Merge branch 'rickard/time_api/master/OTP-11997'

* rickard/time_api/master/OTP-11997: (22 commits)
  Update primary bootstrap
  inets: Suppress deprecated warning on erlang:now/0
  inets: Cleanup of multiple copies of functions Add inets_lib with common functions used by multiple modules
  inets: Update comments
  Suppress deprecated warning on erlang:now/0
  Use new time API and be back-compatible in inets Remove unused functions and removed redundant test
  asn1 test SUITE: Eliminate use of now/0
  Disable deprecated warning on erlang:now/0 in diameter_lib
  Use new time API and be back-compatible in ssh
  Replace all calls to now/0 in CT with new time API functions
  test_server: Replace usage of erlang:now() with usage of new API
  Replace usage of erlang:now() with usage of new API
  Replace usage of erlang:now() with usage of new API
  Replace usage of erlang:now() with usage of new API
  Replace usage of erlang:now() with usage of new API
  otp_SUITE: Warn for calls to erlang:now/0
  Replace usage of erlang:now() with usage of new API
  Multiple timer wheels
  Erlang based BIF timer implementation for scalability
  Implement ethread events with timeout
  ...

36 files changed, 3859 insertions, 1111 deletions

diff --git a/erts/emulator/beam/atom.names b/erts/emulator/beam/atom.names
index c097866c7e..ae3f30d82f 100644
--- a/erts/emulator/beam/atom.names
+++ b/erts/emulator/beam/atom.names
@@ -109,6 +109,7 @@ atom bag
 atom band
 atom big
 atom bif_return_trap
+atom bif_timer_server
 atom binary
 atom binary_bin_to_list_trap
 atom binary_copy_trap
@@ -144,9 +145,11 @@ atom catchlevel
 atom cd
 atom cdr
 atom cflags
+atom CHANGE='CHANGE'
 atom characters_to_binary_int
 atom characters_to_list_int
 atom clear
+atom clock_service
 atom close
 atom closed
 atom code
@@ -156,6 +159,7 @@ atom compat_rel
 atom compile
 atom compressed
 atom config_h
+atom convert_time_unit
 atom connect
 atom connected
 atom connection_closed
@@ -237,7 +241,7 @@ atom first
 atom firstline
 atom flags
 atom flush
-atom flush_monitor_message
+atom flush_monitor_messages
 atom force
 atom format_cpu_topology
 atom free
@@ -345,6 +349,8 @@ atom message_queue_len
 atom messages
 atom meta
 atom meta_match_spec
+atom micro_seconds
+atom milli_seconds
 atom min_heap_size
 atom min_bin_vheap_size
 atom minor_version
@@ -355,12 +361,15 @@ atom monitored_by
 atom monitor
 atom monitor_nodes
 atom monitors
+atom monotonic
 atom more
 atom multi_scheduling
 atom multiline
+atom nano_seconds
 atom name
 atom named_table
 atom namelist
+atom native
 atom native_addresses
 atom Neq='=/='
 atom Neqeq='/='
@@ -451,6 +460,7 @@ atom ports
 atom port_count
 atom port_limit
 atom port_op
+atom positive
 atom print
 atom priority
 atom private
@@ -510,6 +520,7 @@ atom schedulers_online
 atom scheme
 atom scientific
 atom scope
+atom seconds
 atom sensitive
 atom sequential_tracer
 atom sequential_trace_token
@@ -555,6 +566,7 @@ atom term_to_binary_trap
 atom this
 atom thread_pool_size
 atom threads
+atom time_offset
 atom timeout
 atom timeout_value
 atom Times='*'
diff --git a/erts/emulator/beam/benchmark.h b/erts/emulator/beam/benchmark.h
index 904564a96b..7fc3933f3d 100644
--- a/erts/emulator/beam/benchmark.h
+++ b/erts/emulator/beam/benchmark.h
@@ -141,10 +141,10 @@ extern unsigned long long major_gc;
 
 /* (Assuming Solaris) */
 
-#define BM_TIMER_T hrtime_t
-#define BM_START_TIMER(t) system_clock = sys_gethrtime()
+#define BM_TIMER_T ErtsMonotonicTime
+#define BM_START_TIMER(t) system_clock = ERTS_MONOTONIC_TO_NSEC(erts_os_monotonic_time())
 #define BM_STOP_TIMER(t) do {                                        \
-    BM_TIMER_T tmp = (sys_gethrtime() - system_clock) - timer_time;  \
+    BM_TIMER_T tmp = (ERTS_MONOTONIC_TO_NSEC(erts_os_monotonic_time()) - system_clock) - timer_time;  \
     t##_time += (tmp > 0 ? tmp : 0);                                 \
 } while(0)
 
diff --git a/erts/emulator/beam/bif.c b/erts/emulator/beam/bif.c
index 49996e7f0b..af02a55b69 100644
--- a/erts/emulator/beam/bif.c
+++ b/erts/emulator/beam/bif.c
@@ -42,16 +42,22 @@
 #define ERTS_PTAB_WANT_BIF_IMPL__
 #include "erl_ptab.h"
 #include "erl_bits.h"
+#include "erl_bif_unique.h"
 
-static Export* flush_monitor_message_trap = NULL;
+static Export* flush_monitor_messages_trap = NULL;
 static Export* set_cpu_topology_trap = NULL;
 static Export* await_proc_exit_trap = NULL;
 static Export* await_port_send_result_trap = NULL;
 Export* erts_format_cpu_topology_trap = NULL;
 static Export dsend_continue_trap_export;
+Export *erts_convert_time_unit_trap = NULL;
+
 static Export *await_sched_wall_time_mod_trap;
 static erts_smp_atomic32_t sched_wall_time;
 
+static erts_smp_mtx_t ports_snapshot_mtx;
+erts_smp_atomic_t erts_dead_ports_ptr; /* To store dying ports during snapshot */
+
 #define DECL_AM(S) Eterm AM_ ## S = am_atom_put(#S, sizeof(#S) - 1)
 
 /*
@@ -393,7 +399,7 @@ remote_demonitor(Process *c_p, DistEntry *dep, Eterm ref, Eterm to)
     return res;
 }
 
-static int demonitor(Process *c_p, Eterm ref)
+static int demonitor(Process *c_p, Eterm ref, Eterm *multip)
 {
    ErtsMonitor *mon = NULL;  /* The monitor entry to delete */
    Process  *rp;    /* Local target process */
@@ -417,65 +423,73 @@ static int demonitor(Process *c_p, Eterm ref)
        goto done;
    }
 
-   if (mon->type != MON_ORIGIN) {
-       res = ERTS_DEMONITOR_BADARG;
-       goto done;
-   }
-   to = mon->pid;
-
-   if (is_atom(to)) {
-       /* Monitoring a name at node to */
-       ASSERT(is_node_name_atom(to));
-       dep = erts_sysname_to_connected_dist_entry(to);
-       ASSERT(dep != erts_this_dist_entry);
-       if (dep)
-	   deref_de = 1;
-   } else {
-       ASSERT(is_pid(to));
-       dep = pid_dist_entry(to);
-   }
-   if (dep != erts_this_dist_entry) {
-       res = remote_demonitor(c_p, dep, ref, to);
-       /* remote_demonitor() unlocks link lock on c_p */
-       unlock_link = 0;
-   }
-   else { /* Local monitor */
-       if (deref_de) {
-	   deref_de = 0;
-	   erts_deref_dist_entry(dep);
+   switch (mon->type) {
+   case MON_TIME_OFFSET:
+       *multip = am_true;
+       erts_demonitor_time_offset(ref);
+       res = ERTS_DEMONITOR_TRUE;
+       break;
+   case MON_ORIGIN:
+       to = mon->pid;
+       *multip = am_false;
+       if (is_atom(to)) {
+	   /* Monitoring a name at node to */
+	   ASSERT(is_node_name_atom(to));
+	   dep = erts_sysname_to_connected_dist_entry(to);
+	   ASSERT(dep != erts_this_dist_entry);
+	   if (dep)
+	       deref_de = 1;
+       } else {
+	   ASSERT(is_pid(to));
+	   dep = pid_dist_entry(to);
        }
-       dep = NULL;
-       rp = erts_pid2proc_opt(c_p,
-			      ERTS_PROC_LOCK_MAIN|ERTS_PROC_LOCK_LINK,
-			      to,
-			      ERTS_PROC_LOCK_LINK,
-			      ERTS_P2P_FLG_ALLOW_OTHER_X);
-       mon = erts_remove_monitor(&ERTS_P_MONITORS(c_p), ref);
+       if (dep != erts_this_dist_entry) {
+	   res = remote_demonitor(c_p, dep, ref, to);
+	   /* remote_demonitor() unlocks link lock on c_p */
+	   unlock_link = 0;
+       }
+       else { /* Local monitor */
+	   if (deref_de) {
+	       deref_de = 0;
+	       erts_deref_dist_entry(dep);
+	   }
+	   dep = NULL;
+	   rp = erts_pid2proc_opt(c_p,
+				  ERTS_PROC_LOCK_MAIN|ERTS_PROC_LOCK_LINK,
+				  to,
+				  ERTS_PROC_LOCK_LINK,
+				  ERTS_P2P_FLG_ALLOW_OTHER_X);
+	   mon = erts_remove_monitor(&ERTS_P_MONITORS(c_p), ref);
 #ifndef ERTS_SMP
-       ASSERT(mon);
+	   ASSERT(mon);
 #else
-       if (!mon)
-	   res = ERTS_DEMONITOR_FALSE;
-       else
+	   if (!mon)
+	       res = ERTS_DEMONITOR_FALSE;
+	   else
 #endif
-       {
-	   res = ERTS_DEMONITOR_TRUE;
-	   erts_destroy_monitor(mon);
-       }
-       if (rp) {
-	   ErtsMonitor *rmon;
-	   rmon = erts_remove_monitor(&ERTS_P_MONITORS(rp), ref);
-	   if (rp != c_p)
-	       erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_LINK);
-	   if (rmon != NULL)
-	       erts_destroy_monitor(rmon);
-       }
-       else {
-	   ERTS_SMP_ASSERT_IS_NOT_EXITING(c_p);
-       }
+	   {
+	       res = ERTS_DEMONITOR_TRUE;
+	       erts_destroy_monitor(mon);
+	   }
+	   if (rp) {
+	       ErtsMonitor *rmon;
+	       rmon = erts_remove_monitor(&ERTS_P_MONITORS(rp), ref);
+	       if (rp != c_p)
+		   erts_smp_proc_unlock(rp, ERTS_PROC_LOCK_LINK);
+	       if (rmon != NULL)
+		   erts_destroy_monitor(rmon);
+	   }
+	   else {
+	       ERTS_SMP_ASSERT_IS_NOT_EXITING(c_p);
+	   }
 
+       }
+       break;
+   default:
+       res = ERTS_DEMONITOR_BADARG;
+       *multip = am_false;
+       break;
    }
-
  done:
 
    if (unlock_link)
@@ -492,7 +506,8 @@ static int demonitor(Process *c_p, Eterm ref)
 
 BIF_RETTYPE demonitor_1(BIF_ALIST_1)
 {
-    switch (demonitor(BIF_P, BIF_ARG_1)) {
+    Eterm multi;
+    switch (demonitor(BIF_P, BIF_ARG_1, &multi)) {
     case ERTS_DEMONITOR_FALSE:
     case ERTS_DEMONITOR_TRUE:
 	BIF_RET(am_true);
@@ -510,6 +525,7 @@ BIF_RETTYPE demonitor_1(BIF_ALIST_1)
 BIF_RETTYPE demonitor_2(BIF_ALIST_2)
 {
     Eterm res = am_true;
+    Eterm multi = am_false;
     int info = 0;
     int flush = 0;
     Eterm list = BIF_ARG_2;
@@ -532,13 +548,18 @@ BIF_RETTYPE demonitor_2(BIF_ALIST_2)
     if (is_not_nil(list))
 	goto badarg;
 
-    switch (demonitor(BIF_P, BIF_ARG_1)) {
+    switch (demonitor(BIF_P, BIF_ARG_1, &multi)) {
     case ERTS_DEMONITOR_FALSE:
 	if (info)
 	    res = am_false;
-	if (flush)
-	    BIF_TRAP2(flush_monitor_message_trap, BIF_P, BIF_ARG_1, res);
+	if (flush) {
+	flush_messages:
+	    BIF_TRAP3(flush_monitor_messages_trap, BIF_P,
+		      BIF_ARG_1, multi, res);
+	}
     case ERTS_DEMONITOR_TRUE:
+	if (multi == am_true && flush)
+	    goto flush_messages;
 	BIF_RET(res);
     case ERTS_DEMONITOR_YIELD_TRUE:
 	ERTS_BIF_YIELD_RETURN(BIF_P, am_true);
@@ -597,14 +618,12 @@ erts_queue_monitor_message(Process *p,
 }
 
 static BIF_RETTYPE
-local_pid_monitor(Process *p, Eterm target)
+local_pid_monitor(Process *p, Eterm target, Eterm mon_ref, int bool)
 {
     BIF_RETTYPE ret;
-    Eterm mon_ref;
     Process *rp;
     ErtsProcLocks p_locks = ERTS_PROC_LOCK_MAIN|ERTS_PROC_LOCK_LINK;
 
-    mon_ref = erts_make_ref(p);
     ERTS_BIF_PREP_RET(ret, mon_ref);
     if (target == p->common.id) {
 	return ret;
@@ -617,12 +636,18 @@ local_pid_monitor(Process *p, Eterm target)
     if (!rp) {
 	erts_smp_proc_unlock(p, ERTS_PROC_LOCK_LINK);
 	p_locks &= ~ERTS_PROC_LOCK_LINK;
-	erts_queue_monitor_message(p, &p_locks,
-				   mon_ref, am_process, target, am_noproc);
+	if (bool)
+	    ret = am_false;
+	else
+	    erts_queue_monitor_message(p, &p_locks,
+				       mon_ref, am_process, target, am_noproc);
     }
     else {
 	ASSERT(rp != p);
 
+	if (bool)
+	    ret = am_true;
+
 	erts_add_monitor(&ERTS_P_MONITORS(p), MON_ORIGIN, mon_ref, target, NIL);
 	erts_add_monitor(&ERTS_P_MONITORS(rp), MON_TARGET, mon_ref, p->common.id, NIL);
 
@@ -746,13 +771,28 @@ BIF_RETTYPE monitor_2(BIF_ALIST_2)
     int deref_de = 0;
 
     /* Only process monitors are implemented */
-    if (BIF_ARG_1 != am_process) {
+    switch (BIF_ARG_1) {
+    case am_time_offset: {
+	Eterm ref;
+	if (BIF_ARG_2 != am_clock_service)
+	    goto error;
+	ref = erts_make_ref(BIF_P);
+	erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_LINK);
+	erts_add_monitor(&ERTS_P_MONITORS(BIF_P), MON_TIME_OFFSET,
+			 ref, am_clock_service, NIL);
+	erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_LINK);
+	erts_monitor_time_offset(BIF_P->common.id, ref);
+	BIF_RET(ref);
+    }
+    case am_process:
+	break;
+    default:
 	goto error;
     }
 
     if (is_internal_pid(target)) {
     local_pid:
-	ret = local_pid_monitor(BIF_P, target);
+	ret = local_pid_monitor(BIF_P, target, erts_make_ref(BIF_P), 0);
     } else if (is_external_pid(target)) {
 	dep = external_pid_dist_entry(target);
 	if (dep == erts_this_dist_entry)
@@ -795,6 +835,25 @@ BIF_RETTYPE monitor_2(BIF_ALIST_2)
     return ret;
 }
 
+BIF_RETTYPE erts_internal_monitor_process_2(BIF_ALIST_2)
+{
+    if (is_not_internal_pid(BIF_ARG_1)) {
+	if (is_external_pid(BIF_ARG_1)
+	    && (external_pid_dist_entry(BIF_ARG_1)
+		== erts_this_dist_entry)) {
+	    BIF_RET(am_false);
+	}
+	goto badarg;
+    }
+
+    if (is_not_internal_ref(BIF_ARG_2))
+	goto badarg;
+
+    BIF_RET(local_pid_monitor(BIF_P, BIF_ARG_1, BIF_ARG_2, 1));
+
+badarg:
+    BIF_ERROR(BIF_P, BADARG);
+}
 
 /**********************************************************************/
 /* this is a combination of the spawn and link BIFs */
@@ -3542,91 +3601,6 @@ BIF_RETTYPE self_0(BIF_ALIST_0)
 
 /**********************************************************************/
 
-/*
-   New representation of refs in R9, see erl_term.h
-
-   In the first data word, only the usual 18 bits are used. Ordinarily,
-   in "long refs" all words are used (in other words, practically never
-   wrap around), but for compatibility with older nodes, "short refs"
-   exist. Short refs come into being by being converted from the old
-   external format for refs (tag REFERENCE_EXT). Short refs are
-   converted back to the old external format.
-
-   When converting a long ref to the external format in the case of
-   preparing for sending to an older node, the ref is truncated by only
-   using the first word (with 18 significant bits), and using the old tag
-   REFERENCE_EXT.
-
-   When comparing refs or different size, only the parts up to the length
-   of the shorter operand are used. This has the desirable effect that a
-   long ref sent to an old node and back will be treated as equal to
-   the original, although some of the bits have been lost.
-
-   The hash value for a ref always considers only the first word, since
-   in the above scenario, the original and the copy should have the same
-   hash value.
-*/
-
-static Uint32 reference0; /* Initialized in erts_init_bif */
-static Uint32 reference1;
-static Uint32 reference2;
-static erts_smp_spinlock_t make_ref_lock;
-static erts_smp_mtx_t ports_snapshot_mtx;
-erts_smp_atomic_t erts_dead_ports_ptr; /* To store dying ports during snapshot */
-
-void
-erts_make_ref_in_array(Uint32 ref[ERTS_MAX_REF_NUMBERS])
-{
-    erts_smp_spin_lock(&make_ref_lock);
-
-    reference0++;
-    if (reference0 >= MAX_REFERENCE) {
-	reference0 = 0;
-	reference1++;
-	if (reference1 == 0) {
-	    reference2++;
-	}
-    }
-
-    ref[0] = reference0;
-    ref[1] = reference1;
-    ref[2] = reference2;
-
-    erts_smp_spin_unlock(&make_ref_lock);
-}
-
-Eterm erts_make_ref_in_buffer(Eterm buffer[REF_THING_SIZE])
-{
-    Eterm* hp = buffer;
-    Uint32 ref[ERTS_MAX_REF_NUMBERS];
-
-    erts_make_ref_in_array(ref);
-    write_ref_thing(hp, ref[0], ref[1], ref[2]);
-    return make_internal_ref(hp);
-}
-
-Eterm erts_make_ref(Process *p)
-{
-    Eterm* hp;
-    Uint32 ref[ERTS_MAX_REF_NUMBERS];
-
-    ERTS_SMP_LC_ASSERT(ERTS_PROC_LOCK_MAIN & erts_proc_lc_my_proc_locks(p));
-
-    hp = HAlloc(p, REF_THING_SIZE);
-
-    erts_make_ref_in_array(ref);
-    write_ref_thing(hp, ref[0], ref[1], ref[2]);
-
-    return make_internal_ref(hp);
-}
-
-BIF_RETTYPE make_ref_0(BIF_ALIST_0)
-{
-    return erts_make_ref(BIF_P);
-}
-
-/**********************************************************************/
-
 /* return the time of day */
 
 BIF_RETTYPE time_0(BIF_ALIST_0)
@@ -4607,6 +4581,28 @@ BIF_RETTYPE system_flag_2(BIF_ALIST_2)
 	    break;
 	}
 #endif
+    } else if (BIF_ARG_1 == am_time_offset
+	       && ERTS_IS_ATOM_STR("finalize", BIF_ARG_2)) {
+	ErtsTimeOffsetState res;
+	erts_smp_proc_unlock(BIF_P, ERTS_PROC_LOCK_MAIN);
+	res = erts_finalize_time_offset();
+        erts_smp_proc_lock(BIF_P, ERTS_PROC_LOCK_MAIN);
+	switch (res) {
+	case ERTS_TIME_OFFSET_PRELIMINARY: {
+	    DECL_AM(preliminary);
+	    BIF_RET(AM_preliminary);
+	}
+	case ERTS_TIME_OFFSET_FINAL: {
+	    DECL_AM(final);
+	    BIF_RET(AM_final);
+	}
+	case ERTS_TIME_OFFSET_VOLATILE: {
+	    DECL_AM(volatile);
+	    BIF_RET(AM_volatile);
+	}
+	default:
+	    ERTS_INTERNAL_ERROR("Unknown state");
+	}
     } else if (ERTS_IS_ATOM_STR("scheduling_statistics", BIF_ARG_1)) {
 	int what;
 	if (ERTS_IS_ATOM_STR("disable", BIF_ARG_2))
@@ -4894,11 +4890,6 @@ void erts_init_trap_export(Export* ep, Eterm m, Eterm f, Uint a,
 
 void erts_init_bif(void)
 {
-    reference0 = 0;
-    reference1 = 0;
-    reference2 = 0;
-
-    erts_smp_spinlock_init(&make_ref_lock, "make_ref");
     erts_smp_mtx_init(&ports_snapshot_mtx, "ports_snapshot");
     erts_smp_atomic_init_nob(&erts_dead_ports_ptr, (erts_aint_t) NULL);
 
@@ -4919,9 +4910,13 @@ void erts_init_bif(void)
 			  am_erts_internal, am_dsend_continue_trap, 1,
 			  dsend_continue_trap_1);
 
-    flush_monitor_message_trap = erts_export_put(am_erlang,
-						 am_flush_monitor_message,
-						 2);
+    flush_monitor_messages_trap = erts_export_put(am_erts_internal,
+						  am_flush_monitor_messages,
+						  3);
+
+    erts_convert_time_unit_trap = erts_export_put(am_erlang,
+						  am_convert_time_unit,
+						  3);
 
     set_cpu_topology_trap = erts_export_put(am_erlang,
 					    am_set_cpu_topology,
diff --git a/erts/emulator/beam/bif.h b/erts/emulator/beam/bif.h
index 837cb017ac..d461c3f479 100644
--- a/erts/emulator/beam/bif.h
+++ b/erts/emulator/beam/bif.h
@@ -21,6 +21,7 @@
 #define __BIF_H__
 
 extern Export* erts_format_cpu_topology_trap;
+extern Export *erts_convert_time_unit_trap;
 
 #define BIF_RETTYPE Eterm
 
diff --git a/erts/emulator/beam/bif.tab b/erts/emulator/beam/bif.tab
index 5a0ee2ffc3..471f687101 100644
--- a/erts/emulator/beam/bif.tab
+++ b/erts/emulator/beam/bif.tab
@@ -92,6 +92,8 @@ bif erlang:loaded/0
 bif erlang:localtime/0
 bif erlang:localtime_to_universaltime/2
 bif erlang:make_ref/0
+bif erlang:unique_integer/0
+bif erlang:unique_integer/1
 bif erlang:md5/1
 bif erlang:md5_init/0
 bif erlang:md5_update/2
@@ -104,6 +106,13 @@ ubif erlang:node/1
 ubif erlang:node/0
 bif erlang:nodes/1
 bif erlang:now/0
+bif erlang:monotonic_time/0
+bif erlang:monotonic_time/1
+bif erlang:system_time/0
+bif erlang:system_time/1
+bif erlang:time_offset/0
+bif erlang:time_offset/1
+bif erlang:timestamp/0
 
 bif erlang:open_port/2
 
@@ -160,6 +169,15 @@ bif erts_internal:map_to_tuple_keys/1
 bif erts_internal:map_type/1
 bif erts_internal:map_hashmap_children/1
 
+bif erts_internal:time_unit/0
+
+bif erts_internal:get_bif_timer_servers/0
+bif erts_internal:create_bif_timer/0
+bif erts_internal:access_bif_timer/1
+
+bif erts_internal:monitor_process/2
+bif erts_internal:is_system_process/1
+
 # inet_db support
 bif erlang:port_set_data/2
 bif erlang:port_get_data/1
@@ -202,11 +220,6 @@ bif math:sqrt/1
 bif math:atan2/2
 bif math:pow/2
 
-bif erlang:start_timer/3
-bif erlang:send_after/3
-bif erlang:cancel_timer/1
-bif erlang:read_timer/1
-
 bif erlang:make_tuple/2
 bif erlang:append_element/2
 bif erlang:make_tuple/3
@@ -350,6 +363,8 @@ bif os:getenv/0
 bif os:getenv/1
 bif os:getpid/0
 bif os:timestamp/0
+bif os:system_time/0
+bif os:system_time/1
 
 #
 # Bifs in the erl_ddll module (the module actually does not exist)
diff --git a/erts/emulator/beam/big.c b/erts/emulator/beam/big.c
index d1e46e3063..a4ea9c59ca 100644
--- a/erts/emulator/beam/big.c
+++ b/erts/emulator/beam/big.c
@@ -1577,6 +1577,46 @@ Eterm erts_sint64_to_big(Sint64 x, Eterm **hpp)
     return make_big(hp);
 }
 
+Eterm
+erts_uint64_array_to_big(Uint **hpp, int neg, int len, Uint64 *array)
+{
+    Uint *headerp;
+    int i, pot_digits, digits;
+
+    headerp = *hpp;
+
+    pot_digits = digits = 0;
+    for (i = 0; i < len; i++) {
+#if defined(ARCH_32) || HALFWORD_HEAP
+	Uint low_val = array[i] & ((Uint) 0xffffffff);
+	Uint high_val = (array[i] >> 32) & ((Uint) 0xffffffff);
+	BIG_DIGIT(headerp, pot_digits) = low_val;
+	pot_digits++;
+	if (low_val)
+	    digits = pot_digits;
+	BIG_DIGIT(headerp, pot_digits) = high_val;
+	pot_digits++;
+	if (high_val)
+	    digits = pot_digits;
+#else
+	Uint val = array[i];
+	BIG_DIGIT(headerp, pot_digits) = val;
+	pot_digits++;
+	if (val)
+	    digits = pot_digits;
+#endif
+    }	
+
+    if (neg)
+	*headerp = make_neg_bignum_header(digits);
+    else
+	*headerp = make_pos_bignum_header(digits);
+
+    *hpp = headerp + 1 + digits;
+
+    return make_big(headerp);
+}
+
 /*
 ** Convert a bignum to a double float
 */
diff --git a/erts/emulator/beam/big.h b/erts/emulator/beam/big.h
index da31876d75..4e4611de16 100644
--- a/erts/emulator/beam/big.h
+++ b/erts/emulator/beam/big.h
@@ -104,6 +104,9 @@ typedef Uint  dsize_t;	 /* Vector size type */
    : ERTS_UINT64_BIG_HEAP_SIZE__((X) >= 0 ? (X) : -(Uint64)(X)))
 #define ERTS_UINT64_HEAP_SIZE(X)				\
   (IS_USMALL(0, (X)) ? 0 : ERTS_UINT64_BIG_HEAP_SIZE__((X)))
+#define ERTS_MAX_SINT64_HEAP_SIZE (1 + 2)
+#define ERTS_MAX_UINT64_HEAP_SIZE (1 + 2)
+#define ERTS_UINT64_ARRAY_TO_BIG_MAX_HEAP_SZ(LEN) (2*(LEN)+1)
 
 #else
 
@@ -111,6 +114,9 @@ typedef Uint  dsize_t;	 /* Vector size type */
   (IS_SSMALL((X)) ? 0 : (1 + 1))
 #define ERTS_UINT64_HEAP_SIZE(X)				\
   (IS_USMALL(0, (X)) ? 0 : (1 + 1))
+#define ERTS_MAX_SINT64_HEAP_SIZE (1 + 1)
+#define ERTS_MAX_UINT64_HEAP_SIZE (1 + 1)
+#define ERTS_UINT64_ARRAY_TO_BIG_MAX_HEAP_SZ(LEN) ((LEN)+1)
 
 #endif
 
@@ -156,6 +162,7 @@ int term_to_Uint(Eterm, Uint*);
 int term_to_UWord(Eterm, UWord*);
 int term_to_Sint(Eterm, Sint*);
 #if HAVE_INT64
+Eterm erts_uint64_array_to_big(Uint **, int, int, Uint64 *);
 int term_to_Uint64(Eterm, Uint64*);
 int term_to_Sint64(Eterm, Sint64*);
 #endif
diff --git a/erts/emulator/beam/erl_alloc.types b/erts/emulator/beam/erl_alloc.types
index 61def65235..e2f8da38b9 100644
--- a/erts/emulator/beam/erl_alloc.types
+++ b/erts/emulator/beam/erl_alloc.types
@@ -269,6 +269,7 @@ type    BUSY_CALLER_TAB	SHORT_LIVED	SYSTEM		busy_caller_table
 type    BUSY_CALLER	SHORT_LIVED	SYSTEM		busy_caller
 type	PROC_SYS_TSK	SHORT_LIVED	PROCESSES	proc_sys_task
 type	PROC_SYS_TSK_QS	SHORT_LIVED	PROCESSES	proc_sys_task_queues
+type    NEW_TIME_OFFSET	SHORT_LIVED	SYSTEM		new_time_offset
 
 +if threads_no_smp
 # Need thread safe allocs, but std_alloc and fix_alloc are not;
@@ -364,6 +365,7 @@ type	AINFO_REQ	STANDARD_LOW	SYSTEM		alloc_info_request
 type	SCHED_WTIME_REQ	STANDARD_LOW	SYSTEM		sched_wall_time_request
 type	GC_INFO_REQ	STANDARD_LOW	SYSTEM		gc_info_request
 type	PORT_DATA_HEAP	STANDARD_LOW	SYSTEM		port_data_heap
+type	BIF_TIMER_DATA	LONG_LIVED_LOW	SYSTEM		bif_timer_data
 
 +else # "fullword"
 
@@ -384,6 +386,7 @@ type	AINFO_REQ	SHORT_LIVED	SYSTEM		alloc_info_request
 type	SCHED_WTIME_REQ	SHORT_LIVED	SYSTEM		sched_wall_time_request
 type	GC_INFO_REQ	SHORT_LIVED	SYSTEM		gc_info_request
 type	PORT_DATA_HEAP	STANDARD	SYSTEM		port_data_heap
+type	BIF_TIMER_DATA	LONG_LIVED	SYSTEM		bif_timer_data
 
 +endif
 
diff --git a/erts/emulator/beam/erl_bif_binary.c b/erts/emulator/beam/erl_bif_binary.c
index bd0d7c71cc..934904d58e 100644
--- a/erts/emulator/beam/erl_bif_binary.c
+++ b/erts/emulator/beam/erl_bif_binary.c
@@ -38,6 +38,7 @@
 #include "big.h"
 #include "erl_binary.h"
 #include "erl_bits.h"
+#include "erl_bif_unique.h"
 
 
 /*
diff --git a/erts/emulator/beam/erl_bif_ddll.c b/erts/emulator/beam/erl_bif_ddll.c
index 56cd2ba04f..fc4f819f56 100644
--- a/erts/emulator/beam/erl_bif_ddll.c
+++ b/erts/emulator/beam/erl_bif_ddll.c
@@ -45,6 +45,7 @@
 #include "big.h"
 #include "dist.h"
 #include "erl_version.h"
+#include "erl_bif_unique.h"
 #include "dtrace-wrapper.h"
 
 #ifdef ERTS_SMP
diff --git a/erts/emulator/beam/erl_bif_info.c b/erts/emulator/beam/erl_bif_info.c
index 0774ab51af..2eeebab9a3 100644
--- a/erts/emulator/beam/erl_bif_info.c
+++ b/erts/emulator/beam/erl_bif_info.c
@@ -42,6 +42,7 @@
 #include "erl_cpu_topology.h"
 #include "erl_async.h"
 #include "erl_thr_progress.h"
+#include "erl_bif_unique.h"
 #define ERTS_PTAB_WANT_DEBUG_FUNCS__
 #include "erl_ptab.h"
 #ifdef HIPE
@@ -540,6 +541,7 @@ pi_locks(Eterm info)
     switch (info) {
     case am_status:
     case am_priority:
+    case am_trap_exit:
 	return ERTS_PROC_LOCK_STATUS;
     case am_links:
     case am_monitors:
@@ -592,7 +594,7 @@ static Eterm pi_args[] = {
     am_min_bin_vheap_size,
     am_current_location,
     am_current_stacktrace,
-};    
+};
 
 #define ERTS_PI_ARGS ((int) (sizeof(pi_args)/sizeof(Eterm)))
 
@@ -2102,6 +2104,46 @@ BIF_RETTYPE system_info_1(BIF_ALIST_1)
 	BIF_RET(am_opt);
 #endif
 	BIF_RET(res);
+    } else if (BIF_ARG_1 == am_time_offset) {
+	switch (erts_time_offset_state()) {
+	case ERTS_TIME_OFFSET_PRELIMINARY: {
+	    ERTS_DECL_AM(preliminary);
+	    BIF_RET(AM_preliminary);
+	}
+	case ERTS_TIME_OFFSET_FINAL: {
+	    ERTS_DECL_AM(final);
+	    BIF_RET(AM_final);
+	}
+	case ERTS_TIME_OFFSET_VOLATILE: {
+	    ERTS_DECL_AM(volatile);
+	    BIF_RET(AM_volatile);
+	}
+	default:
+	    ERTS_INTERNAL_ERROR("Invalid time offset state");
+	}
+    } else if (ERTS_IS_ATOM_STR("os_monotonic_time_source", BIF_ARG_1)) {
+	BIF_RET(erts_monotonic_time_source(BIF_P));
+    } else if (ERTS_IS_ATOM_STR("time_correction", BIF_ARG_1)) {
+	BIF_RET(erts_has_time_correction() ? am_true : am_false);
+    } else if (ERTS_IS_ATOM_STR("start_time", BIF_ARG_1)) {
+	BIF_RET(erts_get_monotonic_start_time(BIF_P));
+    } else if (ERTS_IS_ATOM_STR("time_warp_mode", BIF_ARG_1)) {
+	switch (erts_time_warp_mode()) {
+	case ERTS_NO_TIME_WARP_MODE: {
+	    ERTS_DECL_AM(no_time_warp);
+	    BIF_RET(AM_no_time_warp);
+	}
+	case ERTS_SINGLE_TIME_WARP_MODE: {
+	    ERTS_DECL_AM(single_time_warp);
+	    BIF_RET(AM_single_time_warp);
+	}
+	case ERTS_MULTI_TIME_WARP_MODE: {
+	    ERTS_DECL_AM(multi_time_warp);
+	    BIF_RET(AM_multi_time_warp);
+	}
+	default:
+	    ERTS_INTERNAL_ERROR("Invalid time warp mode");
+	}
     } else if (BIF_ARG_1 == am_allocated_areas) {
 	res = erts_allocated_areas(NULL, NULL, BIF_P);
 	BIF_RET(res);
@@ -2703,9 +2745,11 @@ BIF_RETTYPE system_info_1(BIF_ALIST_1)
         BIF_RET(make_small(erts_db_get_max_tabs()));
     }
     else if (ERTS_IS_ATOM_STR("tolerant_timeofday",BIF_ARG_1)) {
-	BIF_RET(erts_disable_tolerant_timeofday
-		? am_disabled
-		: am_enabled);
+	if (erts_has_time_correction()
+	    && erts_time_offset_state() == ERTS_TIME_OFFSET_FINAL) {
+	    BIF_RET(am_enabled);
+	}
+	BIF_RET(am_disabled);
     }
     else if (ERTS_IS_ATOM_STR("eager_check_io",BIF_ARG_1)) {
 	BIF_RET(erts_eager_check_io ? am_true : am_false);
@@ -3403,6 +3447,29 @@ BIF_RETTYPE erts_debug_get_internal_state_1(BIF_ALIST_1)
         else if (ERTS_IS_ATOM_STR("mmap", BIF_ARG_1)) {
             BIF_RET(erts_mmap_debug_info(BIF_P));
         }
+	else if (ERTS_IS_ATOM_STR("unique_monotonic_integer_state", BIF_ARG_1)) {
+	    BIF_RET(erts_debug_get_unique_monotonic_integer_state(BIF_P));
+	}
+	else if (ERTS_IS_ATOM_STR("min_unique_monotonic_integer", BIF_ARG_1)) {
+	    Sint64 value = erts_get_min_unique_monotonic_integer();
+	    if (IS_SSMALL(value))
+		BIF_RET(make_small(value));
+	    else {
+		Uint hsz = ERTS_SINT64_HEAP_SIZE(value);
+		Eterm *hp = HAlloc(BIF_P, hsz);
+		BIF_RET(erts_sint64_to_big(value, &hp));
+	    }
+	}
+	else if (ERTS_IS_ATOM_STR("min_unique_integer", BIF_ARG_1)) {
+	    Sint64 value = erts_get_min_unique_integer();
+	    if (IS_SSMALL(value))
+		BIF_RET(make_small(value));
+	    else {
+		Uint hsz = ERTS_SINT64_HEAP_SIZE(value);
+		Eterm *hp = HAlloc(BIF_P, hsz);
+		BIF_RET(erts_sint64_to_big(value, &hp));
+	    }
+	}
     }
     else if (is_tuple(BIF_ARG_1)) {
 	Eterm* tp = tuple_val(BIF_ARG_1);
@@ -3619,6 +3686,38 @@ BIF_RETTYPE erts_debug_get_internal_state_1(BIF_ALIST_1)
 
 	    break;
 	}
+	case 3: {
+	    if (ERTS_IS_ATOM_STR("check_time_config", tp[1])) {
+		int res, time_correction;
+		ErtsTimeWarpMode time_warp_mode;
+		if (tp[2] == am_true)
+		    time_correction = !0;
+		else if (tp[2] == am_false)
+		    time_correction = 0;
+		else
+		    break;
+		if (ERTS_IS_ATOM_STR("no_time_warp", tp[3]))
+		    time_warp_mode = ERTS_NO_TIME_WARP_MODE;
+		else if (ERTS_IS_ATOM_STR("single_time_warp", tp[3]))
+		    time_warp_mode = ERTS_SINGLE_TIME_WARP_MODE;
+		else if (ERTS_IS_ATOM_STR("multi_time_warp", tp[3]))
+		    time_warp_mode = ERTS_MULTI_TIME_WARP_MODE;
+		else
+		    break;
+		res = erts_check_time_adj_support(time_correction,
+						  time_warp_mode);
+		BIF_RET(res ? am_true : am_false);
+	    }
+	    else if (ERTS_IS_ATOM_STR("make_unique_integer", tp[1])) {
+	      Eterm res = erts_debug_make_unique_integer(BIF_P,
+							 tp[2],
+							 tp[3]);
+	      if (is_non_value(res))
+		  break;
+	      BIF_RET(res);
+	    }
+	    break;
+	}
 	default:
 	    break;
 	}
@@ -3626,6 +3725,24 @@ BIF_RETTYPE erts_debug_get_internal_state_1(BIF_ALIST_1)
     BIF_ERROR(BIF_P, BADARG);
 }
 
+BIF_RETTYPE erts_internal_is_system_process_1(BIF_ALIST_1)
+{
+    if (is_internal_pid(BIF_ARG_1)) {
+	Process *rp = erts_proc_lookup(BIF_ARG_1);
+	if (rp && (rp->static_flags & ERTS_STC_FLG_SYSTEM_PROC))
+	    BIF_RET(am_true);
+	BIF_RET(am_false);
+    }
+
+    if (is_external_pid(BIF_ARG_1)
+	&& external_pid_dist_entry(BIF_ARG_1) == erts_this_dist_entry) {
+	BIF_RET(am_false);
+    }
+
+    BIF_ERROR(BIF_P, BADARG);
+}
+
+
 static erts_smp_atomic_t hipe_test_reschedule_flag;
 
 
@@ -3927,6 +4044,10 @@ BIF_RETTYPE erts_debug_set_internal_state_2(BIF_ALIST_2)
 #endif
             erl_exit(ERTS_DUMP_EXIT, "%T", BIF_ARG_2);
         }
+	else if (ERTS_IS_ATOM_STR("unique_monotonic_integer_state", BIF_ARG_1)) {
+	    int res = erts_debug_set_unique_monotonic_integer_state(BIF_ARG_2);
+	    BIF_RET(res ? am_true : am_false);
+	}
     }
 
     BIF_ERROR(BIF_P, BADARG);
diff --git a/erts/emulator/beam/erl_bif_timer.c b/erts/emulator/beam/erl_bif_timer.c
index 03ac97283c..0bd8d20c34 100644
--- a/erts/emulator/beam/erl_bif_timer.c
+++ b/erts/emulator/beam/erl_bif_timer.c
@@ -27,6 +27,7 @@
 #include "error.h"
 #include "big.h"
 #include "erl_thr_progress.h"
+#include "erl_bif_unique.h"
 
 /****************************************************************************
 ** BIF Timer support
@@ -480,7 +481,7 @@ setup_bif_timer(Uint32 xflags,
 
     tab_insert(btm);
     ASSERT(btm == tab_find(ref));
-    btm->tm.active = 0; /* MUST be initalized */
+    erts_init_timer(&btm->tm);
     erts_set_timer(&btm->tm,
 		  (ErlTimeoutProc) bif_timer_timeout,
 		  (ErlCancelProc) bif_timer_cleanup,
@@ -489,8 +490,9 @@ setup_bif_timer(Uint32 xflags,
     return ref;
 }
 
+BIF_RETTYPE old_send_after_3(BIF_ALIST_3);
 /* send_after(Time, Pid, Message) -> Ref */
-BIF_RETTYPE send_after_3(BIF_ALIST_3)
+BIF_RETTYPE old_send_after_3(BIF_ALIST_3)
 {
     Eterm res;
 
@@ -510,8 +512,9 @@ BIF_RETTYPE send_after_3(BIF_ALIST_3)
     }
 }
 
+BIF_RETTYPE old_start_timer_3(BIF_ALIST_3);
 /* start_timer(Time, Pid, Message) -> Ref */
-BIF_RETTYPE start_timer_3(BIF_ALIST_3)
+BIF_RETTYPE old_start_timer_3(BIF_ALIST_3)
 {
     Eterm res;
 
@@ -531,8 +534,9 @@ BIF_RETTYPE start_timer_3(BIF_ALIST_3)
     }
 }
 
+BIF_RETTYPE old_cancel_timer_1(BIF_ALIST_1);
 /* cancel_timer(Ref) -> false | RemainingTime */
-BIF_RETTYPE cancel_timer_1(BIF_ALIST_1)
+BIF_RETTYPE old_cancel_timer_1(BIF_ALIST_1)
 {
     Eterm res;
     ErtsBifTimer *btm;
@@ -569,8 +573,9 @@ BIF_RETTYPE cancel_timer_1(BIF_ALIST_1)
     BIF_RET(res);
 }
 
+BIF_RETTYPE old_read_timer_1(BIF_ALIST_1);
 /* read_timer(Ref) -> false | RemainingTime */
-BIF_RETTYPE read_timer_1(BIF_ALIST_1)
+BIF_RETTYPE old_read_timer_1(BIF_ALIST_1)
 {
     Eterm res;
     ErtsBifTimer *btm;
@@ -652,7 +657,7 @@ erts_cancel_bif_timers(Process *p, ErtsProcLocks plocks)
     erts_smp_btm_rwunlock();
 }
 
-void erts_bif_timer_init(void)
+static void erts_old_bif_timer_init(void)
 {
     int i;
     no_bif_timers = 0;
@@ -703,3 +708,146 @@ erts_bif_timer_foreach(void (*func)(Eterm, Eterm, ErlHeapFragment *, void *),
 	}
     }
 }
+
+typedef struct {
+    Uint ref_heap[REF_THING_SIZE];
+    Eterm pid[1];
+} ErtsBifTimerServers;
+
+static ErtsBifTimerServers *bif_timer_servers;
+
+void erts_bif_timer_init(void)
+{
+    erts_old_bif_timer_init();
+}
+
+void
+erts_bif_timer_start_servers(Eterm parent)
+{
+    Process *parent_proc;
+    Eterm *hp, btr_ref, arg_list_end;
+    ErlSpawnOpts so;
+    int i;
+
+    bif_timer_servers = erts_alloc(ERTS_ALC_T_BIF_TIMER_DATA,
+				   (sizeof(ErtsBifTimerServers)
+				    + (sizeof(Eterm)*(erts_no_schedulers-1))));
+
+    so.flags = SPO_USE_ARGS|SPO_SYSTEM_PROC|SPO_PREFER_SCHED|SPO_OFF_HEAP_MSGS;
+    so.min_heap_size  = H_MIN_SIZE;
+    so.min_vheap_size = BIN_VH_MIN_SIZE;
+    so.priority       = PRIORITY_MAX;
+    so.max_gen_gcs    = (Uint16) erts_smp_atomic32_read_nob(&erts_max_gen_gcs);
+
+    /*
+     * Parent is "init" and schedulers have not yet been started, so it
+     * *should* be alive and well...
+     */
+    ASSERT(is_internal_pid(parent));
+    parent_proc = (Process *) erts_ptab_pix2intptr_ddrb(&erts_proc,
+							internal_pid_index(parent));
+    ASSERT(parent_proc);
+    ASSERT(parent_proc->common.id == parent);
+    ASSERT(!ERTS_PROC_IS_EXITING(parent_proc));
+
+    erts_smp_proc_lock(parent_proc, ERTS_PROC_LOCK_MAIN);
+
+    hp = HAlloc(parent_proc, 2*erts_no_schedulers + 2 + REF_THING_SIZE);
+
+    btr_ref = erts_make_ref_in_buffer(hp);
+    hp += REF_THING_SIZE;
+
+    arg_list_end = CONS(hp, btr_ref, NIL);
+    hp += 2;
+
+    for (i = 0; i < erts_no_schedulers; i++) {
+	int sched = i+1;
+	Eterm arg_list = CONS(hp, make_small(i+1), arg_list_end);
+	hp += 2;
+
+	so.scheduler = sched; /* Preferred scheduler */
+
+	bif_timer_servers->pid[i] = erl_create_process(parent_proc,
+						       am_erts_internal,
+						       am_bif_timer_server,
+						       arg_list,
+						       &so);
+    }
+
+    erts_smp_proc_unlock(parent_proc, ERTS_PROC_LOCK_MAIN);
+
+    hp = internal_ref_val(btr_ref);
+    for (i = 0; i < REF_THING_SIZE; i++)
+	bif_timer_servers->ref_heap[i] = hp[i];
+}
+
+BIF_RETTYPE
+erts_internal_get_bif_timer_servers_0(BIF_ALIST_0)
+{
+    int i;
+    Eterm *hp, res = NIL;
+
+    hp = HAlloc(BIF_P, erts_no_schedulers*2);
+    for (i = erts_no_schedulers-1; i >= 0; i--) {
+	res = CONS(hp, bif_timer_servers->pid[i], res);
+	hp += 2;
+    }
+    BIF_RET(res);
+}
+
+BIF_RETTYPE
+erts_internal_access_bif_timer_1(BIF_ALIST_1)
+{
+    int ix;
+    Uint32 *rdp;
+    Eterm ref, pid, *hp, res;
+
+    if (is_not_internal_ref(BIF_ARG_1)) {
+	if (is_not_ref(BIF_ARG_1))
+	    BIF_ERROR(BIF_P, BADARG);
+	BIF_RET(am_undefined);
+    }
+
+    rdp = internal_ref_numbers(BIF_ARG_1);
+    ix = (int) erts_get_ref_numbers_thr_id(rdp);
+    if (ix < 1 || erts_no_schedulers < ix)
+	BIF_RET(am_undefined);
+
+    pid = bif_timer_servers->pid[ix-1];
+    ASSERT(is_internal_pid(pid));
+
+    hp = HAlloc(BIF_P, 3 /* 2-tuple */ + REF_THING_SIZE);
+    for (ix = 0; ix < REF_THING_SIZE; ix++)
+	hp[ix] = bif_timer_servers->ref_heap[ix];
+    ref = make_internal_ref(&hp[0]);
+    hp += REF_THING_SIZE;
+
+    res = TUPLE2(hp, ref, pid);
+    BIF_RET(res);
+}
+
+BIF_RETTYPE
+erts_internal_create_bif_timer_0(BIF_ALIST_0)
+{
+    ErtsSchedulerData *esdp = ERTS_PROC_GET_SCHDATA(BIF_P);
+    Eterm *hp, btr_ref, t_ref, pid, res;
+    int ix;
+
+    hp = HAlloc(BIF_P, 4 /* 3-tuple */ + 2*REF_THING_SIZE);
+    for (ix = 0; ix < REF_THING_SIZE; ix++)
+	hp[ix] = bif_timer_servers->ref_heap[ix];
+    btr_ref = make_internal_ref(&hp[0]);
+    hp += REF_THING_SIZE;
+
+    t_ref = erts_sched_make_ref_in_buffer(esdp, hp);
+    hp += REF_THING_SIZE;
+
+    ASSERT(erts_get_ref_numbers_thr_id(internal_ref_numbers(t_ref))
+	   == (Uint32) esdp->no);
+
+    pid = bif_timer_servers->pid[((int) esdp->no) - 1];
+    
+    res = TUPLE3(hp, btr_ref, pid, t_ref);
+
+    BIF_RET(res);
+}
diff --git a/erts/emulator/beam/erl_bif_timer.h b/erts/emulator/beam/erl_bif_timer.h
index 1197c176f5..c2f5dfd3c3 100644
--- a/erts/emulator/beam/erl_bif_timer.h
+++ b/erts/emulator/beam/erl_bif_timer.h
@@ -33,4 +33,5 @@ void erts_cancel_bif_timers(Process *p, ErtsProcLocks plocks);
 void erts_bif_timer_init(void);
 void erts_bif_timer_foreach(void (*func)(Eterm,Eterm,ErlHeapFragment *,void *),
 			    void *arg);
+void erts_bif_timer_start_servers(Eterm);
 #endif
diff --git a/erts/emulator/beam/erl_bif_trace.c b/erts/emulator/beam/erl_bif_trace.c
index f5e582b1c5..ac57205c47 100644
--- a/erts/emulator/beam/erl_bif_trace.c
+++ b/erts/emulator/beam/erl_bif_trace.c
@@ -38,6 +38,7 @@
 #include "beam_bp.h"
 #include "erl_binary.h"
 #include "erl_thr_progress.h"
+#include "erl_bif_unique.h"
 
 #define DECL_AM(S) Eterm AM_ ## S = am_atom_put(#S, sizeof(#S) - 1)
 
diff --git a/erts/emulator/beam/erl_bif_unique.c b/erts/emulator/beam/erl_bif_unique.c
new file mode 100644
index 0000000000..57b0bab72f
--- /dev/null
+++ b/erts/emulator/beam/erl_bif_unique.c
@@ -0,0 +1,556 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2014. All Rights Reserved.
+ *
+ * The contents of this file are subject to the Erlang Public License,
+ * Version 1.1, (the "License"); you may not use this file except in
+ * compliance with the License. You should have received a copy of the
+ * Erlang Public License along with this software. If not, it can be
+ * retrieved online at http://www.erlang.org/.
+ *
+ * Software distributed under the License is distributed on an "AS IS"
+ * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+ * the License for the specific language governing rights and limitations
+ * under the License.
+ *
+ * %CopyrightEnd%
+ */
+
+#ifdef HAVE_CONFIG_H
+#  include "config.h"
+#endif
+
+#include "sys.h"
+#include "erl_vm.h"
+#include "erl_alloc.h"
+#include "export.h"
+#include "bif.h"
+#include "erl_bif_unique.h"
+
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *\
+ * Reference                                                         *
+\*                                                                   */
+
+static union {
+    erts_atomic64_t count;
+    char align__[ERTS_CACHE_LINE_SIZE];
+} global_reference erts_align_attribute(ERTS_CACHE_LINE_SIZE);
+
+
+/*
+ * ref[0] indicate thread creating reference as follows:
+ *
+ * - ref[0] == 0 => Non-scheduler thread;
+ * - else; ref[0] <= erts_no_schedulers =>
+ *      ordinary scheduler with id == ref[0];
+ * - else; ref[0] <= erts_no_schedulers
+ *                   + erts_no_dirty_cpu_schedulers =>
+ *      dirty cpu scheduler with id == 'ref[0] - erts_no_schedulers';
+ * - else =>
+ *      dirty io scheduler with id == 'ref[0]
+ *                                     - erts_no_schedulers
+ *                                     - erts_no_dirty_cpu_schedulers'
+ */
+
+#ifdef DEBUG
+static Uint32 max_thr_id;
+#endif
+
+static void
+init_reference(void)
+{
+#ifdef DEBUG
+    max_thr_id = (Uint32) erts_no_schedulers;
+#ifdef ERTS_DIRTY_SCHEDULERS
+    max_thr_id += (Uint32) erts_no_dirty_cpu_schedulers;
+    max_thr_id += (Uint32) erts_no_dirty_io_schedulers;
+#endif
+#endif
+    erts_atomic64_init_nob(&global_reference.count, 0);
+}
+
+static ERTS_INLINE void
+global_make_ref_in_array(Uint32 thr_id, Uint32 ref[ERTS_MAX_REF_NUMBERS])
+{
+    Uint64 value;
+
+    value = (Uint64) erts_atomic64_inc_read_mb(&global_reference.count);
+    
+    erts_set_ref_numbers(ref, thr_id, value);
+}
+
+static ERTS_INLINE void
+make_ref_in_array(Uint32 ref[ERTS_MAX_REF_NUMBERS])
+{
+    ErtsSchedulerData *esdp = erts_get_scheduler_data();
+    if (esdp)
+	erts_sched_make_ref_in_array(esdp, ref);
+    else
+	global_make_ref_in_array(0, ref);
+}
+
+void
+erts_make_ref_in_array(Uint32 ref[ERTS_MAX_REF_NUMBERS])
+{
+    make_ref_in_array(ref);
+}
+
+Eterm erts_make_ref_in_buffer(Eterm buffer[REF_THING_SIZE])
+{
+    Eterm* hp = buffer;
+    Uint32 ref[ERTS_MAX_REF_NUMBERS];
+
+    make_ref_in_array(ref);
+    write_ref_thing(hp, ref[0], ref[1], ref[2]);
+    return make_internal_ref(hp);
+}
+
+Eterm erts_make_ref(Process *c_p)
+{
+    Eterm* hp;
+    Uint32 ref[ERTS_MAX_REF_NUMBERS];
+
+    ERTS_SMP_LC_ASSERT(ERTS_PROC_LOCK_MAIN & erts_proc_lc_my_proc_locks(c_p));
+
+    hp = HAlloc(c_p, REF_THING_SIZE);
+
+    make_ref_in_array(ref);
+    write_ref_thing(hp, ref[0], ref[1], ref[2]);
+
+    return make_internal_ref(hp);
+}
+
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *\
+ * Unique Integer                                                    *
+\*                                                                   */
+
+static struct {
+    union {
+	struct {
+	    int left_shift;
+	    int right_shift;
+	    Uint64 mask;
+	    Uint64 val0_max;
+	} o;
+	char align__[ERTS_CACHE_LINE_SIZE];
+    } r;
+    union {
+	erts_atomic64_t val1;
+	char align__[ERTS_CACHE_LINE_SIZE];
+    } w;
+} unique_data erts_align_attribute(ERTS_CACHE_LINE_SIZE);
+
+static void
+init_unique_integer(void)
+{
+    int bits;
+    unique_data.r.o.val0_max = (Uint64) erts_no_schedulers;
+#ifdef ERTS_DIRTY_SCHEDULERS
+    unique_data.r.o.val0_max += (Uint64) erts_no_dirty_cpu_schedulers;
+    unique_data.r.o.val0_max += (Uint64) erts_no_dirty_io_schedulers;
+#endif
+    bits = erts_fit_in_bits_int64(unique_data.r.o.val0_max);
+    unique_data.r.o.left_shift = bits;
+    unique_data.r.o.right_shift = 64 - bits;
+    unique_data.r.o.mask = (((Uint64) 1) << bits) - 1;
+    erts_atomic64_init_nob(&unique_data.w.val1, -1);
+}
+
+#define ERTS_MAX_UNIQUE_INT_HEAP_SIZE ERTS_UINT64_ARRAY_TO_BIG_MAX_HEAP_SZ(2)
+
+static ERTS_INLINE Eterm
+bld_unique_integer_term(Eterm **hpp, Uint *szp,
+			Uint64 val0, Uint64 val1,
+			int positive)
+{
+    Uint hsz;
+    Uint64 unique_val[2];
+
+    unique_val[0] = ((Uint64) val0);
+    unique_val[0] |= ((Uint64) val1) << unique_data.r.o.left_shift;
+    unique_val[1] = ((Uint64) val1) >> unique_data.r.o.right_shift;
+    unique_val[1] &= unique_data.r.o.mask;
+
+    if (positive) {
+	unique_val[0]++;
+	if (unique_val[0] == 0)
+	    unique_val[1]++;
+    }
+    else {
+	ASSERT(MIN_SMALL < 0);
+	if (unique_val[1] == 0
+	    && unique_val[0] < ((Uint64) -1*((Sint64) MIN_SMALL))) {
+	    Sint64 s_unique_val = (Sint64) unique_val[0];
+	    s_unique_val += MIN_SMALL;
+	    ASSERT(MIN_SMALL <= s_unique_val && s_unique_val < 0);
+	    if (szp)
+		*szp = 0;
+	    if (!hpp)
+		return THE_NON_VALUE;
+	    return make_small((Sint) s_unique_val);
+	}
+	if (unique_val[0] < ((Uint64) -1*((Sint64) MIN_SMALL))) {
+	    ASSERT(unique_val[1] != 0);
+	    unique_val[1] -= 1;
+	}
+	unique_val[0] += MIN_SMALL;
+    }
+
+    if (!unique_val[1]) {
+	if (unique_val[0] <= MAX_SMALL) {
+	    if (szp)
+		*szp = 0;
+	    if (!hpp)
+		return THE_NON_VALUE;
+	    return make_small((Uint) unique_val[0]);
+	}
+
+	if (szp)
+	    *szp = ERTS_UINT64_HEAP_SIZE(unique_val[0]);
+	if (!hpp)
+	    return THE_NON_VALUE;
+	return erts_uint64_to_big(unique_val[0], hpp);
+    }
+    else {
+	Eterm tmp, *tmp_hp, res;
+	DeclareTmpHeapNoproc(local_heap, 2*ERTS_MAX_UNIQUE_INT_HEAP_SIZE);
+
+	UseTmpHeapNoproc(2*ERTS_MAX_UNIQUE_INT_HEAP_SIZE);
+
+	tmp_hp = local_heap;
+
+	tmp = erts_uint64_array_to_big(&tmp_hp, 0, 2, unique_val);
+	ASSERT(is_big(tmp));
+
+	hsz = big_arity(tmp) + 1;
+
+	ASSERT(hsz <= ERTS_MAX_UNIQUE_INT_HEAP_SIZE);
+
+	if (szp)
+	    *szp = hsz;
+
+	if (!hpp)
+	    res = THE_NON_VALUE;
+	else {
+	    int hix;
+	    Eterm *hp = *hpp;
+	    tmp_hp = big_val(tmp);
+	    for (hix = 0; hix < hsz; hix++)
+		hp[hix] = tmp_hp[hix];
+
+	    *hpp = hp + hsz;
+	    res = make_big(hp);
+	}
+
+	UnUseTmpHeapNoproc(2*ERTS_MAX_UNIQUE_INT_HEAP_SIZE);
+
+	return res;
+    }
+}
+
+static ERTS_INLINE Eterm unique_integer_bif(Process *c_p, int positive)
+{
+    ErtsSchedulerData *esdp;
+    Uint64 thr_id, unique;
+    Uint hsz;
+    Eterm *hp;
+
+    esdp = ERTS_PROC_GET_SCHDATA(c_p);
+    thr_id = (Uint64) esdp->thr_id;
+    unique = esdp->unique++;
+    bld_unique_integer_term(NULL, &hsz, thr_id, unique, positive);
+    hp = hsz ? HAlloc(c_p, hsz) : NULL;
+    return bld_unique_integer_term(&hp, NULL, thr_id, unique, positive);
+}
+
+Uint
+erts_raw_unique_integer_heap_size(Uint64 val[ERTS_UNIQUE_INT_RAW_VALUES])
+{
+    Uint sz;
+    bld_unique_integer_term(NULL, &sz, val[0], val[1], 0);
+    return sz;
+}
+
+Eterm
+erts_raw_make_unique_integer(Eterm **hpp, Uint64 val[ERTS_UNIQUE_INT_RAW_VALUES])
+{
+    return bld_unique_integer_term(hpp, NULL, val[0], val[1], 0);
+}
+
+void
+erts_raw_get_unique_integer(Uint64 val[ERTS_UNIQUE_INT_RAW_VALUES])
+{
+    ErtsSchedulerData *esdp = erts_get_scheduler_data();
+    if (esdp) {
+	val[0] = (Uint64) esdp->thr_id;
+	val[1] = esdp->unique++;
+    }
+    else {
+	val[0] = (Uint64) 0;
+	val[1] = (Uint64) erts_atomic64_inc_read_nob(&unique_data.w.val1);
+    }
+}
+
+
+Sint64
+erts_get_min_unique_integer(void)
+{
+    return (Sint64) MIN_SMALL;
+}
+
+/* --- Debug --- */
+
+Eterm
+erts_debug_make_unique_integer(Process *c_p, Eterm etval0, Eterm etval1)
+{
+    Uint64 val0, val1;
+    Uint hsz;
+    Eterm res, *hp, *end_hp;
+
+    if (!term_to_Uint64(etval0, &val0))
+	return THE_NON_VALUE;
+
+    if (!term_to_Uint64(etval1, &val1))
+	return THE_NON_VALUE;
+
+    bld_unique_integer_term(NULL, &hsz, val0, val1, 0);
+
+    hp = HAlloc(c_p, hsz);
+    end_hp = hp + hsz;
+
+    res = bld_unique_integer_term(&hp, NULL, val0, val1, 0);
+    if (hp != end_hp)
+	ERTS_INTERNAL_ERROR("Heap allocation error");
+
+    return res;
+}
+
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *\
+ * Strict Monotonic Counter                                          *
+\*                                                                   */
+
+static struct {
+    union {
+	erts_atomic64_t value;
+	char align__[ERTS_CACHE_LINE_SIZE];
+    } w;
+} raw_unique_monotonic_integer erts_align_attribute(ERTS_CACHE_LINE_SIZE);
+
+#if defined(ARCH_32) || HALFWORD_HEAP
+#  define ERTS_UNIQUE_MONOTONIC_OFFSET ERTS_SINT64_MIN
+#else
+#  define ERTS_UNIQUE_MONOTONIC_OFFSET MIN_SMALL
+#endif
+
+static void
+init_unique_monotonic_integer(void)
+{
+    erts_atomic64_init_nob(&raw_unique_monotonic_integer.w.value,
+			   (erts_aint64_t) -1);
+}
+
+static ERTS_INLINE Uint64
+get_raw_unique_monotonic_integer(void)
+{
+    return (Uint64) erts_atomic64_inc_read_mb(&raw_unique_monotonic_integer.w.value);
+}
+
+static ERTS_INLINE Uint
+get_unique_monotonic_integer_heap_size(Uint64 raw, int positive)
+{
+    if (positive) {
+	Uint64 value = raw+1;
+	return ERTS_UINT64_HEAP_SIZE(value);
+    }
+    else {
+	Sint64 value = ((Sint64) raw) + ERTS_UNIQUE_MONOTONIC_OFFSET;
+	if (IS_SSMALL(value))
+	    return 0;
+#if defined(ARCH_32) || HALFWORD_HEAP
+	return ERTS_SINT64_HEAP_SIZE(value);
+#else
+	return ERTS_UINT64_HEAP_SIZE((Uint64) value);
+#endif
+    }
+}
+
+static ERTS_INLINE Eterm
+make_unique_monotonic_integer_value(Eterm *hp, Uint hsz, Uint64 raw, int positive)
+{
+    Eterm res;
+#ifdef DEBUG
+    Eterm *end_hp = hp + hsz;
+#endif
+
+    if (positive) {
+	Uint64 value = raw+1;
+	res = hsz ? erts_uint64_to_big(value, &hp) : make_small(value);
+    }
+    else {
+	Sint64 value = ((Sint64) raw) + ERTS_UNIQUE_MONOTONIC_OFFSET;
+	if (hsz == 0)
+	    res = make_small(value);
+	else {
+#if defined(ARCH_32) || HALFWORD_HEAP
+	    res = erts_sint64_to_big(value, &hp);
+#else 
+	    res = erts_uint64_to_big((Uint64) value, &hp);
+#endif
+	}
+    }
+
+    ASSERT(end_hp == hp);
+
+    return res;
+}
+
+static ERTS_INLINE Eterm
+unique_monotonic_integer_bif(Process *c_p, int positive)
+{
+    Uint64 raw;
+    Uint hsz;
+    Eterm *hp;
+
+    raw = get_raw_unique_monotonic_integer();
+    hsz = get_unique_monotonic_integer_heap_size(raw, positive);
+    hp = hsz ? HAlloc(c_p, hsz) : NULL;
+    return make_unique_monotonic_integer_value(hp, hsz, raw, positive);
+}
+
+Sint64
+erts_raw_get_unique_monotonic_integer(void)
+{
+    return get_raw_unique_monotonic_integer();
+}
+
+Uint
+erts_raw_unique_monotonic_integer_heap_size(Sint64 raw)
+{
+    return get_unique_monotonic_integer_heap_size(raw, 0);
+}
+
+Eterm
+erts_raw_make_unique_monotonic_integer_value(Eterm **hpp, Sint64 raw)
+{
+    Uint hsz = get_unique_monotonic_integer_heap_size(raw, 0);
+    Eterm res = make_unique_monotonic_integer_value(*hpp, hsz, raw, 0);
+    *hpp += hsz;
+    return res;
+}
+
+Sint64
+erts_get_min_unique_monotonic_integer(void)
+{
+    return ERTS_UNIQUE_MONOTONIC_OFFSET;
+}
+
+/* --- Debug --- */
+
+int
+erts_debug_set_unique_monotonic_integer_state(Eterm et_value)
+{
+    Sint64 value;
+
+    if (!term_to_Sint64(et_value, &value)) {
+	Uint64 uvalue;
+	if (!term_to_Uint64(et_value, &uvalue))
+	    return 0;
+	value = (Sint64) uvalue;
+    }
+
+    erts_atomic64_set_mb(&raw_unique_monotonic_integer.w.value,
+			 (erts_aint64_t) value);
+    return 1;
+}
+
+Eterm
+erts_debug_get_unique_monotonic_integer_state(Process *c_p)
+{
+    Uint64 value;
+    Eterm hsz, *hp;
+
+    value = (Uint64) erts_atomic64_read_mb(&raw_unique_monotonic_integer.w.value);
+
+    if (IS_USMALL(0, value))
+	return make_small(value);
+    hsz = ERTS_UINT64_HEAP_SIZE(value);
+    hp = HAlloc(c_p, hsz);
+    return erts_uint64_to_big(value, &hp);
+}
+
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *\
+ * Initilazation                                                     *
+\*                                                                   */
+
+void
+erts_bif_unique_init(void)
+{
+    init_reference();
+    init_unique_monotonic_integer();
+    init_unique_integer();
+}
+
+void
+erts_sched_bif_unique_init(ErtsSchedulerData *esdp)
+{
+    esdp->unique = (Uint64) 0;
+    esdp->ref = (Uint64) 0;
+}
+
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *\
+ * The BIFs                                                          *
+\*                                                                   */
+
+
+BIF_RETTYPE make_ref_0(BIF_ALIST_0)
+{
+    BIF_RETTYPE res;
+    Eterm* hp;
+
+    ERTS_SMP_LC_ASSERT(ERTS_PROC_LOCK_MAIN & erts_proc_lc_my_proc_locks(BIF_P));
+
+    hp = HAlloc(BIF_P, REF_THING_SIZE);
+
+    res = erts_sched_make_ref_in_buffer(ERTS_PROC_GET_SCHDATA(BIF_P), hp);
+
+    BIF_RET(res);
+}
+
+BIF_RETTYPE unique_integer_0(BIF_ALIST_0)
+{
+    BIF_RET(unique_integer_bif(BIF_P, 0));
+}
+
+BIF_RETTYPE unique_integer_1(BIF_ALIST_1)
+{
+    Eterm modlist = BIF_ARG_1;
+    int monotonic = 0;
+    int positive = 0;
+    BIF_RETTYPE res;
+
+    while (is_list(modlist)) {
+	Eterm *consp = list_val(modlist);
+	switch (CAR(consp)) {
+	case am_monotonic:
+	    monotonic = 1;
+	    break;
+	case am_positive:
+	    positive = 1;
+	    break;
+	default:
+	    BIF_ERROR(BIF_P, BADARG);
+	}
+	modlist = CDR(consp);
+    }
+
+    if (is_not_nil(modlist))
+	BIF_ERROR(BIF_P, BADARG);
+
+    if (monotonic)
+	res = unique_monotonic_integer_bif(BIF_P, positive);
+    else
+	res = unique_integer_bif(BIF_P, positive);
+
+    BIF_RET(res);
+}
diff --git a/erts/emulator/beam/erl_bif_unique.h b/erts/emulator/beam/erl_bif_unique.h
new file mode 100644
index 0000000000..cd001172a1
--- /dev/null
+++ b/erts/emulator/beam/erl_bif_unique.h
@@ -0,0 +1,131 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 2014. All Rights Reserved.
+ *
+ * The contents of this file are subject to the Erlang Public License,
+ * Version 1.1, (the "License"); you may not use this file except in
+ * compliance with the License. You should have received a copy of the
+ * Erlang Public License along with this software. If not, it can be
+ * retrieved online at http://www.erlang.org/.
+ *
+ * Software distributed under the License is distributed on an "AS IS"
+ * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+ * the License for the specific language governing rights and limitations
+ * under the License.
+ *
+ * %CopyrightEnd%
+ */
+
+#ifndef ERTS_BIF_UNIQUE_H__
+#define ERTS_BIF_UNIQUE_H__
+
+#include "erl_process.h"
+#include "big.h"
+
+void erts_bif_unique_init(void);
+void erts_sched_bif_unique_init(ErtsSchedulerData *esdp);
+
+/* reference */
+Eterm erts_make_ref(Process *);
+Eterm erts_make_ref_in_buffer(Eterm buffer[REF_THING_SIZE]);
+void erts_make_ref_in_array(Uint32 ref[ERTS_MAX_REF_NUMBERS]);
+
+/* strict monotonic counter */
+
+#define ERTS_MAX_UNIQUE_MONOTONIC_INTEGER_HEAP_SIZE ERTS_MAX_UINT64_HEAP_SIZE
+
+/*
+ * Note that a raw value is an intermediate value that 
+ * not necessarily correspond to the end result.
+ */
+Sint64 erts_raw_get_unique_monotonic_integer(void);
+Uint erts_raw_unique_monotonic_integer_heap_size(Sint64 raw);
+Eterm erts_raw_make_unique_monotonic_integer_value(Eterm **hpp, Sint64 raw);
+
+Sint64 erts_get_min_unique_monotonic_integer(void);
+
+int erts_debug_set_unique_monotonic_integer_state(Eterm et_value);
+Eterm erts_debug_get_unique_monotonic_integer_state(Process *c_p);
+
+/* unique integer */
+#define ERTS_UNIQUE_INT_RAW_VALUES 2
+#define ERTS_MAX_UNIQUE_INT_HEAP_SIZE ERTS_UINT64_ARRAY_TO_BIG_MAX_HEAP_SZ(2)
+
+Uint erts_raw_unique_integer_heap_size(Uint64 val[ERTS_UNIQUE_INT_RAW_VALUES]);
+Eterm erts_raw_make_unique_integer(Eterm **hpp, Uint64 val[ERTS_UNIQUE_INT_RAW_VALUES]);
+void erts_raw_get_unique_integer(Uint64 val[ERTS_UNIQUE_INT_RAW_VALUES]);
+Sint64 erts_get_min_unique_integer(void);
+
+Eterm erts_debug_make_unique_integer(Process *c_p,
+				     Eterm etval0,
+				     Eterm etval1);
+
+
+ERTS_GLB_INLINE void erts_set_ref_numbers(Uint32 ref[ERTS_MAX_REF_NUMBERS],
+					  Uint32 thr_id, Uint64 value);
+ERTS_GLB_INLINE Uint32 erts_get_ref_numbers_thr_id(Uint32 ref[ERTS_MAX_REF_NUMBERS]);
+ERTS_GLB_INLINE Uint64 erts_get_ref_numbers_value(Uint32 ref[ERTS_MAX_REF_NUMBERS]);
+ERTS_GLB_INLINE void erts_sched_make_ref_in_array(ErtsSchedulerData *esdp,
+						  Uint32 ref[ERTS_MAX_REF_NUMBERS]);
+ERTS_GLB_INLINE Eterm erts_sched_make_ref_in_buffer(ErtsSchedulerData *esdp,
+						    Eterm buffer[REF_THING_SIZE]);
+
+#if ERTS_GLB_INLINE_INCL_FUNC_DEF
+
+ERTS_GLB_INLINE void
+erts_set_ref_numbers(Uint32 ref[ERTS_MAX_REF_NUMBERS], Uint32 thr_id, Uint64 value)
+{
+    /*
+     * We cannot use thread id in the first 18-bit word since
+     * the hash/phash/phash2 BIFs only hash on this word. If
+     * we did, we would get really poor hash values. Instead
+     * we have to shuffle the bits a bit.
+     */
+    ASSERT(thr_id == (thr_id & ((Uint32) 0x3ffff)));
+    ref[0] = (Uint32) (value & ((Uint64) 0x3ffff));
+    ref[1] = (((Uint32) (value & ((Uint64) 0xfffc0000)))
+	      | (thr_id & ((Uint32) 0x3ffff)));
+    ref[2] = (Uint32) ((value >> 32) & ((Uint64) 0xffffffff));
+}
+
+ERTS_GLB_INLINE Uint32
+erts_get_ref_numbers_thr_id(Uint32 ref[ERTS_MAX_REF_NUMBERS])
+{
+    return ref[1] & ((Uint32) 0x3ffff);
+}
+
+ERTS_GLB_INLINE Uint64
+erts_get_ref_numbers_value(Uint32 ref[ERTS_MAX_REF_NUMBERS])
+{
+    return (((((Uint64) ref[2]) & ((Uint64) 0xffffffff)) << 32)
+	    | (((Uint64) ref[1]) & ((Uint64) 0xfffc0000))
+	    | (((Uint64) ref[0]) & ((Uint64) 0x3ffff)));
+}
+
+ERTS_GLB_INLINE void
+erts_sched_make_ref_in_array(ErtsSchedulerData *esdp,
+			     Uint32 ref[ERTS_MAX_REF_NUMBERS])
+{
+    Uint64 value;
+
+    ASSERT(esdp);
+    value = esdp->ref++;
+    erts_set_ref_numbers(ref, (Uint32) esdp->thr_id, value);
+}
+
+ERTS_GLB_INLINE Eterm
+erts_sched_make_ref_in_buffer(ErtsSchedulerData *esdp,
+			      Eterm buffer[REF_THING_SIZE])
+{
+    Eterm* hp = buffer;
+    Uint32 ref[ERTS_MAX_REF_NUMBERS];
+
+    erts_sched_make_ref_in_array(esdp, ref);
+    write_ref_thing(hp, ref[0], ref[1], ref[2]);
+    return make_internal_ref(hp);
+}
+
+#endif /* ERTS_GLB_INLINE_INCL_FUNC_DEF */
+
+#endif /*  ERTS_BIF_UNIQUE_H__ */
diff --git a/erts/emulator/beam/erl_gc.c b/erts/emulator/beam/erl_gc.c
index d1a7ee113b..4a116c0740 100644
--- a/erts/emulator/beam/erl_gc.c
+++ b/erts/emulator/beam/erl_gc.c
@@ -39,6 +39,7 @@
 #include "hipe_mode_switch.h"
 #endif
 #include "dtrace-wrapper.h"
+#include "erl_bif_unique.h"
 
 #define ERTS_INACT_WR_PB_LEAVE_MUCH_LIMIT 1
 #define ERTS_INACT_WR_PB_LEAVE_MUCH_PERCENTAGE 20
@@ -96,10 +97,10 @@ typedef struct {
 
 static Uint setup_rootset(Process*, Eterm*, int, Rootset*);
 static void cleanup_rootset(Rootset *rootset);
-static Uint combined_message_size(Process* p);
+static Uint combined_message_size(Process* p, int off_heap_msgs);
 static void remove_message_buffers(Process* p);
-static int major_collection(Process* p, int need, Eterm* objv, int nobj, Uint *recl);
-static int minor_collection(Process* p, int need, Eterm* objv, int nobj, Uint *recl);
+static int major_collection(Process* p, int need, Eterm* objv, int nobj, Uint *recl, int off_heap_msgs);
+static int minor_collection(Process* p, int need, Eterm* objv, int nobj, Uint *recl, int off_heap_msgs);
 static void do_minor(Process *p, Uint new_sz, Eterm* objv, int nobj);
 static Eterm* sweep_rootset(Rootset *rootset, Eterm* htop, char* src, Uint src_size);
 static Eterm* sweep_one_area(Eterm* n_hp, Eterm* n_htop, char* src, Uint src_size);
@@ -402,7 +403,9 @@ erts_garbage_collect(Process* p, int need, Eterm* objv, int nobj)
 {
     Uint reclaimed_now = 0;
     int done = 0;
+    int off_heap_msgs;
     Uint ms1, s1, us1;
+    erts_aint32_t state;
     ErtsSchedulerData *esdp;
 #ifdef USE_VM_PROBES
     DTRACE_CHARBUF(pidbuf, DTRACE_TERM_BUF_SIZE);
@@ -419,7 +422,8 @@ erts_garbage_collect(Process* p, int need, Eterm* objv, int nobj)
         trace_gc(p, am_gc_start);
     }
 
-    erts_smp_atomic32_read_bor_nob(&p->state, ERTS_PSFLG_GC);
+    state = erts_smp_atomic32_read_bor_nob(&p->state, ERTS_PSFLG_GC);
+    off_heap_msgs = state & ERTS_PSFLG_OFF_HEAP_MSGS;
     if (erts_system_monitor_long_gc != 0) {
 	get_now(&ms1, &s1, &us1);
     }
@@ -445,11 +449,11 @@ erts_garbage_collect(Process* p, int need, Eterm* objv, int nobj)
     while (!done) {
 	if ((FLAGS(p) & F_NEED_FULLSWEEP) != 0) {
 	    DTRACE2(gc_major_start, pidbuf, need);
-	    done = major_collection(p, need, objv, nobj, &reclaimed_now);
+	    done = major_collection(p, need, objv, nobj, &reclaimed_now, off_heap_msgs);
 	    DTRACE2(gc_major_end, pidbuf, reclaimed_now);
 	} else {
 	    DTRACE2(gc_minor_start, pidbuf, need);
-	    done = minor_collection(p, need, objv, nobj, &reclaimed_now);
+	    done = minor_collection(p, need, objv, nobj, &reclaimed_now, off_heap_msgs);
 	    DTRACE2(gc_minor_end, pidbuf, reclaimed_now);
 	}
     }
@@ -832,7 +836,7 @@ erts_garbage_collect_literals(Process* p, Eterm* literals,
 }
 
 static int
-minor_collection(Process* p, int need, Eterm* objv, int nobj, Uint *recl)
+minor_collection(Process* p, int need, Eterm* objv, int nobj, Uint *recl, int off_heap_msgs)
 {
     Uint mature = HIGH_WATER(p) - HEAP_START(p);
 
@@ -871,20 +875,22 @@ minor_collection(Process* p, int need, Eterm* objv, int nobj, Uint *recl)
 	Uint size_after;
 	Uint need_after;
 	Uint stack_size = STACK_SZ_ON_HEAP(p);
-	Uint fragments = MBUF_SIZE(p) + combined_message_size(p);
+	Uint fragments = MBUF_SIZE(p) + combined_message_size(p, off_heap_msgs);
 	Uint size_before = fragments + (HEAP_TOP(p) - HEAP_START(p));
 	Uint new_sz = next_heap_size(p, HEAP_SIZE(p) + fragments, 0);
 
         do_minor(p, new_sz, objv, nobj);
 
-	/*
-	 * Copy newly received message onto the end of the new heap.
-	 */
-	ErtsGcQuickSanityCheck(p);
-	for (msgp = p->msg.first; msgp; msgp = msgp->next) {
-	    if (msgp->data.attached) {
-		erts_move_msg_attached_data_to_heap(&p->htop, &p->off_heap, msgp);
-		ErtsGcQuickSanityCheck(p);
+	if (!off_heap_msgs) {
+	    /*
+	     * Copy newly received message onto the end of the new heap.
+	     */
+	    ErtsGcQuickSanityCheck(p);
+	    for (msgp = p->msg.first; msgp; msgp = msgp->next) {
+		if (msgp->data.attached) {
+		    erts_move_msg_attached_data_to_heap(&p->htop, &p->off_heap, msgp);
+		    ErtsGcQuickSanityCheck(p);
+		}
 	    }
 	}
 	ErtsGcQuickSanityCheck(p);
@@ -1210,7 +1216,7 @@ do_minor(Process *p, Uint new_sz, Eterm* objv, int nobj)
  */
 
 static int
-major_collection(Process* p, int need, Eterm* objv, int nobj, Uint *recl)
+major_collection(Process* p, int need, Eterm* objv, int nobj, Uint *recl, int off_heap_msgs)
 {
     Rootset rootset;
     Roots* roots;
@@ -1223,8 +1229,7 @@ major_collection(Process* p, int need, Eterm* objv, int nobj, Uint *recl)
     Uint oh_size = (char *) OLD_HTOP(p) - oh;
     Uint n;
     Uint new_sz;
-    Uint fragments = MBUF_SIZE(p) + combined_message_size(p);
-    ErlMessage *msgp;
+    Uint fragments = MBUF_SIZE(p) + combined_message_size(p, off_heap_msgs);
 
     size_before = fragments + (HEAP_TOP(p) - HEAP_START(p));
 
@@ -1434,13 +1439,16 @@ major_collection(Process* p, int need, Eterm* objv, int nobj, Uint *recl)
 
     ErtsGcQuickSanityCheck(p);
 
-    /*
-     * Copy newly received message onto the end of the new heap.
-     */
-    for (msgp = p->msg.first; msgp; msgp = msgp->next) {
-	if (msgp->data.attached) {
-	    erts_move_msg_attached_data_to_heap(&p->htop, &p->off_heap, msgp);
-	    ErtsGcQuickSanityCheck(p);
+    if (!off_heap_msgs) {
+	ErlMessage *msgp;
+	/*
+	 * Copy newly received message onto the end of the new heap.
+	 */
+	for (msgp = p->msg.first; msgp; msgp = msgp->next) {
+	    if (msgp->data.attached) {
+		erts_move_msg_attached_data_to_heap(&p->htop, &p->off_heap, msgp);
+		ErtsGcQuickSanityCheck(p);
+	    }
 	}
     }
 
@@ -1501,15 +1509,17 @@ adjust_after_fullsweep(Process *p, Uint size_before, int need, Eterm *objv, int
  * mbuf list.
  */
 static Uint
-combined_message_size(Process* p)
+combined_message_size(Process* p, int off_heap_msgs)
 {
-    Uint sz = 0;
+    Uint sz;
     ErlMessage *msgp;
 
-    for (msgp = p->msg.first; msgp; msgp = msgp->next) {
-	if (msgp->data.attached) {
+    if (off_heap_msgs)
+	return 0;
+
+    for (sz = 0, msgp = p->msg.first; msgp; msgp = msgp->next) {
+	if (msgp->data.attached)
 	    sz += erts_msg_attached_data_size(msgp);
-	}
     }
     return sz;
 }
diff --git a/erts/emulator/beam/erl_init.c b/erts/emulator/beam/erl_init.c
index fe065e196d..5aeb5b2590 100644
--- a/erts/emulator/beam/erl_init.c
+++ b/erts/emulator/beam/erl_init.c
@@ -45,6 +45,7 @@
 #include "erl_thr_queue.h"
 #include "erl_async.h"
 #include "erl_ptab.h"
+#include "erl_bif_unique.h"
 
 #ifdef HIPE
 #include "hipe_mode_switch.h"	/* for hipe_mode_switch_init() */
@@ -134,7 +135,9 @@ static void erl_init(int ncpu,
 		     int legacy_proc_tab,
 		     int port_tab_sz,
 		     int port_tab_sz_ignore_files,
-		     int legacy_port_tab);
+		     int legacy_port_tab,
+		     int time_correction,
+		     ErtsTimeWarpMode time_warp_mode);
 
 static erts_atomic_t exiting;
 
@@ -185,10 +188,6 @@ static int no_dirty_io_schedulers;
 Uint32 verbose;             /* See erl_debug.h for information about verbose */
 #endif
 
-int erts_disable_tolerant_timeofday; /* Time correction can be disabled it is
-				      * not and/or it is too slow.
-				      */
-
 int erts_atom_table_size = ATOM_LIMIT;	/* Maximum number of atoms */
 
 int erts_pd_initial_size = 10;
@@ -268,6 +267,19 @@ this_rel_num(void)
     return this_rel;
 }
 
+static ERTS_INLINE void
+set_default_time_adj(int *time_correction_p, ErtsTimeWarpMode *time_warp_mode_p)
+{
+    *time_correction_p = 1;
+    *time_warp_mode_p = ERTS_NO_TIME_WARP_MODE;
+    if (!erts_check_time_adj_support(*time_correction_p,
+				     *time_warp_mode_p)) {
+	*time_correction_p = 0;
+	ASSERT(erts_check_time_adj_support(*time_correction_p,
+					   *time_warp_mode_p));
+    }
+}
+
 /*
  * Common error printout function, all error messages
  * that don't go to the error logger go through here.
@@ -283,13 +295,22 @@ static int early_init(int *argc, char **argv);
 void
 erts_short_init(void)
 {
-    int ncpu = early_init(NULL, NULL);
+    
+    int ncpu;
+    int time_correction;
+    ErtsTimeWarpMode time_warp_mode;
+
+    set_default_time_adj(&time_correction,
+			 &time_warp_mode);
+    ncpu = early_init(NULL, NULL);
     erl_init(ncpu,
 	     ERTS_DEFAULT_MAX_PROCESSES,
 	     0,
 	     ERTS_DEFAULT_MAX_PORTS,
 	     0,
-	     0);
+	     0,
+	     time_correction,
+	     time_warp_mode);
     erts_initialized = 1;
 }
 
@@ -299,12 +320,15 @@ erl_init(int ncpu,
 	 int legacy_proc_tab,
 	 int port_tab_sz,
 	 int port_tab_sz_ignore_files,
-	 int legacy_port_tab)
+	 int legacy_port_tab,
+	 int time_correction,
+	 ErtsTimeWarpMode time_warp_mode)
 {
     init_benchmarking();
 
+    erts_bif_unique_init();
     erts_init_monitors();
-    erts_init_time();
+    erts_init_time(time_correction, time_warp_mode);
     erts_init_sys_common_misc();
     erts_init_process(ncpu, proc_tab_sz, legacy_proc_tab);
     erts_init_scheduling(no_schedulers,
@@ -315,6 +339,7 @@ erl_init(int ncpu,
 			 no_dirty_io_schedulers
 #endif
 			 );
+    erts_late_init_time_sup();
     erts_init_cpu_topology(); /* Must be after init_scheduling */
     erts_init_gc(); /* Must be after init_scheduling */
     erts_alloc_late_init();
@@ -364,12 +389,13 @@ erl_init(int ncpu,
     erl_nif_init();
 }
 
-static void
+static Eterm
 erl_first_process_otp(char* modname, void* code, unsigned size, int argc, char** argv)
 {
     int i;
     Eterm start_mod;
     Eterm args;
+    Eterm res;
     Eterm* hp;
     Process parent;
     ErlSpawnOpts so;
@@ -399,10 +425,11 @@ erl_first_process_otp(char* modname, void* code, unsigned size, int argc, char**
     hp += 2;
     args = CONS(hp, env, args);
 
-    so.flags = 0;
-    (void) erl_create_process(&parent, start_mod, am_start, args, &so);
+    so.flags = SPO_SYSTEM_PROC;
+    res = erl_create_process(&parent, start_mod, am_start, args, &so);
     erts_smp_proc_unlock(&parent, ERTS_PROC_LOCK_MAIN);
     erts_cleanup_empty_process(&parent);
+    return res;
 }
 
 Eterm
@@ -508,9 +535,9 @@ void erts_usage(void)
 
     /*    erts_fprintf(stderr, "-b func    set the boot function (default boot)\n"); */
 
-    erts_fprintf(stderr, "-c             disable continuous date/time correction with\n");
-    erts_fprintf(stderr, "               respect to uptime\n");
-
+    erts_fprintf(stderr, "-c bool        enable or disable time correction\n");
+    erts_fprintf(stderr, "-C mode        set time warp mode; valid modes are:\n");
+    erts_fprintf(stderr, "               no_time_warp|single_time_warp|multi_time_warp\n");
     erts_fprintf(stderr, "-d             don't write a crash dump for internally detected errors\n");
     erts_fprintf(stderr, "               (halt(String) will still produce a crash dump)\n");
     erts_fprintf(stderr, "-fn[u|a|l]     Control how filenames are interpreted\n");
@@ -682,7 +709,6 @@ early_init(int *argc, char **argv) /*
 
     erts_sched_compact_load = 1;
     erts_printf_eterm_func = erts_printf_term;
-    erts_disable_tolerant_timeofday = 0;
     display_items = 200;
     erts_backtrace_depth = DEFAULT_BACKTRACE_SIZE;
     erts_async_max_threads = ERTS_DEFAULT_NO_ASYNC_THREADS;
@@ -1145,6 +1171,7 @@ early_init(int *argc, char **argv) /*
 
     /* Creates threads on Windows that depend on the arguments, so has to be after erl_sys_args */
     erl_sys_init();
+    erts_early_init_time_sup();
 
     erts_ets_realloc_always_moves = 0;
     erts_ets_always_compress = 0;
@@ -1188,7 +1215,11 @@ erl_start(int argc, char **argv)
     int port_tab_sz_ignore_files = 0;
     int legacy_proc_tab = 0;
     int legacy_port_tab = 0;
+    int time_correction;
+    ErtsTimeWarpMode time_warp_mode;
 
+    set_default_time_adj(&time_correction,
+			 &time_warp_mode);
 
     envbufsz = sizeof(envbuf);
     if (erts_sys_getenv_raw(ERL_MAX_ETS_TABLES_ENV, envbuf, &envbufsz) == 0)
@@ -1906,9 +1937,55 @@ erl_start(int argc, char **argv)
 	    }
 	    break;
 	}
+	case 'C':
+	    arg = get_arg(argv[i]+2, argv[i+1], &i);
+	    if (sys_strcmp(arg, "no_time_warp") == 0)
+		time_warp_mode = ERTS_NO_TIME_WARP_MODE;
+	    else if (sys_strcmp(arg, "single_time_warp") == 0)
+		time_warp_mode = ERTS_SINGLE_TIME_WARP_MODE;
+	    else if (sys_strcmp(arg, "multi_time_warp") == 0)
+		time_warp_mode = ERTS_MULTI_TIME_WARP_MODE;
+	    else {
+		erts_fprintf(stderr,
+			     "Invalid time warp mode: %s\n", arg);
+		erts_usage();
+	    }
+	    break;
 	case 'c':
-	    if (argv[i][2] == 0) { /* -c: documented option */
-		erts_disable_tolerant_timeofday = 1;
+	    if (sys_strcmp(argv[i]+2, "false") == 0)
+		goto time_correction_false;
+	    else if (sys_strcmp(argv[i]+2, "true") == 0)
+		goto time_correction_true;
+#ifdef ERTS_OPCODE_COUNTER_SUPPORT
+	    else if (argv[i][2] == 'i') { /* -ci: undcoumented option*/
+		count_instructions = 1;
+	    }
+#endif
+	    else if (argv[i][2] == '\0') {
+		if (i + 1 >= argc)
+		    goto time_correction_false;
+		else {
+		    if (sys_strcmp(argv[i+1], "false") == 0) {
+			(void) get_arg(argv[i]+2, argv[i+1], &i);
+			goto time_correction_false;
+		    }
+		    else if (sys_strcmp(argv[i+1], "true") == 0) {
+			(void) get_arg(argv[i]+2, argv[i+1], &i);
+		    time_correction_true:
+			time_correction = 1;
+			break;
+		    }
+		    else {
+		    time_correction_false:
+			time_correction = 0;
+			break;
+		    }
+		}
+	    }
+	    else {
+		arg = get_arg(argv[i]+2, argv[i+1], &i);
+		erts_fprintf(stderr, "Invalid time correnction value: %s\n", arg);
+		erts_usage();
 	    }
 	    break;
 	case 'W':
@@ -1955,6 +2032,30 @@ erl_start(int argc, char **argv)
 	i++;
     }
 
+    if (!erts_check_time_adj_support(time_correction, time_warp_mode)) {
+	char *time_correction_str = time_correction ? "Enabled" : "Disabled";
+	char *time_warp_str = "undefined";
+	switch (time_warp_mode) {
+	case ERTS_NO_TIME_WARP_MODE:
+	    time_warp_str = "no";
+	    break;
+	case ERTS_SINGLE_TIME_WARP_MODE:
+	    time_warp_str = "single";
+	    break;
+	case ERTS_MULTI_TIME_WARP_MODE:
+	    time_warp_str = "multi";
+	    break;
+	default:
+	    time_warp_str = "undefined";
+	    break;
+	}
+	erts_fprintf(stderr, "%s time correction with %s time warp mode "
+		     "is not supported on this platform\n",
+		     time_correction_str,
+		     time_warp_str);
+	erts_usage();
+    }
+
 /* Output format on windows for sprintf defaults to three exponents.
  * We use two-exponent to mimic normal sprintf behaviour.
  */
@@ -1988,7 +2089,9 @@ erl_start(int argc, char **argv)
 	     legacy_proc_tab,
 	     port_tab_sz,
 	     port_tab_sz_ignore_files,
-	     legacy_port_tab);
+	     legacy_port_tab,
+	     time_correction,
+	     time_warp_mode);
 
     load_preloaded();
     erts_end_staging_code_ix();
@@ -1996,7 +2099,11 @@ erl_start(int argc, char **argv)
 
     erts_initialized = 1;
 
-    erl_first_process_otp("otp_ring0", NULL, 0, boot_argc, boot_argv);
+    {
+	Eterm init = erl_first_process_otp("otp_ring0", NULL, 0,
+					   boot_argc, boot_argv);
+	erts_bif_timer_start_servers(init);
+    }
 
 #ifdef ERTS_SMP
     erts_start_schedulers();
diff --git a/erts/emulator/beam/erl_lock_check.c b/erts/emulator/beam/erl_lock_check.c
index b105ece6f1..261460d054 100644
--- a/erts/emulator/beam/erl_lock_check.c
+++ b/erts/emulator/beam/erl_lock_check.c
@@ -140,7 +140,6 @@ static erts_lc_lock_order_t erts_lock_order[] = {
     {	"async_enq_mtx",			NULL			},
 #ifdef ERTS_SMP
     {	"atom_tab",				NULL			},
-    {	"make_ref",				NULL			},
     {	"misc_op_list_pre_alloc_lock",		"address"		},
     {	"message_pre_alloc_lock",		"address"		},
     {	"ptimer_pre_alloc_lock",		"address",		},
@@ -168,6 +167,8 @@ static erts_lc_lock_order_t erts_lock_order[] = {
     {	"timer_wheel",				NULL			},
     {	"system_block",				NULL			},
     {	"timeofday",				NULL			},
+    {	"get_time",				NULL			},
+    {	"get_corrected_time",			NULL			},
     {	"breakpoints",				NULL			},
     {	"pollsets_lock",			NULL			},
     {	"pix_lock",				"address"		},
@@ -184,10 +185,8 @@ static erts_lc_lock_order_t erts_lock_order[] = {
     {   "efile_drv dtrace mutex",               NULL                    },
 #endif
     {	"mtrace_buf",				NULL			},
-#ifdef __WIN32__
 #ifdef ERTS_SMP
-    {   "sys_gethrtime",                        NULL                    },
-#endif
+    {	"os_monotonic_time",			NULL			},
 #endif
     {	"erts_alloc_hard_debug",		NULL			},
     {	"hard_dbg_mseg",		        NULL	                },
diff --git a/erts/emulator/beam/erl_lock_count.c b/erts/emulator/beam/erl_lock_count.c
index cf6996ea06..ddeb56a6be 100644
--- a/erts/emulator/beam/erl_lock_count.c
+++ b/erts/emulator/beam/erl_lock_count.c
@@ -104,11 +104,10 @@ static void lcnt_clear_stats(erts_lcnt_lock_stats_t *stats) {
 }
 
 static void lcnt_time(erts_lcnt_time_t *time) {
-#if 0 || defined(HAVE_GETHRTIME)
-    SysHrTime hr_time;
-    hr_time  = sys_gethrtime();
-    time->s  = (unsigned long)(hr_time / 1000000000LL);
-    time->ns = (unsigned long)(hr_time - 1000000000LL*time->s);
+#if 0 || defined(ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT)
+    ErtsMonotonicTime mtime = ERTS_MONOTONIC_TO_NSEC(erts_os_monotonic_time());
+    time->s  = (unsigned long) (mtime / 1000000000LL);
+    time->ns = (unsigned long) (mtime - 1000000000LL*time->s);
 #else
   SysTimeval tv;
   sys_gettimeofday(&tv);
diff --git a/erts/emulator/beam/erl_lock_count.h b/erts/emulator/beam/erl_lock_count.h
index ffbb93da1b..09fadd7e9e 100644
--- a/erts/emulator/beam/erl_lock_count.h
+++ b/erts/emulator/beam/erl_lock_count.h
@@ -76,7 +76,7 @@
 
 /* histogram */
 #define ERTS_LCNT_HISTOGRAM_MAX_NS    (((unsigned long)1LL << 28) - 1)
-#if 0 || defined(HAVE_GETHRTIME)
+#if 0 || defined(ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT)
 #define ERTS_LCNT_HISTOGRAM_SLOT_SIZE (30)
 #define ERTS_LCNT_HISTOGRAM_RSHIFT    (0)
 #else
diff --git a/erts/emulator/beam/erl_message.c b/erts/emulator/beam/erl_message.c
index 43a03c793e..22cbae10d1 100644
--- a/erts/emulator/beam/erl_message.c
+++ b/erts/emulator/beam/erl_message.c
@@ -994,7 +994,7 @@ erts_send_message(Process* sender,
 #endif
 	    );
         BM_SWAP_TIMER(send,system);
-    } else if (sender == receiver) {
+    } else if (sender == receiver && !(sender->flags & F_OFF_HEAP_MSGS)) {
 	/* Drop message if receiver has a pending exit ... */
 #ifdef ERTS_SMP
 	ErtsProcLocks need_locks = (~(*receiver_locks)
diff --git a/erts/emulator/beam/erl_message.h b/erts/emulator/beam/erl_message.h
index 6b8c3cebc7..8713941769 100644
--- a/erts/emulator/beam/erl_message.h
+++ b/erts/emulator/beam/erl_message.h
@@ -213,15 +213,25 @@ do {									\
     if ((M)->data.attached) {						\
 	Uint need__ = erts_msg_attached_data_size((M));			\
  	if ((ST) - (HT) >= need__) {					\
-	    Uint *htop__ = (HT);					\
+	    Uint *htop__;						\
+	move__attached__msg__data____:					\
+	    htop__ = (HT);						\
 	    erts_move_msg_attached_data_to_heap(&htop__, &MSO((P)), (M));\
 	    ASSERT(htop__ - (HT) <= need__);				\
 	    (HT) = htop__;						\
 	}								\
 	else {								\
+	    int off_heap_msgs__ = (int) (P)->flags & F_OFF_HEAP_MSGS;	\
+	    if (!off_heap_msgs__)					\
+		need__ = 0;						\
 	    { SWPO ; }							\
-	    (FC) -= erts_garbage_collect((P), 0, NULL, 0);		\
+	    (FC) -= erts_garbage_collect((P), need__, NULL, 0);		\
 	    { SWPI ; }							\
+	    if (off_heap_msgs__) {					\
+		ASSERT((M)->data.attached);				\
+		ASSERT((ST) - (HT) >= need__);				\
+		goto move__attached__msg__data____;			\
+	    }								\
 	}								\
 	ASSERT(!(M)->data.attached);					\
     }									\
diff --git a/erts/emulator/beam/erl_monitors.h b/erts/emulator/beam/erl_monitors.h
index fb11dbbd22..9972890db7 100644
--- a/erts/emulator/beam/erl_monitors.h
+++ b/erts/emulator/beam/erl_monitors.h
@@ -82,6 +82,7 @@
 /* Type tags for monitors */
 #define MON_ORIGIN 1
 #define MON_TARGET 3
+#define MON_TIME_OFFSET 7
 
 /* Type tags for links */
 #define LINK_PID 1   /* ...Or port */
@@ -103,7 +104,7 @@ typedef struct erts_monitor_or_link {
 typedef struct erts_monitor {
     struct erts_monitor *left, *right; 
     Sint16 balance;
-    Uint16 type;  /* MON_ORIGIN | MON_TARGET */
+    Uint16 type;  /* MON_ORIGIN | MON_TARGET | MON_TIME_OFFSET */
     Eterm ref;
     Eterm pid;    /* In case of distributed named monitor, this is the
 		     nodename atom in MON_ORIGIN process, otherwise a pid or
diff --git a/erts/emulator/beam/erl_nif.c b/erts/emulator/beam/erl_nif.c
index e28365cb1b..c7c8b3fee3 100644
--- a/erts/emulator/beam/erl_nif.c
+++ b/erts/emulator/beam/erl_nif.c
@@ -36,6 +36,7 @@
 #include "erl_thr_progress.h"
 #include "dtrace-wrapper.h"
 #include "erl_process.h"
+#include "erl_bif_unique.h"
 #if defined(USE_DYNAMIC_TRACE) && (defined(USE_DTRACE) || defined(USE_SYSTEMTAP))
 #define HAVE_USE_DTRACE 1
 #endif
diff --git a/erts/emulator/beam/erl_process.c b/erts/emulator/beam/erl_process.c
index ba09ee57c2..f74a2ee54c 100644
--- a/erts/emulator/beam/erl_process.c
+++ b/erts/emulator/beam/erl_process.c
@@ -43,6 +43,7 @@
 #include "erl_async.h"
 #include "dtrace-wrapper.h"
 #include "erl_ptab.h"
+#include "erl_bif_unique.h"
 
 
 #define ERTS_DELAYED_WAKEUP_INFINITY (~(Uint64) 0)
@@ -701,8 +702,8 @@ init_sched_wall_time(ErtsSchedWallTime *swtp)
 static ERTS_INLINE Uint64
 sched_wall_time_ts(void)
 {
-#ifdef HAVE_GETHRTIME
-    return (Uint64) sys_gethrtime();
+#ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT
+    return (Uint64) erts_os_monotonic_time();
 #else
     Uint64 res;
     SysTimeval tv;
@@ -2185,7 +2186,7 @@ aux_work_timeout_late_init(void)
 {
     aux_work_tmo->initialized = 1;
     if (erts_atomic32_read_nob(&aux_work_tmo->refc)) {
-	aux_work_tmo->timer.data.active = 0;
+	erts_init_timer(&aux_work_tmo->timer.data);
 	erts_set_timer(&aux_work_tmo->timer.data,
 		       aux_work_timeout,
 		       NULL,
@@ -2218,7 +2219,6 @@ aux_work_timeout(void *unused)
     if (refc != 1
 	|| 1 != erts_atomic32_cmpxchg_relb(&aux_work_tmo->refc, 0, 1)) {
 	/* Setup next timeout... */
-	aux_work_tmo->timer.data.active = 0;
 	erts_set_timer(&aux_work_tmo->timer.data,
 		       aux_work_timeout,
 		       NULL,
@@ -2237,7 +2237,7 @@ setup_aux_work_timer(void)
     else
 #endif
     {
-	aux_work_tmo->timer.data.active = 0;
+	erts_init_timer(&aux_work_tmo->timer.data);
 	erts_set_timer(&aux_work_tmo->timer.data,
 		       aux_work_timeout,
 		       NULL,
@@ -2638,6 +2638,13 @@ thr_prgr_fin_wait(void *vssi)
 
 static void init_aux_work_data(ErtsAuxWorkData *awdp, ErtsSchedulerData *esdp, char *dawwp);
 
+void
+erts_interupt_aux_thread_timed(ErtsMonotonicTime timeout_time)
+{
+    /* TODO only poke when needed (based on timeout_time) */
+    erts_sched_poke(ERTS_SCHED_SLEEP_INFO_IX(-1));
+}
+
 static void *
 aux_thread(void *unused)
 {
@@ -2646,6 +2653,11 @@ aux_thread(void *unused)
     erts_aint32_t aux_work;
     ErtsThrPrgrCallbacks callbacks;
     int thr_prgr_active = 1;
+    ErtsTimerWheel *timer_wheel = erts_default_timer_wheel;
+    ErtsNextTimeoutRef nxt_tmo_ref = erts_get_next_timeout_reference(timer_wheel);
+
+    if (!timer_wheel)
+	ERTS_INTERNAL_ERROR("Missing aux timer wheel");
 
 #ifdef ERTS_ENABLE_LOCK_CHECK
     {
@@ -2669,6 +2681,7 @@ aux_thread(void *unused)
     sched_prep_spin_wait(ssi);
 
     while (1) {
+	ErtsMonotonicTime current_time;
 	erts_aint32_t flgs;
 
 	aux_work = erts_atomic32_read_acqb(&ssi->aux_work);
@@ -2680,28 +2693,56 @@ aux_thread(void *unused)
 		erts_thr_progress_leader_update(NULL);
 	}
 
-	if (!aux_work) {
-	    if (thr_prgr_active)
-		erts_thr_progress_active(NULL, thr_prgr_active = 0);
-	    erts_thr_progress_prepare_wait(NULL);
+	if (aux_work) {
+	    current_time = erts_get_monotonic_time();
+	    if (current_time >= erts_next_timeout_time(nxt_tmo_ref)) {
+		if (!thr_prgr_active)
+		    erts_thr_progress_active(NULL, thr_prgr_active = 1);
+		erts_bump_timers(timer_wheel, current_time);
+	    }
+	}
+	else {
+	    ErtsMonotonicTime timeout_time;
+	    timeout_time = erts_check_next_timeout_time(timer_wheel,
+							ERTS_SEC_TO_MONOTONIC(10*60));
+	    current_time = erts_get_monotonic_time();
+	    if (current_time >= timeout_time) {
+		if (!thr_prgr_active)
+		    erts_thr_progress_active(NULL, thr_prgr_active = 1);
+	    }
+	    else {
+		if (thr_prgr_active)
+		    erts_thr_progress_active(NULL, thr_prgr_active = 0);
+		erts_thr_progress_prepare_wait(NULL);
 
-	    ERTS_SCHED_FAIR_YIELD();
+		ERTS_SCHED_FAIR_YIELD();
 
-	    flgs = sched_spin_wait(ssi, 0);
+		flgs = sched_spin_wait(ssi, 0);
 
-	    if (flgs & ERTS_SSI_FLG_SLEEPING) {
-		ASSERT(flgs & ERTS_SSI_FLG_WAITING);
-		flgs = sched_set_sleeptype(ssi, ERTS_SSI_FLG_TSE_SLEEPING);
 		if (flgs & ERTS_SSI_FLG_SLEEPING) {
-		    int res;
-		    ASSERT(flgs & ERTS_SSI_FLG_TSE_SLEEPING);
 		    ASSERT(flgs & ERTS_SSI_FLG_WAITING);
-		    do {
-			res = erts_tse_wait(ssi->event);
-		    } while (res == EINTR);
+		    flgs = sched_set_sleeptype(ssi, ERTS_SSI_FLG_TSE_SLEEPING);
+		    if (flgs & ERTS_SSI_FLG_SLEEPING) {
+			int res;
+			ASSERT(flgs & ERTS_SSI_FLG_TSE_SLEEPING);
+			ASSERT(flgs & ERTS_SSI_FLG_WAITING);
+			current_time = erts_get_monotonic_time();
+			do {
+			    Sint64 timeout;
+			    if (current_time >= timeout_time)
+				break;
+			    timeout = ERTS_MONOTONIC_TO_NSEC(timeout_time
+							     - current_time
+							     - 1) + 1;
+			    res = erts_tse_twait(ssi->event, timeout);
+			    current_time = erts_get_monotonic_time();
+			} while (res == EINTR);
+		    }
 		}
+		erts_thr_progress_finalize_wait(NULL);
 	    }
-	    erts_thr_progress_finalize_wait(NULL);
+	    if (current_time >= timeout_time)
+		erts_bump_timers(timer_wheel, current_time);
 	}
 
 	flgs = sched_prep_spin_wait(ssi);
@@ -2768,6 +2809,7 @@ scheduler_wait(int *fcalls, ErtsSchedulerData *esdp, ErtsRunQueue *rq)
 	    sched_wall_time_change(esdp, thr_prgr_active);
 
 	while (1) {
+	    ErtsMonotonicTime current_time;
 
 	    aux_work = erts_atomic32_read_acqb(&ssi->aux_work);
 	    if (aux_work) {
@@ -2781,34 +2823,65 @@ scheduler_wait(int *fcalls, ErtsSchedulerData *esdp, ErtsRunQueue *rq)
 		    erts_thr_progress_leader_update(esdp);
 	    }
 
-	    if (aux_work)
+	    if (aux_work) {
 		flgs = erts_smp_atomic32_read_acqb(&ssi->flags);
+		current_time = erts_get_monotonic_time();
+		if (current_time >= erts_next_timeout_time(esdp->next_tmo_ref)) {
+		    if (!ERTS_SCHEDULER_IS_DIRTY(esdp) && !thr_prgr_active) {
+			erts_thr_progress_active(esdp, thr_prgr_active = 1);
+			sched_wall_time_change(esdp, 1);
+		    }
+		    erts_bump_timers(esdp->timer_wheel, current_time);
+		}
+	    }
 	    else {
-		if (!ERTS_SCHEDULER_IS_DIRTY(esdp)) {
-		    if (thr_prgr_active) {
-			erts_thr_progress_active(esdp, thr_prgr_active = 0);
-			sched_wall_time_change(esdp, 0);
+		ErtsMonotonicTime timeout_time;
+		timeout_time = erts_check_next_timeout_time(esdp->timer_wheel,
+							    ERTS_SEC_TO_MONOTONIC(10*60));
+		current_time = erts_get_monotonic_time();
+		if (current_time >= timeout_time) {
+		    if (!ERTS_SCHEDULER_IS_DIRTY(esdp) && !thr_prgr_active) {
+			erts_thr_progress_active(esdp, thr_prgr_active = 1);
+			sched_wall_time_change(esdp, 1);
 		    }
-		    erts_thr_progress_prepare_wait(esdp);
 		}
+		else {
+		    if (!ERTS_SCHEDULER_IS_DIRTY(esdp)) {
+			if (thr_prgr_active) {
+			    erts_thr_progress_active(esdp, thr_prgr_active = 0);
+			    sched_wall_time_change(esdp, 0);
+			}
+			erts_thr_progress_prepare_wait(esdp);
+		    }
 
-		ERTS_SCHED_FAIR_YIELD();
+		    ERTS_SCHED_FAIR_YIELD();
 
-		flgs = sched_spin_wait(ssi, spincount);
-		if (flgs & ERTS_SSI_FLG_SLEEPING) {
-		    ASSERT(flgs & ERTS_SSI_FLG_WAITING);
-		    flgs = sched_set_sleeptype(ssi, ERTS_SSI_FLG_TSE_SLEEPING);
+		    flgs = sched_spin_wait(ssi, spincount);
 		    if (flgs & ERTS_SSI_FLG_SLEEPING) {
-			int res;
-			ASSERT(flgs & ERTS_SSI_FLG_TSE_SLEEPING);
 			ASSERT(flgs & ERTS_SSI_FLG_WAITING);
-			do {
-			    res = erts_tse_wait(ssi->event);
-			} while (res == EINTR);
+			flgs = sched_set_sleeptype(ssi, ERTS_SSI_FLG_TSE_SLEEPING);
+			if (flgs & ERTS_SSI_FLG_SLEEPING) {
+			    int res;
+			    ASSERT(flgs & ERTS_SSI_FLG_TSE_SLEEPING);
+			    ASSERT(flgs & ERTS_SSI_FLG_WAITING);
+			    current_time = erts_get_monotonic_time();
+			    do {
+				Sint64 timeout;
+				if (current_time >= timeout_time)
+				    break;
+				timeout = ERTS_MONOTONIC_TO_NSEC(timeout_time
+								 - current_time
+								 - 1) + 1;
+				res = erts_tse_twait(ssi->event, timeout);
+				current_time = erts_get_monotonic_time();
+			    } while (res == EINTR);
+			}
 		    }
+		    if (!ERTS_SCHEDULER_IS_DIRTY(esdp))
+			erts_thr_progress_finalize_wait(esdp);
 		}
-		if (!ERTS_SCHEDULER_IS_DIRTY(esdp))
-		    erts_thr_progress_finalize_wait(esdp);
+		if (current_time >= timeout_time)
+		    erts_bump_timers(esdp->timer_wheel, current_time);
 	    }
 
 	    if (!(flgs & ERTS_SSI_FLG_WAITING)) {
@@ -2841,7 +2914,6 @@ scheduler_wait(int *fcalls, ErtsSchedulerData *esdp, ErtsRunQueue *rq)
     else
 #endif
     {
-	erts_aint_t dt;
 
 	erts_smp_atomic32_set_relb(&function_calls, 0);
 	*fcalls = 0;
@@ -2866,6 +2938,7 @@ scheduler_wait(int *fcalls, ErtsSchedulerData *esdp, ErtsRunQueue *rq)
 	    goto sys_aux_work;
 
 	while (spincount-- > 0) {
+	    ErtsMonotonicTime current_time;
 
 	sys_poll_aux_work:
 
@@ -2875,8 +2948,9 @@ scheduler_wait(int *fcalls, ErtsSchedulerData *esdp, ErtsRunQueue *rq)
 	    ASSERT(!erts_port_task_have_outstanding_io_tasks());
 	    erl_sys_schedule(1); /* Might give us something to do */
 
-	    dt = erts_do_time_read_and_reset();
-	    if (dt) erts_bump_timer(dt);
+	    current_time = erts_get_monotonic_time();
+	    if (current_time >= erts_next_timeout_time(esdp->next_tmo_ref))
+		erts_bump_timers(esdp->timer_wheel, current_time);
 
 	sys_aux_work:
 #ifndef ERTS_SMP
@@ -2991,8 +3065,11 @@ scheduler_wait(int *fcalls, ErtsSchedulerData *esdp, ErtsRunQueue *rq)
 
 	erl_sys_schedule(0);
 
-	dt = erts_do_time_read_and_reset();
-	if (dt) erts_bump_timer(dt);
+	{
+	    ErtsMonotonicTime current_time = erts_get_monotonic_time();
+	    if (current_time >= erts_next_timeout_time(esdp->next_tmo_ref))
+		erts_bump_timers(esdp->timer_wheel, current_time);
+	}
 
 #ifndef ERTS_SMP
 	if (rq->len == 0 && !rq->misc.start)
@@ -5262,6 +5339,10 @@ init_scheduler_data(ErtsSchedulerData* esdp, int num,
 #else
     esdp->no = (Uint) num;
 #endif
+
+    esdp->timer_wheel = erts_default_timer_wheel;
+    esdp->next_tmo_ref = erts_get_next_timeout_reference(esdp->timer_wheel);
+
     esdp->ssi = ssi;
     esdp->current_process = NULL;
     esdp->current_port = NULL;
@@ -5274,6 +5355,9 @@ init_scheduler_data(ErtsSchedulerData* esdp, int num,
     esdp->run_queue = runq;
     esdp->run_queue->scheduler = esdp;
 
+    esdp->thr_id = (Uint32) num;
+    erts_sched_bif_unique_init(esdp);
+
     if (daww_ptr) {
 	init_aux_work_data(&esdp->aux_work_data, esdp, *daww_ptr);
 #ifdef ERTS_SMP
@@ -5834,6 +5918,13 @@ schedule_out_process(ErtsRunQueue *c_rq, erts_aint32_t state, Process *p, Proces
     int check_emigration_need;
 #endif
 
+#ifdef ERTS_SMP
+    if ((p->static_flags & ERTS_STC_FLG_PREFER_SCHED)
+	&& p->preferred_run_queue != RUNQ_READ_RQ(&p->run_queue)) {
+	RUNQ_SET_RQ(&p->run_queue, p->preferred_run_queue);
+    }
+#endif
+
     a = state;
 
     while (1) {
@@ -5872,6 +5963,7 @@ schedule_out_process(ErtsRunQueue *c_rq, erts_aint32_t state, Process *p, Proces
 	    free_proxy_proc(proxy);
 
 	erts_smp_runq_lock(c_rq);
+
 	return 0;
 
 #ifdef ERTS_DIRTY_SCHEDULERS
@@ -6584,7 +6676,7 @@ suspend_scheduler(ErtsSchedulerData *esdp)
 			    int res;
 
 			    do {
-				res = erts_tse_wait(ssi->event);
+				res = erts_tse_twait(ssi->event, -1);
 			    } while (res == EINTR);
 			}
 		    }
@@ -6747,6 +6839,7 @@ suspend_scheduler(ErtsSchedulerData *esdp)
 	    erts_smp_mtx_unlock(&schdlr_sspnd.mtx);
 
 	    while (1) {
+		ErtsMonotonicTime current_time;
 		erts_aint32_t qmask;
 		erts_aint32_t flgs;
 
@@ -6771,30 +6864,64 @@ suspend_scheduler(ErtsSchedulerData *esdp)
 		    }
 		}
 
-		if (!aux_work) {
-		    if (thr_prgr_active) {
-			erts_thr_progress_active(esdp, thr_prgr_active = 0);
-			sched_wall_time_change(esdp, 0);
+		if (aux_work) {
+		    current_time = erts_get_monotonic_time();
+		    if (current_time >= erts_next_timeout_time(esdp->next_tmo_ref)) {
+			if (!thr_prgr_active) {
+			    erts_thr_progress_active(esdp, thr_prgr_active = 1);
+			    sched_wall_time_change(esdp, 1);
+			}
+			erts_bump_timers(esdp->timer_wheel, current_time);
 		    }
-		    erts_thr_progress_prepare_wait(esdp);
-		    flgs = sched_spin_suspended(ssi,
-						ERTS_SCHED_SUSPEND_SLEEP_SPINCOUNT);
-		    if (flgs == (ERTS_SSI_FLG_SLEEPING
-				 | ERTS_SSI_FLG_WAITING
-				 | ERTS_SSI_FLG_SUSPENDED)) {
-			flgs = sched_set_suspended_sleeptype(ssi);
+		}
+		else {
+		    ErtsMonotonicTime timeout_time;
+		    timeout_time = erts_check_next_timeout_time(esdp->timer_wheel,
+								ERTS_SEC_TO_MONOTONIC(60*60));
+		    current_time = erts_get_monotonic_time();
+
+		    if (current_time >= timeout_time) {
+			if (!thr_prgr_active) {
+			    erts_thr_progress_active(esdp, thr_prgr_active = 1);
+			    sched_wall_time_change(esdp, 1);
+			}
+		    }
+		    else {		    
+			if (thr_prgr_active) {
+			    erts_thr_progress_active(esdp, thr_prgr_active = 0);
+			    sched_wall_time_change(esdp, 0);
+			}
+			erts_thr_progress_prepare_wait(esdp);
+			flgs = sched_spin_suspended(ssi,
+						    ERTS_SCHED_SUSPEND_SLEEP_SPINCOUNT);
 			if (flgs == (ERTS_SSI_FLG_SLEEPING
-				     | ERTS_SSI_FLG_TSE_SLEEPING
 				     | ERTS_SSI_FLG_WAITING
 				     | ERTS_SSI_FLG_SUSPENDED)) {
-			    int res;
-
-			    do {
-				res = erts_tse_wait(ssi->event);
-			    } while (res == EINTR);
+			    flgs = sched_set_suspended_sleeptype(ssi);
+			    if (flgs == (ERTS_SSI_FLG_SLEEPING
+					 | ERTS_SSI_FLG_TSE_SLEEPING
+					 | ERTS_SSI_FLG_WAITING
+					 | ERTS_SSI_FLG_SUSPENDED)) {
+				int res;
+
+				current_time = erts_get_monotonic_time();
+				do {
+				    Sint64 timeout;
+				    if (current_time >= timeout_time)
+					break;
+				    timeout = ERTS_MONOTONIC_TO_NSEC(timeout_time
+								     - current_time
+								     - 1) + 1;
+				    res = erts_tse_twait(ssi->event, timeout);
+				    current_time = erts_get_monotonic_time();
+				} while (res == EINTR);
+			    }
 			}
+			erts_thr_progress_finalize_wait(esdp);
 		    }
-		    erts_thr_progress_finalize_wait(esdp);
+
+		    if (current_time >= timeout_time)
+			erts_bump_timers(esdp->timer_wheel, current_time);
 		}
 
 		flgs = sched_prep_spin_suspended(ssi, (ERTS_SSI_FLG_WAITING
@@ -7613,6 +7740,9 @@ sched_thread_func(void *vesdp)
     ErtsThrPrgrCallbacks callbacks;
     ErtsSchedulerData *esdp = vesdp;
     Uint no = esdp->no;
+
+    esdp->timer_wheel = erts_create_timer_wheel((int) no);
+    esdp->next_tmo_ref = erts_get_next_timeout_reference(esdp->timer_wheel);
 #ifdef ERTS_SMP
     ERTS_SCHED_SLEEP_INFO_IX(no - 1)->event = erts_tse_fetch();
     callbacks.arg = (void *) esdp->ssi;
@@ -7715,6 +7845,8 @@ sched_dirty_cpu_thread_func(void *vesdp)
     callbacks.wait = NULL;
     callbacks.finalize_wait = NULL;
 
+    esdp->thr_id += erts_no_schedulers;
+
     erts_thr_progress_register_unmanaged_thread(&callbacks);
 #ifdef ERTS_ENABLE_LOCK_CHECK
     {
@@ -7776,6 +7908,8 @@ sched_dirty_io_thread_func(void *vesdp)
     callbacks.wait = NULL;
     callbacks.finalize_wait = NULL;
 
+    esdp->thr_id += erts_no_schedulers + erts_no_dirty_cpu_schedulers;
+
     erts_thr_progress_register_unmanaged_thread(&callbacks);
 #ifdef ERTS_ENABLE_LOCK_CHECK
     {
@@ -8878,7 +9012,6 @@ Process *schedule(Process *p, int calls)
 {
     Process *proxy_p = NULL;
     ErtsRunQueue *rq;
-    erts_aint_t dt;
     ErtsSchedulerData *esdp;
     int context_reds;
     int fcalls;
@@ -9008,11 +9141,13 @@ Process *schedule(Process *p, int calls)
 
 	ERTS_SMP_CHK_NO_PROC_LOCKS;
 
-	dt = erts_do_time_read_and_reset();
-	if (dt) {
-	    erts_smp_runq_unlock(rq);
-	    erts_bump_timer(dt);
-	    erts_smp_runq_lock(rq);
+	{
+	    ErtsMonotonicTime current_time = erts_get_monotonic_time();
+	    if (current_time >= erts_next_timeout_time(esdp->next_tmo_ref)) {
+		erts_smp_runq_unlock(rq);
+		erts_bump_timers(esdp->timer_wheel, current_time);
+		erts_smp_runq_lock(rq);
+	    }
 	}
 	BM_STOP_TIMER(system);
 
@@ -9158,6 +9293,7 @@ Process *schedule(Process *p, int calls)
 	else if (!ERTS_SCHEDULER_IS_DIRTY(esdp) &&
 		 (fcalls > input_reductions &&
 		  prepare_for_sys_schedule(esdp, !0))) {
+	    ErtsMonotonicTime current_time;
 	    /*
 	     * Schedule system-level activities.
 	     */
@@ -9170,8 +9306,10 @@ Process *schedule(Process *p, int calls)
 #endif
 	    erts_smp_runq_unlock(rq);
 	    erl_sys_schedule(1);
-	    dt = erts_do_time_read_and_reset();
-	    if (dt) erts_bump_timer(dt);
+
+	    current_time = erts_get_monotonic_time();
+	    if (current_time >= erts_next_timeout_time(esdp->next_tmo_ref))
+		erts_bump_timers(esdp->timer_wheel, current_time);
 
 #ifdef ERTS_SMP
 	    erts_smp_runq_lock(rq);
@@ -10476,7 +10614,10 @@ erl_create_process(Process* parent, /* Parent of process (default group leader).
 	    int ix = so->scheduler-1;
 	    ASSERT(0 <= ix && ix < erts_no_run_queues);
 	    rq = ERTS_RUNQ_IX(ix);
-	    state |= ERTS_PSFLG_BOUND;
+	    if (!(so->flags & SPO_PREFER_SCHED)) {
+		/* Unsupported feature... */
+		state |= ERTS_PSFLG_BOUND;
+	    }
 	}
 	prio = (erts_aint32_t) so->priority;
     }
@@ -10484,6 +10625,9 @@ erl_create_process(Process* parent, /* Parent of process (default group leader).
     state |= (((prio & ERTS_PSFLGS_PRIO_MASK) << ERTS_PSFLGS_ACT_PRIO_OFFSET)
 	      | ((prio & ERTS_PSFLGS_PRIO_MASK) << ERTS_PSFLGS_USR_PRIO_OFFSET));
 
+    if (so->flags & SPO_OFF_HEAP_MSGS)
+	state |= ERTS_PSFLG_OFF_HEAP_MSGS;
+
     if (!rq)
 	rq = erts_get_runq_proc(parent);
 
@@ -10507,11 +10651,25 @@ erl_create_process(Process* parent, /* Parent of process (default group leader).
     heap_need = arg_size;
 
     p->flags = erts_default_process_flags;
+    if (so->flags & SPO_OFF_HEAP_MSGS)
+	p->flags |= F_OFF_HEAP_MSGS;
 
+#ifdef ERTS_SMP
+    p->preferred_run_queue = NULL;
+#endif
+    p->static_flags = 0;
+    if (so->flags & SPO_SYSTEM_PROC)
+	p->static_flags |= ERTS_STC_FLG_SYSTEM_PROC;
     if (so->flags & SPO_USE_ARGS) {
 	p->min_heap_size  = so->min_heap_size;
 	p->min_vheap_size = so->min_vheap_size;
 	p->max_gen_gcs    = so->max_gen_gcs;
+	if (so->flags & SPO_PREFER_SCHED) {
+#ifdef ERTS_SMP
+	    p->preferred_run_queue = rq;
+#endif
+	    p->static_flags |= ERTS_STC_FLG_PREFER_SCHED;
+	}
     } else {
 	p->min_heap_size  = H_MIN_SIZE;
 	p->min_vheap_size = BIN_VH_MIN_SIZE;
@@ -10589,7 +10747,7 @@ erl_create_process(Process* parent, /* Parent of process (default group leader).
 #ifdef ERTS_SMP
     p->common.u.alive.ptimer = NULL;
 #else
-    sys_memset(&p->common.u.alive.tm, 0, sizeof(ErlTimer));
+    erts_init_timer(&p->common.u.alive.tm);
 #endif
 
     p->common.u.alive.reg = NULL;
@@ -10782,7 +10940,7 @@ void erts_init_empty_process(Process *p)
 #ifdef ERTS_SMP
     p->common.u.alive.ptimer = NULL;
 #else
-    memset(&(p->common.u.alive.tm), 0, sizeof(ErlTimer));
+    erts_init_timer(&p->common.u.alive.tm);
 #endif
     p->next = NULL;
     p->off_heap.first = NULL;
@@ -10832,6 +10990,8 @@ void erts_init_empty_process(Process *p)
 
     p->parent = NIL;
     p->approx_started = 0;
+    p->static_flags = 0;
+
     p->common.u.alive.started_interval = 0;
 
 #ifdef HIPE
@@ -10857,6 +11017,7 @@ void erts_init_empty_process(Process *p)
     p->pending_suspenders = NULL;
     p->pending_exit.reason = THE_NON_VALUE;
     p->pending_exit.bp = NULL;
+    p->preferred_run_queue = NULL;
     erts_proc_lock_init(p);
     erts_smp_proc_unlock(p, ERTS_PROC_LOCKS_ALL);
     RUNQ_SET_RQ(&p->run_queue, ERTS_RUNQ_IX(0));
@@ -11482,7 +11643,8 @@ static void doit_exit_monitor(ErtsMonitor *mon, void *vpcontext)
     ErtsMonitor *rmon;
     Process *rp;
 
-    if (mon->type == MON_ORIGIN) {
+    switch (mon->type) {
+    case MON_ORIGIN:
 	/* We are monitoring someone else, we need to demonitor that one.. */
 	if (is_atom(mon->pid)) { /* remote by name */
 	    ASSERT(is_node_name_atom(mon->pid));
@@ -11545,7 +11707,8 @@ static void doit_exit_monitor(ErtsMonitor *mon, void *vpcontext)
 		}
 	    }
 	}
-    } else { /* type == MON_TARGET */
+	break;
+    case MON_TARGET:
 	ASSERT(mon->type == MON_TARGET);
 	ASSERT(is_pid(mon->pid) || is_internal_port(mon->pid));
 	if (is_internal_port(mon->pid)) {
@@ -11604,6 +11767,12 @@ static void doit_exit_monitor(ErtsMonitor *mon, void *vpcontext)
 		}
 	    }
 	}
+	break;
+    case MON_TIME_OFFSET:
+	erts_demonitor_time_offset(mon->ref);
+	break;
+    default:
+	ERTS_INTERNAL_ERROR("Invalid monitor type");
     }
  done:
     /* As the monitors are previously removed from the process, 
@@ -11762,6 +11931,9 @@ erts_do_exit_process(Process* p, Eterm reason)
     }
 #endif
 
+    if (p->static_flags & ERTS_STC_FLG_SYSTEM_PROC)
+	erl_exit(1, "System process %T terminated: %T\n", p->common.id, reason);
+
 #ifdef ERTS_SMP
     ERTS_SMP_CHK_HAVE_ONLY_MAIN_PROC_LOCK(p);
     /* By locking all locks (main lock is already locked) when going
diff --git a/erts/emulator/beam/erl_process.h b/erts/emulator/beam/erl_process.h
index d12ac792af..743711cc3b 100644
--- a/erts/emulator/beam/erl_process.h
+++ b/erts/emulator/beam/erl_process.h
@@ -348,7 +348,7 @@ typedef struct {
 } ErtsRunQueueInfo;
 
 
-#ifdef HAVE_GETHRTIME
+#ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT
 #  undef ERTS_HAVE_SCHED_UTIL_BALANCING_SUPPORT_OPT
 #  define ERTS_HAVE_SCHED_UTIL_BALANCING_SUPPORT_OPT 1
 #endif
@@ -564,6 +564,8 @@ struct ErtsSchedulerData_ {
     Eterm* x_reg_array;		/* X registers */
     FloatDef* f_reg_array;	/* Floating point registers. */
 
+    ErtsTimerWheel *timer_wheel;
+    ErtsNextTimeoutRef next_tmo_ref;
 #ifdef ERTS_SMP
     ethr_tid tid;		/* Thread id */
     struct erl_bits_state erl_bits_state; /* erl_bits.c state */
@@ -590,6 +592,10 @@ struct ErtsSchedulerData_ {
     ErtsAuxWorkData aux_work_data;
     ErtsAtomCacheMap atom_cache_map;
 
+    Uint32 thr_id;
+    Uint64 unique;
+    Uint64 ref;
+
     ErtsSchedAllocData alloc_data;
 
     Uint64 reductions;
@@ -936,6 +942,8 @@ struct process {
     Eterm parent;		/* Pid of process that created this process. */
     erts_approx_time_t approx_started; /* Time when started. */
 
+    Uint32 static_flags;        /* Flags that do *not* change */
+
     /* This is the place, where all fields that differs between memory
      * architectures, have gone to.
      */
@@ -967,6 +975,7 @@ struct process {
     ErtsSchedulerData *scheduler_data;
     Eterm suspendee;
     ErtsPendingSuspend *pending_suspenders;
+    ErtsRunQueue *preferred_run_queue;
     erts_smp_atomic_t run_queue;
 #ifdef HIPE
     struct hipe_process_state_smp hipe_smp;
@@ -1076,14 +1085,15 @@ void erts_check_for_holes(Process* p);
 #define ERTS_PSFLG_RUNNING_SYS		ERTS_PSFLG_BIT(15)
 #define ERTS_PSFLG_PROXY		ERTS_PSFLG_BIT(16)
 #define ERTS_PSFLG_DELAYED_SYS		ERTS_PSFLG_BIT(17)
+#define ERTS_PSFLG_OFF_HEAP_MSGS	ERTS_PSFLG_BIT(18)
 #ifdef ERTS_DIRTY_SCHEDULERS
-#define ERTS_PSFLG_DIRTY_CPU_PROC	ERTS_PSFLG_BIT(18)
-#define ERTS_PSFLG_DIRTY_IO_PROC	ERTS_PSFLG_BIT(19)
-#define ERTS_PSFLG_DIRTY_CPU_PROC_IN_Q	ERTS_PSFLG_BIT(20)
-#define ERTS_PSFLG_DIRTY_IO_PROC_IN_Q	ERTS_PSFLG_BIT(21)
-#define ERTS_PSFLG_MAX  (ERTS_PSFLGS_ZERO_BIT_OFFSET + 22)
+#define ERTS_PSFLG_DIRTY_CPU_PROC	ERTS_PSFLG_BIT(19)
+#define ERTS_PSFLG_DIRTY_IO_PROC	ERTS_PSFLG_BIT(20)
+#define ERTS_PSFLG_DIRTY_CPU_PROC_IN_Q	ERTS_PSFLG_BIT(21)
+#define ERTS_PSFLG_DIRTY_IO_PROC_IN_Q	ERTS_PSFLG_BIT(22)
+#define ERTS_PSFLG_MAX  (ERTS_PSFLGS_ZERO_BIT_OFFSET + 23)
 #else
-#define ERTS_PSFLG_MAX  (ERTS_PSFLGS_ZERO_BIT_OFFSET + 18)
+#define ERTS_PSFLG_MAX  (ERTS_PSFLGS_ZERO_BIT_OFFSET + 19)
 #endif
 
 #define ERTS_PSFLGS_IN_PRQ_MASK 	(ERTS_PSFLG_IN_PRQ_MAX		\
@@ -1098,6 +1108,12 @@ void erts_check_for_holes(Process* p);
 #define ERTS_PSFLGS_GET_PRQ_PRIO(PSFLGS) \
     (((PSFLGS) >> ERTS_PSFLGS_USR_PRIO_OFFSET) & ERTS_PSFLGS_PRIO_MASK)
 
+/*
+ * Static flags that do not change after process creation.
+ */
+#define ERTS_STC_FLG_SYSTEM_PROC	(((Uint32) 1) << 0)
+#define ERTS_STC_FLG_PREFER_SCHED	(((Uint32) 1) << 1)
+
 /* The sequential tracing token is a tuple of size 5:
  *
  *    {Flags, Label, Serial, Sender}
@@ -1125,6 +1141,9 @@ void erts_check_for_holes(Process* p);
 #define SPO_LINK 1
 #define SPO_USE_ARGS 2
 #define SPO_MONITOR 4
+#define SPO_OFF_HEAP_MSGS 8
+#define SPO_SYSTEM_PROC 16
+#define SPO_PREFER_SCHED 32
 
 /*
  * The following struct contains options for a process to be spawned.
@@ -1212,6 +1231,7 @@ extern struct erts_system_profile_flags_t erts_system_profile_flags;
 #define F_P2PNR_RESCHED      (1 <<  9) /* Process has been rescheduled via erts_pid2proc_not_running() */
 #define F_FORCE_GC           (1 << 10) /* Force gc at process in-scheduling */
 #define F_DISABLE_GC         (1 << 11) /* Disable GC */
+#define F_OFF_HEAP_MSGS      (1 << 12)
 
 /* process trace_flags */
 #define F_SENSITIVE          (1 << 0)
@@ -2228,6 +2248,8 @@ extern int erts_disable_proc_not_running_opt;
 
 void erts_smp_notify_inc_runq(ErtsRunQueue *runq);
 
+void erts_interupt_aux_thread_timed(ErtsMonotonicTime timeout_time);
+
 #ifdef ERTS_SMP
 void erts_sched_finish_poke(ErtsSchedulerSleepInfo *, erts_aint32_t);
 ERTS_GLB_INLINE void erts_sched_poke(ErtsSchedulerSleepInfo *ssi);
diff --git a/erts/emulator/beam/erl_thr_progress.c b/erts/emulator/beam/erl_thr_progress.c
index c2365c5cf7..4c9b00d2ee 100644
--- a/erts/emulator/beam/erl_thr_progress.c
+++ b/erts/emulator/beam/erl_thr_progress.c
@@ -1359,18 +1359,16 @@ void
 erts_thr_progress_fatal_error_wait(SWord timeout) {
     erts_aint32_t bc;
     SWord time_left = timeout;
-    SysTimeval to;
+    ErtsMonotonicTime timeout_time;
 
     /*
      * Counting poll intervals may give us a too long timeout
-     * if cpu is busy. If we got tolerant time of day we use it
-     * to prevent this.
+     * if cpu is busy. We use timeout time to try to prevent
+     * this. In case we havn't got time correction this may
+     * however fail too...
      */
-    if (!erts_disable_tolerant_timeofday) {
-        erts_get_timeval(&to);
-        to.tv_sec += timeout / 1000;
-        to.tv_sec += timeout % 1000;
-    }
+    timeout_time = erts_get_monotonic_time();
+    timeout_time += ERTS_MSEC_TO_MONOTONIC((ErtsMonotonicTime) timeout);
 
     while (1) {
 	if (erts_milli_sleep(ERTS_THR_PRGR_FTL_ERR_BLCK_POLL_INTERVAL) == 0)
@@ -1380,14 +1378,8 @@ erts_thr_progress_fatal_error_wait(SWord timeout) {
 	    break; /* Succefully blocked all managed threads */
 	if (time_left <= 0)
 	    break; /* Timeout */
-	if (!erts_disable_tolerant_timeofday) {
-	    SysTimeval now;
-	    erts_get_timeval(&now);
-	    if (now.tv_sec > to.tv_sec)
-		break; /* Timeout */
-	    if (now.tv_sec == to.tv_sec && now.tv_usec >= to.tv_usec)
-		break; /* Timeout */
-	}
+	if (timeout_time <= erts_get_monotonic_time())
+	    break; /* Timeout */
     }
 }
 
diff --git a/erts/emulator/beam/erl_threads.h b/erts/emulator/beam/erl_threads.h
index 1fd800d524..dc20ac207f 100644
--- a/erts/emulator/beam/erl_threads.h
+++ b/erts/emulator/beam/erl_threads.h
@@ -652,6 +652,8 @@ ERTS_GLB_INLINE void erts_tse_set(erts_tse_t *ep);
 ERTS_GLB_INLINE void erts_tse_reset(erts_tse_t *ep);
 ERTS_GLB_INLINE int erts_tse_wait(erts_tse_t *ep);
 ERTS_GLB_INLINE int erts_tse_swait(erts_tse_t *ep, int spincount);
+ERTS_GLB_INLINE int erts_tse_twait(erts_tse_t *ep, Sint64 tmo);
+ERTS_GLB_INLINE int erts_tse_stwait(erts_tse_t *ep, int spincount, Sint64 tmo);
 ERTS_GLB_INLINE int erts_tse_is_tmp(erts_tse_t *ep);
 ERTS_GLB_INLINE void erts_thr_set_main_status(int, int);
 ERTS_GLB_INLINE int erts_thr_get_main_status(void);
@@ -3490,6 +3492,27 @@ ERTS_GLB_INLINE int erts_tse_swait(erts_tse_t *ep, int spincount)
 #endif
 }
 
+ERTS_GLB_INLINE int erts_tse_twait(erts_tse_t *ep, Sint64 tmo)
+{
+#ifdef USE_THREADS
+    return ethr_event_twait(&((ethr_ts_event *) ep)->event,
+			    (ethr_sint64_t) tmo);
+#else
+    return ENOTSUP;
+#endif
+}
+
+ERTS_GLB_INLINE int erts_tse_stwait(erts_tse_t *ep, int spincount, Sint64 tmo)
+{
+#ifdef USE_THREADS
+    return ethr_event_stwait(&((ethr_ts_event *) ep)->event,
+			     spincount,
+			     (ethr_sint64_t) tmo);
+#else
+    return ENOTSUP;
+#endif
+}
+
 ERTS_GLB_INLINE int erts_tse_is_tmp(erts_tse_t *ep)
 {
 #ifdef USE_THREADS
diff --git a/erts/emulator/beam/erl_time.h b/erts/emulator/beam/erl_time.h
index 7ed1a395ad..f201a8b4e3 100644
--- a/erts/emulator/beam/erl_time.h
+++ b/erts/emulator/beam/erl_time.h
@@ -20,11 +20,16 @@
 #ifndef ERL_TIME_H__
 #define ERL_TIME_H__
 
-#define ERTS_SHORT_TIME_T_MAX ERTS_AINT32_T_MAX
-#define ERTS_SHORT_TIME_T_MIN ERTS_AINT32_T_MIN
-typedef erts_aint32_t erts_short_time_t;
+#if defined(DEBUG) || 0
+#define ERTS_TIME_ASSERT(B) ERTS_ASSERT(B)
+#else
+#define ERTS_TIME_ASSERT(B) ((void) 1)
+#endif
+
+typedef struct ErtsTimerWheel_ ErtsTimerWheel;
+typedef erts_atomic64_t * ErtsNextTimeoutRef;
+extern ErtsTimerWheel *erts_default_timer_wheel;
 
-extern erts_smp_atomic32_t do_time;	/* set at clock interrupt */
 extern SysTimeval erts_first_emu_time;
 
 /*
@@ -34,8 +39,8 @@ typedef struct erl_timer {
     struct erl_timer* next;	/* next entry tiw slot or chain */
     struct erl_timer* prev;	/* prev entry tiw slot or chain */
     Uint slot;			/* slot in timer wheel */
-    Uint count;			/* number of loops remaining */
-    int    active;		/* 1=activated, 0=deactivated */
+    erts_smp_atomic_t wheel;
+    ErtsMonotonicTime timeout_pos; /* Timeout in absolute clock ticks */
     /* called when timeout */
     void (*timeout)(void*);
     /* called when cancel (may be NULL) */
@@ -62,7 +67,6 @@ union ErtsSmpPTimer_ {
     ErtsSmpPTimer *next;
 };
 
-
 void erts_create_smp_ptimer(ErtsSmpPTimer **timer_ref,
 			    Eterm id,
 			    ErlTimeoutProc timeout_func,
@@ -70,36 +74,43 @@ void erts_create_smp_ptimer(ErtsSmpPTimer **timer_ref,
 void erts_cancel_smp_ptimer(ErtsSmpPTimer *ptimer);
 #endif
 
+void erts_monitor_time_offset(Eterm id, Eterm ref);
+int erts_demonitor_time_offset(Eterm ref);
+
+void erts_early_init_time_sup(void);
+void erts_late_init_time_sup(void);
+
 /* timer-wheel api */
 
-void erts_init_time(void);
+ErtsTimerWheel *erts_create_timer_wheel(int);
+ErtsNextTimeoutRef erts_get_next_timeout_reference(ErtsTimerWheel *);
+void erts_init_time(int time_correction, ErtsTimeWarpMode time_warp_mode);
 void erts_set_timer(ErlTimer*, ErlTimeoutProc, ErlCancelProc, void*, Uint);
 void erts_cancel_timer(ErlTimer*);
-void erts_bump_timer(erts_short_time_t);
-Uint erts_timer_wheel_memory_size(void);
 Uint erts_time_left(ErlTimer *);
-erts_short_time_t erts_next_time(void);
+void erts_bump_timers(ErtsTimerWheel *, ErtsMonotonicTime);
+Uint erts_timer_wheel_memory_size(void);
 
 #ifdef DEBUG
 void erts_p_slpq(void);
 #endif
 
-ERTS_GLB_INLINE erts_short_time_t erts_do_time_read_and_reset(void);
-ERTS_GLB_INLINE void erts_do_time_add(erts_short_time_t);
+ErtsMonotonicTime erts_check_next_timeout_time(ErtsTimerWheel *,
+					       ErtsMonotonicTime);
+
+ERTS_GLB_INLINE void erts_init_timer(ErlTimer *p);
+ERTS_GLB_INLINE ErtsMonotonicTime erts_next_timeout_time(ErtsNextTimeoutRef);
 
 #if ERTS_GLB_INLINE_INCL_FUNC_DEF
 
-ERTS_GLB_INLINE erts_short_time_t erts_do_time_read_and_reset(void)
+ERTS_GLB_INLINE void erts_init_timer(ErlTimer *p)
 {
-    erts_short_time_t time = erts_smp_atomic32_xchg_acqb(&do_time, 0);
-    if (time < 0)
-	erl_exit(ERTS_ABORT_EXIT, "Internal time management error\n");
-    return time;
+    erts_smp_atomic_init_nob(&p->wheel, (erts_aint_t) NULL);
 }
 
-ERTS_GLB_INLINE void erts_do_time_add(erts_short_time_t elapsed)
+ERTS_GLB_INLINE ErtsMonotonicTime erts_next_timeout_time(ErtsNextTimeoutRef nxt_tmo_ref)
 {
-    erts_smp_atomic32_add_relb(&do_time, elapsed);
+    return (ErtsMonotonicTime) erts_atomic64_read_acqb((erts_atomic64_t *) nxt_tmo_ref);
 }
 
 #endif /* #if ERTS_GLB_INLINE_INCL_FUNC_DEF */
@@ -121,25 +132,228 @@ void erts_get_now_cpu(Uint* megasec, Uint* sec, Uint* microsec);
 typedef UWord erts_approx_time_t;
 erts_approx_time_t erts_get_approx_time(void);
 
-void erts_get_timeval(SysTimeval *tv);
-erts_time_t erts_get_time(void);
+int erts_has_time_correction(void);
+int erts_check_time_adj_support(int time_correction,
+				ErtsTimeWarpMode time_warp_mode);
+
+ErtsTimeWarpMode erts_time_warp_mode(void);
+
+typedef enum {
+    ERTS_TIME_OFFSET_PRELIMINARY,
+    ERTS_TIME_OFFSET_FINAL,
+    ERTS_TIME_OFFSET_VOLATILE
+} ErtsTimeOffsetState;
+
+ErtsTimeOffsetState erts_time_offset_state(void); 
+ErtsTimeOffsetState erts_finalize_time_offset(void); 
+struct process;
+Eterm erts_get_monotonic_start_time(struct process *c_p);
+Eterm erts_monotonic_time_source(struct process*c_p);
+
+#ifdef SYS_CLOCK_RESOLUTION
+#define ERTS_CLKTCK_RESOLUTION ((ErtsMonotonicTime) (SYS_CLOCK_RESOLUTION*1000))
+#else
+#define ERTS_CLKTCK_RESOLUTION (erts_time_sup__.r.o.clktck_resolution)
+#endif
+
+struct erts_time_sup_read_only__ {
+    ErtsMonotonicTime monotonic_time_unit;
+#ifndef SYS_CLOCK_RESOLUTION
+    ErtsMonotonicTime clktck_resolution;
+#endif
+};
+
+typedef struct {
+    union {
+	struct erts_time_sup_read_only__ o;
+	char align__[(((sizeof(struct erts_time_sup_read_only__) - 1)
+		       / ASSUMED_CACHE_LINE_SIZE) + 1)
+		     * ASSUMED_CACHE_LINE_SIZE];
+    } r;
+} ErtsTimeSupData;
+
+extern ErtsTimeSupData erts_time_sup__;
 
-ERTS_GLB_INLINE int erts_cmp_timeval(SysTimeval *t1p, SysTimeval *t2p);
+ERTS_GLB_INLINE Uint64
+erts_time_unit_conversion(Uint64 value,
+			  Uint32 from_time_unit,
+			  Uint32 to_time_unit);
 
 #if ERTS_GLB_INLINE_INCL_FUNC_DEF
 
-ERTS_GLB_INLINE int
-erts_cmp_timeval(SysTimeval *t1p, SysTimeval *t2p)
+ERTS_GLB_INLINE Uint64
+erts_time_unit_conversion(Uint64 value,
+			  Uint32 from_time_unit,
+			  Uint32 to_time_unit)
 {
-    if (t1p->tv_sec == t2p->tv_sec) {
-	if (t1p->tv_usec < t2p->tv_usec)
-	    return -1;
-	else if (t1p->tv_usec > t2p->tv_usec)
-	    return 1;
-	return 0;
-    }
-    return t1p->tv_sec < t2p->tv_sec ? -1 : 1;
+    Uint64 high, low, result;
+    if (value <= ~((Uint64) 0)/to_time_unit)
+	return (value*to_time_unit)/from_time_unit;
+
+    low = value & ((Uint64) 0xffffffff);
+    high = (value >> 32) & ((Uint64) 0xffffffff);
+
+    low *= to_time_unit;
+    high *= to_time_unit;
+
+    high += (low >> 32) & ((Uint64) 0xffffffff);
+    low &= ((Uint64) 0xffffffff);
+
+    result = high % from_time_unit;
+    high /= from_time_unit;
+    high <<= 32;
+
+    result <<= 32;
+    result += low;
+    result /= from_time_unit;
+    result += high;
+
+    return result;
 }
 
-#endif /* #if ERTS_GLB_INLINE_INCL_FUNC_DEF */
+#endif /* ERTS_GLB_INLINE_INCL_FUNC_DEF */
+
+#if ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT
+
+/*
+ * If the monotonic time unit is a compile time constant,
+ * it is assumed (and need) to be a power of 10.
+ */
+
+#define ERTS_MONOTONIC_TIME_UNIT \
+    ((ErtsMonotonicTime) ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT)
+
+#if ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT == 1000*1000*1000
+/* Nano-second time unit */
+
+#define ERTS_MONOTONIC_TO_SEC__(NSEC) ((NSEC) / (1000*1000*1000))
+#define ERTS_MONOTONIC_TO_MSEC__(NSEC) ((NSEC) / (1000*1000))
+#define ERTS_MONOTONIC_TO_USEC__(NSEC) ((NSEC) / 1000)
+#define ERTS_MONOTONIC_TO_NSEC__(NSEC) (NSEC)
+
+#define ERTS_SEC_TO_MONOTONIC__(SEC) (((ErtsMonotonicTime) (SEC))*(1000*1000*1000))
+#define ERTS_MSEC_TO_MONOTONIC__(MSEC) (((ErtsMonotonicTime) (MSEC))*(1000*1000))
+#define ERTS_USEC_TO_MONOTONIC__(USEC) (((ErtsMonotonicTime) (USEC))*1000)
+#define ERTS_NSEC_TO_MONOTONIC__(NSEC) ((ErtsMonotonicTime) (NSEC))
+
+#elif ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT == 1000*1000
+/* Micro-second time unit */
+
+#define ERTS_MONOTONIC_TO_SEC__(USEC) ((USEC) / (1000*1000))
+#define ERTS_MONOTONIC_TO_MSEC__(USEC) ((USEC) / 1000)
+#define ERTS_MONOTONIC_TO_USEC__(USEC) (USEC)
+#define ERTS_MONOTONIC_TO_NSEC__(USEC) ((USEC)*1000)
+
+#define ERTS_SEC_TO_MONOTONIC__(SEC) (((ErtsMonotonicTime) (SEC))*(1000*1000))
+#define ERTS_MSEC_TO_MONOTONIC__(MSEC) (((ErtsMonotonicTime) (MSEC))*1000)
+#define ERTS_USEC_TO_MONOTONIC__(USEC) ((ErtsMonotonicTime) (USEC))
+#define ERTS_NSEC_TO_MONOTONIC__(NSEC) (((ErtsMonotonicTime) (NSEC))/1000)
+
+#elif ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT == 1000
+/* Milli-second time unit */
+
+#define ERTS_MONOTONIC_TO_SEC__(MSEC) ((USEC)/(1000))
+#define ERTS_MONOTONIC_TO_MSEC__(MSEC) (MSEC)
+#define ERTS_MONOTONIC_TO_USEC__(MSEC) ((MSEC)*1000)
+#define ERTS_MONOTONIC_TO_NSEC__(MSEC) ((MSEC)*(1000*1000))
+
+#define ERTS_SEC_TO_MONOTONIC__(SEC) (((ErtsMonotonicTime) (SEC))*1000)
+#define ERTS_MSEC_TO_MONOTONIC__(MSEC) ((ErtsMonotonicTime) (MSEC))
+#define ERTS_USEC_TO_MONOTONIC__(USEC) (((ErtsMonotonicTime) (USEC))/1000)
+#define ERTS_NSEC_TO_MONOTONIC__(NSEC) (((ErtsMonotonicTime) (NSEC))/(1000*1000))
+
+#else
+#error Missing implementation for monotonic time unit
+#endif
+
+#define ERTS_MONOTONIC_TO_CLKTCKS__(MON) \
+    ((MON) / (ERTS_MONOTONIC_TIME_UNIT/ERTS_CLKTCK_RESOLUTION))
+#define ERTS_CLKTCKS_TO_MONOTONIC__(TCKS) \
+    ((TCKS) * (ERTS_MONOTONIC_TIME_UNIT/ERTS_CLKTCK_RESOLUTION))
+
+#else /* !ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT */
+
+#define ERTS_MONOTONIC_TIME_UNIT (erts_time_sup__.r.o.monotonic_time_unit)
+
+#define ERTS_CONV_FROM_MON_UNIT___(M, TO)				\
+    ((ErtsMonotonicTime)						\
+     erts_time_unit_conversion((Uint64) (M),				\
+			       (Uint32) ERTS_MONOTONIC_TIME_UNIT,	\
+			       (Uint32) (TO)))
+
+#define ERTS_CONV_TO_MON_UNIT___(M, FROM)				\
+    ((ErtsMonotonicTime)						\
+     erts_time_unit_conversion((Uint64) (M),				\
+			       (Uint32) (FROM),				\
+			       (Uint32) ERTS_MONOTONIC_TIME_UNIT))	\
+
+#define ERTS_MONOTONIC_TO_SEC__(M) \
+    ERTS_CONV_FROM_MON_UNIT___((M), 1)
+#define ERTS_MONOTONIC_TO_MSEC__(M) \
+    ERTS_CONV_FROM_MON_UNIT___((M), 1000)
+#define ERTS_MONOTONIC_TO_USEC__(M) \
+    ERTS_CONV_FROM_MON_UNIT___((M), 1000*1000)
+#define ERTS_MONOTONIC_TO_NSEC__(M) \
+    ERTS_CONV_FROM_MON_UNIT___((M), 1000*1000*1000)
+
+#define ERTS_SEC_TO_MONOTONIC__(SEC) \
+    ERTS_CONV_TO_MON_UNIT___((SEC), 1)
+#define ERTS_MSEC_TO_MONOTONIC__(MSEC) \
+    ERTS_CONV_TO_MON_UNIT___((MSEC), 1000)
+#define ERTS_USEC_TO_MONOTONIC__(USEC) \
+    ERTS_CONV_TO_MON_UNIT___((USEC), 1000*1000)
+#define ERTS_NSEC_TO_MONOTONIC__(NSEC) \
+    ERTS_CONV_TO_MON_UNIT___((NSEC), 1000*1000*1000)
+
+#define ERTS_MONOTONIC_TO_CLKTCKS__(MON) \
+    ERTS_CONV_FROM_MON_UNIT___((MON), ERTS_CLKTCK_RESOLUTION)
+#define ERTS_CLKTCKS_TO_MONOTONIC__(TCKS) \
+    ERTS_CONV_TO_MON_UNIT___((TCKS), ERTS_CLKTCK_RESOLUTION)
+
+#endif /* !ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT */
+
+#define ERTS_MSEC_TO_CLKTCKS__(MON) \
+    ((MON) * (ERTS_CLKTCK_RESOLUTION/1000))
+#define ERTS_CLKTCKS_TO_MSEC__(TCKS) \
+    ((TCKS) / (ERTS_CLKTCK_RESOLUTION/1000))
+
+#define ERTS_MONOTONIC_TO_SEC(X)	\
+    (ERTS_TIME_ASSERT((X) >= 0),	\
+     ERTS_MONOTONIC_TO_SEC__((X)))
+#define ERTS_MONOTONIC_TO_MSEC(X)	\
+    (ERTS_TIME_ASSERT((X) >= 0),	\
+     ERTS_MONOTONIC_TO_MSEC__((X)))
+#define ERTS_MONOTONIC_TO_USEC(X)	\
+    (ERTS_TIME_ASSERT((X) >= 0),	\
+     ERTS_MONOTONIC_TO_USEC__((X)))
+#define ERTS_MONOTONIC_TO_NSEC(X)	\
+    (ERTS_TIME_ASSERT((X) >= 0),	\
+     ERTS_MONOTONIC_TO_NSEC__((X)))
+#define ERTS_SEC_TO_MONOTONIC(X)	\
+    (ERTS_TIME_ASSERT((X) >= 0),	\
+     ERTS_SEC_TO_MONOTONIC__((X)))
+#define ERTS_MSEC_TO_MONOTONIC(X)	\
+    (ERTS_TIME_ASSERT((X) >= 0),	\
+     ERTS_MSEC_TO_MONOTONIC__((X)))
+#define ERTS_USEC_TO_MONOTONIC(X)	\
+    (ERTS_TIME_ASSERT((X) >= 0),	\
+     ERTS_USEC_TO_MONOTONIC__((X)))
+#define ERTS_NSEC_TO_MONOTONIC(X)	\
+    (ERTS_TIME_ASSERT((X) >= 0),	\
+     ERTS_NSEC_TO_MONOTONIC__((X)))
+
+#define ERTS_MONOTONIC_TO_CLKTCKS(X) \
+    (ERTS_TIME_ASSERT((X) >= 0),		\
+     ERTS_MONOTONIC_TO_CLKTCKS__((X)))
+#define ERTS_CLKTCKS_TO_MONOTONIC(X) \
+    (ERTS_TIME_ASSERT((X) >= 0),		\
+     ERTS_CLKTCKS_TO_MONOTONIC__((X)))
+
+#define ERTS_MSEC_TO_CLKTCKS(X) \
+    (ERTS_TIME_ASSERT((X) >= 0),		\
+     ERTS_MSEC_TO_CLKTCKS__((X)))
+#define ERTS_CLKTCKS_TO_MSEC(X) \
+    (ERTS_TIME_ASSERT((X) >= 0),		\
+     ERTS_CLKTCKS_TO_MSEC__((X)))
+
 #endif /* ERL_TIME_H__ */
diff --git a/erts/emulator/beam/erl_time_sup.c b/erts/emulator/beam/erl_time_sup.c
index 3272a5326d..d47d1682d7 100644
--- a/erts/emulator/beam/erl_time_sup.c
+++ b/erts/emulator/beam/erl_time_sup.c
@@ -18,60 +18,8 @@
  */
 
 /*
-** Support routines for the timer wheel
-**
-** This code contains two strategies for dealing with 
-** date/time changes in the system. 
-** If the system has some kind of high resolution timer (HAVE_GETHRTIME),
-** the high resolution timer is used to correct the time-of-day and the
-** timeouts, the base source is the hrtimer, but at certain intervals the 
-** OS time-of-day is checked and if it is not within certain bounds, the 
-** delivered time gets slowly adjusted for each call until
-** it corresponds to the system time (built-in adjtime...). 
-** The call gethrtime() is detected by autoconf on Unix, but other 
-** platforms may define it in erl_*_sys.h and implement 
-** their own high resolution timer. The high resolution timer
-** strategy is (probably) best on all systems where the timer have 
-** a resolution higher or equal to gettimeofday (or what's implemented
-** is sys_gettimeofday()). The actual resolution is the interesting thing,
-** not the unit's thats used (i.e. on VxWorks, nanoseconds can be
-** retrieved in terms of units, but the actual resolution is the same as 
-** for the clock ticks).
-** If the systems best timer routine is kernel ticks returned from 
-** sys_times(), and the actual resolution of sys_gettimeofday() is
-** better (like most unixes that does not have any realtime extensions), 
-** another strategy is used. The tolerant gettimeofday() corrects 
-** the value with respect to uptime (sys_times() return value) and checks 
-** for correction both when delivering timeticks and delivering nowtime.
-** this strategy is slower, but accurate on systems without better timer 
-** routines. The kernel tick resolution is not enough to implement
-** a gethrtime routine. On Linux and other non solaris unix-boxes the second 
-** strategy is used, on all other platforms we use the first.
-** 
-** The following is expected (from sys.[ch] and erl_*_sys.h):
-**
-** 64 bit integers. So it is, and so it will be.
-**
-** sys_init_time(), will return the clock resolution in MS and
-** that's about it. More could be added of course
-** If the clock-rate is constant (i.e. 1 ms) one can define 
-** SYS_CLOCK_RESOLUTION (to 1),
-** which makes erts_deliver_time/erts_time_remaining a bit faster.
-**
-** if HAVE_GETHRTIME is defined:
-**    sys_gethrtime() will return a SysHrTime (long long) representing 
-**    nanoseconds, sys_init_hrtime() will do any initialization.
-** else
-**    a long (64bit) integer type called Sint64 should be defined.
-**
-** sys_times() will return clock_ticks since start and 
-**    fill in a SysTimes structure (struct tms). Instead of CLK_TCK, 
-**    SYS_CLK_TCK is used to determine the resolution of kernel ticks.
-**
-** sys_gettimeofday() will take a SysTimeval (a struct timeval) as parameter
-**    and fill it in as gettimeofday(X,NULL).
-**
-*/
+ * Support routines for the time
+ */
 
 #ifdef HAVE_CONFIG_H
 #  include "config.h"
@@ -80,384 +28,1029 @@
 #include "sys.h"
 #include "erl_vm.h"
 #include "global.h"
-
+ 
 static erts_smp_mtx_t erts_timeofday_mtx;
-
-static SysTimeval inittv; /* Used everywhere, the initial time-of-day */
+static erts_smp_mtx_t erts_get_time_mtx;
 
 static SysTimes t_start; /* Used in elapsed_time_both */
-static SysTimeval gtv; /* Used in wall_clock_elapsed_time_both */
-static SysTimeval then; /* Used in get_now */
-static SysTimeval last_emu_time; /* Used in erts_get_emu_time() */
-SysTimeval erts_first_emu_time; /* Used in erts_get_emu_time() */
+static ErtsMonotonicTime prev_wall_clock_elapsed; /* Used in wall_clock_elapsed_time_both */
+static ErtsMonotonicTime previous_now; /* Used in get_now */
+
+static ErtsMonitor *time_offset_monitors = NULL;
+static Uint no_time_offset_monitors = 0;
 
-union {
-    erts_smp_atomic_t time;
-    char align[ERTS_CACHE_LINE_SIZE];
-} approx erts_align_attribute(ERTS_CACHE_LINE_SIZE);
+#ifdef DEBUG
+static int time_sup_initialized = 0;
+#endif
+
+#define ERTS_MONOTONIC_TIME_KILO \
+    ((ErtsMonotonicTime) 1000)
+#define ERTS_MONOTONIC_TIME_MEGA \
+    (ERTS_MONOTONIC_TIME_KILO*ERTS_MONOTONIC_TIME_KILO)
+#define ERTS_MONOTONIC_TIME_GIGA \
+    (ERTS_MONOTONIC_TIME_MEGA*ERTS_MONOTONIC_TIME_KILO)
+#define ERTS_MONOTONIC_TIME_TERA \
+    (ERTS_MONOTONIC_TIME_GIGA*ERTS_MONOTONIC_TIME_KILO)
 
 static void
-init_approx_time(void)
+schedule_send_time_offset_changed_notifications(ErtsMonotonicTime new_offset);
+
+/*
+ * NOTE! ERTS_MONOTONIC_TIME_START *need* to be a multiple
+ *       of ERTS_MONOTONIC_TIME_UNIT.
+ */
+
+#if ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT
+
+#ifdef ARCH_32
+/*
+ * Want to use a big-num of arity 2 as long as possible (584 years
+ * in the nano-second time unit case).
+ */
+#define ERTS_MONOTONIC_TIME_START		\
+    (((((((ErtsMonotonicTime) 1) << 32)-1)	\
+       / ERTS_MONOTONIC_TIME_UNIT)		\
+      * ERTS_MONOTONIC_TIME_UNIT)		\
+     + ERTS_MONOTONIC_TIME_UNIT)
+
+#else /* ARCH_64 */
+
+#if ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT <= 1000*1000
+
+/*
+ * Using micro second time unit or lower. Start at zero since
+ * time will remain an immediate for a very long time anyway
+ * (18279 years in the micro second case)...
+ */
+#define ERTS_MONOTONIC_TIME_START ((ErtsMonotonicTime) 0)
+
+#else /* ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT > 1000*1000 */
+
+/*
+ * Want to use an immediate as long as possible (36 years in the
+ * nano-second time unit case).
+*/
+#define ERTS_MONOTONIC_TIME_START 		\
+    ((((ErtsMonotonicTime) MIN_SMALL)		\
+      / ERTS_MONOTONIC_TIME_UNIT)		\
+     * ERTS_MONOTONIC_TIME_UNIT)
+
+#endif /* ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT > 1000*1000 */
+
+#endif /* ARCH_64 */
+
+#define ERTS_MONOTONIC_OFFSET_NATIVE ERTS_MONOTONIC_TIME_START
+#define ERTS_MONOTONIC_OFFSET_NSEC ERTS_MONOTONIC_TO_NSEC__(ERTS_MONOTONIC_TIME_START)
+#define ERTS_MONOTONIC_OFFSET_USEC ERTS_MONOTONIC_TO_USEC__(ERTS_MONOTONIC_TIME_START)
+#define ERTS_MONOTONIC_OFFSET_MSEC ERTS_MONOTONIC_TO_MSEC__(ERTS_MONOTONIC_TIME_START)
+#define ERTS_MONOTONIC_OFFSET_SEC ERTS_MONOTONIC_TO_SEC__(ERTS_MONOTONIC_TIME_START)
+
+#else /* ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT */
+
+/*
+ * Initialized in erts_init_time_sup()...
+ */
+
+#define ERTS_MONOTONIC_TIME_START (time_sup.r.o.start)
+#define ERTS_MONOTONIC_OFFSET_NATIVE (time_sup.r.o.start_offset.native)
+#define ERTS_MONOTONIC_OFFSET_NSEC (time_sup.r.o.start_offset.nsec)
+#define ERTS_MONOTONIC_OFFSET_USEC (time_sup.r.o.start_offset.usec)
+#define ERTS_MONOTONIC_OFFSET_MSEC (time_sup.r.o.start_offset.msec)
+#define ERTS_MONOTONIC_OFFSET_SEC (time_sup.r.o.start_offset.sec)
+
+#endif /* ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT */
+
+#define ERTS_MONOTONIC_TO_SYS_TIME_VAL(TVP, MT)				\
+    do {								\
+	ErtsMonotonicTime sec__, usec__;				\
+	sec__ = ERTS_MONOTONIC_TO_SEC((MT));				\
+	usec__ = ERTS_MONOTONIC_TO_USEC((MT)) - sec__*1000000;		\
+	ASSERT(usec__ < 1000000);					\
+	(TVP)->tv_sec = sec__;						\
+	(TVP)->tv_usec = usec__;					\
+    } while (0)
+
+#define ERTS_MAX_SYSTEM_TIME_DIFF ERTS_MSEC_TO_MONOTONIC(10)
+#define ERTS_SYSTEM_TIME_DIFF_EXCEED_LIMIT(ESYSTIME, OSSYSTIME)		\
+    (((Uint64) (ESYSTIME)) - (((Uint64) (OSSYSTIME))			\
+			      - ERTS_MAX_SYSTEM_TIME_DIFF)		\
+     > 2*ERTS_MAX_SYSTEM_TIME_DIFF)
+
+#define ERTS_TIME_CORRECTION_LARGE_ADJ_DIFF (ERTS_MAX_SYSTEM_TIME_DIFF/2)
+#define ERTS_TIME_CORRECTION_SMALL_ADJ_DIFF ERTS_USEC_TO_MONOTONIC(500)
+
+struct time_sup_read_only__ {
+    ErtsMonotonicTime (*get_time)(void);
+    int correction;
+    ErtsTimeWarpMode warp_mode;
+#ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT
+    ErtsMonotonicTime moffset;
+    int os_monotonic_disable;
+    char *os_monotonic_func;
+    char *os_monotonic_clock_id;
+    int os_monotonic_locked;
+    Uint64 os_monotonic_resolution;
+#endif
+#if !ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT
+    ErtsMonotonicTime start;
+    struct {
+	ErtsMonotonicTime native;
+	ErtsMonotonicTime nsec;
+	ErtsMonotonicTime usec;
+	ErtsMonotonicTime msec;
+	ErtsMonotonicTime sec;
+    } start_offset;
+#endif
+};
+
+typedef struct {
+#ifndef ERTS_HAVE_CORRECTED_OS_MONOTONIC
+    ErtsMonotonicTime drift; /* Correction for os monotonic drift */
+#endif
+    ErtsMonotonicTime error; /* Correction for error between system times */
+} ErtsMonotonicCorrection;
+
+typedef struct {
+    ErtsMonotonicTime erl_mtime;
+    ErtsMonotonicTime os_mtime;
+    ErtsMonotonicCorrection correction;
+} ErtsMonotonicCorrectionInstance;
+
+#define ERTS_DRIFT_INTERVALS 5
+typedef struct {
+    struct {
+	struct {
+	    ErtsMonotonicTime sys;
+	    ErtsMonotonicTime mon;
+	} diff;
+	struct {
+	    ErtsMonotonicTime sys;
+	    ErtsMonotonicTime mon;
+	} time;
+    } intervals[ERTS_DRIFT_INTERVALS];
+    struct {
+	ErtsMonotonicTime sys;
+	ErtsMonotonicTime mon;
+    } acc;
+    int ix;
+    int dirty_counter;
+} ErtsMonotonicDriftData;
+
+typedef struct {
+    ErtsMonotonicCorrectionInstance prev;
+    ErtsMonotonicCorrectionInstance curr;    
+#ifndef ERTS_HAVE_CORRECTED_OS_MONOTONIC
+    ErtsMonotonicDriftData drift;
+#endif
+    ErtsMonotonicTime last_check;
+    int short_check_interval;
+} ErtsMonotonicCorrectionData;
+
+struct time_sup_infrequently_changed__ {
+#ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT
+    struct {
+	erts_smp_rwmtx_t rwmtx;
+	ErlTimer timer;
+	ErtsMonotonicCorrectionData cdata;
+    } parmon;
+    ErtsMonotonicTime minit;
+#endif
+    int finalized_offset;
+    SysTimeval inittv; /* Used everywhere, the initial time-of-day */
+    ErtsMonotonicTime not_corrected_moffset;
+    erts_atomic64_t offset;
+};
+
+struct time_sup_frequently_changed__ {
+    ErtsMonotonicTime last_not_corrected_time;
+};
+
+static struct {
+    union {
+	struct time_sup_read_only__ o;
+	char align__[ERTS_ALC_CACHE_LINE_ALIGN_SIZE(sizeof(struct time_sup_read_only__))];
+    } r;
+    union {
+	struct time_sup_infrequently_changed__ c;
+	char align__[ERTS_ALC_CACHE_LINE_ALIGN_SIZE(sizeof(struct time_sup_infrequently_changed__))];
+    } inf;
+    union {
+	struct time_sup_frequently_changed__ c;
+	char align__[ERTS_ALC_CACHE_LINE_ALIGN_SIZE(sizeof(struct time_sup_frequently_changed__))];
+    } f;
+} time_sup erts_align_attribute(ERTS_CACHE_LINE_SIZE);
+
+ErtsTimeSupData erts_time_sup__ erts_align_attribute(ERTS_CACHE_LINE_SIZE);
+
+/*
+ * erts_get_approx_time() returns an *approximate* time
+ * in seconds. NOTE that this time may jump backwards!!!
+ */
+erts_approx_time_t
+erts_get_approx_time(void)
 {
-    erts_smp_atomic_init_nob(&approx.time, 0);
+    SysTimeval tv;
+    sys_gettimeofday(&tv);
+
+    return (erts_approx_time_t) tv.tv_sec;
 }
 
-static ERTS_INLINE erts_approx_time_t
-get_approx_time(void)
+static ERTS_INLINE void
+init_time_offset(ErtsMonotonicTime offset)
 {
-    return (erts_approx_time_t) erts_smp_atomic_read_nob(&approx.time);
+    erts_atomic64_init_nob(&time_sup.inf.c.offset, (erts_aint64_t) offset);
 }
 
 static ERTS_INLINE void
-update_approx_time(SysTimeval *tv)
+set_time_offset(ErtsMonotonicTime offset)
 {
-    erts_approx_time_t new_secs = (erts_approx_time_t) tv->tv_sec;
-    erts_approx_time_t old_secs = get_approx_time();
-    if (old_secs != new_secs)
-	erts_smp_atomic_set_nob(&approx.time, new_secs);
+    erts_atomic64_set_relb(&time_sup.inf.c.offset, (erts_aint64_t) offset);
 }
 
-/*
- * erts_get_approx_time() returns an *approximate* time
- * in seconds. NOTE that this time may jump backwards!!!
- */
-erts_approx_time_t
-erts_get_approx_time(void)
+static ERTS_INLINE ErtsMonotonicTime
+get_time_offset(void)
 {
-    return get_approx_time();
+    return (ErtsMonotonicTime) erts_atomic64_read_acqb(&time_sup.inf.c.offset);
 }
 
-#ifdef HAVE_GETHRTIME
 
-int erts_disable_tolerant_timeofday;
+#ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT
+
+/*
+ * Time correction adjustments made due to
+ * error between Erlang system time and OS
+ * system time:
+ * - Large adjustment ~1%
+ * - Small adjustment ~0.05%
+ */
+#define ERTS_TCORR_ERR_UNIT 2048
+#define ERTS_TCORR_ERR_LARGE_ADJ 20
+#define ERTS_TCORR_ERR_SMALL_ADJ 1
 
-static SysHrTime hr_init_time, hr_last_correction_check, 
-    hr_correction, hr_last_time;
+#define ERTS_INIT_SHORT_INTERVAL_COUNTER 10
+#define ERTS_LONG_TIME_CORRECTION_CHECK ERTS_SEC_TO_MONOTONIC(60)
+#define ERTS_SHORT_TIME_CORRECTION_CHECK ERTS_SEC_TO_MONOTONIC(15)
 
-static void init_tolerant_timeofday(void)
+#define ERTS_TIME_DRIFT_MAX_ADJ_DIFF ERTS_USEC_TO_MONOTONIC(100)
+#define ERTS_TIME_DRIFT_MIN_ADJ_DIFF ERTS_USEC_TO_MONOTONIC(5)
+
+static ERTS_INLINE ErtsMonotonicTime
+calc_corrected_erl_mtime(ErtsMonotonicTime os_mtime,
+			 ErtsMonotonicCorrectionInstance *cip,
+			 ErtsMonotonicTime *os_mdiff_p)
 {
-    /* Should be in sys.c */
-#if defined(HAVE_SYSCONF) && defined(_SC_NPROCESSORS_CONF)
-    if (sysconf(_SC_NPROCESSORS_CONF) > 1) {
-	char b[1024];
-	int maj,min,build;
-	os_flavor(b,1024);
-	os_version(&maj,&min,&build);
-	if (!strcmp(b,"sunos") && maj <= 5 && min <= 7) {
-	    erts_disable_tolerant_timeofday = 1;
-	}
-    }
+    ErtsMonotonicTime erl_mtime, diff = os_mtime - cip->os_mtime;
+    ERTS_TIME_ASSERT(diff >= 0);
+#ifndef ERTS_HAVE_CORRECTED_OS_MONOTONIC
+    diff += (cip->correction.drift*diff)/ERTS_MONOTONIC_TIME_UNIT;
 #endif
-    hr_init_time = sys_gethrtime();
-    hr_last_correction_check = hr_last_time = hr_init_time;
-    hr_correction = 0;
+    erl_mtime = cip->erl_mtime;
+    erl_mtime += diff;
+    erl_mtime += cip->correction.error*(diff/ERTS_TCORR_ERR_UNIT);
+    if (os_mdiff_p)
+	*os_mdiff_p = diff;
+    return erl_mtime;
 }
 
-static void get_tolerant_timeofday(SysTimeval *tv)
+static ErtsMonotonicTime get_corrected_time(void)
 {
-    SysHrTime diff_time, curr;
+    ErtsMonotonicTime os_mtime;
+    ErtsMonotonicCorrectionData cdata;
+    ErtsMonotonicCorrectionInstance *cip;
+
+    erts_smp_rwmtx_rlock(&time_sup.inf.c.parmon.rwmtx);
+
+    os_mtime = erts_os_monotonic_time();
+
+    cdata = time_sup.inf.c.parmon.cdata;
 
-    if (erts_disable_tolerant_timeofday) {
-	sys_gettimeofday(tv);
-	return;
+    erts_smp_rwmtx_runlock(&time_sup.inf.c.parmon.rwmtx);
+
+    if (os_mtime >= cdata.curr.os_mtime)
+	cip = &cdata.curr;
+    else {
+	if (os_mtime < cdata.prev.os_mtime)
+	    erl_exit(ERTS_ABORT_EXIT,
+		     "OS monotonic time stepped backwards\n");
+	cip = &cdata.prev;
     }
-    *tv = inittv;
-    diff_time = ((curr = sys_gethrtime()) + hr_correction - hr_init_time) / 1000; 
 
-    if (curr < hr_init_time) {
-	erl_exit(1,"Unexpected behaviour from operating system high "
-		 "resolution timer");
+    return calc_corrected_erl_mtime(os_mtime, cip, NULL);
+}
+
+static void
+check_time_correction(void *unused)
+{
+    ErtsMonotonicCorrectionData cdata;
+    ErtsMonotonicCorrection new_correction;
+    ErtsMonotonicCorrectionInstance *cip;
+    ErtsMonotonicTime mdiff, sdiff, os_mtime, erl_mtime, os_stime, erl_stime, time_offset;
+    Uint timeout;
+    SysTimeval tod;
+    int set_new_correction, begin_short_intervals = 0;
+
+    erts_smp_rwmtx_rlock(&time_sup.inf.c.parmon.rwmtx);
+
+    ASSERT(time_sup.inf.c.finalized_offset);
+
+    os_mtime = erts_os_monotonic_time();
+    sys_gettimeofday(&tod);
+
+    cdata = time_sup.inf.c.parmon.cdata;
+
+    erts_smp_rwmtx_runlock(&time_sup.inf.c.parmon.rwmtx);
+
+    if (os_mtime < cdata.curr.os_mtime)
+	erl_exit(ERTS_ABORT_EXIT,
+		 "OS monotonic time stepped backwards\n");
+    cip = &cdata.curr;
+
+    erl_mtime = calc_corrected_erl_mtime(os_mtime, cip, &mdiff);
+    time_offset = get_time_offset();
+    erl_stime = erl_mtime + time_offset;
+
+    os_stime = ERTS_SEC_TO_MONOTONIC(tod.tv_sec);
+    os_stime += ERTS_USEC_TO_MONOTONIC(tod.tv_usec);
+
+    sdiff = erl_stime - os_stime;
+
+    new_correction = cip->correction;
+    
+    if (time_sup.r.o.warp_mode == ERTS_MULTI_TIME_WARP_MODE
+	&& (sdiff < -2*ERTS_TIME_CORRECTION_SMALL_ADJ_DIFF
+	    || 2*ERTS_TIME_CORRECTION_SMALL_ADJ_DIFF < sdiff)) {
+	/* System time diff exeeded limits; change time offset... */
+	time_offset -= sdiff;
+	sdiff = 0;
+	set_time_offset(time_offset);
+	schedule_send_time_offset_changed_notifications(time_offset);
+	begin_short_intervals = 1;
+	if (cdata.curr.correction.error == 0)
+	    set_new_correction = 0;
+	else {
+	    set_new_correction = 1;
+	    new_correction.error = 0;
+	}
+    }
+    else if (cdata.curr.correction.error == 0) {
+	if (sdiff < -ERTS_TIME_CORRECTION_SMALL_ADJ_DIFF) {
+	    set_new_correction = 1;
+	    if (sdiff < -ERTS_TIME_CORRECTION_LARGE_ADJ_DIFF)
+		new_correction.error = ERTS_TCORR_ERR_LARGE_ADJ;
+	    else
+		new_correction.error = ERTS_TCORR_ERR_SMALL_ADJ;
+	}
+	else if (sdiff > ERTS_TIME_CORRECTION_SMALL_ADJ_DIFF) {
+	    set_new_correction = 1;
+	    if (sdiff > ERTS_TIME_CORRECTION_LARGE_ADJ_DIFF)
+		new_correction.error = -ERTS_TCORR_ERR_LARGE_ADJ;
+	    else
+		new_correction.error = -ERTS_TCORR_ERR_SMALL_ADJ;
+	}
+	else {
+	    set_new_correction = 0;
+	}
+    }
+    else if (cdata.curr.correction.error > 0) {
+	if (sdiff < 0) {
+	    if (cdata.curr.correction.error == ERTS_TCORR_ERR_LARGE_ADJ
+		|| -ERTS_TIME_CORRECTION_LARGE_ADJ_DIFF <= sdiff)
+		set_new_correction = 0;
+	    else {
+		new_correction.error = ERTS_TCORR_ERR_LARGE_ADJ;
+		set_new_correction = 1;
+	    }
+	}
+	else if (sdiff > ERTS_TIME_CORRECTION_SMALL_ADJ_DIFF) {
+	    set_new_correction = 1;
+	    if (sdiff > ERTS_TIME_CORRECTION_LARGE_ADJ_DIFF)
+		new_correction.error = -ERTS_TCORR_ERR_LARGE_ADJ;
+	    else
+		new_correction.error = -ERTS_TCORR_ERR_SMALL_ADJ;
+	}
+	else {
+	    set_new_correction = 1;
+	    new_correction.error = 0;
+	}
+    }
+    else /* if (cdata.curr.correction.error < 0) */ { 
+	if (0 < sdiff) {
+	    if (cdata.curr.correction.error == -ERTS_TCORR_ERR_LARGE_ADJ
+		|| sdiff <= ERTS_TIME_CORRECTION_LARGE_ADJ_DIFF)
+		set_new_correction = 0;
+	    else {
+		new_correction.error = -ERTS_TCORR_ERR_LARGE_ADJ;
+		set_new_correction = 1;
+	    }
+	    set_new_correction = 0;
+	}
+	else if (sdiff < -ERTS_TIME_CORRECTION_SMALL_ADJ_DIFF) {
+	    set_new_correction = 1;
+	    if (sdiff < -ERTS_TIME_CORRECTION_LARGE_ADJ_DIFF)
+		new_correction.error = ERTS_TCORR_ERR_LARGE_ADJ;
+	    else
+		new_correction.error = ERTS_TCORR_ERR_SMALL_ADJ;
+	}
+	else {
+	    set_new_correction = 1;
+	    new_correction.error = 0;
+	}
     }
 
-    if ((curr - hr_last_correction_check) / 1000 > 1000000) {
-	/* Check the correction need */
-	SysHrTime tv_diff, diffdiff;
-	SysTimeval tmp;
-	int done = 0;
-
-	sys_gettimeofday(&tmp);
-	tv_diff = ((SysHrTime) tmp.tv_sec) * 1000000 + tmp.tv_usec;
-	tv_diff -= ((SysHrTime) inittv.tv_sec) * 1000000 + inittv.tv_usec;
-	diffdiff = diff_time - tv_diff;
-	if (diffdiff > 10000) {
-	    SysHrTime corr = (curr - hr_last_time) / 100;
-	    if (corr / 1000 >= diffdiff) {
-		++done;
-		hr_correction -= ((SysHrTime)diffdiff) * 1000;
-	    } else {
-		hr_correction -= corr;
+#ifndef ERTS_HAVE_CORRECTED_OS_MONOTONIC
+    {
+	ErtsMonotonicDriftData *ddp = &time_sup.inf.c.parmon.cdata.drift;
+	int ix = ddp->ix;
+	ErtsMonotonicTime mtime_diff, old_os_mtime;
+
+	old_os_mtime = ddp->intervals[ix].time.mon;
+	mtime_diff = os_mtime - old_os_mtime;
+
+	if (mtime_diff >= ERTS_SEC_TO_MONOTONIC(10)) {
+	    ErtsMonotonicTime drift_adj, drift_adj_diff, old_os_stime,
+		stime_diff, mtime_acc, stime_acc, avg_drift_adj;
+
+	    old_os_stime = ddp->intervals[ix].time.sys;
+
+	    mtime_acc = ddp->acc.mon;
+	    stime_acc = ddp->acc.sys;
+
+	    avg_drift_adj = ((stime_acc - mtime_acc)*ERTS_MONOTONIC_TIME_UNIT) / mtime_acc;
+
+	    mtime_diff = os_mtime - old_os_mtime;
+	    stime_diff = os_stime - old_os_stime;
+	    drift_adj = ((stime_diff - mtime_diff)*ERTS_MONOTONIC_TIME_UNIT) / mtime_diff;
+	    
+	    ix++;
+	    if (ix >= ERTS_DRIFT_INTERVALS)
+		ix = 0;
+	    mtime_acc -= ddp->intervals[ix].diff.mon;
+	    mtime_acc += mtime_diff;
+	    stime_acc -= ddp->intervals[ix].diff.sys;
+	    stime_acc += stime_diff;
+
+	    ddp->intervals[ix].diff.mon = mtime_diff;
+	    ddp->intervals[ix].diff.sys = stime_diff;
+	    ddp->intervals[ix].time.mon = os_mtime;
+	    ddp->intervals[ix].time.sys = os_stime;
+
+	    ddp->ix = ix;
+	    ddp->acc.mon = mtime_acc;
+	    ddp->acc.sys = stime_acc;
+
+	    /*
+	     * If calculated drift adjustment is if off by more than 20% from the
+	     * average drift we interpret this as a discontinous leap in system
+	     * time and ignore it. If it actually is a change in drift we will
+	     * later detect this when the average drift change.
+	     */
+	    drift_adj_diff = avg_drift_adj - drift_adj;
+	    if (drift_adj_diff < -ERTS_TIME_DRIFT_MAX_ADJ_DIFF
+		|| ERTS_TIME_DRIFT_MAX_ADJ_DIFF < drift_adj_diff) {
+		ddp->dirty_counter = ERTS_DRIFT_INTERVALS;
+		begin_short_intervals = 1;
 	    }
-	    diff_time = (curr + hr_correction - hr_init_time) / 1000; 
-	} else if (diffdiff < -10000) {
-	    SysHrTime corr = (curr - hr_last_time) / 100;
-	    if (corr / 1000 >= -diffdiff) {
-		++done;
-		hr_correction -= ((SysHrTime)diffdiff) * 1000;
-	    } else {
-		hr_correction += corr;
+	    else {
+		if (ddp->dirty_counter <= 0) {
+		    drift_adj = ((stime_acc - mtime_acc)*ERTS_MONOTONIC_TIME_UNIT) / mtime_acc;
+		}
+		if (ddp->dirty_counter >= 0) {
+		    if (ddp->dirty_counter == 0) {
+			/* Force set new drift correction... */
+			set_new_correction = 1;
+		    }
+		    ddp->dirty_counter--;
+		}
+		drift_adj_diff = drift_adj - new_correction.drift;
+		if (drift_adj_diff) {
+		    if (drift_adj_diff > ERTS_TIME_DRIFT_MAX_ADJ_DIFF)
+			drift_adj_diff = ERTS_TIME_DRIFT_MAX_ADJ_DIFF;
+		    else if (drift_adj_diff < -ERTS_TIME_DRIFT_MAX_ADJ_DIFF)
+			drift_adj_diff = -ERTS_TIME_DRIFT_MAX_ADJ_DIFF;
+		    new_correction.drift += drift_adj_diff;
+
+		    if (drift_adj_diff < -ERTS_TIME_DRIFT_MIN_ADJ_DIFF
+			|| ERTS_TIME_DRIFT_MIN_ADJ_DIFF < drift_adj_diff) {
+			set_new_correction = 1;
+		    }
+		}
 	    }
-	    diff_time = (curr + hr_correction - hr_init_time) / 1000; 
-	} else {
-	    ++done;
 	}
-	if (done) {
-	    hr_last_correction_check = curr;
+    }
+#endif
+
+    begin_short_intervals |= set_new_correction;
+    
+    if (begin_short_intervals) {
+	time_sup.inf.c.parmon.cdata.short_check_interval
+	    = ERTS_INIT_SHORT_INTERVAL_COUNTER;
+    }
+    else if ((os_mtime - time_sup.inf.c.parmon.cdata.last_check
+	      >= ERTS_SHORT_TIME_CORRECTION_CHECK - ERTS_MONOTONIC_TIME_UNIT)
+	     && time_sup.inf.c.parmon.cdata.short_check_interval > 0) {
+	time_sup.inf.c.parmon.cdata.short_check_interval--;
+    }
+    time_sup.inf.c.parmon.cdata.last_check = os_mtime;
+
+    if (new_correction.error == 0)
+	timeout = ERTS_MONOTONIC_TO_MSEC(ERTS_LONG_TIME_CORRECTION_CHECK);
+    else {
+	ErtsMonotonicTime ecorr = new_correction.error;
+	if (sdiff < 0)
+	    sdiff = -1*sdiff;
+	if (ecorr < 0)
+	    ecorr = -1*ecorr;
+	if (sdiff > ecorr*(ERTS_LONG_TIME_CORRECTION_CHECK/ERTS_TCORR_ERR_UNIT))
+	    timeout = ERTS_MONOTONIC_TO_MSEC(ERTS_LONG_TIME_CORRECTION_CHECK);
+	else {
+	    timeout = ERTS_MONOTONIC_TO_MSEC((ERTS_TCORR_ERR_UNIT*sdiff)/ecorr);
+	    if (timeout < 10)
+		timeout = 10;
 	}
     }
-    tv->tv_sec += (int) (diff_time / ((SysHrTime) 1000000));
-    tv->tv_usec += (int) (diff_time % ((SysHrTime) 1000000));
-    if (tv->tv_usec >= 1000000) {
-	tv->tv_usec -= 1000000;
-	tv->tv_sec += 1;
+
+    if (timeout > ERTS_MONOTONIC_TO_MSEC(ERTS_SHORT_TIME_CORRECTION_CHECK)
+	&& time_sup.inf.c.parmon.cdata.short_check_interval) {
+	timeout = ERTS_MONOTONIC_TO_MSEC(ERTS_SHORT_TIME_CORRECTION_CHECK);
     }
-    hr_last_time = curr;
-}
+    
+    if (set_new_correction) {
+	erts_smp_rwmtx_rwlock(&time_sup.inf.c.parmon.rwmtx);
 
-#define correction (hr_correction/1000000)
+	os_mtime = erts_os_monotonic_time();
 
-#else /* !HAVE_GETHRTIME */
-#if !defined(CORRECT_USING_TIMES) 
-#define init_tolerant_timeofday() 
-#define get_tolerant_timeofday(tvp) sys_gettimeofday(tvp)
-#else
+	/* Save previous correction instance */
+	time_sup.inf.c.parmon.cdata.prev = *cip;
 
-typedef Sint64 Milli;
-
-static clock_t init_ct;
-static Sint64 ct_wrap;
-static Milli init_tv_m;
-static Milli correction_supress; 
-static Milli last_ct_diff;
-static Milli last_cc; 
-static clock_t last_ct;
-
-/* sys_times() might need to be wrapped and the values shifted (right)
-   a bit to cope with newer linux (2.5.*) kernels, this has to be taken care 
-   of dynamically to start with, a special version that uses
-   the times() return value as a high resolution timer can be made
-   to fully utilize the faster ticks, like on windows, but for now, we'll
-   settle with this silly workaround */
-#ifdef ERTS_WRAP_SYS_TIMES 
-#define KERNEL_TICKS() (sys_times_wrap() &  \
-			((1UL << ((sizeof(clock_t) * 8) - 1)) - 1)) 
-#else
-SysTimes dummy_tms;
+	/*
+	 * Current correction instance begin when
+	 * OS monotonic time has increased one unit.
+	 */
+	os_mtime++;
 
-#define KERNEL_TICKS() (sys_times(&dummy_tms) &  \
-			((1UL << ((sizeof(clock_t) * 8) - 1)) - 1)) 
+	/*
+	 * Erlang monotonic time corresponding to
+	 * next OS monotonic time using previous
+	 * correction.
+	 */
+	erl_mtime = calc_corrected_erl_mtime(os_mtime, cip, NULL);
 
-#endif
+	/*
+	 * Save new current correction instance.
+	 */
+	time_sup.inf.c.parmon.cdata.curr.erl_mtime = erl_mtime;
+	time_sup.inf.c.parmon.cdata.curr.os_mtime = os_mtime;
+	time_sup.inf.c.parmon.cdata.curr.correction = new_correction;
 
-static void init_tolerant_timeofday(void)
-{
-    last_ct = init_ct = KERNEL_TICKS();
-    last_cc = 0;
-    init_tv_m = (((Milli) inittv.tv_sec) * 1000) + 
-	(inittv.tv_usec / 1000);
-    ct_wrap = 0;
-    correction_supress = 0;
+	erts_smp_rwmtx_rwunlock(&time_sup.inf.c.parmon.rwmtx);
+    }
+
+    erts_set_timer(&time_sup.inf.c.parmon.timer,
+		   check_time_correction,
+		   NULL,
+		   NULL,
+		   timeout);
 }
 
+#ifndef ERTS_HAVE_CORRECTED_OS_MONOTONIC
 
-static void get_tolerant_timeofday(SysTimeval *tvp)
+static void
+init_check_time_correction(void *unused)
 {
-    clock_t current_ct;
-    SysTimeval current_tv;
-    Milli ct_diff;
-    Milli tv_diff;
-    Milli current_correction;
-    Milli act_correction;	/* long shown to be too small */
-    Milli max_adjust;
-
-    if (erts_disable_tolerant_timeofday) {
-	sys_gettimeofday(tvp);
-	return;
+    ErtsMonotonicDriftData *ddp;
+    ErtsMonotonicTime old_mtime, old_stime, mtime, stime, mtime_diff, stime_diff;
+    int ix;
+    SysTimeval tod;
+
+    ddp = &time_sup.inf.c.parmon.cdata.drift;
+    ix = ddp->ix;
+    old_mtime = ddp->intervals[0].time.mon;
+    old_stime = ddp->intervals[0].time.sys;
+
+    mtime = erts_os_monotonic_time();
+    sys_gettimeofday(&tod);
+
+    stime = ERTS_SEC_TO_MONOTONIC(tod.tv_sec);
+    stime += ERTS_USEC_TO_MONOTONIC(tod.tv_usec);
+
+    mtime_diff = mtime - old_mtime;
+    stime_diff = stime - old_stime;
+    if (100*stime_diff  < 80*mtime_diff || 120*mtime_diff < 100*stime_diff ) {
+	/* Had a system time leap... pretend no drift... */
+	stime_diff = mtime_diff;
+    }
+    
+    /*
+     * We use old time values in order to trigger
+     * a drift adjustment, and repeat this interval
+     * in all slots...
+     */
+    for (ix = 0; ix < ERTS_DRIFT_INTERVALS; ix++) {
+	ddp->intervals[ix].diff.mon = mtime_diff;
+	ddp->intervals[ix].diff.sys = stime_diff;
+	ddp->intervals[ix].time.mon = old_mtime;
+	ddp->intervals[ix].time.sys = old_stime;
     }
 
-#ifdef ERTS_WRAP_SYS_TIMES 
-#define TICK_MS (1000 / SYS_CLK_TCK_WRAP)
+    ddp->acc.sys = stime_diff*ERTS_DRIFT_INTERVALS;
+    ddp->acc.mon = mtime_diff*ERTS_DRIFT_INTERVALS;
+    ddp->ix = 0;
+    ddp->dirty_counter = ERTS_DRIFT_INTERVALS;
+
+    check_time_correction(NULL);
+}
+
+#endif
+
+static ErtsMonotonicTime
+finalize_corrected_time_offset(SysTimeval *todp)
+{
+    ErtsMonotonicTime os_mtime;
+    ErtsMonotonicCorrectionData cdata;
+    ErtsMonotonicCorrectionInstance *cip;
+
+    erts_smp_rwmtx_rlock(&time_sup.inf.c.parmon.rwmtx);
+
+    os_mtime = erts_os_monotonic_time();
+    sys_gettimeofday(todp);
+
+    cdata = time_sup.inf.c.parmon.cdata;
+
+    erts_smp_rwmtx_runlock(&time_sup.inf.c.parmon.rwmtx);
+
+    if (os_mtime < cdata.curr.os_mtime)
+	erl_exit(ERTS_ABORT_EXIT,
+		 "OS monotonic time stepped backwards\n");
+    cip = &cdata.curr;
+
+    return calc_corrected_erl_mtime(os_mtime, cip, NULL);
+}
+
+static void
+late_init_time_correction(void)
+{
+    if (time_sup.inf.c.finalized_offset) {
+	erts_init_timer(&time_sup.inf.c.parmon.timer);
+	erts_set_timer(&time_sup.inf.c.parmon.timer,
+#ifndef ERTS_HAVE_CORRECTED_OS_MONOTONIC
+		       init_check_time_correction,
 #else
-#define TICK_MS (1000 / SYS_CLK_TCK)
+		       check_time_correction,
 #endif
-    current_ct = KERNEL_TICKS();
-    sys_gettimeofday(&current_tv);
-
-    /* I dont know if uptime can move some units backwards
-       on some systems, but I allow for small backward 
-       jumps to avoid such problems if they exist...*/
-    if (last_ct > 100 && current_ct < (last_ct - 100)) {
-	ct_wrap += ((Sint64) 1) << ((sizeof(clock_t) * 8) - 1);
+		       NULL,
+		       NULL,
+		       ERTS_MONOTONIC_TO_MSEC(ERTS_SHORT_TIME_CORRECTION_CHECK));
     }
-    last_ct = current_ct;
-    ct_diff = ((ct_wrap + current_ct) - init_ct) * TICK_MS;
+}
 
-    /*
-     * We will adjust the time in milliseconds and we allow for 1% 
-     * adjustments, but if this function is called more often then every 100 
-     * millisecond (which is obviously possible), we will never adjust, so 
-     * we accumulate small times by setting last_ct_diff iff max_adjust > 0
-     */
-    if ((max_adjust = (ct_diff - last_ct_diff)/100) > 0)
-	last_ct_diff = ct_diff;
+#endif /* ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT */
 
-    tv_diff = ((((Milli) current_tv.tv_sec) * 1000) + 
-	       (current_tv.tv_usec / 1000)) - init_tv_m;
+static ErtsMonotonicTime get_not_corrected_time(void)
+{
+    SysTimeval tmp_tv;
+    ErtsMonotonicTime stime, mtime;
 
-    current_correction = ((ct_diff - tv_diff) / TICK_MS) * TICK_MS; /* trunc */
+    erts_smp_mtx_lock(&erts_get_time_mtx);
 
-    /* 
-     * We allow the current_correction value to wobble a little, as it
-     * suffers from the low resolution of the kernel ticks. 
-     * if it hasn't changed more than one tick in either direction, 
-     * we will keep the old value.
-     */
-    if ((last_cc > current_correction + TICK_MS) ||
-	(last_cc < current_correction - TICK_MS)) {
-	last_cc = current_correction;
-    } else {
-	current_correction = last_cc;
-    }
-    
-    /*
-     * As time goes, we try to get the actual correction to 0, 
-     * that is, make erlangs time correspond to the systems dito.
-     * The act correction is what we seem to need (current_correction)
-     * minus the correction suppression. The correction supression
-     * will change slowly (max 1% of elapsed time) but in millisecond steps.
-     */
-    act_correction = current_correction - correction_supress;
-    if (max_adjust > 0) {
-	/*
-	 * Here we slowly adjust erlangs time to correspond with the 
-	 * system time by changing the correction_supress variable.
-	 * It can change max_adjust milliseconds which is 1% of elapsed time
-	 */
-	if (act_correction > 0) {
-	    if (current_correction - correction_supress > max_adjust) {
-		correction_supress += max_adjust;
-	    } else {
-		correction_supress = current_correction;
-	    }
-	    act_correction = current_correction - correction_supress;
-	} else if (act_correction < 0) {
-	    if (correction_supress - current_correction > max_adjust) {
-		correction_supress -= max_adjust;
-	    } else {
-		correction_supress = current_correction;
+    sys_gettimeofday(&tmp_tv);
+
+    stime = ERTS_SEC_TO_MONOTONIC(tmp_tv.tv_sec);
+    stime += ERTS_USEC_TO_MONOTONIC(tmp_tv.tv_usec);
+
+    mtime = stime - time_sup.inf.c.not_corrected_moffset;
+
+    if (mtime >= time_sup.f.c.last_not_corrected_time)
+	time_sup.f.c.last_not_corrected_time = mtime;
+    else {
+	mtime = time_sup.f.c.last_not_corrected_time;
+
+	if (time_sup.r.o.warp_mode == ERTS_MULTI_TIME_WARP_MODE) {
+	    ErtsMonotonicTime new_offset = stime - mtime;
+	    new_offset = ERTS_MONOTONIC_TO_USEC(new_offset);
+	    new_offset = ERTS_USEC_TO_MONOTONIC(new_offset);
+	    if (time_sup.inf.c.not_corrected_moffset != new_offset) {
+		time_sup.inf.c.not_corrected_moffset = new_offset;
+		set_time_offset(new_offset);
+		schedule_send_time_offset_changed_notifications(new_offset);
 	    }
-	    act_correction = current_correction - correction_supress;
 	}
+
     }
-    /*
-     * The actual correction will correct the timeval so that system 
-     * time warps gets smothed down.
-     */
-    current_tv.tv_sec += act_correction / 1000;
-    current_tv.tv_usec += (act_correction % 1000) * 1000;
-
-    if (current_tv.tv_usec >= 1000000) {
-	++current_tv.tv_sec ;
-	current_tv.tv_usec -= 1000000;
-    } else if (current_tv.tv_usec < 0) {
-	--current_tv.tv_sec;
-	current_tv.tv_usec += 1000000;
-    }
-    *tvp = current_tv;
-#undef TICK_MS
+
+    ASSERT(stime == mtime + time_sup.inf.c.not_corrected_moffset);
+
+    erts_smp_mtx_unlock(&erts_get_time_mtx);
+
+    return mtime;
 }
 
-#endif /* CORRECT_USING_TIMES */
-#endif /* !HAVE_GETHRTIME */
+int erts_check_time_adj_support(int time_correction,
+				ErtsTimeWarpMode time_warp_mode)
+{
+    if (!time_correction)
+	return 1;
 
-/*
-** Why this? Well, most platforms have a constant clock resolution of 1,
-** we dont want the deliver_time/time_remaining routines to waste 
-** time dividing and multiplying by/with a variable that's always one.
-** so the return value of sys_init_time is ignored on those platforms.
-*/
- 
-#ifndef SYS_CLOCK_RESOLUTION
-static int clock_resolution;
-#define CLOCK_RESOLUTION clock_resolution
+    /* User wants time correction */
+
+#ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT
+    return !time_sup.r.o.os_monotonic_disable;
 #else
-#define CLOCK_RESOLUTION SYS_CLOCK_RESOLUTION
+    return 0;
 #endif
+}
 
-/*
-** The clock resolution should really be the resolution of the 
-** time function in use, which on most platforms 
-** is 1. On VxWorks the resolution should be
-** the number of ticks per second (or 1, which would work nicely to).
-**
-** Setting lower resolutions is mostly interesting when timers are used
-** instead of something like select.
-*/
-
-static SysTimeval last_delivered; 
-
-static void init_erts_deliver_time(const SysTimeval *inittv)
+int
+erts_has_time_correction(void)
 {
-    /* We set the initial values for deliver_time here */
-    last_delivered = *inittv;
-    last_delivered.tv_usec = 1000 * (last_delivered.tv_usec / 1000); 
-                                                   /* ms resolution */
+    return time_sup.r.o.correction;
 }
 
-static void do_erts_deliver_time(const SysTimeval *current)
+void
+erts_early_init_time_sup(void)
 {
-    SysTimeval cur_time;
-    erts_time_t elapsed;
-    
-    /* calculate and deliver appropriate number of ticks */
-    cur_time = *current;
-    cur_time.tv_usec = 1000 * (cur_time.tv_usec / 1000); /* ms resolution */
-    elapsed = (1000 * (cur_time.tv_sec - last_delivered.tv_sec) +
-	       (cur_time.tv_usec - last_delivered.tv_usec) / 1000) / 
-	CLOCK_RESOLUTION;
+    ErtsSysInitTimeResult sys_init_time_res
+	= ERTS_SYS_INIT_TIME_RESULT_INITER;
 
-    /* Sometimes the time jump backwards,
-       resulting in a negative elapsed time. We compensate for
-       this by simply pretend as if the time stood still. :) */
+    sys_init_time(&sys_init_time_res);
 
-    if (elapsed > 0) {
+    erts_time_sup__.r.o.monotonic_time_unit
+	= sys_init_time_res.os_monotonic_time_unit;
 
-	ASSERT(elapsed < ((erts_time_t) ERTS_SHORT_TIME_T_MAX));
+#ifndef SYS_CLOCK_RESOLUTION
+    erts_time_sup__.r.o.clktck_resolution
+	= sys_init_time_res.sys_clock_resolution;
+    erts_time_sup__.r.o.clktck_resolution *= 1000;
+#endif
 
-	erts_do_time_add((erts_short_time_t) elapsed);
-	last_delivered = cur_time;
-    }
+#ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT
+    time_sup.r.o.os_monotonic_disable
+	= !sys_init_time_res.have_os_monotonic;
+    time_sup.r.o.os_monotonic_func
+	= sys_init_time_res.os_monotonic_info.func;
+    time_sup.r.o.os_monotonic_clock_id
+	= sys_init_time_res.os_monotonic_info.clock_id;
+    time_sup.r.o.os_monotonic_locked
+	= sys_init_time_res.os_monotonic_info.locked_use;
+    time_sup.r.o.os_monotonic_resolution
+	= sys_init_time_res.os_monotonic_info.resolution;
+#endif
 }
 
 int 
-erts_init_time_sup(void)
+erts_init_time_sup(int time_correction, ErtsTimeWarpMode time_warp_mode)
 {
+#if !ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT
+    ErtsMonotonicTime abs_start;
+#endif
+
+    ASSERT(ERTS_MONOTONIC_TIME_MIN < ERTS_MONOTONIC_TIME_MAX);
+
     erts_smp_mtx_init(&erts_timeofday_mtx, "timeofday");
+    erts_smp_mtx_init(&erts_get_time_mtx, "get_time");
 
-    init_approx_time();
+    time_sup.r.o.correction = time_correction;
+    time_sup.r.o.warp_mode = time_warp_mode;
+ 
+    if (time_warp_mode == ERTS_SINGLE_TIME_WARP_MODE)
+	time_sup.inf.c.finalized_offset = 0;
+    else
+	time_sup.inf.c.finalized_offset = ~0;
+
+#if !ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT
+
+#ifdef ARCH_32
+    time_sup.r.o.start = ((((ErtsMonotonicTime) 1) << 32)-1);
+    time_sup.r.o.start /= ERTS_MONOTONIC_TIME_UNIT;
+    time_sup.r.o.start *= ERTS_MONOTONIC_TIME_UNIT;
+    time_sup.r.o.start += ERTS_MONOTONIC_TIME_UNIT;
+    abs_start = time_sup.r.o.start;
+#else /* ARCH_64 */
+    if (ERTS_MONOTONIC_TIME_UNIT <= 1000*1000)
+	abs_start = time_sup.r.o.start = 0;
+    else {
+	time_sup.r.o.start = ((ErtsMonotonicTime) MIN_SMALL);
+	time_sup.r.o.start /= ERTS_MONOTONIC_TIME_UNIT;
+	time_sup.r.o.start *= ERTS_MONOTONIC_TIME_UNIT;
+	abs_start = -1*time_sup.r.o.start;
+    }
+#endif
 
-    last_emu_time.tv_sec = 0;
-    last_emu_time.tv_usec = 0;
+    time_sup.r.o.start_offset.native = time_sup.r.o.start;
+    time_sup.r.o.start_offset.nsec = (ErtsMonotonicTime)
+	erts_time_unit_conversion((Uint64) abs_start,
+				  (Uint32) ERTS_MONOTONIC_TIME_UNIT,
+				  (Uint32) 1000*1000*1000);
+    time_sup.r.o.start_offset.usec = (ErtsMonotonicTime)
+	erts_time_unit_conversion((Uint64) abs_start,
+				  (Uint32) ERTS_MONOTONIC_TIME_UNIT,
+				  (Uint32) 1000*1000);
+    time_sup.r.o.start_offset.msec = (ErtsMonotonicTime)
+	erts_time_unit_conversion((Uint64) abs_start,
+				  (Uint32) ERTS_MONOTONIC_TIME_UNIT,
+				  (Uint32) 1000);
+    time_sup.r.o.start_offset.sec = (ErtsMonotonicTime)
+	erts_time_unit_conversion((Uint64) abs_start,
+				  (Uint32) ERTS_MONOTONIC_TIME_UNIT,
+				  (Uint32) 1);
+    if (time_sup.r.o.start < 0) {
+	time_sup.r.o.start_offset.nsec *= -1;
+	time_sup.r.o.start_offset.usec *= -1;
+	time_sup.r.o.start_offset.msec *= -1;
+	time_sup.r.o.start_offset.sec *= -1;
+    }
 
-#ifndef SYS_CLOCK_RESOLUTION
-    clock_resolution = sys_init_time();
-#else
-    (void) sys_init_time();
 #endif
-    sys_gettimeofday(&inittv);
+
+    if (ERTS_MONOTONIC_TIME_UNIT < ERTS_CLKTCK_RESOLUTION)
+	ERTS_INTERNAL_ERROR("Too small monotonic time time unit");
+
+#ifndef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT
+    time_sup.r.o.correction = 0;
+#else
+    if (time_sup.r.o.os_monotonic_disable)
+	time_sup.r.o.correction = 0;
+
+    if (time_sup.r.o.correction) {
+	ErtsMonotonicCorrectionData *cdatap;
+	erts_smp_rwmtx_opt_t rwmtx_opts = ERTS_SMP_RWMTX_OPT_DEFAULT_INITER;
+	ErtsMonotonicTime offset;
+	time_sup.inf.c.minit = erts_os_monotonic_time();
+	sys_gettimeofday(&time_sup.inf.c.inittv);
+	time_sup.r.o.moffset = -1*time_sup.inf.c.minit;
+	offset = ERTS_SEC_TO_MONOTONIC(time_sup.inf.c.inittv.tv_sec);
+	offset += ERTS_USEC_TO_MONOTONIC(time_sup.inf.c.inittv.tv_usec);
+	init_time_offset(offset);
+
+	rwmtx_opts.type = ERTS_SMP_RWMTX_TYPE_EXTREMELY_FREQUENT_READ;
+	rwmtx_opts.lived = ERTS_SMP_RWMTX_LONG_LIVED;
+
+	erts_smp_rwmtx_init_opt(&time_sup.inf.c.parmon.rwmtx,
+				&rwmtx_opts, "get_corrected_time");
+
+	cdatap = &time_sup.inf.c.parmon.cdata;
     
-#ifdef HAVE_GETHRTIME
-    sys_init_hrtime();
+#ifndef ERTS_HAVE_CORRECTED_OS_MONOTONIC
+	cdatap->drift.intervals[0].time.sys
+	    = ERTS_SEC_TO_MONOTONIC(time_sup.inf.c.inittv.tv_sec);
+	cdatap->drift.intervals[0].time.sys
+	    += ERTS_USEC_TO_MONOTONIC(time_sup.inf.c.inittv.tv_usec);
+	cdatap->drift.intervals[0].time.mon = time_sup.inf.c.minit;
+	cdatap->curr.correction.drift = 0;
+#endif
+	cdatap->curr.correction.error = 0;
+	cdatap->curr.erl_mtime = 0;
+	cdatap->curr.os_mtime = time_sup.inf.c.minit;
+	cdatap->last_check = time_sup.inf.c.minit;
+	cdatap->short_check_interval = ERTS_INIT_SHORT_INTERVAL_COUNTER;
+	cdatap->prev = cdatap->curr;
+
+	time_sup.r.o.get_time = get_corrected_time;
+    }
+    else
 #endif
-    init_tolerant_timeofday();
+    {
+	ErtsMonotonicTime stime, offset;
+	time_sup.r.o.get_time = get_not_corrected_time;
+	stime = ERTS_SEC_TO_MONOTONIC(time_sup.inf.c.inittv.tv_sec);
+	stime += ERTS_USEC_TO_MONOTONIC(time_sup.inf.c.inittv.tv_usec);
+	offset = stime;
+	time_sup.inf.c.not_corrected_moffset = offset;
+	init_time_offset(offset);
+	time_sup.f.c.last_not_corrected_time = 0;
+    }
+
+    prev_wall_clock_elapsed = 0;
 
-    init_erts_deliver_time(&inittv);
-    gtv = inittv;
-    then.tv_sec = then.tv_usec = 0;
+    previous_now = ERTS_MONOTONIC_TO_USEC(get_time_offset());
 
-    erts_deliver_time();
+#ifdef DEBUG
+    time_sup_initialized = 1;
+#endif
 
-    return CLOCK_RESOLUTION;
+    return ERTS_CLKTCK_RESOLUTION/1000;
 }    
+
+void
+erts_late_init_time_sup(void)
+{
+#ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT
+    /* Timer wheel must be initialized */
+    if (time_sup.r.o.get_time == get_corrected_time)
+	late_init_time_correction();
+#endif
+}
+
+ErtsTimeWarpMode erts_time_warp_mode(void)
+{
+    return time_sup.r.o.warp_mode;
+}
+
+ErtsTimeOffsetState erts_time_offset_state(void)
+{
+    switch (time_sup.r.o.warp_mode) {
+    case ERTS_NO_TIME_WARP_MODE:
+	return ERTS_TIME_OFFSET_FINAL;
+    case ERTS_SINGLE_TIME_WARP_MODE:
+	if (time_sup.inf.c.finalized_offset)
+	    return ERTS_TIME_OFFSET_FINAL;
+	return ERTS_TIME_OFFSET_PRELIMINARY;
+    case ERTS_MULTI_TIME_WARP_MODE:
+	return ERTS_TIME_OFFSET_VOLATILE;
+    default:
+	ERTS_INTERNAL_ERROR("Invalid time warp mode");
+	return ERTS_TIME_OFFSET_VOLATILE;
+    }
+}
+
+/*
+ * erts_finalize_time_offset() will only change time offset
+ * the first time it is called when the emulator has been
+ * started in "single time warp" mode. Returns previous
+ * state:
+ * * ERTS_TIME_OFFSET_PRELIMINARY - Finalization performed
+ * * ERTS_TIME_OFFSET_FINAL - Already finialized; nothing changed
+ * * ERTS_TIME_OFFSET_VOLATILE - Not supported, either in
+ * * no correction mode (or multi time warp mode; not yet implemented).
+ */
+
+ErtsTimeOffsetState
+erts_finalize_time_offset(void)
+{
+    switch (time_sup.r.o.warp_mode) {
+    case ERTS_NO_TIME_WARP_MODE:
+	return ERTS_TIME_OFFSET_FINAL;
+    case ERTS_MULTI_TIME_WARP_MODE:
+	return ERTS_TIME_OFFSET_VOLATILE;
+    case ERTS_SINGLE_TIME_WARP_MODE: {
+	ErtsTimeOffsetState res = ERTS_TIME_OFFSET_FINAL;
+
+	erts_smp_mtx_lock(&erts_get_time_mtx);
+
+	if (!time_sup.inf.c.finalized_offset) {
+	    ErtsMonotonicTime mtime, new_offset;
+	    SysTimeval tv;
+
+#ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT
+	    if (!time_sup.r.o.correction)
+#endif
+	    {
+		ErtsMonotonicTime stime;
+		sys_gettimeofday(&tv);
+
+		stime = ERTS_SEC_TO_MONOTONIC(tv.tv_sec);
+		stime += ERTS_USEC_TO_MONOTONIC(tv.tv_usec);
+
+		mtime = stime - time_sup.inf.c.not_corrected_moffset;
+
+		if (mtime >= time_sup.f.c.last_not_corrected_time) {
+		    time_sup.f.c.last_not_corrected_time = mtime;
+		    new_offset = time_sup.inf.c.not_corrected_moffset;
+		}
+		else {
+		    mtime = time_sup.f.c.last_not_corrected_time;
+
+		    ASSERT(time_sup.inf.c.not_corrected_moffset != stime - mtime);
+		    new_offset = stime - mtime;
+		    time_sup.inf.c.not_corrected_moffset = new_offset;
+		}
+
+	    }
+#ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT
+	    else {
+		mtime = finalize_corrected_time_offset(&tv);
+		new_offset = ERTS_SEC_TO_MONOTONIC(tv.tv_sec);
+		new_offset += ERTS_USEC_TO_MONOTONIC(tv.tv_usec);
+		new_offset -= mtime;
+
+	    }
+#endif
+	    new_offset = ERTS_MONOTONIC_TO_USEC(new_offset);
+	    new_offset = ERTS_USEC_TO_MONOTONIC(new_offset);
+
+	    set_time_offset(new_offset);
+	    schedule_send_time_offset_changed_notifications(new_offset);
+
+	    time_sup.inf.c.finalized_offset = ~0;
+	    res = ERTS_TIME_OFFSET_PRELIMINARY;
+	}
+
+	erts_smp_mtx_unlock(&erts_get_time_mtx);
+
+#ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT
+	if (res == ERTS_TIME_OFFSET_PRELIMINARY
+	    && time_sup.r.o.get_time == get_corrected_time) {
+	    late_init_time_correction();
+	}
+#endif
+
+	return res;
+    }
+    default:
+	ERTS_INTERNAL_ERROR("Invalid time warp mode");
+	return ERTS_TIME_OFFSET_VOLATILE;
+    }
+}
+
 /* info functions */
 
 void 
@@ -498,23 +1091,16 @@ elapsed_time_both(UWord *ms_user, UWord *ms_sys,
 void 
 wall_clock_elapsed_time_both(UWord *ms_total, UWord *ms_diff)
 {
-    UWord prev_total;
-    SysTimeval tv;
+    ErtsMonotonicTime now, elapsed;
 
     erts_smp_mtx_lock(&erts_timeofday_mtx);
 
-    get_tolerant_timeofday(&tv);
-
-    *ms_total = 1000 * (tv.tv_sec - inittv.tv_sec) +
-	(tv.tv_usec - inittv.tv_usec) / 1000;
+    now = time_sup.r.o.get_time();
 
-    prev_total = 1000 * (gtv.tv_sec - inittv.tv_sec) +
-	(gtv.tv_usec - inittv.tv_usec) / 1000;
-    *ms_diff = *ms_total - prev_total;
-    gtv = tv;
-
-    /* must sync the machine's idea of time here */
-    do_erts_deliver_time(&tv);
+    elapsed = ERTS_MONOTONIC_TO_MSEC(now);
+    *ms_total = (UWord) elapsed;
+    *ms_diff = (UWord) (elapsed - prev_wall_clock_elapsed);
+    prev_wall_clock_elapsed = elapsed;
 
     erts_smp_mtx_unlock(&erts_timeofday_mtx);
 }
@@ -890,38 +1476,41 @@ univ_to_local(Sint *year, Sint *month, Sint *day,
     return 0;
 }
 
-
 /* get a timestamp */
 void
 get_now(Uint* megasec, Uint* sec, Uint* microsec)
 {
-    SysTimeval now;
+    ErtsMonotonicTime now_megasec, now_sec, now, mtime, time_offset;
     
+    mtime = time_sup.r.o.get_time();
+    time_offset = get_time_offset();
+    now = ERTS_MONOTONIC_TO_USEC(mtime + time_offset);
+
     erts_smp_mtx_lock(&erts_timeofday_mtx);
-    
-    get_tolerant_timeofday(&now);
-    do_erts_deliver_time(&now);
-
-    /* Make sure time is later than last */
-    if (then.tv_sec > now.tv_sec ||
-	(then.tv_sec == now.tv_sec && then.tv_usec >= now.tv_usec)) {
-	now = then;
-	now.tv_usec++;
-    }
-    /* Check for carry from above + general reasonability */
-    if (now.tv_usec >= 1000000) {
-	now.tv_usec = 0;
-	now.tv_sec++;
-    }
-    then = now;
+
+    /* Make sure now time is later than last time */
+    if (now <= previous_now)
+	now = previous_now + 1;
+
+    previous_now = now;
     
     erts_smp_mtx_unlock(&erts_timeofday_mtx);
-    
-    *megasec = (Uint) (now.tv_sec / 1000000);
-    *sec = (Uint) (now.tv_sec % 1000000);
-    *microsec = (Uint) (now.tv_usec);
 
-    update_approx_time(&now);
+    now_megasec = now / ERTS_MONOTONIC_TIME_TERA;
+    now_sec = now / ERTS_MONOTONIC_TIME_MEGA;
+    *megasec = (Uint) now_megasec;
+    *sec = (Uint) (now_sec - now_megasec*ERTS_MONOTONIC_TIME_MEGA);
+    *microsec = (Uint) (now - now_sec*ERTS_MONOTONIC_TIME_MEGA);
+
+    ASSERT(((ErtsMonotonicTime) *megasec)*ERTS_MONOTONIC_TIME_TERA
+	   + ((ErtsMonotonicTime) *sec)*ERTS_MONOTONIC_TIME_MEGA
+	   + ((ErtsMonotonicTime) *microsec) == now);
+}
+
+ErtsMonotonicTime
+erts_get_monotonic_time(void)
+{
+    return time_sup.r.o.get_time();
 }
 
 void
@@ -934,102 +1523,466 @@ get_sys_now(Uint* megasec, Uint* sec, Uint* microsec)
     *megasec = (Uint) (now.tv_sec / 1000000);
     *sec = (Uint) (now.tv_sec % 1000000);
     *microsec = (Uint) (now.tv_usec);
-
-    update_approx_time(&now);
 }
 
+#ifdef HAVE_ERTS_NOW_CPU
+void erts_get_now_cpu(Uint* megasec, Uint* sec, Uint* microsec) {
+  SysCpuTime t;
+  SysTimespec tp;
 
-/* deliver elapsed *ticks* to the machine - takes a pointer
-   to a struct timeval representing current time (to save
-   a gettimeofday() where possible) or NULL */
+  sys_get_proc_cputime(t, tp);
+  *microsec = (Uint)(tp.tv_nsec / 1000);
+  t = (tp.tv_sec / 1000000);
+  *megasec = (Uint)(t % 1000000);
+  *sec = (Uint)(tp.tv_sec % 1000000);
+}
+#endif
 
-void erts_deliver_time(void) {
-    SysTimeval now;
-    
-    erts_smp_mtx_lock(&erts_timeofday_mtx);
-    
-    get_tolerant_timeofday(&now);
-    do_erts_deliver_time(&now);
-    
-    erts_smp_mtx_unlock(&erts_timeofday_mtx);
+#include "big.h"
 
-    update_approx_time(&now);
+void
+erts_monitor_time_offset(Eterm id, Eterm ref)
+{
+    erts_smp_mtx_lock(&erts_get_time_mtx);
+    erts_add_monitor(&time_offset_monitors, MON_TIME_OFFSET, ref, id, NIL);
+    no_time_offset_monitors++;
+    erts_smp_mtx_unlock(&erts_get_time_mtx);
 }
 
-/* get *real* time (not ticks) remaining until next timeout - if there
-   isn't one, give a "long" time, that is guaranteed
-   to not cause overflow when we report elapsed time later on */
+int
+erts_demonitor_time_offset(Eterm ref)
+{
+    int res;
+    ErtsMonitor *mon;
+    ASSERT(is_internal_ref(ref));
+    erts_smp_mtx_lock(&erts_get_time_mtx);
+    mon = erts_remove_monitor(&time_offset_monitors, ref);
+    if (!mon)
+	res = 0;
+    else {
+	ASSERT(no_time_offset_monitors > 0);
+	no_time_offset_monitors--;
+	res = 1;
+    }
+    erts_smp_mtx_unlock(&erts_get_time_mtx);
+    if (res)
+	erts_destroy_monitor(mon);
+    return res;
+}
 
-void erts_time_remaining(SysTimeval *rem_time)
+typedef struct {
+    Eterm pid;
+    Eterm ref;
+    Eterm heap[REF_THING_SIZE];
+} ErtsTimeOffsetMonitorInfo;
+
+typedef struct {
+    Uint ix;
+    ErtsTimeOffsetMonitorInfo *to_mon_info;
+} ErtsTimeOffsetMonitorContext;
+
+static void
+save_time_offset_monitor(ErtsMonitor *mon, void *vcntxt)
 {
-    erts_time_t ticks;
-    SysTimeval cur_time;
-    erts_time_t elapsed;
-
-    /* erts_next_time() returns no of ticks to next timeout or -1 if none */
-
-    ticks = (erts_time_t) erts_next_time();
-    if (ticks == (erts_time_t) -1) {
-	/* timer queue empty */
-	/* this will cause at most 100000000 ticks */
-	rem_time->tv_sec = 100000;
-	rem_time->tv_usec = 0;
-    } else {
-	/* next timeout after ticks ticks */
-	ticks *= CLOCK_RESOLUTION;
-	
-	erts_smp_mtx_lock(&erts_timeofday_mtx);
-	
-	get_tolerant_timeofday(&cur_time);
-	cur_time.tv_usec = 1000 * 
-	    (cur_time.tv_usec / 1000);/* ms resolution*/
-	elapsed = 1000 * (cur_time.tv_sec - last_delivered.tv_sec) +
-	    (cur_time.tv_usec - last_delivered.tv_usec) / 1000;
-	
-	erts_smp_mtx_unlock(&erts_timeofday_mtx);
+    ErtsTimeOffsetMonitorContext *cntxt;
+    Eterm *from_hp, *to_hp;
+    Uint mix;
+    int hix;
+
+    cntxt = (ErtsTimeOffsetMonitorContext *) vcntxt;
+    mix = (cntxt->ix)++;
+    cntxt->to_mon_info[mix].pid = mon->pid;
+    to_hp = &cntxt->to_mon_info[mix].heap[0];
+
+    ASSERT(is_internal_ref(mon->ref));
+    from_hp = internal_ref_val(mon->ref);
+    ASSERT(thing_arityval(*from_hp) + 1 == REF_THING_SIZE);
+
+    for (hix = 0; hix < REF_THING_SIZE; hix++)
+	to_hp[hix] = from_hp[hix];
+
+    cntxt->to_mon_info[mix].ref
+	= make_internal_ref(&cntxt->to_mon_info[mix].heap[0]);
+
+}
+
+static void
+send_time_offset_changed_notifications(void *new_offsetp)
+{
+    ErtsMonotonicTime new_offset;
+    ErtsTimeOffsetMonitorInfo *to_mon_info;
+    Uint no_monitors;
+    char *tmp = NULL;
+
+#ifdef ARCH_64
+    new_offset = (ErtsMonotonicTime) new_offsetp;
+#else
+    new_offset = *((ErtsMonotonicTime *) new_offsetp);
+    erts_free(ERTS_ALC_T_NEW_TIME_OFFSET, new_offsetp);
+#endif
+    new_offset -= ERTS_MONOTONIC_OFFSET_NATIVE;
+
+    erts_smp_mtx_lock(&erts_get_time_mtx);
+
+    no_monitors = no_time_offset_monitors;
+    if (no_monitors) {
+	ErtsTimeOffsetMonitorContext cntxt;
+	Uint alloc_sz;
 	
-	if (ticks <= elapsed) { /* Ooops, better hurry */
-	    rem_time->tv_sec = rem_time->tv_usec = 0;
-	    return;
+	/* Monitor info array size */
+	alloc_sz = no_monitors*sizeof(ErtsTimeOffsetMonitorInfo);
+	/* + template max size */
+	alloc_sz += 6*sizeof(Eterm); /* 5-tuple */
+	alloc_sz += ERTS_MAX_SINT64_HEAP_SIZE*sizeof(Eterm); /* max offset size */
+	tmp = erts_alloc(ERTS_ALC_T_TMP, alloc_sz);
+
+	to_mon_info = (ErtsTimeOffsetMonitorInfo *) tmp;
+	cntxt.ix = 0;
+	cntxt.to_mon_info = to_mon_info;
+
+	erts_doforall_monitors(time_offset_monitors,
+			       save_time_offset_monitor,
+			       &cntxt);
+
+	ASSERT(cntxt.ix == no_monitors);
+    }
+
+    erts_smp_mtx_unlock(&erts_get_time_mtx);
+
+    if (no_monitors) {
+	Eterm *hp, *patch_refp, new_offset_term, message_template;
+	Uint mix, hsz;
+
+	/* Make message template */
+
+	hp = (Eterm *) (tmp + no_monitors*sizeof(ErtsTimeOffsetMonitorInfo));
+
+	hsz = 6; /* 5-tuple */
+	hsz += REF_THING_SIZE;
+	hsz += ERTS_SINT64_HEAP_SIZE(new_offset);
+
+	if (IS_SSMALL(new_offset))
+	    new_offset_term = make_small(new_offset);
+	else
+	    new_offset_term = erts_sint64_to_big(new_offset, &hp);
+	message_template = TUPLE5(hp,
+				  am_CHANGE,
+				  THE_NON_VALUE, /* Patch point for ref */
+				  am_time_offset,
+				  am_clock_service,
+				  new_offset_term);
+	patch_refp = &hp[2];
+
+	ASSERT(*patch_refp == THE_NON_VALUE);
+
+	for (mix = 0; mix < no_monitors; mix++) {
+	    Process *rp = erts_proc_lookup(to_mon_info[mix].pid);
+	    if (rp) {
+		Eterm ref = to_mon_info[mix].ref;
+		ErtsProcLocks rp_locks = ERTS_PROC_LOCK_LINK;
+		erts_smp_proc_lock(rp, ERTS_PROC_LOCK_LINK);
+		if (erts_lookup_monitor(ERTS_P_MONITORS(rp), ref)) {
+		    ErlHeapFragment *bp;
+		    ErlOffHeap *ohp;
+		    Eterm message;
+
+		    hp = erts_alloc_message_heap(hsz, &bp, &ohp, rp, &rp_locks);
+		    *patch_refp = ref;
+		    ASSERT(hsz == size_object(message_template));
+		    message = copy_struct(message_template, hsz, &hp, ohp);
+		    erts_queue_message(rp, &rp_locks, bp, message, NIL
+#ifdef USE_VM_PROBES
+				       , NIL
+#endif
+			);
+		}
+		erts_smp_proc_unlock(rp, rp_locks);
+	    }
 	}
-	rem_time->tv_sec = (ticks - elapsed) / 1000;
-	rem_time->tv_usec = 1000 * ((ticks - elapsed) % 1000);
+
+	erts_free(ERTS_ALC_T_TMP, tmp);
     }
 }
 
-void erts_get_timeval(SysTimeval *tv)
+static void
+schedule_send_time_offset_changed_notifications(ErtsMonotonicTime new_offset)
 {
-    erts_smp_mtx_lock(&erts_timeofday_mtx);
-    get_tolerant_timeofday(tv);
-    erts_smp_mtx_unlock(&erts_timeofday_mtx);
-    update_approx_time(tv);
+#ifdef ARCH_64
+    void *new_offsetp = (void *) new_offset;
+    ASSERT(sizeof(void *) == sizeof(ErtsMonotonicTime));
+#else
+    void *new_offsetp = erts_alloc(ERTS_ALC_T_NEW_TIME_OFFSET,
+				   sizeof(ErtsMonotonicTime));
+    *((ErtsMonotonicTime *) new_offsetp) = new_offset;
+#endif
+    erts_schedule_misc_aux_work(1,
+				send_time_offset_changed_notifications,
+				new_offsetp);
 }
 
-erts_time_t
-erts_get_time(void)
+static ERTS_INLINE Eterm
+make_time_val(Process *c_p, ErtsMonotonicTime time_val)
 {
-    SysTimeval sys_tv;
-    
-    erts_smp_mtx_lock(&erts_timeofday_mtx);
-    
-    get_tolerant_timeofday(&sys_tv);
-    
-    erts_smp_mtx_unlock(&erts_timeofday_mtx);
+    Sint64 val = (Sint64) time_val;
+    Eterm *hp;
+    Uint sz;
 
-    update_approx_time(&sys_tv);
+    if (IS_SSMALL(val))
+	return make_small(val);
 
-    return sys_tv.tv_sec;
+    sz = ERTS_SINT64_HEAP_SIZE(val);
+    hp = HAlloc(c_p, sz);
+    return erts_sint64_to_big(val, &hp);
 }
 
-#ifdef HAVE_ERTS_NOW_CPU
-void erts_get_now_cpu(Uint* megasec, Uint* sec, Uint* microsec) {
-  SysCpuTime t;
-  SysTimespec tp;
+Eterm
+erts_get_monotonic_start_time(struct process *c_p)
+{
+    return make_time_val(c_p, ERTS_MONOTONIC_OFFSET_NATIVE);
+}
 
-  sys_get_proc_cputime(t, tp);
-  *microsec = (Uint)(tp.tv_nsec / 1000);
-  t = (tp.tv_sec / 1000000);
-  *megasec = (Uint)(t % 1000000);
-  *sec = (Uint)(tp.tv_sec % 1000000);
+static Eterm
+bld_monotonic_time_source(Uint **hpp, Uint *szp, Sint64 os_mtime)
+{
+#ifndef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT
+    return NIL;
+#else
+    int i = 0;
+    Eterm k[5];
+    Eterm v[5];
+
+    if (time_sup.r.o.os_monotonic_disable)
+	return NIL;
+
+    k[i] = erts_bld_atom(hpp, szp, "function");
+    v[i++] = erts_bld_atom(hpp, szp, time_sup.r.o.os_monotonic_func);
+
+    if (time_sup.r.o.os_monotonic_clock_id) {
+	k[i] = erts_bld_atom(hpp, szp, "clock_id");
+	v[i++] = erts_bld_atom(hpp, szp, time_sup.r.o.os_monotonic_clock_id);
+    }
+
+    if (time_sup.r.o.os_monotonic_resolution) {
+	k[i] = erts_bld_atom(hpp, szp, "resolution");
+	v[i++] = erts_bld_uint64(hpp, szp, time_sup.r.o.os_monotonic_resolution);
+    }
+
+    k[i] = erts_bld_atom(hpp, szp, "parallel");
+    v[i++] = time_sup.r.o.os_monotonic_locked ? am_no : am_yes;
+
+    k[i] = erts_bld_atom(hpp, szp, "time");
+    v[i++] = erts_bld_sint64(hpp, szp, os_mtime);
+
+    return erts_bld_2tup_list(hpp, szp, (Sint) i, k, v);
+#endif
 }
+
+Eterm
+erts_monotonic_time_source(struct process *c_p)
+{
+    Uint hsz = 0;
+    Eterm *hp = NULL;
+    Sint64 os_mtime = 0;
+#ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT
+    if (!time_sup.r.o.os_monotonic_disable)
+	os_mtime = (Sint64) erts_os_monotonic_time();
+#endif
+
+    bld_monotonic_time_source(NULL, &hsz, os_mtime);
+    if (hsz)
+	hp = HAlloc(c_p, hsz);
+    return bld_monotonic_time_source(&hp, NULL, os_mtime);
+}
+
+
+#include "bif.h"
+
+static ERTS_INLINE Eterm
+time_unit_conversion(Process *c_p, Eterm term, ErtsMonotonicTime val, ErtsMonotonicTime muloff)
+{
+    ErtsMonotonicTime result;
+    BIF_RETTYPE ret;
+
+    if (val < 0)
+	goto trap_to_erlang_code;
+
+    /* Convert to common user specified time units */
+    switch (term) {
+    case am_seconds:
+    case make_small(1):
+	result = ERTS_MONOTONIC_TO_SEC(val) + muloff*ERTS_MONOTONIC_OFFSET_SEC;
+	ERTS_BIF_PREP_RET(ret, make_time_val(c_p, result));
+	break;
+    case am_milli_seconds:
+    case make_small(1000):
+	result = ERTS_MONOTONIC_TO_MSEC(val) + muloff*ERTS_MONOTONIC_OFFSET_MSEC;
+	ERTS_BIF_PREP_RET(ret, make_time_val(c_p, result));
+	break;
+    case am_micro_seconds:
+    case make_small(1000*1000):
+	result = ERTS_MONOTONIC_TO_USEC(val) + muloff*ERTS_MONOTONIC_OFFSET_USEC;
+	ERTS_BIF_PREP_RET(ret, make_time_val(c_p, result));
+	break;
+#ifdef ARCH_64
+    case am_nano_seconds:
+    case make_small(1000*1000*1000):
+	result = ERTS_MONOTONIC_TO_NSEC(val) + muloff*ERTS_MONOTONIC_OFFSET_NSEC;
+	ERTS_BIF_PREP_RET(ret, make_time_val(c_p, result));
+	break;
 #endif
+    default: {
+	Eterm value, native_res;
+#ifndef ARCH_64
+	Sint user_res;
+	if (term == am_nano_seconds)
+	    goto to_nano_seconds;
+	if (term_to_Sint(term, &user_res)) {
+	    if (user_res == 1000*1000*1000) {
+	    to_nano_seconds:
+		result = (ERTS_MONOTONIC_TO_NSEC(val)
+			  + muloff*ERTS_MONOTONIC_OFFSET_NSEC);
+		ERTS_BIF_PREP_RET(ret, make_time_val(c_p, result));
+		break;
+	    }
+	    if (user_res <= 0)
+		goto badarg;
+	}
+#else
+	if (is_small(term)) {
+	    if (signed_val(term) <= 0)
+		goto badarg;
+	}
+#endif
+	else if (is_big(term)) {
+	    if (big_sign(term))
+		goto badarg;
+	}
+	else {
+	badarg:
+	    ERTS_BIF_PREP_ERROR(ret, c_p, BADARG);
+	    break;
+	}
+
+	trap_to_erlang_code:
+	/* Do it in erlang code instead; pass along values to use... */
+	value = make_time_val(c_p, val + muloff*ERTS_MONOTONIC_OFFSET_NATIVE);
+	native_res = make_time_val(c_p, ERTS_MONOTONIC_TIME_UNIT);
+
+	ERTS_BIF_PREP_TRAP3(ret, erts_convert_time_unit_trap, c_p,
+			    value, native_res, term);
+
+	break;
+    }
+    }
+
+    return ret;
+}
+
+/* Built in functions */
+
+BIF_RETTYPE monotonic_time_0(BIF_ALIST_0)
+{
+    ErtsMonotonicTime mtime = time_sup.r.o.get_time();
+    mtime += ERTS_MONOTONIC_OFFSET_NATIVE;
+    BIF_RET(make_time_val(BIF_P, mtime));
+}
+
+BIF_RETTYPE monotonic_time_1(BIF_ALIST_1)
+{
+    BIF_RET(time_unit_conversion(BIF_P, BIF_ARG_1, time_sup.r.o.get_time(), 1));
+}
+
+BIF_RETTYPE system_time_0(BIF_ALIST_0)
+{
+    ErtsMonotonicTime mtime, offset;
+    mtime = time_sup.r.o.get_time();
+    offset = get_time_offset();
+    BIF_RET(make_time_val(BIF_P, mtime + offset));
+}
+
+BIF_RETTYPE system_time_1(BIF_ALIST_0)
+{
+    ErtsMonotonicTime mtime, offset;
+    mtime = time_sup.r.o.get_time();
+    offset = get_time_offset();
+    BIF_RET(time_unit_conversion(BIF_P, BIF_ARG_1, mtime + offset, 0));
+}
+
+BIF_RETTYPE erts_internal_time_unit_0(BIF_ALIST_0)
+{
+    BIF_RET(make_time_val(BIF_P, ERTS_MONOTONIC_TIME_UNIT));
+}
+
+BIF_RETTYPE time_offset_0(BIF_ALIST_0)
+{
+    ErtsMonotonicTime time_offset = get_time_offset();
+    time_offset -= ERTS_MONOTONIC_OFFSET_NATIVE;
+    BIF_RET(make_time_val(BIF_P, time_offset));
+}
+
+BIF_RETTYPE time_offset_1(BIF_ALIST_1)
+{
+    BIF_RET(time_unit_conversion(BIF_P, BIF_ARG_1, get_time_offset(), -1));
+}
+
+
+BIF_RETTYPE timestamp_0(BIF_ALIST_0)
+{
+    Eterm *hp, res;
+    ErtsMonotonicTime stime, mtime, all_sec, offset;
+    Uint mega_sec, sec, micro_sec;
+
+    mtime = time_sup.r.o.get_time();
+    offset = get_time_offset();
+    stime = ERTS_MONOTONIC_TO_USEC(mtime + offset);
+    all_sec = stime / ERTS_MONOTONIC_TIME_MEGA;
+    mega_sec = (Uint) (stime / ERTS_MONOTONIC_TIME_TERA);
+    sec = (Uint) (all_sec - (((ErtsMonotonicTime) mega_sec)
+			     * ERTS_MONOTONIC_TIME_MEGA));
+    micro_sec = (Uint) (stime - all_sec*ERTS_MONOTONIC_TIME_MEGA);
+
+    ASSERT(((ErtsMonotonicTime) mega_sec)*ERTS_MONOTONIC_TIME_TERA
+	   + ((ErtsMonotonicTime) sec)*ERTS_MONOTONIC_TIME_MEGA
+	   + micro_sec == stime);
+
+    /*
+     * Mega seconds is the only value that potentially
+     * ever could be a bignum. However, that wont happen
+     * during at least the next 4 million years...
+     *
+     * (System time will also have wrapped in the
+     * 64-bit integer before we get there...)
+     */
+
+    ASSERT(IS_USMALL(0, mega_sec));
+    ASSERT(IS_USMALL(0, sec));
+    ASSERT(IS_USMALL(0, micro_sec));
+
+    hp = HAlloc(BIF_P, 4);
+    res = TUPLE3(hp,
+		 make_small(mega_sec),
+		 make_small(sec),
+		 make_small(micro_sec));
+    BIF_RET(res);
+}
+
+BIF_RETTYPE os_system_time_0(BIF_ALIST_0)
+{
+    ErtsMonotonicTime stime;
+    SysTimeval tod;
+    sys_gettimeofday(&tod);
+    stime = ERTS_SEC_TO_MONOTONIC(tod.tv_sec);
+    stime += ERTS_USEC_TO_MONOTONIC(tod.tv_usec);
+    BIF_RET(make_time_val(BIF_P, stime));
+}
+
+BIF_RETTYPE os_system_time_1(BIF_ALIST_0)
+{
+    ErtsMonotonicTime stime;
+    SysTimeval tod;
+    sys_gettimeofday(&tod);
+    stime = ERTS_SEC_TO_MONOTONIC(tod.tv_sec);
+    stime += ERTS_USEC_TO_MONOTONIC(tod.tv_usec);
+    BIF_RET(time_unit_conversion(BIF_P, BIF_ARG_1, stime, 0));
+}
+
diff --git a/erts/emulator/beam/global.h b/erts/emulator/beam/global.h
index 42daa2c9ef..634fe533d0 100644
--- a/erts/emulator/beam/global.h
+++ b/erts/emulator/beam/global.h
@@ -348,8 +348,6 @@ extern Uint display_items;	/* no of items to display in traces etc */
 extern int erts_backtrace_depth;
 extern erts_smp_atomic32_t erts_max_gen_gcs;
 
-extern int erts_disable_tolerant_timeofday;
-
 extern int bif_reductions;      /* reductions + fcalls (when doing call_bif) */
 extern int stackdump_on_exit;
 
@@ -789,9 +787,6 @@ erts_bld_port_info(Eterm **hpp,
 void erts_bif_info_init(void);
 
 /* bif.c */
-Eterm erts_make_ref(Process *);
-Eterm erts_make_ref_in_buffer(Eterm buffer[REF_THING_SIZE]);
-void erts_make_ref_in_array(Uint32 ref[ERTS_MAX_REF_NUMBERS]);
 
 ERTS_GLB_INLINE Eterm
 erts_proc_store_ref(Process *c_p, Uint32 ref[ERTS_MAX_REF_NUMBERS]);
@@ -1310,7 +1305,9 @@ erts_alloc_message_heap_state(Uint size,
     state = erts_smp_atomic32_read_acqb(&receiver->state);
     if (statep)
 	*statep = state;
-    if (state & (ERTS_PSFLG_EXITING|ERTS_PSFLG_PENDING_EXIT))
+    if (state & (ERTS_PSFLG_OFF_HEAP_MSGS
+		 | ERTS_PSFLG_EXITING
+		 | ERTS_PSFLG_PENDING_EXIT))
 	goto allocate_in_mbuf;
 #endif
 
@@ -1330,7 +1327,9 @@ erts_alloc_message_heap_state(Uint size,
 	state = erts_smp_atomic32_read_nob(&receiver->state);
 	if (statep)
 	    *statep = state;
-	if ((state & (ERTS_PSFLG_EXITING|ERTS_PSFLG_PENDING_EXIT))
+	if ((state & (ERTS_PSFLG_OFF_HEAP_MSGS
+		      | ERTS_PSFLG_EXITING
+		      | ERTS_PSFLG_PENDING_EXIT))
 	    || (receiver->flags & F_DISABLE_GC)
 	    || HEAP_LIMIT(receiver) - HEAP_TOP(receiver) <= size) {
 	    /*
diff --git a/erts/emulator/beam/io.c b/erts/emulator/beam/io.c
index fb0edbcb1a..8ffe718334 100644
--- a/erts/emulator/beam/io.c
+++ b/erts/emulator/beam/io.c
@@ -47,6 +47,7 @@
 #include "external.h"
 #include "dtrace-wrapper.h"
 #include "erl_map.h"
+#include "erl_bif_unique.h"
 
 extern ErlDrvEntry fd_driver_entry;
 #ifndef __OSE__
diff --git a/erts/emulator/beam/sys.h b/erts/emulator/beam/sys.h
index d2a8b9e7f4..aeb28e72f3 100644
--- a/erts/emulator/beam/sys.h
+++ b/erts/emulator/beam/sys.h
@@ -21,6 +21,25 @@
 #define __SYS_H__
 
 
+#if defined(DEBUG) || defined(ERTS_ENABLE_LOCK_CHECK)
+#  undef ERTS_CAN_INLINE
+#  define ERTS_CAN_INLINE 0
+#  undef ERTS_INLINE
+#  define ERTS_INLINE
+#endif
+
+#if ERTS_CAN_INLINE
+#define ERTS_GLB_INLINE static ERTS_INLINE
+#else
+#define ERTS_GLB_INLINE
+#endif
+
+#if ERTS_CAN_INLINE || defined(ERTS_DO_INCL_GLB_INLINE_FUNC_DEF) 
+#  define ERTS_GLB_INLINE_INCL_FUNC_DEF 1
+#else
+#  define ERTS_GLB_INLINE_INCL_FUNC_DEF 0
+#endif
+
 #if defined(VALGRIND) && !defined(NO_FPE_SIGNALS)
 #  define NO_FPE_SIGNALS
 #endif
@@ -132,24 +151,8 @@ typedef ERTS_SYS_FD_TYPE ErtsSysFdType;
 #  endif
 #endif
 
-#if defined(DEBUG) || defined(ERTS_ENABLE_LOCK_CHECK)
-#  undef ERTS_CAN_INLINE
-#  define ERTS_CAN_INLINE 0
-#  undef ERTS_INLINE
-#  define ERTS_INLINE
-#endif
-
-#if ERTS_CAN_INLINE
-#define ERTS_GLB_INLINE static ERTS_INLINE
-#else
-#define ERTS_GLB_INLINE
-#endif
-
-#if ERTS_CAN_INLINE || defined(ERTS_DO_INCL_GLB_INLINE_FUNC_DEF) 
-#  define ERTS_GLB_INLINE_INCL_FUNC_DEF 1
-#else
-#  define ERTS_GLB_INLINE_INCL_FUNC_DEF 0
-#endif
+#define ERTS_MK_VSN_INT(Major, Minor, Build) \
+    ((((Major) & 0x3ff) << 20) | (((Minor) & 0x3ff) << 10) | ((Build) & 0x3ff))
 
 #ifndef ERTS_EXIT_AFTER_DUMP
 #  define ERTS_EXIT_AFTER_DUMP exit
@@ -385,17 +388,45 @@ typedef Sint SWord;
 typedef UWord BeamInstr;
 
 #ifndef HAVE_INT64
-#if SIZEOF_LONG == 8
-#define HAVE_INT64 1
+#  if SIZEOF_LONG == 8
+#    define HAVE_INT64 1
 typedef unsigned long Uint64;
 typedef long          Sint64;
-#elif SIZEOF_LONG_LONG == 8
-#define HAVE_INT64 1
+#    ifdef ULONG_MAX
+#      define ERTS_UINT64_MAX ULONG_MAX
+#    endif
+#    ifdef LONG_MAX
+#      define ERTS_SINT64_MAX LONG_MAX
+#    endif
+#    ifdef LONG_MIN
+#      define ERTS_SINT64_MIN LONG_MIN
+#    endif
+#  elif SIZEOF_LONG_LONG == 8
+#    define HAVE_INT64 1
 typedef unsigned long long Uint64;
 typedef long long          Sint64;
-#else
-#define HAVE_INT64 0
+#    ifdef ULLONG_MAX
+#      define ERTS_UINT64_MAX ULLONG_MAX
+#    endif
+#    ifdef LLONG_MAX
+#      define ERTS_SINT64_MAX LLONG_MAX
+#    endif
+#    ifdef LLONG_MIN
+#      define ERTS_SINT64_MIN LLONG_MIN
+#    endif
+#  else
+#    error "No 64-bit integer type found"
+#  endif
+#endif
+
+#ifndef ERTS_UINT64_MAX
+#  define ERTS_UINT64_MAX (~((Uint64) 0))
 #endif
+#ifndef ERTS_SINT64_MAX
+#  define ERTS_SINT64_MAX ((Sint64) ((((Uint64) 1) << 63)-1))
+#endif
+#ifndef ERTS_SINT64_MIN
+#  define ERTS_SINT64_MIN (-1*(((Sint64) 1) << 63))
 #endif
 
 #if SIZEOF_LONG == 4
@@ -672,10 +703,31 @@ extern char *erts_default_arg0;
 
 extern char os_type[];
 
-extern int sys_init_time(void);
+typedef enum {
+    ERTS_NO_TIME_WARP_MODE,
+    ERTS_SINGLE_TIME_WARP_MODE,
+    ERTS_MULTI_TIME_WARP_MODE
+} ErtsTimeWarpMode;
+
+typedef struct {
+    int have_os_monotonic;
+    ErtsMonotonicTime os_monotonic_time_unit;
+    ErtsMonotonicTime sys_clock_resolution;
+    struct {
+	Uint64 resolution;
+	char *func;
+	char *clock_id;
+	int locked_use;
+    } os_monotonic_info;
+} ErtsSysInitTimeResult;
+
+#define ERTS_SYS_INIT_TIME_RESULT_INITER \
+    {0, (ErtsMonotonicTime) -1, (ErtsMonotonicTime) 1}
+
+extern void sys_init_time(ErtsSysInitTimeResult *);
 extern void erts_deliver_time(void);
 extern void erts_time_remaining(SysTimeval *);
-extern int erts_init_time_sup(void);
+extern int erts_init_time_sup(int, ErtsTimeWarpMode);
 extern void erts_sys_init_float(void);
 extern void erts_thread_init_float(void);
 extern void erts_thread_disable_fpe(void);
@@ -726,7 +778,7 @@ extern char *erts_sys_ddll_error(int code);
 
 void erts_sys_schedule_interrupt(int set);
 #ifdef ERTS_SMP
-void erts_sys_schedule_interrupt_timed(int set, erts_short_time_t msec);
+void erts_sys_schedule_interrupt_timed(int, ErtsMonotonicTime);
 void erts_sys_main_thread(void);
 #endif
 
@@ -765,6 +817,7 @@ int univ_to_local(
 int local_to_univ(Sint *year, Sint *month, Sint *day, 
 		  Sint *hour, Sint *minute, Sint *second, int isdst);
 void get_now(Uint*, Uint*, Uint*);
+ErtsMonotonicTime erts_get_monotonic_time(void);
 void get_sys_now(Uint*, Uint*, Uint*);
 void set_break_quit(void (*)(void), void (*)(void));
 
diff --git a/erts/emulator/beam/time.c b/erts/emulator/beam/time.c
index 2fd8e0cf00..9f997e1d0b 100644
--- a/erts/emulator/beam/time.c
+++ b/erts/emulator/beam/time.c
@@ -83,7 +83,8 @@
 #define ASSERT_NO_LOCKED_LOCKS
 #endif
 
-static erts_smp_mtx_t tiw_lock;
+#define ERTS_MONOTONIC_DAY ERTS_SEC_TO_MONOTONIC(60*60*24)
+#define ERTS_CLKTCKS_DAY ERTS_MONOTONIC_TO_CLKTCKS(ERTS_MONOTONIC_DAY)
 
 
 /* BEGIN tiw_lock protected variables 
@@ -91,18 +92,12 @@ static erts_smp_mtx_t tiw_lock;
 ** The individual timer cells in tiw are also protected by the same mutex.
 */
 
+/* timing wheel size NEED to be a power of 2 */
 #ifdef SMALL_MEMORY
-#define TIW_SIZE 8192
+#define TIW_SIZE (1 << 13)
 #else
-#define TIW_SIZE 65536		/* timing wheel size (should be a power of 2) */
+#define TIW_SIZE (1 << 20)
 #endif
-static ErlTimer** tiw;		/* the timing wheel, allocated in init_time() */
-static Uint tiw_pos;		/* current position in wheel */
-static Uint tiw_nto;		/* number of timeouts in wheel */
-static Uint tiw_min;
-static ErlTimer *tiw_min_ptr;
-
-/* END tiw_lock protected variables */
 
 /* Actual interval time chosen by sys_init_time() */
 
@@ -114,83 +109,135 @@ static int tiw_itime; /* Constant after init */
 #  define TIW_ITIME tiw_itime
 #endif
 
-erts_smp_atomic32_t do_time;	/* set at clock interrupt */
-static ERTS_INLINE erts_short_time_t do_time_read(void)
+struct ErtsTimerWheel_ {
+    ErlTimer *w[TIW_SIZE];
+    ErtsMonotonicTime pos;
+    Uint nto;
+    struct {
+	ErlTimer *head;
+	ErlTimer **tail;
+	Uint nto;
+    } at_once;
+    int true_next_timeout_time;
+    ErtsMonotonicTime next_timeout_time;
+    erts_atomic64_t next_timeout;
+    erts_smp_atomic32_t is_bumping;
+    erts_smp_mtx_t lock;
+};
+
+ErtsTimerWheel *erts_default_timer_wheel; /* managed by aux thread */
+
+static ERTS_INLINE ErtsTimerWheel *
+get_timer_wheel(ErlTimer *p)
+{
+    return (ErtsTimerWheel *) erts_smp_atomic_read_acqb(&p->wheel);
+}
+
+static ERTS_INLINE void
+set_timer_wheel(ErlTimer *p, ErtsTimerWheel *tiw)
 {
-    return erts_smp_atomic32_read_acqb(&do_time);
+    erts_smp_atomic_set_relb(&p->wheel, (erts_aint_t) tiw);
 }
 
-static ERTS_INLINE erts_short_time_t do_time_update(void)
+static ERTS_INLINE void
+init_next_timeout(ErtsTimerWheel *tiw,
+		  ErtsMonotonicTime time)
 {
-    return do_time_read();
+    erts_atomic64_init_nob(&tiw->next_timeout,
+			   (erts_aint64_t) time);
 }
 
-static ERTS_INLINE void do_time_init(void)
+static ERTS_INLINE void
+set_next_timeout(ErtsTimerWheel *tiw,
+		 ErtsMonotonicTime time,
+		 int true_timeout)
 {
-    erts_smp_atomic32_init_nob(&do_time, 0);
+    tiw->true_next_timeout_time = true_timeout;
+    tiw->next_timeout_time = time;
+    erts_atomic64_set_relb(&tiw->next_timeout,
+			   (erts_aint64_t) time);
 }
 
 /* get the time (in units of TIW_ITIME) to the next timeout,
    or -1 if there are no timeouts                     */
 
-static erts_short_time_t next_time_internal(void) /* PRE: tiw_lock taken by caller */
+static ERTS_INLINE ErtsMonotonicTime
+find_next_timeout(ErtsTimerWheel *tiw,
+		  ErtsMonotonicTime curr_time,
+		  ErtsMonotonicTime max_search_time)
 {
-    int i, tm, nto;
-    Uint32 min;
-    ErlTimer* p;
-    erts_short_time_t dt;
-  
-    if (tiw_nto == 0)
-	return -1;	/* no timeouts in wheel */
+    int start_ix, tiw_pos_ix;
+    ErlTimer *p;
+    int true_min_timeout;
+    ErtsMonotonicTime min_timeout, min_timeout_pos, slot_timeout_pos, timeout_limit;
+
+    ERTS_SMP_LC_ASSERT(erts_smp_lc_mtx_is_locked(&tiw->lock));
+
+    if (tiw->true_next_timeout_time)
+	return tiw->next_timeout_time;
 
-    if (tiw_min_ptr) {
-	min = tiw_min;
-	dt  = do_time_read();
-	return ((min >= dt) ? (min - dt) : 0);
+    /* We never set next timeout beyond timeout_limit */
+    timeout_limit = curr_time + ERTS_MONOTONIC_DAY;
+
+    if (tiw->nto == 0) { /* no timeouts in wheel */
+	true_min_timeout = tiw->true_next_timeout_time = 0;
+	min_timeout_pos = ERTS_MONOTONIC_TO_CLKTCKS(timeout_limit);
+	goto found_next;
     }
-  
-    /* start going through wheel to find next timeout */
-    tm = nto = 0;
-    min = (Uint32) -1;	/* max Uint32 */
-    i = tiw_pos;
+
+    /*
+     * Don't want others entering trying to bump
+     * timers while we are checking...
+     */
+    set_next_timeout(tiw, timeout_limit, 0);
+
+    true_min_timeout = 1;
+    slot_timeout_pos = tiw->pos;
+    min_timeout_pos = ERTS_MONOTONIC_TO_CLKTCKS(curr_time + max_search_time);
+
+    start_ix = tiw_pos_ix = (int) (tiw->pos & (TIW_SIZE-1));
+
     do {
-	p = tiw[i];
-	while (p != NULL) {
-	    nto++;
-	    if (p->count == 0) {
-		/* found next timeout */
-		dt = do_time_read();
-		/* p->count is zero */
-		tiw_min_ptr = p;
-		tiw_min     = tm;
-		return ((tm >= dt) ? (tm - dt) : 0);
-	    } else {
-		/* keep shortest time in 'min' */
-		if (tm + p->count*TIW_SIZE < min) {
-		    min = tm + p->count*TIW_SIZE;
-		    tiw_min_ptr = p;
-		    tiw_min     = min;
-		}
+	slot_timeout_pos++;
+	if (slot_timeout_pos >= min_timeout_pos) {
+	    true_min_timeout = 0;
+	    break;
+	}
+
+	p = tiw->w[tiw_pos_ix];
+
+	while (p) {
+	    ErtsMonotonicTime timeout_pos;
+	    ASSERT(p != p->next);
+	    timeout_pos = p->timeout_pos;
+	    if (min_timeout_pos > timeout_pos) {
+		min_timeout_pos = timeout_pos;
+		if (min_timeout_pos <= slot_timeout_pos)
+		    goto found_next;
 	    }
 	    p = p->next;
 	}
-	/* when we have found all timeouts the shortest time will be in min */
-	if (nto == tiw_nto) break;
-	tm++;
-	i = (i + 1) % TIW_SIZE;
-    } while (i != tiw_pos);
-    dt = do_time_read();
-    if (min <= (Uint32) dt)
-	return 0;
-    if ((min - (Uint32) dt) > (Uint32) ERTS_SHORT_TIME_T_MAX)
-	return ERTS_SHORT_TIME_T_MAX;
-    return (erts_short_time_t) (min - (Uint32) dt);
+
+	tiw_pos_ix++;
+	if (tiw_pos_ix == TIW_SIZE)
+	    tiw_pos_ix = 0;
+    } while (start_ix != tiw_pos_ix);
+
+found_next:
+
+    min_timeout = ERTS_CLKTCKS_TO_MONOTONIC(min_timeout_pos);
+    if (min_timeout != tiw->next_timeout_time)
+	set_next_timeout(tiw, min_timeout, true_min_timeout);
+
+    return min_timeout;
 }
 
-static void remove_timer(ErlTimer *p) {
+static void
+remove_timer(ErtsTimerWheel *tiw, ErlTimer *p)
+{
     /* first */
     if (!p->prev) {
-	tiw[p->slot] = p->next;
+	tiw->w[p->slot] = p->next;
 	if(p->next)
 	    p->next->prev = NULL;
     } else {
@@ -207,79 +254,164 @@ static void remove_timer(ErlTimer *p) {
 
     p->next = NULL;
     p->prev = NULL;
-    /* Make sure cancel callback isn't called */
-    p->active = 0;
-    tiw_nto--;
+
+    set_timer_wheel(p, NULL);
+    tiw->nto--;
+}
+
+ErtsMonotonicTime
+erts_check_next_timeout_time(ErtsTimerWheel *tiw,
+			     ErtsMonotonicTime max_search_time)
+{
+    ErtsMonotonicTime next, curr;
+
+    curr = erts_get_monotonic_time();
+
+    erts_smp_mtx_lock(&tiw->lock);
+
+    next = find_next_timeout(tiw, curr, max_search_time);
+
+    erts_smp_mtx_unlock(&tiw->lock);
+
+    return next;
 }
 
-/* Private export to erl_time_sup.c */
-erts_short_time_t erts_next_time(void)
+#ifndef DEBUG
+#define ERTS_DBG_CHK_SAFE_TO_SKIP_TO(TIW, TO) ((void) 0)
+#else
+#define ERTS_DBG_CHK_SAFE_TO_SKIP_TO(TIW, TO) debug_check_safe_to_skip_to((TIW), (TO))
+static void
+debug_check_safe_to_skip_to(ErtsTimerWheel *tiw, ErtsMonotonicTime skip_to_pos)
 {
-    erts_short_time_t ret;
+    int slots, ix;
+    ErlTimer *tmr;
+    ErtsMonotonicTime tmp;
+
+    ix = (int) (tiw->pos & (TIW_SIZE-1));
+    tmp = skip_to_pos - tiw->pos;
+    ASSERT(tmp >= 0);
+    if (tmp < (ErtsMonotonicTime) TIW_SIZE)
+	slots = (int) tmp;
+    else
+	slots = TIW_SIZE;
 
-    erts_smp_mtx_lock(&tiw_lock);
-    (void)do_time_update();
-    ret = next_time_internal();
-    erts_smp_mtx_unlock(&tiw_lock);
-    return ret;
+     while (slots > 0) {
+	tmr = tiw->w[ix];
+	while (tmr) {
+	    ASSERT(tmr->timeout_pos > skip_to_pos);
+	    tmr = tmr->next;
+	}
+	ix++;
+	if (ix == TIW_SIZE)
+	    ix = 0;
+	slots--;
+    }
 }
+#endif
 
-static ERTS_INLINE void bump_timer_internal(erts_short_time_t dt) /* PRE: tiw_lock is write-locked */
+void
+erts_bump_timers(ErtsTimerWheel *tiw, ErtsMonotonicTime curr_time)
 {
-    Uint keep_pos;
-    Uint count;
-    ErlTimer *p, **prev, *timeout_head, **timeout_tail;
-    Uint dtime = (Uint) dt;  
-
-    /* no need to bump the position if there aren't any timeouts */
-    if (tiw_nto == 0) {
-	erts_smp_mtx_unlock(&tiw_lock);
-	return;
+    int tiw_pos_ix, slots;
+    ErlTimer *p, *timeout_head, **timeout_tail;
+    ErtsMonotonicTime bump_to, tmp_slots;
+
+    if (erts_smp_atomic32_cmpxchg_nob(&tiw->is_bumping, 1, 0) != 0)
+	return; /* Another thread is currently bumping... */
+
+    bump_to = ERTS_MONOTONIC_TO_CLKTCKS(curr_time);
+
+    erts_smp_mtx_lock(&tiw->lock);
+
+    if (tiw->pos >= bump_to) {
+	timeout_head = NULL;
+	goto done;
     }
 
-    /* if do_time > TIW_SIZE we want to go around just once */
-    count = (Uint)(dtime / TIW_SIZE) + 1;
-    keep_pos = (tiw_pos + dtime) % TIW_SIZE;
-    if (dtime > TIW_SIZE) dtime = TIW_SIZE;
-  
-    timeout_head = NULL;
-    timeout_tail = &timeout_head;
-    while (dtime > 0) {
-	/* this is to decrease the counters with the right amount */
-	/* when dtime >= TIW_SIZE */
-	if (tiw_pos == keep_pos) count--;
-	prev = &tiw[tiw_pos];
-	while ((p = *prev) != NULL) {
-	    ASSERT( p != p->next);
-	    if (p->count < count) {     /* we have a timeout */
-		/* remove min time */
-		if (tiw_min_ptr == p) {
-		    tiw_min_ptr = NULL;
-		    tiw_min = 0;
-		}
+    /* Don't want others here while we are bumping... */
+    set_next_timeout(tiw, curr_time + ERTS_MONOTONIC_DAY, 0);
 
+    if (!tiw->at_once.head) {
+	timeout_head = NULL;
+	timeout_tail = &timeout_head;
+    }
+    else {
+	ASSERT(tiw->nto >= tiw->at_once.nto);
+	timeout_head = tiw->at_once.head;
+	timeout_tail = tiw->at_once.tail;
+	tiw->nto -= tiw->at_once.nto;
+	tiw->at_once.head = NULL;
+	tiw->at_once.tail = &tiw->at_once.head;
+	tiw->at_once.nto = 0;
+    }
+
+    if (tiw->nto == 0) {
+	ERTS_DBG_CHK_SAFE_TO_SKIP_TO(tiw, bump_to);
+	tiw->pos = bump_to;
+	goto done;
+    }
+
+    if (tiw->true_next_timeout_time) {
+	ErtsMonotonicTime skip_until_pos;
+	/*
+	 * No need inspecting slots where we know no timeouts
+	 * to trigger should reside.
+	 */
+
+	skip_until_pos = ERTS_MONOTONIC_TO_CLKTCKS(tiw->next_timeout_time);
+	if (skip_until_pos > bump_to)
+	    skip_until_pos = bump_to;
+
+	ERTS_DBG_CHK_SAFE_TO_SKIP_TO(tiw, skip_until_pos);
+	ASSERT(skip_until_pos > tiw->pos);
+
+	tiw->pos = skip_until_pos - 1;
+    }
+
+    tiw_pos_ix = (int) ((tiw->pos+1) & (TIW_SIZE-1));
+    tmp_slots = (bump_to - tiw->pos);
+    if (tmp_slots < (ErtsMonotonicTime) TIW_SIZE)
+	slots = (int) tmp_slots;
+    else
+	slots = TIW_SIZE;
+ 
+    while (slots > 0) {
+	p = tiw->w[tiw_pos_ix];
+	while (p) {
+	    ErlTimer *next = p->next;
+	    ASSERT(p != next);
+	    if (p->timeout_pos <= bump_to) { /* we have a timeout */
 		/* Remove from list */
-		remove_timer(p);
+		remove_timer(tiw, p);
 		*timeout_tail = p;	/* Insert in timeout queue */
 		timeout_tail = &p->next;
 	    }
-	    else {
-		/* no timeout, just decrease counter */
-		p->count -= count;
-		prev = &p->next;
-	    }
+	    p = next;
 	}
-	tiw_pos = (tiw_pos + 1) % TIW_SIZE;
-	dtime--;
+	tiw_pos_ix++;
+	if (tiw_pos_ix == TIW_SIZE)
+	    tiw_pos_ix = 0;
+	slots--;
     }
-    tiw_pos = keep_pos;
-    if (tiw_min_ptr)
-	tiw_min -= dt;
-    
-    erts_smp_mtx_unlock(&tiw_lock);
+
+    ASSERT(tmp_slots >= (ErtsMonotonicTime) TIW_SIZE
+	   || tiw_pos_ix == (int) ((bump_to+1) & (TIW_SIZE-1)));
+
+    tiw->pos = bump_to;
+
+    /* Search at most two seconds ahead... */
+    (void) find_next_timeout(tiw, curr_time, ERTS_SEC_TO_MONOTONIC(2));
+
+done:
+
+    erts_smp_mtx_unlock(&tiw->lock);
     
+    erts_smp_atomic32_set_nob(&tiw->is_bumping, 0);
+
     /* Call timedout timers callbacks */
     while (timeout_head) {
+	ErlTimeoutProc timeout;
+	void *arg;
 	p = timeout_head;
 	timeout_head = p->next;
 	/* Here comes hairy use of the timer fields!
@@ -288,35 +420,69 @@ static ERTS_INLINE void bump_timer_internal(erts_short_time_t dt) /* PRE: tiw_lo
 	 * accesses any field until the ->timeout
 	 * callback is called.
 	 */
+	ASSERT(p->timeout_pos <= bump_to);
 	p->next = NULL;
 	p->prev = NULL;
 	p->slot = 0;
-	(*p->timeout)(p->arg);
+	timeout = p->timeout;
+	arg = p->arg;
+	(*timeout)(arg);
     }
 }
 
-void erts_bump_timer(erts_short_time_t dt) /* dt is value from do_time */
+Uint
+erts_timer_wheel_memory_size(void)
+{
+#ifdef ERTS_SMP
+    return sizeof(ErtsTimerWheel)*(1 + erts_no_schedulers);
+#else
+    return sizeof(ErtsTimerWheel);
+#endif
+}
+
+ErtsTimerWheel *
+erts_create_timer_wheel(int no)
 {
-    erts_smp_mtx_lock(&tiw_lock);
-    bump_timer_internal(dt);
+    ErtsMonotonicTime mtime;
+    int i;
+    ErtsTimerWheel *tiw;
+    tiw = (ErtsTimerWheel *) erts_alloc(ERTS_ALC_T_TIMER_WHEEL,
+					sizeof(ErtsTimerWheel));
+    for(i = 0; i < TIW_SIZE; i++)
+	tiw->w[i] = NULL;
+
+    erts_smp_atomic32_init_nob(&tiw->is_bumping, 0);
+    erts_smp_mtx_init_x(&tiw->lock, "timer_wheel", make_small(no));
+
+    mtime = erts_get_monotonic_time();
+    tiw->pos = ERTS_MONOTONIC_TO_CLKTCKS(mtime);
+    tiw->nto = 0;
+    tiw->at_once.head = NULL;
+    tiw->at_once.tail = &tiw->at_once.head;
+    tiw->at_once.nto = 0;
+    tiw->true_next_timeout_time = 0;
+    tiw->next_timeout_time = mtime + ERTS_MONOTONIC_DAY;
+    init_next_timeout(tiw, mtime + ERTS_MONOTONIC_DAY);
+    return tiw;
 }
 
-Uint
-erts_timer_wheel_memory_size(void)
+ErtsNextTimeoutRef
+erts_get_next_timeout_reference(ErtsTimerWheel *tiw)
 {
-    return (Uint) TIW_SIZE * sizeof(ErlTimer*);
+    return (ErtsNextTimeoutRef) &tiw->next_timeout;
 }
 
+
 /* this routine links the time cells into a free list at the start
    and sets the time queue as empty */
 void
-erts_init_time(void)
+erts_init_time(int time_correction, ErtsTimeWarpMode time_warp_mode)
 {
-    int i, itime;
+    int itime;
 
     /* system dependent init; must be done before do_time_init()
        if timer thread is enabled */
-    itime = erts_init_time_sup();
+    itime = erts_init_time_sup(time_correction, time_warp_mode);
 #ifdef TIW_ITIME_IS_CONSTANT 
     if (itime != TIW_ITIME) {
 	erl_exit(ERTS_ABORT_EXIT, "timer resolution mismatch %d != %d", itime, TIW_ITIME);
@@ -325,117 +491,110 @@ erts_init_time(void)
     tiw_itime = itime;
 #endif
 
-    erts_smp_mtx_init(&tiw_lock, "timer_wheel");
-
-    tiw = (ErlTimer**) erts_alloc(ERTS_ALC_T_TIMER_WHEEL,
-				  TIW_SIZE * sizeof(ErlTimer*));
-    for(i = 0; i < TIW_SIZE; i++)
-	tiw[i] = NULL;
-    do_time_init();
-    tiw_pos = tiw_nto = 0;
-    tiw_min_ptr = NULL;
-    tiw_min = 0;
+    erts_default_timer_wheel = erts_create_timer_wheel(0);
 }
 
+void
+erts_set_timer(ErlTimer *p, ErlTimeoutProc timeout,
+	       ErlCancelProc cancel, void *arg, Uint to)
+{
+    ErtsMonotonicTime timeout_time, timeout_pos;
+    ErtsMonotonicTime curr_time;
+    ErtsTimerWheel *tiw;
+    ErtsSchedulerData *esdp;
+
+    curr_time = erts_get_monotonic_time();
+    esdp = erts_get_scheduler_data();
+    if (esdp)
+	tiw = esdp->timer_wheel;
+    else
+	tiw = erts_default_timer_wheel;
 
+    erts_smp_mtx_lock(&tiw->lock);
 
+    if (get_timer_wheel(p))
+	ERTS_INTERNAL_ERROR("Double set timer");
 
-/*
-** Insert a process into the time queue, with a timeout 't'
-*/
-static void
-insert_timer(ErlTimer* p, Uint t)
-{
-    Uint tm;
-    Uint64 ticks;
+    p->timeout = timeout;
+    p->cancel = cancel;
+    p->arg = arg;
 
-    /* The current slot (tiw_pos) in timing wheel is the next slot to be
-     * be processed. Hence no extra time tick is needed.
-     *
-     * (x + y - 1)/y is precisely the "number of bins" formula.
-     */
-    ticks = (t + (TIW_ITIME - 1)) / TIW_ITIME;
+    if (to == 0) {
+	timeout_pos = ERTS_MONOTONIC_TO_CLKTCKS(curr_time);
+	tiw->nto++;
+	tiw->at_once.nto++;
+	*tiw->at_once.tail = p;
+	p->next = NULL;
+	p->timeout_pos = timeout_pos;
+	timeout_time = ERTS_CLKTCKS_TO_MONOTONIC(timeout_pos);
+    }
+    else {
+	int tm;
+	ErtsMonotonicTime ticks;
 
-    /* 
-     * Ticks must be a Uint64, or the addition may overflow here,
-     * resulting in an incorrect value for p->count below.
-     */
-    ticks += do_time_update(); /* Add backlog of unprocessed time */
-    
-    /* calculate slot */
-    tm = (ticks + tiw_pos) % TIW_SIZE;
-    p->slot = (Uint) tm;
-    p->count = (Uint) (ticks / TIW_SIZE);
+	ticks = ERTS_MSEC_TO_CLKTCKS(to);
+	timeout_pos = ERTS_MONOTONIC_TO_CLKTCKS(curr_time - 1) + 1 + ticks;
+
+	/* calculate slot */
+	tm = (int) (timeout_pos & (TIW_SIZE-1));
+	p->slot = (Uint) tm;
   
-    /* insert at head of list at slot */
-    p->next = tiw[tm];
-    p->prev = NULL;
-    if (p->next != NULL)
-	p->next->prev = p;
-    tiw[tm] = p;
+	/* insert at head of list at slot */
+	p->next = tiw->w[tm];
+	p->prev = NULL;
+	if (p->next != NULL)
+	    p->next->prev = p;
+	tiw->w[tm] = p;
 
+	tiw->nto++;
 
-    /* insert min time */
-    if ((tiw_nto == 0) || ((tiw_min_ptr != NULL) && (ticks < tiw_min))) {
-	tiw_min = ticks;
-	tiw_min_ptr = p;
-    }
-    if ((tiw_min_ptr == p) && (ticks > tiw_min)) {
-	/* some other timer might be 'min' now */
-	tiw_min = 0;
-	tiw_min_ptr = NULL;
+	timeout_time = ERTS_CLKTCKS_TO_MONOTONIC(timeout_pos);
+	p->timeout_pos = timeout_pos;
+
+	ASSERT(ERTS_MSEC_TO_MONOTONIC(to) <= timeout_time - curr_time);
+	ASSERT(timeout_time - curr_time
+	       < ERTS_MSEC_TO_MONOTONIC(to) + ERTS_CLKTCKS_TO_MONOTONIC(1));
     }
 
-    tiw_nto++;
-}
+    if (timeout_time < tiw->next_timeout_time)
+	set_next_timeout(tiw, timeout_time, 1);
 
-void
-erts_set_timer(ErlTimer* p, ErlTimeoutProc timeout, ErlCancelProc cancel,
-	      void* arg, Uint t)
-{
+    set_timer_wheel(p, tiw);
+
+    erts_smp_mtx_unlock(&tiw->lock);
 
-    erts_deliver_time();
-    erts_smp_mtx_lock(&tiw_lock);
-    if (p->active) { /* XXX assert ? */
-	erts_smp_mtx_unlock(&tiw_lock);
-	return;
-    }
-    p->timeout = timeout;
-    p->cancel = cancel;
-    p->arg = arg;
-    p->active = 1;
-    insert_timer(p, t);
-    erts_smp_mtx_unlock(&tiw_lock);
 #if defined(ERTS_SMP)
-    if (t <= (Uint) ERTS_SHORT_TIME_T_MAX)
-	erts_sys_schedule_interrupt_timed(1, (erts_short_time_t) t);
+    if (tiw == erts_default_timer_wheel)
+	erts_interupt_aux_thread_timed(timeout_time);
 #endif
+
 }
 
 void
-erts_cancel_timer(ErlTimer* p)
+erts_cancel_timer(ErlTimer *p)
 {
-    erts_smp_mtx_lock(&tiw_lock);
-    if (!p->active) { /* allow repeated cancel (drivers) */
-	erts_smp_mtx_unlock(&tiw_lock);
+    ErtsTimerWheel *tiw;
+    ErlCancelProc cancel;
+    void *arg;
+
+    tiw = get_timer_wheel(p);
+    if (!tiw)
 	return;
-    }
+    
+    erts_smp_mtx_lock(&tiw->lock);
+    if (tiw != get_timer_wheel(p))
+	cancel = NULL;
+    else {
+	remove_timer(tiw, p);
+	p->slot = 0;
 
-    /* is it the 'min' timer, remove min */
-    if (p == tiw_min_ptr) {
-	tiw_min_ptr = NULL;
-	tiw_min     = 0;
+	cancel = p->cancel;
+	arg = p->arg;
     }
+    erts_smp_mtx_unlock(&tiw->lock);
 
-    remove_timer(p);
-    p->slot = p->count = 0;
-
-    if (p->cancel != NULL) {
-	erts_smp_mtx_unlock(&tiw_lock);
-	(*p->cancel)(p->arg);
-	return;
-    }
-    erts_smp_mtx_unlock(&tiw_lock);
+    if (cancel)
+	(*cancel)(arg);
 }
 
 /*
@@ -447,59 +606,58 @@ erts_cancel_timer(ErlTimer* p)
 Uint
 erts_time_left(ErlTimer *p)
 {
-    Uint left;
-    erts_short_time_t dt;
+    ErtsTimerWheel *tiw;
+    ErtsMonotonicTime current_time, timeout_time;
 
-    erts_smp_mtx_lock(&tiw_lock);
-
-    if (!p->active) {
-	erts_smp_mtx_unlock(&tiw_lock);
+    tiw = get_timer_wheel(p);
+    if (!tiw)
 	return 0;
-    }
 
-    if (p->slot < tiw_pos)
-	left = (p->count + 1) * TIW_SIZE + p->slot - tiw_pos;
+    erts_smp_mtx_lock(&tiw->lock);
+    if (tiw != get_timer_wheel(p))
+	timeout_time = ERTS_MONOTONIC_TIME_MIN;
     else
-	left = p->count * TIW_SIZE + p->slot - tiw_pos;
-    dt = do_time_read();
-    if (left < dt)
-	left = 0;
-    else
-	left -= dt;
-
-    erts_smp_mtx_unlock(&tiw_lock);
+	timeout_time = ERTS_CLKTCKS_TO_MONOTONIC(p->timeout_pos);
+    erts_smp_mtx_unlock(&tiw->lock);
 
-    return (Uint) left * TIW_ITIME;
+    current_time = erts_get_monotonic_time();
+    if (timeout_time <= current_time)
+	return 0;
+    return (Uint) ERTS_MONOTONIC_TO_MSEC(timeout_time - current_time);
 }
 
 #ifdef DEBUG
 void erts_p_slpq(void)
 {
+    ErtsTimerWheel *tiw = erts_default_timer_wheel;
+    ErtsMonotonicTime current_time = erts_get_monotonic_time();
     int i;
     ErlTimer* p;
   
-    erts_smp_mtx_lock(&tiw_lock);
+    erts_smp_mtx_lock(&tiw->lock);
 
     /* print the whole wheel, starting at the current position */
-    erts_printf("\ntiw_pos = %d tiw_nto %d\n", tiw_pos, tiw_nto);
-    i = tiw_pos;
-    if (tiw[i] != NULL) {
+    erts_printf("\ncurrent time = %bps tiw_pos = %d tiw_nto %d\n",
+		current_time, tiw->pos, tiw->nto);
+    i = tiw->pos;
+    if (tiw->w[i] != NULL) {
 	erts_printf("%d:\n", i);
-	for(p = tiw[i]; p != NULL; p = p->next) {
-	    erts_printf(" (count %d, slot %d)\n",
-			p->count, p->slot);
+	for(p = tiw->w[i]; p != NULL; p = p->next) {
+	    erts_printf(" (timeout time %bps, slot %d)\n",
+			ERTS_CLKTCKS_TO_MONOTONIC(p->timeout_pos),
+			p->slot);
 	}
     }
-    for(i = (i+1)%TIW_SIZE; i != tiw_pos; i = (i+1)%TIW_SIZE) {
-	if (tiw[i] != NULL) {
+    for(i = ((i+1) & (TIW_SIZE-1)); i != (tiw->pos & (TIW_SIZE-1)); i = ((i+1) & (TIW_SIZE-1))) {
+	if (tiw->w[i] != NULL) {
 	    erts_printf("%d:\n", i);
-	    for(p = tiw[i]; p != NULL; p = p->next) {
-		erts_printf(" (count %d, slot %d)\n",
-			    p->count, p->slot);
+	    for(p = tiw->w[i]; p != NULL; p = p->next) {
+		erts_printf(" (timeout time %bps, slot %d)\n",
+			    ERTS_CLKTCKS_TO_MONOTONIC(p->timeout_pos), p->slot);
 	    }
 	}
     }
 
-    erts_smp_mtx_unlock(&tiw_lock);
+    erts_smp_mtx_unlock(&tiw->lock);
 }
 #endif /* DEBUG */
diff --git a/erts/emulator/beam/utils.c b/erts/emulator/beam/utils.c
index 3549e18538..127f1e4a6a 100644
--- a/erts/emulator/beam/utils.c
+++ b/erts/emulator/beam/utils.c
@@ -49,6 +49,7 @@
 #include "beam_bp.h"
 #include "erl_ptab.h"
 #include "erl_check_io.h"
+#include "erl_bif_unique.h"
 #ifdef HIPE
 #  include "hipe_mode_switch.h"
 #endif
@@ -4510,7 +4511,7 @@ erts_create_smp_ptimer(ErtsSmpPTimer **timer_ref,
     res->timer.timeout_func = timeout_func;
     res->timer.timer_ref = timer_ref;
     res->timer.id = id;
-    res->timer.tm.active = 0; /* MUST be initalized */
+    erts_init_timer(&res->timer.tm);
 
     ASSERT(!*timer_ref);
 
@@ -5087,8 +5088,8 @@ erts_smp_ensure_later_interval_acqb(erts_interval_t *icp, Uint64 ic)
  */
 Uint64 erts_timestamp_millis(void)
 {
-#ifdef HAVE_GETHRTIME
-    return (Uint64) (sys_gethrtime() / 1000000);
+#ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT
+    return ERTS_MONOTONIC_TO_MSEC(erts_os_monotonic_time());
 #else
     Uint64 res;
     SysTimeval tv;