\
-BIF_RETTYPE hipe_wrapper_ ## BIF_NAME ## _ ## ARITY (Process* c_p,	\
-						     Eterm* args)	\
+BIF_RETTYPE								\
+nbif_impl_hipe_wrapper_ ## BIF_NAME ## _ ## ARITY (NBIF_ALIST);		\
+BIF_RETTYPE								\
+nbif_impl_hipe_wrapper_ ## BIF_NAME ## _ ## ARITY (NBIF_ALIST)		\
 {									\
     BIF_RETTYPE  res;							\
-    hipe_reserve_beam_trap_frame(c_p, args, ARITY);			\
-    res =  BIF_NAME ## _ ## ARITY (c_p, args);				\
-    if (is_value(res) || c_p->freason != TRAP) {			\
-	hipe_unreserve_beam_trap_frame(c_p);				\
+    hipe_reserve_beam_trap_frame(BIF_P, BIF__ARGS, ARITY);		\
+    res = nbif_impl_ ## BIF_NAME ## _ ## ARITY (NBIF_CALL_ARGS);	\
+    if (is_value(res) || BIF_P->freason != TRAP) {			\
+	hipe_unreserve_beam_trap_frame(BIF_P);				\
     }									\
     return res;								\
 }
diff --git a/erts/emulator/beam/bif.tab b/erts/emulator/beam/bif.tab
index 32600f4338..f461da913e 100644
--- a/erts/emulator/beam/bif.tab
+++ b/erts/emulator/beam/bif.tab
@@ -420,6 +420,9 @@ bif erts_debug:set_internal_state/2
 bif erts_debug:display/1
 bif erts_debug:dist_ext_to_term/2
 bif erts_debug:instructions/0
+bif erts_debug:dirty_cpu/2
+bif erts_debug:dirty_io/2
+bif erts_debug:dirty/3
 
 #
 # Monitor testing bif's...
diff --git a/erts/emulator/beam/erl_bif_info.c b/erts/emulator/beam/erl_bif_info.c
index 009d2b72d3..4659cb5a7b 100644
--- a/erts/emulator/beam/erl_bif_info.c
+++ b/erts/emulator/beam/erl_bif_info.c
@@ -94,6 +94,9 @@ static char erts_system_version[] = ("Erlang/OTP " ERLANG_OTP_RELEASE
 #if defined(ERTS_DIRTY_SCHEDULERS) && defined(ERTS_SMP)
 				     " [ds:%beu:%beu:%beu]"
 #endif
+#if defined(ERTS_DIRTY_SCHEDULERS_TEST)
+				     " [dirty-schedulers-TEST]"
+#endif
 				     " [async-threads:%d]"
 #endif
 #ifdef HIPE
diff --git a/erts/emulator/beam/erl_dirty_bif.tab b/erts/emulator/beam/erl_dirty_bif.tab
new file mode 100644
index 0000000000..69421dcfcc
--- /dev/null
+++ b/erts/emulator/beam/erl_dirty_bif.tab
@@ -0,0 +1,82 @@
+#
+# %CopyrightBegin%
+#
+# Copyright Ericsson AB 2016. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# %CopyrightEnd%
+#
+
+#
+# Static declaration of BIFs that should execute on dirty schedulers.
+#
+# <dirty-bif-decl> ::= <type> <bif>
+# <bif> ::= <module> ":" <name> "/" <arity>
+# <type> ::= dirty-cpu | dirty-io | dirty-cpu-test | dirty-io-test
+#
+# When dirty scheduler support is available, a BIF declared with the
+# 'dirty-cpu' type will unconditionally execute on a dirty CPU scheduler,
+# and a BIF declared with the type 'dirty-io' will unconditionally execute
+# on a dirty IO scheduler. When dirty scheduler support is not available
+# all BIFs will of course execute on normal schedulers.
+#
+# When the emulator has been configured with the debug option
+# '--enable-dirty-schedulers-test', BIFs with the types 'dirty-cpu-test',
+# and 'dirty-io-test' will unconditionally execute on dirty schedulers.
+# When this debug option has not been enabled, these BIFs will be executed
+# on normal schedulers.
+#
+# BIFs marked as 'ubif' in ./bif.tab will be ignored, i.e., will always
+# execute on normal schedulers.
+#
+
+# --- Dirty BIFs ---
+
+dirty-cpu erts_debug:dirty_cpu/2
+dirty-io erts_debug:dirty_io/2
+
+# --- TEST of Dirty BIF functionality ---
+#  Functions below will execute on dirty schedulers when emulator has
+#  been configured for testing dirty schedulers. This is used for test
+#  and debug purposes only. We really do *not* want to execute these
+#  on dirty schedulers on a real system.
+
+dirty-cpu-test erlang:'++'/2
+dirty-cpu-test erlang:append/2
+dirty-cpu-test erlang:'--'/2
+dirty-cpu-test erlang:subtract/2
+dirty-cpu-test erlang:iolist_size/1
+dirty-cpu-test erlang:make_tuple/2
+dirty-cpu-test erlang:make_tuple/3
+dirty-cpu-test erlang:append_element/2
+dirty-cpu-test erlang:insert_element/3
+dirty-cpu-test erlang:delete_element/2
+dirty-cpu-test erlang:atom_to_list/1
+dirty-cpu-test erlang:list_to_atom/1
+dirty-cpu-test erlang:list_to_existing_atom/1
+dirty-cpu-test erlang:integer_to_list/1
+dirty-cpu-test erlang:string_to_integer/1
+dirty-cpu-test erlang:list_to_integer/1
+dirty-cpu-test erlang:list_to_integer/2
+dirty-cpu-test erlang:float_to_list/1
+dirty-cpu-test erlang:float_to_list/2
+dirty-cpu-test erlang:float_to_binary/1
+dirty-cpu-test erlang:float_to_binary/2
+dirty-cpu-test erlang:string_to_float/1
+dirty-cpu-test erlang:list_to_float/1
+dirty-cpu-test erlang:binary_to_float/1
+dirty-cpu-test erlang:tuple_to_list/1
+dirty-cpu-test erlang:list_to_tuple/1
+dirty-cpu-test erlang:display/1
+dirty-cpu-test erlang:display_string/1
diff --git a/erts/emulator/beam/erl_gc.c b/erts/emulator/beam/erl_gc.c
index 643b46c861..6093b0cf39 100644
--- a/erts/emulator/beam/erl_gc.c
+++ b/erts/emulator/beam/erl_gc.c
@@ -42,6 +42,7 @@
 #include "dtrace-wrapper.h"
 #include "erl_bif_unique.h"
 #include "dist.h"
+#include "erl_nfunc_sched.h"
 
 #define ERTS_INACT_WR_PB_LEAVE_MUCH_LIMIT 1
 #define ERTS_INACT_WR_PB_LEAVE_MUCH_PERCENTAGE 20
@@ -2423,17 +2424,10 @@ setup_rootset(Process *p, Eterm *objv, int nobj, Rootset *rootset)
     }
 
     /*
-     * If a NIF has saved arguments, they need to be added
+     * If a NIF or BIF has saved arguments, they need to be added
      */
-    if (ERTS_PROC_GET_NIF_TRAP_EXPORT(p)) {
-	Eterm* argv;
-	int argc;
-	if (erts_setup_nif_gc(p, &argv, &argc)) {
-	    roots[n].v = argv;
-	    roots[n].sz = argc;
-	    n++;
-	}
-    }
+    if (erts_setup_nif_export_rootset(p, &roots[n].v, &roots[n].sz))
+	n++;
 
     ASSERT(n <= rootset->size);
 
@@ -2985,6 +2979,8 @@ static void ERTS_INLINE
 offset_one_rootset(Process *p, Sint offs, char* area, Uint area_size,
 	       Eterm* objv, int nobj)
 {
+    Eterm *v;
+    Uint sz;
     if (p->dictionary)  {
 	offset_heap(ERTS_PD_START(p->dictionary),
 		    ERTS_PD_SIZE(p->dictionary),
@@ -3005,12 +3001,8 @@ offset_one_rootset(Process *p, Sint offs, char* area, Uint area_size,
 	offset_heap_ptr(objv, nobj, offs, area, area_size);
     }
     offset_off_heap(p, offs, area, area_size);
-    if (ERTS_PROC_GET_NIF_TRAP_EXPORT(p)) {
-	Eterm* argv;
-	int argc;
-	if (erts_setup_nif_gc(p, &argv, &argc))
-	    offset_heap_ptr(argv, argc, offs, area, area_size);
-    }
+    if (erts_setup_nif_export_rootset(p, &v, &sz))
+	offset_heap_ptr(v, sz, offs, area, area_size);
 }
 
 static void
diff --git a/erts/emulator/beam/erl_msacc.c b/erts/emulator/beam/erl_msacc.c
index 7ddf49937f..66bb55e6c8 100644
--- a/erts/emulator/beam/erl_msacc.c
+++ b/erts/emulator/beam/erl_msacc.c
@@ -137,8 +137,8 @@ void erts_msacc_init_thread(char *type, int id, int managed) {
 void erts_msacc_set_bif_state(ErtsMsAcc *__erts_msacc_cache, Eterm mod, void *fn) {
 
 #ifdef ERTS_MSACC_EXTENDED_BIFS
-#define BIF_LIST(Mod,Func,Arity,FuncAddr,Num)                           \
-    if (fn == &FuncAddr) {                                             \
+#define BIF_LIST(Mod,Func,Arity,BifFuncAddr,FuncAddr,Num)	       \
+    if (fn == &BifFuncAddr) {                                             \
         ERTS_MSACC_SET_STATE_CACHED_M_X(ERTS_MSACC_STATIC_STATE_COUNT + Num); \
     } else
 #include "erl_bif_list.h"
diff --git a/erts/emulator/beam/erl_msacc.h b/erts/emulator/beam/erl_msacc.h
index 9ef86a1293..d64ef8c8b9 100644
--- a/erts/emulator/beam/erl_msacc.h
+++ b/erts/emulator/beam/erl_msacc.h
@@ -122,7 +122,7 @@ static char *erts_msacc_states[] = {
     "sleep",
     "timers"
 #ifdef ERTS_MSACC_EXTENDED_BIFS
-#define BIF_LIST(Mod,Func,Arity,FuncAddr,Num)   \
+#define BIF_LIST(Mod,Func,Arity,BifFuncAddr,FuncAddr,Num)	\
         ,"bif_" #Mod "_" #Func "_" #Arity
 #include "erl_bif_list.h"
 #undef BIF_LIST
diff --git a/erts/emulator/beam/erl_nfunc_sched.c b/erts/emulator/beam/erl_nfunc_sched.c
new file mode 100644
index 0000000000..0333545255
--- /dev/null
+++ b/erts/emulator/beam/erl_nfunc_sched.c
@@ -0,0 +1,144 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2016. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * %CopyrightEnd%
+ */
+
+#ifdef HAVE_CONFIG_H
+#  include "config.h"
+#endif
+
+#define ERTS_WANT_NFUNC_SCHED_INTERNALS__
+
+#include "global.h"
+#include "erl_process.h"
+#include "bif.h"
+#include "erl_nfunc_sched.h"
+
+NifExport *
+erts_new_proc_nif_export(Process *c_p, int argc)
+{
+    size_t size;
+    int i;
+    NifExport *nep, *old_nep;
+
+    size = sizeof(NifExport) + (argc-1)*sizeof(Eterm);
+    nep = erts_alloc(ERTS_ALC_T_NIF_TRAP_EXPORT, size);
+
+    for (i = 0; i < ERTS_NUM_CODE_IX; i++)
+	nep->exp.addressv[i] = &nep->exp.beam[0];
+
+    nep->argc = -1; /* unused marker */
+    nep->argv_size = argc;
+    old_nep = ERTS_PROC_SET_NIF_TRAP_EXPORT(c_p, nep);
+    if (old_nep)
+	erts_free(ERTS_ALC_T_NIF_TRAP_EXPORT, old_nep);
+    return nep;
+}
+
+void
+erts_destroy_nif_export(Process *p)
+{
+    NifExport *nep = ERTS_PROC_SET_NIF_TRAP_EXPORT(p, NULL);
+    if (nep) {
+	if (nep->m)
+	    erts_nif_export_cleanup_nif_mod(nep);
+	erts_free(ERTS_ALC_T_NIF_TRAP_EXPORT, nep);
+    }
+}
+
+NifExport *
+erts_nif_export_schedule(Process *c_p, Process *dirty_shadow_proc,
+			 ErtsCodeMFA *mfa, void *nif, BeamInstr *pc,
+			 BeamInstr instr,
+			 void *dfunc, void *ifunc,
+			 Eterm mod, Eterm func,
+			 int argc, const Eterm *argv)
+{
+    Process *used_proc;
+    ErtsSchedulerData *esdp;
+    Eterm* reg;
+    NifExport* nep;
+    int i;
+
+    ERTS_SMP_LC_ASSERT(erts_proc_lc_my_proc_locks(c_p)
+		       & ERTS_PROC_LOCK_MAIN);
+
+    if (dirty_shadow_proc) {
+	esdp = erts_get_scheduler_data();
+	ASSERT(esdp && ERTS_SCHEDULER_IS_DIRTY(esdp));
+
+	used_proc = dirty_shadow_proc;
+    }
+    else {
+	esdp = erts_proc_sched_data(c_p);
+	ASSERT(esdp && !ERTS_SCHEDULER_IS_DIRTY(esdp));
+
+	used_proc = c_p;
+	ERTS_VBUMP_ALL_REDS(c_p);
+    }
+
+    reg = esdp->x_reg_array;
+
+    if (mfa)
+	nep = erts_get_proc_nif_export(c_p, (int) mfa->arity);
+    else {
+	/* If no mfa, this is not the first schedule... */
+	nep = ERTS_PROC_GET_NIF_TRAP_EXPORT(c_p);
+	ASSERT(nep && nep->argc >= 0);
+    }
+
+    if (nep->argc < 0) {
+	/*
+	 * First schedule; save things that might
+	 * need to be restored...
+	 */
+	for (i = 0; i < (int) mfa->arity; i++)
+	    nep->argv[i] = reg[i];
+	nep->pc = pc;
+	nep->cp = c_p->cp;
+	ASSERT(nif);
+	nep->nif = nif;
+	nep->mfa = mfa;
+	nep->current = c_p->current;
+	ASSERT(argc >= 0);
+	nep->argc = (int) mfa->arity;
+	nep->m = NULL;
+
+	ASSERT(!erts_check_nif_export_in_area(c_p,
+					      (char *) nep,
+					      (sizeof(NifExport)
+					       + (sizeof(Eterm)
+						  *(nep->argc-1)))));
+    }
+    /* Copy new arguments into register array if necessary... */
+    if (reg != argv) {
+	for (i = 0; i < argc; i++)
+	    reg[i] = argv[i];
+    }
+    ASSERT(is_atom(mod) && is_atom(func));
+    nep->exp.info.mfa.module = mod;
+    nep->exp.info.mfa.function = func;
+    nep->exp.info.mfa.arity = (Uint) argc;
+    nep->exp.beam[0] = (BeamInstr) instr; /* call_nif || apply_bif */
+    nep->exp.beam[1] = (BeamInstr) dfunc;
+    nep->func = ifunc;
+    used_proc->arity = argc;
+    used_proc->freason = TRAP;
+    used_proc->i = (BeamInstr*) nep->exp.addressv[0];
+    return nep;
+}
diff --git a/erts/emulator/beam/erl_nfunc_sched.h b/erts/emulator/beam/erl_nfunc_sched.h
new file mode 100644
index 0000000000..72de7f0eb5
--- /dev/null
+++ b/erts/emulator/beam/erl_nfunc_sched.h
@@ -0,0 +1,289 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2016. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * %CopyrightEnd%
+ */
+
+#ifndef ERL_NFUNC_SCHED_H__
+#define ERL_NFUNC_SCHED_H__
+
+#include "erl_process.h"
+#include "bif.h"
+
+/*
+ * NIF exports need a few more items than the Export struct provides,
+ * including the erl_module_nif* and a NIF function pointer, so the
+ * NifExport below adds those. The Export member must be first in the
+ * struct. A number of values are stored for error handling purposes
+ * only.
+ *
+ * 'argc' is >= 0 when NifExport is in use, and < 0 when not.
+ */
+
+typedef struct {
+    Export exp;
+    struct erl_module_nif* m; /* NIF module, or NULL if BIF */
+    void *func;		/* Indirect NIF or BIF to execute (may be unused) */
+    ErtsCodeMFA *current;/* Current as set when originally called */
+    /* --- The following is only used on error --- */
+    BeamInstr *pc;	/* Program counter */
+    BeamInstr *cp;	/* Continuation pointer */
+    void *nif;		/* Original NIF/BIF call */
+    ErtsCodeMFA *mfa;	/* MFA of original call */
+    int argc;		/* Number of arguments in original call */
+    int argv_size;	/* Allocated size of argv */
+    Eterm argv[1];	/* Saved arguments from the original call */
+} NifExport;
+
+NifExport *erts_new_proc_nif_export(Process *c_p, int argc);
+void erts_destroy_nif_export(Process *p);
+NifExport *erts_nif_export_schedule(Process *c_p, Process *dirty_shadow_proc,
+				    ErtsCodeMFA *mfa, void *nif, BeamInstr *pc,
+				    BeamInstr instr,
+				    void *dfunc, void *ifunc,
+				    Eterm mod, Eterm func,
+				    int argc, const Eterm *argv);
+void erts_nif_export_cleanup_nif_mod(NifExport *ep); /* erl_nif.c */
+ERTS_GLB_INLINE NifExport *erts_get_proc_nif_export(Process *c_p, int extra);
+ERTS_GLB_INLINE int erts_setup_nif_export_rootset(Process* proc, Eterm** objv,
+						  Uint* nobj);
+ERTS_GLB_INLINE int erts_check_nif_export_in_area(Process *p,
+						  char *start, Uint size);
+ERTS_GLB_INLINE void erts_nif_export_restore(Process *c_p, NifExport *ep);
+ERTS_GLB_INLINE void erts_nif_export_restore_error(Process* c_p, BeamInstr **pc,
+						   Eterm *reg, void **nif);
+ERTS_GLB_INLINE Process *erts_proc_shadow2real(Process *c_p);
+
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+
+ERTS_GLB_INLINE NifExport *
+erts_get_proc_nif_export(Process *c_p, int argc)
+{
+    NifExport *nep = ERTS_PROC_GET_NIF_TRAP_EXPORT(c_p);
+    if (!nep || (nep->argc < 0 && nep->argv_size < argc))
+	return erts_new_proc_nif_export(c_p, argc);
+    return nep;
+}
+
+/*
+ * If a process has saved arguments, they need to be part of the GC
+ * rootset. The function below is called from setup_rootset() in
+ * erl_gc.c. Any exception term saved in the NifExport is also made
+ * part of the GC rootset here; it always resides in rootset[0].
+ */
+ERTS_GLB_INLINE int
+erts_setup_nif_export_rootset(Process* proc, Eterm** objv, Uint* nobj)
+{
+    NifExport* ep = (NifExport*) ERTS_PROC_GET_NIF_TRAP_EXPORT(proc);
+
+    if (!ep || ep->argc <= 0)
+	return 0;
+
+    *objv = ep->argv;
+    *nobj = ep->argc;
+    return 1;
+}
+
+/*
+ * Check if nif export points into code area...
+ */
+ERTS_GLB_INLINE int
+erts_check_nif_export_in_area(Process *p, char *start, Uint size)
+{
+    NifExport *nep = ERTS_PROC_GET_NIF_TRAP_EXPORT(p);
+    if (!nep || nep->argc < 0)
+	return 0;
+    if (ErtsInArea(nep->pc, start, size))
+	return 1;
+    if (ErtsInArea(nep->cp, start, size))
+	return 1;
+    if (ErtsInArea(nep->mfa, start, size))
+	return 1;
+    if (ErtsInArea(nep->current, start, size))
+	return 1;
+    return 0;
+}
+
+ERTS_GLB_INLINE void
+erts_nif_export_restore(Process *c_p, NifExport *ep)
+{
+    ASSERT(!ERTS_SCHEDULER_IS_DIRTY(erts_get_scheduler_data()));
+    ERTS_SMP_LC_ASSERT(!(c_p->static_flags
+			 & ERTS_STC_FLG_SHADOW_PROC));
+    ERTS_SMP_LC_ASSERT(erts_proc_lc_my_proc_locks(c_p)
+		       & ERTS_PROC_LOCK_MAIN);
+
+    c_p->current = ep->current;
+    ep->argc = -1; /* Unused nif-export marker... */
+}
+
+ERTS_GLB_INLINE void
+erts_nif_export_restore_error(Process* c_p, BeamInstr **pc, Eterm *reg,
+			      void **nif)
+{
+    NifExport *nep = (NifExport *) ERTS_PROC_GET_NIF_TRAP_EXPORT(c_p);
+    int ix;
+
+    ASSERT(nep);
+    *pc = nep->pc;
+    c_p->cp = nep->cp;
+    *nif = nep->nif;
+    for (ix = 0; ix < nep->argc; ix++)
+	reg[ix] = nep->argv[ix];
+    erts_nif_export_restore(c_p, nep);
+}
+
+ERTS_GLB_INLINE Process *
+erts_proc_shadow2real(Process *c_p)
+{
+#ifdef ERTS_DIRTY_SCHEDULERS
+    if (c_p->static_flags & ERTS_STC_FLG_SHADOW_PROC) {
+	Process *real_c_p = c_p->next;
+	ASSERT(ERTS_SCHEDULER_IS_DIRTY(erts_get_scheduler_data()));
+	ASSERT(real_c_p->common.id == c_p->common.id);
+	return real_c_p;
+    }
+    ASSERT(!ERTS_SCHEDULER_IS_DIRTY(erts_get_scheduler_data()));
+#endif
+    return c_p;
+}
+
+#endif /* ERTS_GLB_INLINE_INCL_FUNC_DEF */
+
+#endif /* ERL_NFUNC_SCHED_H__ */
+
+#if defined(ERTS_WANT_NFUNC_SCHED_INTERNALS__) && !defined(ERTS_NFUNC_SCHED_INTERNALS__)
+#define ERTS_NFUNC_SCHED_INTERNALS__
+
+#define ERTS_I_BEAM_OP_TO_NIF_EXPORT(I)					\
+    (ASSERT(BeamOp(op_apply_bif) == (BeamInstr *) (*(I))		\
+	    || BeamOp(op_call_nif) == (BeamInstr *) (*(I))),		\
+     ((NifExport *) (((char *) (I)) - offsetof(NifExport, exp.beam[0]))))
+
+#ifdef ERTS_DIRTY_SCHEDULERS
+
+#include "erl_message.h"
+#include <stddef.h>
+
+ERTS_GLB_INLINE void erts_flush_dirty_shadow_proc(Process *sproc);
+ERTS_GLB_INLINE void erts_cache_dirty_shadow_proc(Process *sproc);
+ERTS_GLB_INLINE Process *erts_make_dirty_shadow_proc(ErtsSchedulerData *esdp,
+						     Process *c_p);
+
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+
+ERTS_GLB_INLINE void
+erts_flush_dirty_shadow_proc(Process *sproc)
+{
+    Process *c_p = sproc->next;
+
+    ASSERT(sproc->common.id == c_p->common.id);
+    ERTS_SMP_LC_ASSERT(erts_proc_lc_my_proc_locks(c_p)
+		       & ERTS_PROC_LOCK_MAIN);
+
+    ASSERT(c_p->stop == sproc->stop);
+    ASSERT(c_p->hend == sproc->hend);
+    ASSERT(c_p->heap == sproc->heap);
+    ASSERT(c_p->abandoned_heap == sproc->abandoned_heap);
+    ASSERT(c_p->heap_sz == sproc->heap_sz);
+    ASSERT(c_p->high_water == sproc->high_water);
+    ASSERT(c_p->old_heap == sproc->old_heap);
+    ASSERT(c_p->old_htop == sproc->old_htop);
+    ASSERT(c_p->old_hend == sproc->old_hend);
+
+    ASSERT(c_p->htop <= sproc->htop && sproc->htop <= c_p->stop);
+
+    c_p->htop = sproc->htop;
+
+    if (!c_p->mbuf)
+	c_p->mbuf = sproc->mbuf;
+    else if (sproc->mbuf) {
+	ErlHeapFragment *bp;
+	for (bp = sproc->mbuf; bp->next; bp = bp->next)
+	    ASSERT(!bp->off_heap.first);
+	bp->next = c_p->mbuf;
+	c_p->mbuf = sproc->mbuf;
+    }
+
+    c_p->mbuf_sz += sproc->mbuf_sz;
+
+    if (!c_p->off_heap.first)
+	c_p->off_heap.first = sproc->off_heap.first;
+    else if (sproc->off_heap.first) {
+	struct erl_off_heap_header *ohhp;
+	for (ohhp = sproc->off_heap.first; ohhp->next; ohhp = ohhp->next)
+	    ;
+	ohhp->next = c_p->off_heap.first;
+	c_p->off_heap.first = sproc->off_heap.first;
+    }
+
+    c_p->off_heap.overhead += sproc->off_heap.overhead;
+}
+
+ERTS_GLB_INLINE void
+erts_cache_dirty_shadow_proc(Process *sproc)
+{
+    Process *c_p = sproc->next;
+    ASSERT(c_p);
+    ASSERT(sproc->common.id == c_p->common.id);
+    ERTS_SMP_LC_ASSERT(erts_proc_lc_my_proc_locks(c_p)
+		       & ERTS_PROC_LOCK_MAIN);
+
+    sproc->htop = c_p->htop;
+    sproc->stop = c_p->stop;
+    sproc->hend = c_p->hend;
+    sproc->heap = c_p->heap;
+    sproc->abandoned_heap = c_p->abandoned_heap;
+    sproc->heap_sz = c_p->heap_sz;
+    sproc->high_water = c_p->high_water;
+    sproc->old_hend = c_p->old_hend;
+    sproc->old_htop = c_p->old_htop;
+    sproc->old_heap = c_p->old_heap;
+    sproc->mbuf = NULL;
+    sproc->mbuf_sz = 0;
+    ERTS_INIT_OFF_HEAP(&sproc->off_heap);
+}
+
+ERTS_GLB_INLINE Process *
+erts_make_dirty_shadow_proc(ErtsSchedulerData *esdp, Process *c_p)
+{
+    Process *sproc;
+
+    ASSERT(ERTS_SCHEDULER_IS_DIRTY(esdp));
+
+    sproc = esdp->dirty_shadow_process;
+    ASSERT(sproc);
+    ASSERT(sproc->static_flags & ERTS_STC_FLG_SHADOW_PROC);
+    ASSERT(erts_smp_atomic32_read_nob(&sproc->state)
+	   == (ERTS_PSFLG_ACTIVE
+	       | ERTS_PSFLG_DIRTY_RUNNING
+	       | ERTS_PSFLG_PROXY));
+
+    sproc->next = c_p;
+    sproc->common.id = c_p->common.id;
+
+    erts_cache_dirty_shadow_proc(sproc);
+
+    return sproc;
+}
+
+#endif /* ERTS_GLB_INLINE_INCL_FUNC_DEF */
+
+#endif /* ERTS_DIRTY_SCHEDULERS */
+
+#endif /* defined(ERTS_WANT_NFUNC_SCHED_INTERNALS__) && !defined(ERTS_NFUNC_SCHED_INTERNALS__) */
+
diff --git a/erts/emulator/beam/erl_nif.c b/erts/emulator/beam/erl_nif.c
index 5499512dd1..ee4b22f7ca 100644
--- a/erts/emulator/beam/erl_nif.c
+++ b/erts/emulator/beam/erl_nif.c
@@ -55,6 +55,9 @@
 #include "dtrace-wrapper.h"
 #include "erl_process.h"
 #include "erl_bif_unique.h"
+#undef ERTS_WANT_NFUNC_SCHED_INTERNALS__
+#define ERTS_WANT_NFUNC_SCHED_INTERNALS__
+#include "erl_nfunc_sched.h"
 #if defined(USE_DYNAMIC_TRACE) && (defined(USE_DTRACE) || defined(USE_SYSTEMTAP))
 #define HAVE_USE_DTRACE 1
 #endif
@@ -79,8 +82,11 @@ struct erl_module_nif {
     ErlNifFunc _funcs_copy_[1];  /* only used for old libs */
 };
 
+typedef ERL_NIF_TERM (*NativeFunPtr)(ErlNifEnv*, int, const ERL_NIF_TERM[]);
+
 #ifdef DEBUG
 #  define READONLY_CHECK
+#  define ERTS_DBG_NIF_NOT_SCHED_MARKER ((void *) (UWord) 1)
 #endif
 #ifdef READONLY_CHECK
 #  define ADD_READONLY_CHECK(ENV,PTR,SIZE) add_readonly_check(ENV,PTR,SIZE)
@@ -219,38 +225,6 @@ static void cache_env(ErlNifEnv* env);
 static void full_flush_env(ErlNifEnv *env);
 static void flush_env(ErlNifEnv* env);
 
-#ifdef ERTS_DIRTY_SCHEDULERS
-void erts_pre_dirty_nif(ErtsSchedulerData *esdp,
-			ErlNifEnv* env, Process* p,
-			struct erl_module_nif* mod_nif)
-{
-    Process *sproc;
-#ifdef DEBUG
-    erts_aint32_t state = erts_smp_atomic32_read_nob(&p->state);
-
-    ASSERT(!p->scheduler_data);
-    ASSERT((state & ERTS_PSFLG_DIRTY_RUNNING)
-	   && !(state & (ERTS_PSFLG_RUNNING|ERTS_PSFLG_RUNNING_SYS)));
-    ASSERT(esdp);
-#endif
-
-    erts_pre_nif(env, p, mod_nif, NULL);
-
-    sproc = esdp->dirty_shadow_process;
-    ASSERT(sproc);
-    ASSERT(sproc->static_flags & ERTS_STC_FLG_SHADOW_PROC);
-    ASSERT(erts_smp_atomic32_read_nob(&sproc->state)
-	   == (ERTS_PSFLG_ACTIVE
-	       | ERTS_PSFLG_DIRTY_RUNNING
-	       | ERTS_PSFLG_PROXY));
-
-    sproc->next = p;
-    sproc->common.id = p->common.id;
-    env->proc = sproc;
-    full_cache_env(env);
-}
-#endif
-
 /* Temporary object header, auto-deallocated when NIF returns
  * or when independent environment is cleared.
  */
@@ -278,115 +252,158 @@ void erts_post_nif(ErlNifEnv* env)
     env->exiting = ERTS_PROC_IS_EXITING(env->proc);
 }
 
-#ifdef ERTS_DIRTY_SCHEDULERS
-void erts_post_dirty_nif(ErlNifEnv* env)
+
+/*
+ * Initialize a NifExport struct. Create it if needed and store it in the
+ * proc. The direct_fp function is what will be invoked by op_call_nif, and
+ * the indirect_fp function, if not NULL, is what the direct_fp function
+ * will call. If the allocated NifExport isn't enough to hold all of argv,
+ * allocate a larger one. Save 'current' and registers if first time this
+ * call is scheduled.
+ */
+
+static ERTS_INLINE ERL_NIF_TERM
+schedule(ErlNifEnv* env, NativeFunPtr direct_fp, NativeFunPtr indirect_fp,
+	 Eterm mod, Eterm func_name, int argc, const ERL_NIF_TERM argv[])
 {
-    Process *c_p;
-    ASSERT(env->proc->static_flags & ERTS_STC_FLG_SHADOW_PROC);
-    ASSERT(env->proc->next);
-    erts_unblock_fpe(env->fpe_was_unmasked);
-    full_flush_env(env);
-    free_tmp_objs(env);
-    c_p = env->proc->next;
-    env->exiting = ERTS_PROC_IS_EXITING(c_p);
-    ERTS_VBUMP_ALL_REDS(c_p);
+    Export *exp;
+    NifExport *ep;
+    Process *c_p, *dirty_shadow_proc;
+
+    execution_state(env, &c_p, NULL);
+    if (c_p == env->proc)
+	dirty_shadow_proc = NULL;
+    else
+	dirty_shadow_proc = env->proc;
+
+    ERTS_SMP_LC_ASSERT(ERTS_PROC_LOCK_MAIN & erts_proc_lc_my_proc_locks(c_p));
+
+    exp = ErtsContainerStruct(c_p->current, Export, info.mfa);
+
+    ep = erts_nif_export_schedule(c_p, dirty_shadow_proc,
+				  c_p->current,
+				  (BifFunction) exp->beam[1],
+				  c_p->cp,
+				  (BeamInstr) em_call_nif,
+				  direct_fp, indirect_fp,
+				  mod, func_name,
+				  argc, (const Eterm *) argv);
+    if (!ep->m) {
+	/* First time this call is scheduled... */
+	erts_refc_inc(&env->mod_nif->rt_dtor_cnt, 1);
+	ep->m = env->mod_nif;
+    }
+    return (ERL_NIF_TERM) THE_NON_VALUE;
 }
-#endif
 
-static void full_flush_env(ErlNifEnv* env)
-{
 #ifdef ERTS_DIRTY_SCHEDULERS
-    if (env->proc->static_flags & ERTS_STC_FLG_SHADOW_PROC) {
-	/* Dirty nif call using shadow process struct */
-	Process *c_p = env->proc->next;
-
-	ASSERT(is_scheduler() < 0);
-	ASSERT(env->proc->common.id == c_p->common.id);
-	ERTS_SMP_LC_ASSERT(erts_proc_lc_my_proc_locks(c_p)
-			   & ERTS_PROC_LOCK_MAIN);
-
-	if (!env->heap_frag) {
-	    ASSERT(env->hp_end == HEAP_LIMIT(c_p));
-	    ASSERT(env->hp >= HEAP_TOP(c_p));
-	    ASSERT(env->hp <= HEAP_LIMIT(c_p));
-	    HEAP_TOP(c_p) = env->hp;
+
+static ERL_NIF_TERM dirty_nif_finalizer(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM dirty_nif_exception(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]);
+
+int
+erts_call_dirty_nif(ErtsSchedulerData *esdp, Process *c_p, BeamInstr *I, Eterm *reg)
+{
+    int exiting;
+    ERL_NIF_TERM *argv = (ERL_NIF_TERM *) reg;
+    NifExport *nep = ERTS_I_BEAM_OP_TO_NIF_EXPORT(I);
+    ErtsCodeMFA *codemfa = erts_code_to_codemfa(I);
+    NativeFunPtr dirty_nif = (NativeFunPtr) I[1];
+    ErlNifEnv env;
+    ERL_NIF_TERM result;
+#ifdef DEBUG
+    erts_aint32_t state = erts_smp_atomic32_read_nob(&c_p->state);
+
+    ASSERT(nep == ERTS_PROC_GET_NIF_TRAP_EXPORT(c_p));
+
+    ASSERT(!c_p->scheduler_data);
+    ASSERT((state & ERTS_PSFLG_DIRTY_RUNNING)
+	&& !(state & (ERTS_PSFLG_RUNNING|ERTS_PSFLG_RUNNING_SYS)));
+    ASSERT(esdp);
+
+    nep->func = ERTS_DBG_NIF_NOT_SCHED_MARKER;
+#endif
+
+    erts_pre_nif(&env, c_p, nep->m, NULL);
+
+    env.proc = erts_make_dirty_shadow_proc(esdp, c_p);
+
+    env.proc->freason = EXC_NULL;
+    env.proc->fvalue = NIL;
+    env.proc->ftrace = NIL;
+    env.proc->i = c_p->i;
+
+    ASSERT(ERTS_SCHEDULER_IS_DIRTY(erts_proc_sched_data(c_p)));
+
+    erts_smp_atomic32_read_band_mb(&c_p->state, ~(ERTS_PSFLG_DIRTY_CPU_PROC
+						   | ERTS_PSFLG_DIRTY_IO_PROC));
+
+    erts_smp_proc_unlock(c_p, ERTS_PROC_LOCK_MAIN);
+
+    result = (*dirty_nif)(&env, codemfa->arity, argv); /* Call dirty NIF */
+
+    erts_smp_proc_lock(c_p, ERTS_PROC_LOCK_MAIN);
+
+    ASSERT(env.proc->static_flags & ERTS_STC_FLG_SHADOW_PROC);
+    ASSERT(env.proc->next == c_p);
+
+    exiting = ERTS_PROC_IS_EXITING(c_p);
+
+    if (!exiting) {
+	if (env.exception_thrown) {
+	schedule_exception:
+	    schedule(&env, dirty_nif_exception, NULL,
+		     am_erts_internal, am_dirty_nif_exception,
+		     1, &env.proc->fvalue);
+	}
+	else if (is_value(result)) {
+	    schedule(&env, dirty_nif_finalizer, NULL,
+		     am_erts_internal, am_dirty_nif_finalizer,
+		     1, &result);
+	}
+	else if (env.proc->freason != TRAP) { /* user returned garbage... */
+	    ERTS_DECL_AM(badreturn);
+	    (void) enif_raise_exception(&env, AM_badreturn);
+	    goto schedule_exception;
 	}
 	else {
-	    Uint usz;
-	    ASSERT(env->hp_end != HEAP_LIMIT(c_p));
-	    ASSERT(env->hp_end - env->hp <= env->heap_frag->alloc_size);
-
-	    HEAP_TOP(c_p) = HEAP_TOP(env->proc);
-	    usz = env->hp - env->heap_frag->mem;
-	    env->proc->mbuf_sz += usz - env->heap_frag->used_size;
-	    env->heap_frag->used_size = usz;
-
-	    ASSERT(env->heap_frag->used_size <= env->heap_frag->alloc_size);
-
-	    if (c_p->mbuf) {
-		ErlHeapFragment *bp;
-		for (bp = env->proc->mbuf; bp->next; bp = bp->next)
-		    ;
-		bp->next = c_p->mbuf;
-	    }
+	    /* Rescheduled by dirty NIF call... */
+	    ASSERT(nep->func != ERTS_DBG_NIF_NOT_SCHED_MARKER);
+	}
+	c_p->i = env.proc->i;
+	c_p->arity = env.proc->arity;
+    }
 
-	    c_p->mbuf = env->proc->mbuf;
-	    c_p->mbuf_sz += env->proc->mbuf_sz;
+#ifdef DEBUG
+    if (nep->func == ERTS_DBG_NIF_NOT_SCHED_MARKER)
+	nep->func = NULL;
+#endif
 
-	}
+    erts_unblock_fpe(env.fpe_was_unmasked);
+    full_flush_env(&env);
+    free_tmp_objs(&env);
 
-	if (!c_p->off_heap.first)
-	    c_p->off_heap.first = env->proc->off_heap.first;
-	else if (env->proc->off_heap.first) {
-	    struct erl_off_heap_header *ohhp;
-	    for (ohhp = env->proc->off_heap.first; ohhp->next; ohhp = ohhp->next)
-		;
-	    ohhp->next = c_p->off_heap.first;
-	    c_p->off_heap.first = env->proc->off_heap.first;
-	}
-	c_p->off_heap.overhead += env->proc->off_heap.overhead;
+    return exiting;
+}
 
-	return;
-    }
 #endif
 
+static void full_flush_env(ErlNifEnv* env)
+{
     flush_env(env);
+#ifdef ERTS_DIRTY_SCHEDULERS
+    if (env->proc->static_flags & ERTS_STC_FLG_SHADOW_PROC)
+	/* Dirty nif call using shadow process struct */
+	erts_flush_dirty_shadow_proc(env->proc);
+#endif
 }
 
 static void full_cache_env(ErlNifEnv* env)
 {    
 #ifdef ERTS_DIRTY_SCHEDULERS
-    if (env->proc->static_flags & ERTS_STC_FLG_SHADOW_PROC) {
-	/* Dirty nif call using shadow process struct */
-	Process *sproc = env->proc;
-	Process *c_p = sproc->next;
-	ASSERT(c_p);
-	ASSERT(is_scheduler() < 0);
-	ASSERT(env->proc->common.id == c_p->common.id);
-	ERTS_SMP_LC_ASSERT(erts_proc_lc_my_proc_locks(c_p)
-			   & ERTS_PROC_LOCK_MAIN);
-
-	sproc->htop = c_p->htop;
-	sproc->stop = c_p->stop;
-	sproc->hend = c_p->hend;
-	sproc->heap = c_p->heap;
-	sproc->abandoned_heap = c_p->abandoned_heap;
-	sproc->heap_sz = c_p->heap_sz;
-	sproc->high_water = c_p->high_water;
-	sproc->old_hend = c_p->old_hend;
-	sproc->old_htop = c_p->old_htop;
-	sproc->old_heap = c_p->old_heap;
-	sproc->mbuf = NULL;
-	sproc->mbuf_sz = 0;
-	ERTS_INIT_OFF_HEAP(&sproc->off_heap);
-
-	env->hp_end = HEAP_LIMIT(c_p);
-	env->hp = HEAP_TOP(c_p);
-	env->heap_frag = NULL;
-	return;
-    }
+    if (env->proc->static_flags & ERTS_STC_FLG_SHADOW_PROC)
+	erts_cache_dirty_shadow_proc(env->proc);
 #endif
-
     cache_env(env);
 }
 
@@ -1303,22 +1320,15 @@ Eterm enif_make_badarg(ErlNifEnv* env)
 
 Eterm enif_raise_exception(ErlNifEnv* env, ERL_NIF_TERM reason)
 {
-    Process *c_p;
-
-    execution_state(env, &c_p, NULL);
-
     env->exception_thrown = 1;
-    c_p->fvalue = reason;
-    BIF_ERROR(c_p, EXC_ERROR);
+    env->proc->fvalue = reason;
+    BIF_ERROR(env->proc, EXC_ERROR);
 }
 
 int enif_has_pending_exception(ErlNifEnv* env, ERL_NIF_TERM* reason)
 {
-    if (env->exception_thrown && reason != NULL) {
-	Process *c_p;
-	execution_state(env, &c_p, NULL);
-	*reason = c_p->fvalue;
-    }
+    if (env->exception_thrown && reason != NULL)
+	*reason = env->proc->fvalue;
     return env->exception_thrown;
 }
 
@@ -2269,188 +2279,28 @@ int enif_consume_timeslice(ErlNifEnv* env, int percent)
     return ERTS_BIF_REDS_LEFT(proc) == 0;
 }
 
-/*
- * NIF exports need a few more items than the Export struct provides,
- * including the erl_module_nif* and a NIF function pointer, so the
- * NifExport below adds those. The Export member must be first in the
- * struct. The saved_current, exception_thrown, saved_argc, rootset_extra, and
- * rootset members are used to track the MFA, any pending exception, and
- * arguments of the top NIF in case a chain of one or more
- * enif_schedule_nif() calls results in an exception, since in that case
- * the original MFA and registers have to be restored before returning to
- * Erlang to ensure stacktrace information associated with the exception is
- * correct.
- */
-typedef ERL_NIF_TERM (*NativeFunPtr)(ErlNifEnv*, int, const ERL_NIF_TERM[]);
-
-typedef struct {
-    Export exp;
-    struct erl_module_nif* m;
-    NativeFunPtr fp;
-    ErtsCodeMFA *saved_current;
-    int exception_thrown;
-    int saved_argc;
-    int rootset_extra;
-    Eterm rootset[1];
-} NifExport;
-
-/*
- * If a process has saved arguments, they need to be part of the GC
- * rootset. The function below is called from setup_rootset() in
- * erl_gc.c. This function is declared in erl_process.h. Any exception term
- * saved in the NifExport is also made part of the GC rootset here; it
- * always resides in rootset[0].
- */
-int
-erts_setup_nif_gc(Process* proc, Eterm** objv, int* nobj)
-{
-    NifExport* ep = (NifExport*) ERTS_PROC_GET_NIF_TRAP_EXPORT(proc);
-    int gc = ep && (ep->saved_argc > 0 || ep->rootset[0] != NIL);
-
-    if (gc) {
-	*objv = ep->rootset;
-	*nobj = 1 + ep->saved_argc;
-    }
-    return gc;
-}
-
-int
-erts_check_nif_export_in_area(Process *p, char *start, Uint size)
-{
-    NifExport *nep = ERTS_PROC_GET_NIF_TRAP_EXPORT(p);
-    if (!nep || !nep->saved_current)
-	return 0;
-    if (ErtsInArea(nep->saved_current, start, size))
-	return 1;
-    return 0;
-}
-
-/*
- * Allocate a NifExport and set it in proc specific data
- */
-static NifExport*
-allocate_nif_sched_data(Process* proc, int argc)
-{
-    NifExport* ep;
-    size_t total;
-    int i;
-
-    total = sizeof(NifExport) + argc*sizeof(Eterm);
-    ep = erts_alloc(ERTS_ALC_T_NIF_TRAP_EXPORT, total);
-    sys_memset((void*) ep, 0, total);
-    ep->rootset_extra = argc;
-    ep->rootset[0] = NIL;
-    for (i=0; i<ERTS_NUM_CODE_IX; i++) {
-	ep->exp.addressv[i] = &ep->exp.beam[0];
-    }
-    ep->exp.beam[0] = (BeamInstr) em_call_nif;
-    (void) ERTS_PROC_SET_NIF_TRAP_EXPORT(proc, ep);
-    return ep;
-}
-
 static ERTS_INLINE void
-destroy_nif_export(NifExport *nif_export)
+nif_export_cleanup_nif_mod(NifExport *ep)
 {
-    erts_free(ERTS_ALC_T_NIF_TRAP_EXPORT, (void *) nif_export);
+    if (erts_refc_dectest(&ep->m->rt_dtor_cnt, 0) == 0 && ep->m->mod == NULL)
+	close_lib(ep->m);
+    ep->m = NULL;
 }
 
 void
-erts_destroy_nif_export(void *nif_export)
+erts_nif_export_cleanup_nif_mod(NifExport *ep)
 {
-    destroy_nif_export((NifExport *) nif_export);
+    nif_export_cleanup_nif_mod(ep);
 }
 
-/*
- * Initialize a NifExport struct. Create it if needed and store it in the
- * proc. The direct_fp function is what will be invoked by op_call_nif, and
- * the indirect_fp function, if not NULL, is what the direct_fp function
- * will call. If the allocated NifExport isn't enough to hold all of argv,
- * allocate a larger one. Save MFA and registers only if the need_save
- * parameter is true.
- */
-static ERL_NIF_TERM
-init_nif_sched_data(ErlNifEnv* env, NativeFunPtr direct_fp, NativeFunPtr indirect_fp,
-		    int need_save, int argc, const ERL_NIF_TERM argv[])
+static ERTS_INLINE void
+nif_export_restore(Process *c_p, NifExport *ep)
 {
-    Process* proc;
-    Eterm* reg;
-    NifExport* ep;
-    int i, scheduler;
-    int orig_argc;
-
-    execution_state(env, &proc, &scheduler);
-
-    ASSERT(scheduler);
-
-    ERTS_SMP_LC_ASSERT(erts_proc_lc_my_proc_locks(proc)
-		       & ERTS_PROC_LOCK_MAIN);
-
-    reg = erts_proc_sched_data(proc)->x_reg_array;
-
-    ASSERT(!need_save || proc->current);
-    orig_argc = need_save ? (int) proc->current->arity : 0;
-
-    ep = (NifExport*) ERTS_PROC_GET_NIF_TRAP_EXPORT(proc);
-    if (!ep)
-	ep = allocate_nif_sched_data(proc, orig_argc);
-    else if (need_save && ep->rootset_extra < orig_argc) {
-	NifExport* new_ep = allocate_nif_sched_data(proc, orig_argc);
-	destroy_nif_export(ep);
-	ep = new_ep;
-    }
-    if (env->exception_thrown) {
-	ep->exception_thrown = 1;
-	ep->rootset[0] = proc->fvalue;
-    } else {
-	ep->exception_thrown = 0;
-	ep->rootset[0] = NIL;
-    }
-    if (scheduler > 0)
-	ERTS_VBUMP_ALL_REDS(proc);
-    if (need_save) {
-	ep->saved_current = proc->current;
-	ep->saved_argc = orig_argc;
-	for (i = 0; i < orig_argc; i++)
-	    ep->rootset[i+1] = reg[i];
-    }
-    for (i = 0; i < argc; i++)
-	reg[i] = (Eterm) argv[i];
-    proc->i = (BeamInstr*) ep->exp.addressv[0];
-    ep->exp.info.mfa.module = proc->current->module;
-    ep->exp.info.mfa.function = proc->current->function;
-    ep->exp.info.mfa.arity = argc;
-    ep->exp.beam[1] = (BeamInstr) direct_fp;
-    ep->m = env->mod_nif;
-    ep->fp = indirect_fp;
-    proc->freason = TRAP;
-    proc->arity = argc;
-    return THE_NON_VALUE;
+    erts_nif_export_restore(c_p, ep);
+    ASSERT(ep->m);
+    nif_export_cleanup_nif_mod(ep);
 }
 
-/*
- * Restore saved MFA and registers. Registers are restored only when the
- * exception flag is true.
- */
-static void
-restore_nif_mfa(Process* proc, NifExport* ep, int exception)
-{
-    int i;
-
-    ERTS_SMP_LC_ASSERT(!(proc->static_flags
-			 & ERTS_STC_FLG_SHADOW_PROC));
-    ERTS_SMP_LC_ASSERT(erts_proc_lc_my_proc_locks(proc)
-		       & ERTS_PROC_LOCK_MAIN);
-
-    ASSERT(ep->saved_current != &ep->exp.info.mfa);
-    proc->current = ep->saved_current;
-    ep->saved_current = NULL;
-    if (exception) {
-	Eterm* reg = erts_proc_sched_data(proc)->x_reg_array;
-	for (i = 0; i < ep->saved_argc; i++)
-	    reg[i] = ep->rootset[i+1];
-    }
-    ep->saved_argc = 0;
-}
 
 #ifdef ERTS_DIRTY_SCHEDULERS
 
@@ -2459,7 +2309,7 @@ restore_nif_mfa(Process* proc, NifExport* ep, int exception)
  * switch the process off a dirty scheduler thread and back onto a regular
  * scheduler thread, and then return the result from the dirty NIF. It also
  * restores the original NIF MFA when necessary based on the value of
- * ep->fp set by execute_dirty_nif via init_nif_sched_data -- non-NULL
+ * ep->func set by execute_dirty_nif via init_nif_sched_data -- non-NULL
  * means restore, NULL means do not restore.
  */
 static ERL_NIF_TERM
@@ -2474,9 +2324,7 @@ dirty_nif_finalizer(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
     ASSERT(!ERTS_SCHEDULER_IS_DIRTY(erts_proc_sched_data(proc)));
     ep = (NifExport*) ERTS_PROC_GET_NIF_TRAP_EXPORT(proc);
     ASSERT(ep);
-    ASSERT(!ep->exception_thrown);
-    if (ep->fp)
-	restore_nif_mfa(proc, ep, 0);
+    nif_export_restore(proc, ep);
     return argv[0];
 }
 
@@ -2486,148 +2334,100 @@ dirty_nif_finalizer(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
 static ERL_NIF_TERM
 dirty_nif_exception(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
 {
+    ERL_NIF_TERM ret;
     Process* proc;
     NifExport* ep;
+    Eterm exception;
 
     execution_state(env, &proc, NULL);
 
+    ASSERT(argc == 1);
     ASSERT(!ERTS_SCHEDULER_IS_DIRTY(erts_proc_sched_data(proc)));
     ep = (NifExport*) ERTS_PROC_GET_NIF_TRAP_EXPORT(proc);
     ASSERT(ep);
-    ASSERT(ep->exception_thrown);
-    if (ep->fp)
-	restore_nif_mfa(proc, ep, 1);
-    return enif_raise_exception(env, ep->rootset[0]);
+    exception = argv[0]; /* argv overwritten by restore below... */
+    nif_export_cleanup_nif_mod(ep);
+    ret = enif_raise_exception(env, exception);
+
+    /* Restore orig info for error and clear nif export in handle_error() */
+    proc->freason |= EXF_RESTORE_NIF;
+    return ret;
 }
 
 /*
- * Dirty NIF execution wrapper function. Invoke an application's dirty NIF,
- * then check the result and schedule the appropriate finalizer function
- * where needed. Also restore the original NIF MFA when appropriate.
+ * Dirty NIF scheduling wrapper function. Schedule a dirty NIF to execute.
+ * The dirty scheduler thread type (CPU or I/O) is indicated in flags
+ * parameter.
  */
-static ERL_NIF_TERM
-execute_dirty_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
+static ERTS_INLINE ERL_NIF_TERM
+schedule_dirty_nif(ErlNifEnv* env, int flags, NativeFunPtr fp,
+		   Eterm func_name, int argc, const ERL_NIF_TERM argv[])
 {
     Process* proc;
-    NativeFunPtr fp;
-    NifExport* ep;
-    ERL_NIF_TERM result;
-
-    execution_state(env, &proc, NULL);
 
-    ep = ErtsContainerStruct(proc->current, NifExport, exp.info.mfa);
-    fp = ep->fp;
-
-    ASSERT(ERTS_SCHEDULER_IS_DIRTY(erts_proc_sched_data(proc)));
-
-    /*
-     * Set ep->fp to NULL before the native call so we know later whether it scheduled another NIF for execution
-     */
-    ep = (NifExport*) ERTS_PROC_GET_NIF_TRAP_EXPORT(proc);
-    ASSERT(ep && fp);
-
-    ep->fp = NULL;
-    erts_smp_atomic32_read_band_mb(&proc->state, ~(ERTS_PSFLG_DIRTY_CPU_PROC
-						   | ERTS_PSFLG_DIRTY_IO_PROC));
+    ASSERT(is_atom(func_name));
+    ASSERT(fp);
 
-    erts_smp_proc_unlock(proc, ERTS_PROC_LOCK_MAIN);
+    ASSERT(flags==ERL_NIF_DIRTY_JOB_IO_BOUND || flags==ERL_NIF_DIRTY_JOB_CPU_BOUND);
 
-    result = (*fp)(env, argc, argv);
+    execution_state(env, &proc, NULL);
 
-    erts_smp_proc_lock(proc, ERTS_PROC_LOCK_MAIN);
+    (void) erts_smp_atomic32_read_bset_nob(&proc->state,
+					   (ERTS_PSFLG_DIRTY_CPU_PROC
+					    | ERTS_PSFLG_DIRTY_IO_PROC),
+					   (flags == ERL_NIF_DIRTY_JOB_CPU_BOUND
+					    ? ERTS_PSFLG_DIRTY_CPU_PROC
+					    : ERTS_PSFLG_DIRTY_IO_PROC));
 
-    if (erts_refc_dectest(&env->mod_nif->rt_dtor_cnt, 0) == 0 && env->mod_nif->mod == NULL)
-	close_lib(env->mod_nif);
-    /*
-     * If no more NIFs were scheduled by the native call via
-     * enif_schedule_nif(), then ep->fp will still be NULL as set above, in
-     * which case we need to restore the original NIF calling
-     * context. Reuse fp essentially as a boolean for this, passing it to
-     * init_nif_sched_data below. Both dirty_nif_exception and
-     * dirty_nif_finalizer then check ep->fp to decide whether or not to
-     * restore the original calling context.
-     */
-    ep = (NifExport*) ERTS_PROC_GET_NIF_TRAP_EXPORT(proc);
-    ASSERT(ep);
-    if (ep->fp)
-	fp = NULL;
-    if (is_non_value(result) || env->exception_thrown) {
-	if (proc->freason != TRAP) {
-	    return init_nif_sched_data(env, dirty_nif_exception, fp, 0, argc, argv);
-	} else {
-	    if (ep->fp == NULL)
-		restore_nif_mfa(proc, ep, 1);
-	    return THE_NON_VALUE;
-	}
-    }
-    else
-	return init_nif_sched_data(env, dirty_nif_finalizer, fp, 0, 1, &result);
+    return schedule(env, fp, NULL, proc->current->module, func_name, argc, argv);
 }
 
-/*
- * Dirty NIF scheduling wrapper function. Schedule a dirty NIF to execute
- * via the execute_dirty_nif() wrapper function. The dirty scheduler thread
- * type (CPU or I/O) is indicated in flags parameter.
- */
 static ERTS_INLINE ERL_NIF_TERM
-schedule_dirty_nif(ErlNifEnv* env, int flags, int argc, const ERL_NIF_TERM argv[])
+static_schedule_dirty_nif(ErlNifEnv* env, erts_aint32_t dirty_psflg,
+			     int argc, const ERL_NIF_TERM argv[])
 {
-    ERL_NIF_TERM result;
-    erts_aint32_t act, dirty_flag;
-    Process* proc;
+    Process *proc;
+    NifExport *ep;
+    Eterm mod, func;
     NativeFunPtr fp;
-    NifExport* ep;
-    int need_save, scheduler;
 
-    execution_state(env, &proc, &scheduler);
-    if (scheduler <= 0) {
-	ASSERT(scheduler < 0);
-	erts_smp_proc_lock(proc, ERTS_PROC_LOCK_MAIN);
-    }
+    execution_state(env, &proc, NULL);
+
+    /*
+     * Called in order to schedule statically determined
+     * dirty NIF calls...
+     *
+     * Note that 'current' does not point into a NifExport
+     * structure; only a structure with similar
+     * parts (located in code).
+     */
 
     ep = ErtsContainerStruct(proc->current, NifExport, exp.info.mfa);
-    fp = ep->fp;
+    mod = proc->current->module;
+    func = proc->current->function;
+    fp = (NativeFunPtr) ep->func;
 
+    ASSERT(is_atom(mod) && is_atom(func));
     ASSERT(fp);
 
-    ASSERT(flags==ERL_NIF_DIRTY_JOB_IO_BOUND || flags==ERL_NIF_DIRTY_JOB_CPU_BOUND);
-
-    if (flags == ERL_NIF_DIRTY_JOB_CPU_BOUND)
-	dirty_flag = ERTS_PSFLG_DIRTY_CPU_PROC;
-    else
-	dirty_flag = ERTS_PSFLG_DIRTY_IO_PROC;
-
-    act = erts_smp_atomic32_read_bor_nob(&proc->state, dirty_flag);
-    if (!(act & (ERTS_PSFLG_DIRTY_CPU_PROC|ERTS_PSFLG_DIRTY_IO_PROC)))
-	erts_refc_inc(&env->mod_nif->rt_dtor_cnt, 1);
-    else if ((act & (ERTS_PSFLG_DIRTY_CPU_PROC
-		     | ERTS_PSFLG_DIRTY_IO_PROC)) & ~dirty_flag) {
-	/* clear other flag... */
-	if (flags == ERL_NIF_DIRTY_JOB_CPU_BOUND)
-	    dirty_flag = ERTS_PSFLG_DIRTY_IO_PROC;
-	else
-	    dirty_flag = ERTS_PSFLG_DIRTY_CPU_PROC;
-	erts_smp_atomic32_read_band_nob(&proc->state, ~dirty_flag);
-    }
+    (void) erts_smp_atomic32_read_bset_nob(&proc->state,
+					   (ERTS_PSFLG_DIRTY_CPU_PROC
+					    | ERTS_PSFLG_DIRTY_IO_PROC),
+					   dirty_psflg);
 
-    ep = (NifExport*) ERTS_PROC_GET_NIF_TRAP_EXPORT(proc);
-    need_save = (ep == NULL || !ep->saved_current);
-    result = init_nif_sched_data(env, execute_dirty_nif, fp, need_save, argc, argv);
-    if (scheduler <= 0)
-	erts_smp_proc_unlock(proc, ERTS_PROC_LOCK_MAIN);
-    return result;
+    return schedule(env, fp, NULL, mod, func, argc, argv);
 }
 
 static ERL_NIF_TERM
-schedule_dirty_io_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
+static_schedule_dirty_io_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
 {
-    return schedule_dirty_nif(env, ERL_NIF_DIRTY_JOB_IO_BOUND, argc, argv);
+    return static_schedule_dirty_nif(env, ERTS_PSFLG_DIRTY_IO_PROC, argc, argv);
 }
 
 static ERL_NIF_TERM
-schedule_dirty_cpu_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
+static_schedule_dirty_cpu_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
 {
-    return schedule_dirty_nif(env, ERL_NIF_DIRTY_JOB_CPU_BOUND, argc, argv);
+    return static_schedule_dirty_nif(env, ERTS_PSFLG_DIRTY_CPU_PROC, argc, argv);
 }
 
 #endif /* ERTS_DIRTY_SCHEDULERS */
@@ -2646,23 +2446,42 @@ execute_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
     ERL_NIF_TERM result;
 
     execution_state(env, &proc, NULL);
-    ep = ErtsContainerStruct(proc->current, NifExport, exp.info.mfa);
-    fp = ep->fp;
 
-    ASSERT(!env->exception_thrown);
-    ep = (NifExport*) ERTS_PROC_GET_NIF_TRAP_EXPORT(proc);
+    ep = ErtsContainerStruct(proc->current, NifExport, exp.info.mfa);
+    fp = ep->func;
     ASSERT(ep);
-    ep->fp = NULL;
+    ASSERT(!env->exception_thrown);
+
+    fp = (NativeFunPtr) ep->func;
+
+#ifdef DEBUG
+    ep->func = ERTS_DBG_NIF_NOT_SCHED_MARKER;
+#endif
+
     result = (*fp)(env, argc, argv);
-    ep = (NifExport*) ERTS_PROC_GET_NIF_TRAP_EXPORT(proc);
-    ASSERT(ep);
-    /*
-     * If no NIFs were scheduled by the native call via
-     * enif_schedule_nif(), then ep->fp will still be NULL as set above, in
-     * which case we need to restore the original NIF MFA.
-     */
-    if (ep->fp == NULL)
-	restore_nif_mfa(proc, ep, env->exception_thrown);
+
+    ASSERT(ep == ERTS_PROC_GET_NIF_TRAP_EXPORT(proc));
+
+    if (is_value(result) || proc->freason != TRAP) {
+	/* Done (not rescheduled)... */
+	ASSERT(ep->func == ERTS_DBG_NIF_NOT_SCHED_MARKER);
+	if (!env->exception_thrown)
+	    nif_export_restore(proc, ep);
+	else {
+	    nif_export_cleanup_nif_mod(ep);
+	    /*
+	     * Restore orig info for error and clear nif
+	     * export in handle_error()
+	     */
+	    proc->freason |= EXF_RESTORE_NIF;
+	}
+    }
+
+#ifdef DEBUG
+    if (ep->func == ERTS_DBG_NIF_NOT_SCHED_MARKER)
+	ep->func = NULL;
+#endif
+
     return result;
 }
 
@@ -2672,9 +2491,8 @@ enif_schedule_nif(ErlNifEnv* env, const char* fun_name, int flags,
 		  int argc, const ERL_NIF_TERM argv[])
 {
     Process* proc;
-    NifExport* ep;
     ERL_NIF_TERM fun_name_atom, result;
-    int need_save, scheduler;
+    int scheduler;
 
     if (argc > MAX_ARG)
 	return enif_make_badarg(env);
@@ -2689,35 +2507,16 @@ enif_schedule_nif(ErlNifEnv* env, const char* fun_name, int flags,
 	erts_smp_proc_lock(proc, ERTS_PROC_LOCK_MAIN);
     }
 
-    ep = (NifExport*) ERTS_PROC_GET_NIF_TRAP_EXPORT(proc);
-    need_save = (ep == NULL || !ep->saved_current);
-
-    if (flags) {
+    if (flags == 0)
+	result = schedule(env, execute_nif, fp, proc->current->module,
+			  fun_name_atom, argc, argv);
 #ifdef ERTS_DIRTY_SCHEDULERS
-	NativeFunPtr sched_fun;
-	int chkflgs = (flags & (ERL_NIF_DIRTY_JOB_IO_BOUND|ERL_NIF_DIRTY_JOB_CPU_BOUND));
-	if (chkflgs == ERL_NIF_DIRTY_JOB_IO_BOUND)
-	    sched_fun = schedule_dirty_io_nif;
-	else if (chkflgs == ERL_NIF_DIRTY_JOB_CPU_BOUND)
-	    sched_fun = schedule_dirty_cpu_nif;
-	else {
-	    result = enif_make_badarg(env);
-	    goto done;
-	}
-	result = init_nif_sched_data(env, sched_fun, fp, need_save, argc, argv);
-#else
-	result = enif_make_badarg(env);
+    else if (!(flags & ~(ERL_NIF_DIRTY_JOB_IO_BOUND|ERL_NIF_DIRTY_JOB_CPU_BOUND)))
+	result = schedule_dirty_nif(env, flags, fp, fun_name_atom, argc, argv);
 #endif
-	goto done;
-    }
     else
-	result = init_nif_sched_data(env, execute_nif, fp, need_save, argc, argv);
-
-    ep = (NifExport*) ERTS_PROC_GET_NIF_TRAP_EXPORT(proc);
-    ASSERT(ep);
-    ep->exp.info.mfa.function = (BeamInstr) fun_name_atom;
+	result = enif_make_badarg(env);
 
-done:
     if (scheduler < 0)
 	erts_smp_proc_unlock(proc, ERTS_PROC_LOCK_MAIN);
 
@@ -3416,8 +3215,8 @@ BIF_RETTYPE load_nif_2(BIF_ALIST_2)
 	    if (f->flags) {
 		code_ptr[3] = (BeamInstr) f->fptr;
 		code_ptr[1] = (f->flags == ERL_NIF_DIRTY_JOB_IO_BOUND) ?
-		    (BeamInstr) schedule_dirty_io_nif :
-		    (BeamInstr) schedule_dirty_cpu_nif;
+		    (BeamInstr) static_schedule_dirty_io_nif :
+		    (BeamInstr) static_schedule_dirty_cpu_nif;
 	    }
 	    else
 #endif
diff --git a/erts/emulator/beam/erl_process.c b/erts/emulator/beam/erl_process.c
index 6928b282ee..955b98b35b 100644
--- a/erts/emulator/beam/erl_process.c
+++ b/erts/emulator/beam/erl_process.c
@@ -48,6 +48,7 @@
 #include "erl_bif_unique.h"
 #define ERTS_WANT_TIMER_WHEEL_API
 #include "erl_time.h"
+#include "erl_nfunc_sched.h"
 
 #define ERTS_CHECK_TIME_REDS CONTEXT_REDS
 #define ERTS_DELAYED_WAKEUP_INFINITY (~(Uint64) 0)
@@ -193,12 +194,6 @@ static ErtsAuxWorkData *aux_thread_aux_work_data;
 #define ERTS_SCHDLR_SSPND_CHNG_ONLN		(((erts_aint32_t) 1) << 2)
 #define ERTS_SCHDLR_SSPND_CHNG_DCPU_ONLN	(((erts_aint32_t) 1) << 3)
 
-typedef enum {
-    ERTS_SCHED_NORMAL,
-    ERTS_SCHED_DIRTY_CPU,
-    ERTS_SCHED_DIRTY_IO
-} ErtsSchedType;
-
 typedef struct {
     int ongoing;
     ErtsProcList *blckrs;
@@ -10102,9 +10097,6 @@ Process *erts_schedule(ErtsSchedulerData *esdp, Process *p, int calls)
 		goto sunlock_sched_out_proc;
 	    }
 
-	    ASSERT((state & ERTS_PSFLG_DIRTY_ACTIVE_SYS)
-		   || *p->i == (BeamInstr) em_call_nif);
-
 	    ASSERT(rq == ERTS_DIRTY_CPU_RUNQ
 		   ? (state & (ERTS_PSFLG_DIRTY_CPU_PROC
 			       | ERTS_PSFLG_DIRTY_ACTIVE_SYS))
@@ -11976,7 +11968,6 @@ delete_process(Process* p)
     ErtsPSD *psd;
     struct saved_calls *scb;
     process_breakpoint_time_t *pbt;
-    void *nif_export;
 
     VERBOSE(DEBUG_PROCESSES, ("Removing process: %T\n",p->common.id));
     VERBOSE(DEBUG_SHCOPY, ("[pid=%T] delete process: %p %p %p %p\n", p->common.id,
@@ -11993,9 +11984,7 @@ delete_process(Process* p)
     if (pbt)
         erts_free(ERTS_ALC_T_BPD, (void *) pbt);
 
-    nif_export = ERTS_PROC_SET_NIF_TRAP_EXPORT(p, NULL);
-    if (nif_export)
-	erts_destroy_nif_export(nif_export);
+    erts_destroy_nif_export(p);
 
     /* Cleanup psd */
 
@@ -13564,6 +13553,9 @@ erts_dbg_check_halloc_lock(Process *p)
     ErtsSchedulerData *esdp;
     if (ERTS_PROC_LOCK_MAIN & erts_proc_lc_my_proc_locks(p))
 	return 1;
+    if ((p->static_flags & ERTS_STC_FLG_SHADOW_PROC)
+	&& ERTS_SCHEDULER_IS_DIRTY(erts_get_scheduler_data()))
+	return 1;
     if (p->common.id == ERTS_INVALID_PID)
 	return 1;
     esdp = erts_proc_sched_data(p);
diff --git a/erts/emulator/beam/erl_process.h b/erts/emulator/beam/erl_process.h
index 7193b7d1db..58a50f8cf4 100644
--- a/erts/emulator/beam/erl_process.h
+++ b/erts/emulator/beam/erl_process.h
@@ -838,8 +838,8 @@ typedef struct {
 #define ERTS_PSD_DELAYED_GC_TASK_QS_GET_LOCKS ERTS_PROC_LOCK_MAIN
 #define ERTS_PSD_DELAYED_GC_TASK_QS_SET_LOCKS ERTS_PROC_LOCK_MAIN
 
-#define ERTS_PSD_NIF_TRAP_EXPORT_GET_LOCKS ((ErtsProcLocks) 0)
-#define ERTS_PSD_NIF_TRAP_EXPORT_SET_LOCKS ((ErtsProcLocks) 0)
+#define ERTS_PSD_NIF_TRAP_EXPORT_GET_LOCKS ERTS_PROC_LOCK_MAIN
+#define ERTS_PSD_NIF_TRAP_EXPORT_SET_LOCKS ERTS_PROC_LOCK_MAIN
 
 typedef struct {
     ErtsProcLocks get_locks;
@@ -1582,10 +1582,6 @@ Uint64 erts_get_proc_interval(void);
 Uint64 erts_ensure_later_proc_interval(Uint64);
 Uint64 erts_step_proc_interval(void);
 
-int erts_setup_nif_gc(Process* proc, Eterm** objv, int* nobj); /* see erl_nif.c */
-void erts_destroy_nif_export(void *); /* see erl_nif.c */
-int erts_check_nif_export_in_area(Process *p, char *start, Uint size);
-
 ErtsProcList *erts_proclist_create(Process *);
 ErtsProcList *erts_proclist_copy(ErtsProcList *);
 void erts_proclist_destroy(ErtsProcList *);
diff --git a/erts/emulator/beam/error.h b/erts/emulator/beam/error.h
index e431c3051b..99a8ff6bad 100644
--- a/erts/emulator/beam/error.h
+++ b/erts/emulator/beam/error.h
@@ -39,14 +39,11 @@
  */
 
 /*
- * Bits 0-1 index the 'exception class tag' table.
- */
-#define EXC_CLASSBITS 3
-#define GET_EXC_CLASS(x) ((x) & EXC_CLASSBITS)
-
-/*
  * Exception class tags (indices into the 'exception_tag' array)
  */
+#define EXTAG_OFFSET	0
+#define EXTAG_BITS	2
+
 #define EXTAG_ERROR	0
 #define EXTAG_EXIT	1
 #define EXTAG_THROWN	2
@@ -54,20 +51,31 @@
 #define NUMBER_EXC_TAGS 3	/* The number of exception class tags */
 
 /*
- * Exit code flags (bits 2-7)
+ * Index to the 'exception class tag' table.
+ */
+#define EXC_CLASSBITS	((1<<EXTAG_BITS)-1)
+#define GET_EXC_CLASS(x) ((x) & EXC_CLASSBITS)
+
+/*
+ * Exit code flags
  *
  * These flags make is easier and quicker to decide what to do with the
  * exception in the early stages, before a handler is found, and also
  * maintains some separation between the class tag and the actions.
  */
-#define EXF_PANIC	(1<<2)	/* ignore catches */
-#define EXF_THROWN	(1<<3)	/* nonlocal return */
-#define EXF_LOG		(1<<4)	/* write to logger on termination */
-#define EXF_NATIVE	(1<<5)	/* occurred in native code */
-#define EXF_SAVETRACE	(1<<6)	/* save stack trace in internal form */
-#define EXF_ARGLIST	(1<<7)	/* has arglist for top of trace */
+#define EXF_OFFSET	EXTAG_BITS
+#define EXF_BITS	7
 
-#define EXC_FLAGBITS 0x00fc
+#define EXF_PANIC	(1<<(0+EXF_OFFSET))	/* ignore catches */
+#define EXF_THROWN	(1<<(1+EXF_OFFSET))	/* nonlocal return */
+#define EXF_LOG		(1<<(2+EXF_OFFSET))	/* write to logger on termination */
+#define EXF_NATIVE	(1<<(3+EXF_OFFSET))	/* occurred in native code */
+#define EXF_SAVETRACE	(1<<(4+EXF_OFFSET))	/* save stack trace in internal form */
+#define EXF_ARGLIST	(1<<(5+EXF_OFFSET))	/* has arglist for top of trace */
+#define EXF_RESTORE_NIF	(1<<(6+EXF_OFFSET))	/* restore original bif/nif */
+
+#define EXC_FLAGBITS	(((1<<(EXF_BITS+EXF_OFFSET))-1) \
+			 & ~((1<<(EXF_OFFSET))-1))
 
 /*
  * The primary fields of an exception code
@@ -77,11 +85,16 @@
 #define NATIVE_EXCEPTION(x) ((x) | EXF_NATIVE)
 
 /*
- * Bits 8-12 of the error code are used for indexing into
+ * Error code used for indexing into
  * the short-hand error descriptor table.
  */
-#define EXC_INDEXBITS 0x1f00
-#define GET_EXC_INDEX(x) (((x) & EXC_INDEXBITS) >> 8)
+#define EXC_OFFSET	(EXF_OFFSET+EXF_BITS)
+#define EXC_BITS	5
+
+#define EXC_INDEXBITS	(((1<<(EXC_BITS+EXC_OFFSET))-1) \
+			 & ~((1<<(EXC_OFFSET))-1))
+
+#define GET_EXC_INDEX(x) (((x) & EXC_INDEXBITS) >> EXC_OFFSET)
 
 /*
  * Exit codes used for raising a fresh exception. The primary exceptions
@@ -107,46 +120,46 @@
 					/* Error with given arglist term
 					 * (exit reason in p->fvalue) */
 
-#define EXC_NORMAL		((1 << 8) | EXC_EXIT)
+#define EXC_NORMAL		((1 << EXC_OFFSET) | EXC_EXIT)
 					/* Normal exit (reason 'normal') */
-#define EXC_INTERNAL_ERROR	((2 << 8) | EXC_ERROR | EXF_PANIC)
+#define EXC_INTERNAL_ERROR	((2 << EXC_OFFSET) | EXC_ERROR | EXF_PANIC)
 					/* Things that shouldn't happen */
-#define EXC_BADARG		((3 << 8) | EXC_ERROR)
+#define EXC_BADARG		((3 << EXC_OFFSET) | EXC_ERROR)
 					/* Bad argument to a BIF */
-#define EXC_BADARITH		((4 << 8) | EXC_ERROR)
+#define EXC_BADARITH		((4 << EXC_OFFSET) | EXC_ERROR)
 					/* Bad arithmetic */
-#define EXC_BADMATCH		((5 << 8) | EXC_ERROR)
+#define EXC_BADMATCH		((5 << EXC_OFFSET) | EXC_ERROR)
 					/* Bad match in function body */
-#define EXC_FUNCTION_CLAUSE	((6 << 8) | EXC_ERROR)
+#define EXC_FUNCTION_CLAUSE	((6 << EXC_OFFSET) | EXC_ERROR)
 					 /* No matching function head */
-#define EXC_CASE_CLAUSE		((7 << 8) | EXC_ERROR)
+#define EXC_CASE_CLAUSE		((7 << EXC_OFFSET) | EXC_ERROR)
 					/* No matching case clause */
-#define EXC_IF_CLAUSE		((8 << 8) | EXC_ERROR)
+#define EXC_IF_CLAUSE		((8 << EXC_OFFSET) | EXC_ERROR)
 					/* No matching if clause */
-#define EXC_UNDEF		((9 << 8) | EXC_ERROR)
+#define EXC_UNDEF		((9 << EXC_OFFSET) | EXC_ERROR)
 				 	/* No farity that matches */
-#define EXC_BADFUN		((10 << 8) | EXC_ERROR)
+#define EXC_BADFUN		((10 << EXC_OFFSET) | EXC_ERROR)
 					/* Not an existing fun */
-#define EXC_BADARITY		((11 << 8) | EXC_ERROR)
+#define EXC_BADARITY		((11 << EXC_OFFSET) | EXC_ERROR)
 					/* Attempt to call fun with
 					 * wrong number of arguments. */
-#define EXC_TIMEOUT_VALUE	((12 << 8) | EXC_ERROR)
+#define EXC_TIMEOUT_VALUE	((12 << EXC_OFFSET) | EXC_ERROR)
 					/* Bad time out value */
-#define EXC_NOPROC		((13 << 8) | EXC_ERROR)
+#define EXC_NOPROC		((13 << EXC_OFFSET) | EXC_ERROR)
 					/* No process or port */
-#define EXC_NOTALIVE		((14 << 8) | EXC_ERROR)
+#define EXC_NOTALIVE		((14 << EXC_OFFSET) | EXC_ERROR)
 					/* Not distributed */
-#define EXC_SYSTEM_LIMIT	((15 << 8) | EXC_ERROR)
+#define EXC_SYSTEM_LIMIT	((15 << EXC_OFFSET) | EXC_ERROR)
 					/* Ran out of something */
-#define EXC_TRY_CLAUSE		((16 << 8) | EXC_ERROR)
+#define EXC_TRY_CLAUSE		((16 << EXC_OFFSET) | EXC_ERROR)
 					/* No matching try clause */
-#define EXC_NOTSUP		((17 << 8) | EXC_ERROR)
+#define EXC_NOTSUP		((17 << EXC_OFFSET) | EXC_ERROR)
 					/* Not supported */
 
-#define EXC_BADMAP		((18 << 8) | EXC_ERROR)
+#define EXC_BADMAP		((18 << EXC_OFFSET) | EXC_ERROR)
 					/* Bad map */
 
-#define EXC_BADKEY		((19 << 8) | EXC_ERROR)
+#define EXC_BADKEY		((19 << EXC_OFFSET) | EXC_ERROR)
 					/* Bad key in map */
 
 #define NUMBER_EXIT_CODES 20	/* The number of exit code indices */
@@ -154,7 +167,7 @@
 /*
  * Internal pseudo-error codes.
  */
-#define TRAP		(1 << 8)	/* BIF Trap to erlang code */
+#define TRAP		(1 << EXC_OFFSET)	/* BIF Trap to erlang code */
 
 /*
  * Aliases for some common exit codes.
@@ -201,6 +214,7 @@ struct StackTrace {
     BeamInstr* pc;
     ErtsCodeMFA* current;
     int depth;	/* number of saved pointers in trace[] */
+    ErtsCodeMFA mfa; /* in case we need to make a copy of mfa */
     BeamInstr *trace[1];  /* varying size - must be last in struct */
 };
 
diff --git a/erts/emulator/beam/global.h b/erts/emulator/beam/global.h
index 2b2f3c5cdc..d5ca3b04eb 100644
--- a/erts/emulator/beam/global.h
+++ b/erts/emulator/beam/global.h
@@ -61,12 +61,6 @@ struct enif_environment_t /* ErlNifEnv */
 extern void erts_pre_nif(struct enif_environment_t*, Process*,
 			 struct erl_module_nif*, Process* tracee);
 extern void erts_post_nif(struct enif_environment_t* env);
-#ifdef ERTS_DIRTY_SCHEDULERS
-extern void erts_pre_dirty_nif(ErtsSchedulerData *,
-			       struct enif_environment_t*, Process*,
-			       struct erl_module_nif*);
-extern void erts_post_dirty_nif(struct enif_environment_t* env);
-#endif
 extern Eterm erts_nif_taints(Process* p);
 extern void erts_print_nif_taints(fmtfn_t to, void* to_arg);
 void erts_unload_nif(struct erl_module_nif* nif);
@@ -78,6 +72,12 @@ extern Eterm erts_nif_call_function(Process *p, Process *tracee,
                                     struct enif_func_t *,
                                     int argc, Eterm *argv);
 
+#ifdef ERTS_DIRTY_SCHEDULERS
+int erts_call_dirty_nif(ErtsSchedulerData *esdp, Process *c_p,
+			BeamInstr *I, Eterm *reg);
+#endif /* ERTS_DIRTY_SCHEDULERS */
+
+
 /* Driver handle (wrapper for old plain handle) */
 #define ERL_DE_OK      0
 #define ERL_DE_UNLOAD  1
@@ -993,7 +993,7 @@ void erts_queue_monitor_message(Process *,
 				Eterm,
 				Eterm);
 void erts_init_trap_export(Export* ep, Eterm m, Eterm f, Uint a,
-			   Eterm (*bif)(Process*,Eterm*));
+			   Eterm (*bif)(Process*, Eterm*, BeamInstr*));
 void erts_init_bif(void);
 Eterm erl_send(Process *p, Eterm to, Eterm msg);
 
diff --git a/erts/emulator/beam/utils.c b/erts/emulator/beam/utils.c
index ec502d5a78..3fa48da1ec 100644
--- a/erts/emulator/beam/utils.c
+++ b/erts/emulator/beam/utils.c
@@ -56,6 +56,8 @@
 #ifdef HIPE
 #  include "hipe_mode_switch.h"
 #endif
+#define ERTS_WANT_NFUNC_SCHED_INTERNALS__
+#include "erl_nfunc_sched.h"
 
 #undef M_TRIM_THRESHOLD
 #undef M_TOP_PAD