Merge branch 'rickard/time_api/OTP-11997'

* rickard/time_api/OTP-11997:
  Better OS system time implementation
  Documentation adjustments
  Fix zero timout timers
  erts_sys_hrtime() for lcnt
  Better support for poor os monotonic sources

Conflicts:
	erts/preloaded/ebin/erlang.beam

20 files changed, 1102 insertions, 398 deletions

diff --git a/erts/aclocal.m4 b/erts/aclocal.m4
index b2d30449cd..fb5ae4f02d 100644
--- a/erts/aclocal.m4
+++ b/erts/aclocal.m4
@@ -745,11 +745,9 @@ AC_DEFUN(ERL_MONOTONIC_CLOCK,
      done
   ])
   
-  AC_CHECK_FUNC(clock_getres)
-
-  AC_CHECK_FUNC(gethrtime)
+  AC_CHECK_FUNCS([clock_getres gethrtime])
   
-  AC_CACHE_CHECK([for mach clock_get_time()], erl_cv_mach_clock_get_time,
+  AC_CACHE_CHECK([for mach clock_get_time()], erl_cv_mach_clock_get_time_monotonic,
   [
      AC_TRY_COMPILE([
 #include <mach/clock.h>
@@ -764,13 +762,13 @@ AC_DEFUN(ERL_MONOTONIC_CLOCK,
     res = clock_get_time(clk_srv, &time_spec);
     mach_port_deallocate(mach_task_self(), clk_srv);
     			],
-    			erl_cv_mach_clock_get_time=yes,
-			erl_cv_mach_clock_get_time=no)
+    			erl_cv_mach_clock_get_time_monotonic=yes,
+			erl_cv_mach_clock_get_time_monotonic=no)
   ])
   
-  case $erl_cv_clock_gettime_monotonic-$ac_cv_func_gethrtime-$erl_cv_mach_clock_get_time-$host_os in
+  case $erl_cv_clock_gettime_monotonic-$ac_cv_func_gethrtime-$erl_cv_mach_clock_get_time_monotonic-$host_os in
     *-*-*-win32)
-      erl_monotonic_clock_func=GetTickCount
+      erl_monotonic_clock_func=WindowsAPI
       ;;
     CLOCK_*-*-*-linux*)
       if test X$cross_compiling != Xyes; then
@@ -835,6 +833,70 @@ AC_DEFUN(ERL_MONOTONIC_CLOCK,
  
 ])
 
+AC_DEFUN(ERL_WALL_CLOCK,
+[
+  AC_CACHE_CHECK([for clock_gettime() with wall clock type], erl_cv_clock_gettime_wall,
+  [
+     for clock_type in CLOCK_REALTIME; do
+       AC_TRY_COMPILE([
+#include <time.h>
+		      ],
+		      [
+    struct timespec ts;
+    long long result;
+    clock_gettime($clock_type,&ts);
+    result = ((long long) ts.tv_sec) * 1000000000LL + 
+    ((long long) ts.tv_nsec);
+		      ],
+		      erl_cv_clock_gettime_wall=$clock_type,
+		      erl_cv_clock_gettime_wall=no)
+       test $erl_cv_clock_gettime_wall = no || break
+     done
+  ])
+  
+  AC_CHECK_FUNCS([clock_getres gettimeofday])
+  
+  AC_CACHE_CHECK([for mach clock_get_time()], erl_cv_mach_clock_get_time_wall,
+  [
+     AC_TRY_COMPILE([
+#include <mach/clock.h>
+#include <mach/mach.h>
+			],
+	 		[
+    kern_return_t res;
+    clock_serv_t clk_srv;
+    mach_timespec_t time_spec;
+
+    host_get_clock_service(mach_host_self(), CALENDAR_CLOCK, &clk_srv);
+    res = clock_get_time(clk_srv, &time_spec);
+    mach_port_deallocate(mach_task_self(), clk_srv);
+    			],
+    			erl_cv_mach_clock_get_time_wall=yes,
+			erl_cv_mach_clock_get_time_wall=no)
+  ])
+
+  erl_wall_clock_id=
+  case $erl_cv_clock_gettime_wall-$erl_cv_mach_clock_get_time_wall-$ac_cv_func_gettimeofday-$host_os in
+    *-*-*-win32)
+      erl_wall_clock_func=WindowsAPI
+      ;;
+    no-yes-*-*)
+      erl_wall_clock_func=mach_clock_get_time
+      erl_wall_clock_id=CALENDAR_CLOCK
+      ;;
+    CLOCK_*-*-*-*)
+      erl_wall_clock_func=clock_gettime
+      erl_wall_clock_id=$erl_cv_clock_gettime_wall
+      ;;
+    no-no-yes-*)
+      erl_wall_clock_func=gettimeofday
+      ;;
+    *)
+      erl_wall_clock_func=none
+      ;;
+  esac
+])
+
 dnl ----------------------------------------------------------------------
 dnl
 dnl LM_CHECK_THR_LIB
@@ -2079,6 +2141,27 @@ dnl
 AC_DEFUN(ERL_TIME_CORRECTION,
 [
 
+ERL_WALL_CLOCK
+
+case $erl_wall_clock_func in
+  mach_clock_get_time)
+    AC_DEFINE(OS_SYSTEM_TIME_USING_MACH_CLOCK_GET_TIME, [1], [Define if you want to implement erts_os_system_time() using mach clock_get_time()])
+    ;;
+  clock_gettime)
+    AC_DEFINE(OS_SYSTEM_TIME_USING_CLOCK_GETTIME, [1], [Define if you want to implement erts_os_system_time() using clock_gettime()])
+    ;;
+  gettimeofday)
+    AC_DEFINE(OS_SYSTEM_TIME_GETTIMEOFDAY,  [1], [Define if you want to implement erts_os_system_time() using gettimeofday()])
+    ;;
+  *)
+    ;;
+esac
+
+if test "x$erl_wall_clock_id" != "x"; then
+    AC_DEFINE_UNQUOTED(WALL_CLOCK_ID_STR, ["$erl_wall_clock_id"], [Define as a string of wall clock id to use])
+    AC_DEFINE_UNQUOTED(WALL_CLOCK_ID, [$erl_wall_clock_id], [Define to wall clock id to use])
+fi
+
 ERL_MONOTONIC_CLOCK
 
 case $erl_monotonic_clock_func in
diff --git a/erts/doc/src/erlang.xml b/erts/doc/src/erlang.xml
index 880c294c73..ba5f80a9c1 100644
--- a/erts/doc/src/erlang.xml
+++ b/erts/doc/src/erlang.xml
@@ -110,10 +110,17 @@
 	  <note>
 	    <p>The value of the <c>native</c> time unit gives
 	    you more or less no information at all about the
-	    quality of time values. It sets an upper bound for
-	    the resolution as well as for the precision, but it
-	    gives absolutely no information at all about the
-	    accuracy.</p>
+	    quality of time values. It sets a limit for
+	    the
+	    <seealso marker="time_correction#Time_Resolution">resolution</seealso>
+	    as well as for the
+	    <seealso marker="time_correction#Time_Precision">precision</seealso>
+	    of time values,
+	    but it gives absolutely no information at all about the
+	    <seealso marker="time_correction#Time_Accuracy">accuracy</seealso>
+	    of time values. The resolution of the <c>native</c> time
+	    unit and the resolution of time values may differ
+	    significantly.</p>
 	  </note>
 	  </item>
 
@@ -6038,6 +6045,8 @@ ok
       <name name="system_info" arity="1" clause_i="62"/>
       <name name="system_info" arity="1" clause_i="63"/>
       <name name="system_info" arity="1" clause_i="64"/>
+      <name name="system_info" arity="1" clause_i="65"/>
+      <name name="system_info" arity="1" clause_i="66"/>
       <fsummary>Information about the system</fsummary>
       <desc>
         <p>Returns various information about the current system
@@ -6449,20 +6458,33 @@ ok
 	      <c>Function</c>.</p></item>
 
 	      <tag><c>{resolution, OsMonotonicTimeResolution}</c></tag>
-	      <item><p>Highest possible resolution of current
-	      OS monotonic time source as parts per second. If
-	      no resolution information can be retreived from
-	      the OS, <c>OsMonotonicTimeResolution</c> will be
+	      <item><p>Highest possible
+	      <seealso marker="time_correction#Time_Resolution">resolution</seealso>
+	      of current OS monotonic time source as parts per
+	      second. If no resolution information can be retreived
+	      from the OS, <c>OsMonotonicTimeResolution</c> will be
 	      set to the resolution of the time unit of
 	      <c>Function</c>s return value. That is, the actual
 	      resolution may be lower than
 	      <c>OsMonotonicTimeResolution</c>. Also note that
 	      the resolution does not say anything about the
-	      accuracy, and that the precision might not align
-	      with the resolution. You do, however, know that the
-	      precision won't be higher than
+	      <seealso marker="time_correction#Time_Accuracy">accuracy</seealso>,
+	      and that the
+	      <seealso marker="time_correction#Time_Precision">precision</seealso>
+	      might not align with the resolution. You do,
+	      however, know that the precision won't be
+	      better than
 	      <c>OsMonotonicTimeResolution</c>.</p></item>
 
+	      <tag><c>{extended, Extended}</c></tag>
+	      <item><p><c>Extended</c> equals <c>yes</c> if
+	      the range of time values has been extended;
+	      otherwise, <c>Extended</c> equals <c>no</c>. The
+	      range needs to be extended if <c>Function</c>
+	      returns values that wrap fast. This typically
+	      is the case when the return value is a 32-bit
+	      value.</p></item>
+
 	      <tag><c>{parallel, Parallel}</c></tag>
 	      <item><p><c>Parallel</c> equals <c>yes</c> if
 	      <c>Function</c> is called in parallel from multiple
@@ -6476,6 +6498,59 @@ ok
 	      <seealso marker="#type_time_unit">time unit</seealso>.</p></item>
 	    </taglist>
           </item>
+          <tag><marker id="system_info_os_system_time_source"><c>os_system_time_source</c></marker></tag>
+          <item>
+            <p>Returns a list containing information about the source of
+	    <seealso marker="erts:time_correction#OS_System_Time">OS
+	    system time</seealso> that is used by the runtime system.</p>
+	    <p>The list contains two-tuples with <c>Key</c>s
+	    as first element, and <c>Value</c>s as second element. The
+	    order if these tuples is undefined. Currently the following
+	    tuples may be part of the list, but more tuples may be
+	    introduced in the future:</p>
+	    <taglist>
+	      <tag><c>{function, Function}</c></tag>
+	      <item><p><c>Function</c> is the name of the funcion
+	      used.</p></item>
+
+	      <tag><c>{clock_id, ClockId}</c></tag>
+	      <item><p>This tuple only exist if <c>Function</c>
+	      can be used with different clocks. <c>ClockId</c>
+	      corresponds to the clock identifer used when calling
+	      <c>Function</c>.</p></item>
+
+	      <tag><c>{resolution, OsSystemTimeResolution}</c></tag>
+	      <item><p>Highest possible
+	      <seealso marker="time_correction#Time_Resolution">resolution</seealso>
+	      of current OS system time source as parts per
+	      second. If no resolution information can be retreived
+	      from the OS, <c>OsSystemTimeResolution</c> will be
+	      set to the resolution of the time unit of
+	      <c>Function</c>s return value. That is, the actual
+	      resolution may be lower than
+	      <c>OsSystemTimeResolution</c>. Also note that
+	      the resolution does not say anything about the
+	      <seealso marker="time_correction#Time_Accuracy">accuracy</seealso>,
+	      and that the
+	      <seealso marker="time_correction#Time_Precision">precision</seealso>
+	      might not align with the resolution. You do,
+	      however, know that the precision won't be
+	      better than
+	      <c>OsSystemTimeResolution</c>.</p></item>
+
+	      <tag><c>{parallel, Parallel}</c></tag>
+	      <item><p><c>Parallel</c> equals <c>yes</c> if
+	      <c>Function</c> is called in parallel from multiple
+	      threads. If it is not called in parallel, because
+	      calls needs to be serialized, <c>Parallel</c> equals
+	      <c>no</c>.</p></item>
+
+	      <tag><c>{time, OsSystemTime}</c></tag>
+	      <item><p><c>OsSystemTime</c> equals current OS
+	      system time in <c>native</c>
+	      <seealso marker="#type_time_unit">time unit</seealso>.</p></item>
+	    </taglist>
+          </item>
 	  <tag><marker id="system_info_port_parallelism"><c>port_parallelism</c></marker></tag>
 	  <item><p>Returns the default port parallelism scheduling hint used.
 	  For more information see the
diff --git a/erts/doc/src/time_correction.xml b/erts/doc/src/time_correction.xml
index 3bc3d04186..979a37d7ff 100644
--- a/erts/doc/src/time_correction.xml
+++ b/erts/doc/src/time_correction.xml
@@ -114,6 +114,29 @@
       happened yet), POSIX time would make a one second leap forward.</p>
     </section>
 
+    <marker id="Time_Resolution"/>
+    <section>
+      <title>Time Resolution</title>
+      <p>The shortest time interval that can be distinguished when
+      reading time values.</p>
+    </section>
+
+    <marker id="Time_Precision"/>
+    <section>
+      <title>Time Precision</title>
+      <p>The shortest time interval that can be be distinguished
+      repeatedly and reliably when reading time values. Precision
+      is limited by the
+      <seealso marker="#Time_Resolution">resolution</seealso>, but
+      resolution and precision might differ significantly.</p>
+    </section>
+
+    <marker id="Time_Accuracy"/>
+    <section>
+      <title>Time Accuracy</title>
+      <p>The correctness of time values.</p>
+    </section>
+
     <marker id="OS_System_Time"/>
     <section>
       <title>OS System Time</title>
@@ -124,7 +147,9 @@
       This may or may not be an accurate view of POSIX time. This time
       may typically be adjusted both backwards and forwards without
       limitation. That is, huge leaps both backwards and forwards in time
-      may be observed.</p>
+      may be observed. You can get information about the Erlang runtime
+      system's source of OS system time by calling
+      <seealso marker="erlang#system_info_os_system_time_source"><c>erlang:system_info(os_system_time_source)</c></seealso>.</p>
     </section>
 
     <marker id="OS_Monotonic_Time"/>
@@ -138,7 +163,9 @@
       point in time that is not connected to
       <seealso marker="#OS_System_Time">OS system time</seealso>. Note that
       this type of time is not necessarily provided by all operating
-      systems.</p>
+      systems. You can get information about the Erlang runtime
+      system's source of OS monotonic time by calling
+      <seealso marker="erlang#system_info_os_monotonic_time_source"><c>erlang:system_info(os_monotonic_time_source)</c></seealso>.</p>
     </section>
 
     <marker id="Erlang_System_Time"/>
@@ -162,8 +189,10 @@
       Erlang runtime system. The Erlang monotonic time increase since
       some unspecified point in time. It can be retrieved by calling
       <seealso marker="erlang#monotonic_time/0"><c>erlang:monotonic_time()</c></seealso>.
-      The accuracy, and precision of Erlang monotonic time heavily
-      depends on the accuracy and precision of
+      The
+      <seealso marker="#Time_Accuracy">accuracy</seealso>, and
+      <seealso marker="#Time_Precision">precision</seealso> of Erlang
+      monotonic time heavily depends on the accuracy and precision of
       <seealso marker="#OS_Monotonic_Time">OS monotonic time</seealso>,
       the accuracy and precision of
       <seealso marker="#OS_System_Time">OS system time</seealso> as well
@@ -572,6 +601,7 @@
       <item><p><seealso marker="erlang#monitor/2"><c>erlang:monitor(time_offset, clock_service)</c></seealso></p></item>
       <item><p><seealso marker="erlang#system_flag_time_offset"><c>erlang:system_flag(time_offset, finalize)</c></seealso></p></item>
       <item><p><seealso marker="erlang#system_info_os_monotonic_time_source"><c>erlang:system_info(os_monotonic_time_source)</c></seealso></p></item>
+      <item><p><seealso marker="erlang#system_info_os_system_time_source"><c>erlang:system_info(os_system_time_source)</c></seealso></p></item>
       <item><p><seealso marker="erlang#system_info_time_offset"><c>erlang:system_info(time_offset)</c></seealso></p></item>
       <item><p><seealso marker="erlang#system_info_time_warp_mode"><c>erlang:system_info(time_warp_mode)</c></seealso></p></item>
       <item><p><seealso marker="erlang#system_info_time_correction"><c>erlang:system_info(time_correction)</c></seealso></p></item>
@@ -827,8 +857,9 @@ EventTag = {Time, UMI}</code>
     when it is not available. Fortunately almost all of the new
     API can easily be implemented using existing primitives
     (except for
-    <seealso marker="erlang#system_info_start_time"><c>erlang:system_info(start_time)</c></seealso>, and
-    <seealso marker="erlang#system_info_os_monotonic_time_source"><c>erlang:system_info(os_monotonic_time_source)</c></seealso>).
+    <seealso marker="erlang#system_info_start_time"><c>erlang:system_info(start_time)</c></seealso>,
+    <seealso marker="erlang#system_info_os_monotonic_time_source"><c>erlang:system_info(os_monotonic_time_source)</c></seealso>, and
+    <seealso marker="erlang#system_info_os_system_time_source"><c>erlang:system_info(os_system_time_source)</c></seealso>).
     By wrapping the API with functions that fall back on
     <c>erlang:now/0</c> when the new API is not available,
     and using these wrappers instead of using the API directly
diff --git a/erts/emulator/Makefile.in b/erts/emulator/Makefile.in
index 1429a6cf2c..b4a17e76e7 100644
--- a/erts/emulator/Makefile.in
+++ b/erts/emulator/Makefile.in
@@ -888,7 +888,8 @@ OS_OBJS +=	$(OBJDIR)/erl_mseg.o \
 		$(OBJDIR)/erl_mmap.o \
 		$(OBJDIR)/erl_$(ERLANG_OSTYPE)_sys_ddll.o \
 		$(OBJDIR)/erl_mtrace_sys_wrap.o \
-		$(OBJDIR)/erl_sys_common_misc.o
+		$(OBJDIR)/erl_sys_common_misc.o \
+		$(OBJDIR)/erl_os_monotonic_time_extender.o
 
 HIPE_ARCH64_OBJS=$(OBJDIR)/hipe_bif64.o
 
diff --git a/erts/emulator/beam/erl_bif_info.c b/erts/emulator/beam/erl_bif_info.c
index 2eeebab9a3..b2658a1fd6 100644
--- a/erts/emulator/beam/erl_bif_info.c
+++ b/erts/emulator/beam/erl_bif_info.c
@@ -2123,6 +2123,8 @@ BIF_RETTYPE system_info_1(BIF_ALIST_1)
 	}
     } 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("os_system_time_source", BIF_ARG_1)) {
+	BIF_RET(erts_system_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)) {
diff --git a/erts/emulator/beam/erl_lock_count.c b/erts/emulator/beam/erl_lock_count.c
index ddeb56a6be..c6d8f4df95 100644
--- a/erts/emulator/beam/erl_lock_count.c
+++ b/erts/emulator/beam/erl_lock_count.c
@@ -104,16 +104,13 @@ static void lcnt_clear_stats(erts_lcnt_lock_stats_t *stats) {
 }
 
 static void lcnt_time(erts_lcnt_time_t *time) {
-#if 0 || defined(ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT)
-    ErtsMonotonicTime mtime = ERTS_MONOTONIC_TO_NSEC(erts_os_monotonic_time());
+    /*
+     * erts_sys_hrtime() is the highest resolution
+     * we could find, it may or may not be monotonic...
+     */
+    ErtsMonotonicTime mtime = erts_sys_hrtime();
     time->s  = (unsigned long) (mtime / 1000000000LL);
     time->ns = (unsigned long) (mtime - 1000000000LL*time->s);
-#else
-  SysTimeval tv;
-  sys_gettimeofday(&tv);
-  time->s  = tv.tv_sec;
-  time->ns = tv.tv_usec*1000LL;
-#endif
 }
 
 static void lcnt_time_diff(erts_lcnt_time_t *d, erts_lcnt_time_t *t1, erts_lcnt_time_t *t0) {
diff --git a/erts/emulator/beam/erl_time.h b/erts/emulator/beam/erl_time.h
index c9cda4d10e..cb7764addc 100644
--- a/erts/emulator/beam/erl_time.h
+++ b/erts/emulator/beam/erl_time.h
@@ -148,6 +148,7 @@ 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);
+Eterm erts_system_time_source(struct process*c_p);
 
 #ifdef SYS_CLOCK_RESOLUTION
 #define ERTS_CLKTCK_RESOLUTION ((ErtsMonotonicTime) (SYS_CLOCK_RESOLUTION*1000))
@@ -219,6 +220,10 @@ erts_time_unit_conversion(Uint64 value,
  * it is assumed (and need) to be a power of 10.
  */
 
+#if ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT < 1000*1000
+#  error Compile time time unit needs to be at least 1000000
+#endif
+
 #define ERTS_MONOTONIC_TIME_UNIT \
     ((ErtsMonotonicTime) ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT)
 
@@ -248,19 +253,6 @@ erts_time_unit_conversion(Uint64 value,
 #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
diff --git a/erts/emulator/beam/erl_time_sup.c b/erts/emulator/beam/erl_time_sup.c
index b809fa8316..ef39f4b5f4 100644
--- a/erts/emulator/beam/erl_time_sup.c
+++ b/erts/emulator/beam/erl_time_sup.c
@@ -21,6 +21,8 @@
  * Support routines for the time
  */
 
+/* #define ERTS_TIME_CORRECTION_PRINT */
+
 #ifdef HAVE_CONFIG_H
 #  include "config.h"
 #endif
@@ -75,12 +77,12 @@ schedule_send_time_offset_changed_notifications(ErtsMonotonicTime new_offset);
 
 #else /* ARCH_64 */
 
-#if ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT <= 1000*1000
+#if ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT <= 10*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)...
+ * (1827 years in the 10 micro second case)...
  */
 #define ERTS_MONOTONIC_TIME_START ((ErtsMonotonicTime) 0)
 
@@ -99,11 +101,16 @@ schedule_send_time_offset_changed_notifications(ErtsMonotonicTime new_offset);
 
 #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)
+#define ERTS_MONOTONIC_OFFSET_NATIVE \
+    (ERTS_MONOTONIC_TIME_START - ERTS_MONOTONIC_TIME_UNIT)
+#define ERTS_MONOTONIC_OFFSET_NSEC					\
+    ERTS_MONOTONIC_TO_NSEC__(ERTS_MONOTONIC_OFFSET_NATIVE)
+#define ERTS_MONOTONIC_OFFSET_USEC					\
+    ERTS_MONOTONIC_TO_USEC__(ERTS_MONOTONIC_OFFSET_NATIVE)
+#define ERTS_MONOTONIC_OFFSET_MSEC					\
+    ERTS_MONOTONIC_TO_MSEC__(ERTS_MONOTONIC_OFFSET_NATIVE)
+#define ERTS_MONOTONIC_OFFSET_SEC					\
+    ERTS_MONOTONIC_TO_SEC__(ERTS_MONOTONIC_OFFSET_NATIVE)
 
 #else /* ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT */
 
@@ -120,36 +127,23 @@ schedule_send_time_offset_changed_notifications(ErtsMonotonicTime new_offset);
 
 #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;
+    int os_monotonic_time_disable;
+    char *os_monotonic_time_func;
+    char *os_monotonic_time_clock_id;
+    int os_monotonic_time_locked;
+    Uint64 os_monotonic_time_resolution;
+    Uint64 os_monotonic_time_extended;
+    char *os_system_time_func;
+    char *os_system_time_clock_id;
+    int os_system_time_locked;
+    Uint64 os_system_time_resolution;
+    Uint64 os_system_time_extended;
 #endif
 #if !ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT
     ErtsMonotonicTime start;
@@ -161,6 +155,10 @@ struct time_sup_read_only__ {
 	ErtsMonotonicTime sec;
     } start_offset;
 #endif
+    struct {
+	ErtsMonotonicTime large_diff;
+	ErtsMonotonicTime small_diff;
+    } adj;
 };
 
 typedef struct {
@@ -216,7 +214,7 @@ struct time_sup_infrequently_changed__ {
     ErtsMonotonicTime minit;
 #endif
     int finalized_offset;
-    SysTimeval inittv; /* Used everywhere, the initial time-of-day */
+    ErtsSystemTime sinit;
     ErtsMonotonicTime not_corrected_moffset;
     erts_atomic64_t offset;
 };
@@ -249,10 +247,8 @@ ErtsTimeSupData erts_time_sup__ erts_align_attribute(ERTS_CACHE_LINE_SIZE);
 erts_approx_time_t
 erts_get_approx_time(void)
 {
-    SysTimeval tv;
-    sys_gettimeofday(&tv);
-
-    return (erts_approx_time_t) tv.tv_sec;
+    ErtsSystemTime stime = erts_os_system_time();
+    return (erts_approx_time_t) ERTS_MONOTONIC_TO_SEC(stime);
 }
 
 static ERTS_INLINE void
@@ -338,15 +334,78 @@ static ErtsMonotonicTime get_corrected_time(void)
     return calc_corrected_erl_mtime(os_mtime, cip, NULL);
 }
 
+#ifdef ERTS_TIME_CORRECTION_PRINT
+
+static ERTS_INLINE void
+print_correction(int change,
+		 ErtsMonotonicTime sdiff,
+		 ErtsMonotonicTime old_ecorr,
+		 ErtsMonotonicTime old_dcorr,
+		 ErtsMonotonicTime new_ecorr,
+		 ErtsMonotonicTime new_dcorr,
+		 Uint tmo)
+{
+    ErtsMonotonicTime usec_sdiff;
+    if (sdiff < 0)
+	usec_sdiff = -1*ERTS_MONOTONIC_TO_USEC(-1*sdiff);
+    else
+	usec_sdiff = ERTS_MONOTONIC_TO_USEC(sdiff);
+
+    if (!change)
+	fprintf(stderr,
+		"sdiff = %lld usec : [ec=%lld ppm, dc=%lld ppm] : "
+		"tmo = %lld msec\r\n",
+		(long long) usec_sdiff,
+		(long long) (1000000*old_ecorr) / ERTS_TCORR_ERR_UNIT,
+		(long long) (1000000*old_dcorr) / ERTS_MONOTONIC_TIME_UNIT,
+		(long long) tmo);
+    else
+	fprintf(stderr,
+		"sdiff = %lld usec : [ec=%lld ppm, dc=%lld ppm] "
+		"-> [ec=%lld ppm, dc=%lld ppm] : tmo = %lld msec\r\n",
+		(long long) usec_sdiff,
+		(long long) (1000000*old_ecorr) / ERTS_TCORR_ERR_UNIT,
+		(long long) (1000000*old_dcorr) / ERTS_MONOTONIC_TIME_UNIT,
+		(long long) (1000000*new_ecorr) / ERTS_TCORR_ERR_UNIT,
+		(long long) (1000000*new_dcorr) / ERTS_MONOTONIC_TIME_UNIT,
+		(long long) tmo);
+
+}
+
+#endif
+
 static void
 check_time_correction(void *unused)
 {
+#ifndef ERTS_TIME_CORRECTION_PRINT
+#  define ERTS_PRINT_CORRECTION
+#else
+#  ifdef ERTS_HAVE_CORRECTED_OS_MONOTONIC
+#    define ERTS_PRINT_CORRECTION		\
+    print_correction(set_new_correction,	\
+		     sdiff,			\
+		     cip->correction.error,	\
+		     0,				\
+		     new_correction.error,	\
+		     0,				\
+		     timeout)
+#  else
+#    define ERTS_PRINT_CORRECTION		\
+    print_correction(set_new_correction,	\
+		     sdiff,			\
+		     cip->correction.error,	\
+		     cip->correction.drift,	\
+		     new_correction.error,	\
+		     new_correction.drift,	\
+		     timeout)
+#  endif
+#endif
     ErtsMonotonicCorrectionData cdata;
     ErtsMonotonicCorrection new_correction;
     ErtsMonotonicCorrectionInstance *cip;
-    ErtsMonotonicTime mdiff, sdiff, os_mtime, erl_mtime, os_stime, erl_stime, time_offset;
+    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);
@@ -354,7 +413,7 @@ check_time_correction(void *unused)
     ASSERT(time_sup.inf.c.finalized_offset);
 
     os_mtime = erts_os_monotonic_time();
-    sys_gettimeofday(&tod);
+    os_stime = erts_os_system_time();
 
     cdata = time_sup.inf.c.parmon.cdata;
 
@@ -369,16 +428,13 @@ check_time_correction(void *unused)
     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)) {
+	&& (sdiff < -2*time_sup.r.o.adj.small_diff
+	    || 2*time_sup.r.o.adj.small_diff < sdiff)) {
 	/* System time diff exeeded limits; change time offset... */
 	time_offset -= sdiff;
 	sdiff = 0;
@@ -393,16 +449,16 @@ check_time_correction(void *unused)
 	}
     }
     else if (cdata.curr.correction.error == 0) {
-	if (sdiff < -ERTS_TIME_CORRECTION_SMALL_ADJ_DIFF) {
+	if (sdiff < -time_sup.r.o.adj.small_diff) {
 	    set_new_correction = 1;
-	    if (sdiff < -ERTS_TIME_CORRECTION_LARGE_ADJ_DIFF)
+	    if (sdiff < -time_sup.r.o.adj.large_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) {
+	else if (sdiff > time_sup.r.o.adj.small_diff) {
 	    set_new_correction = 1;
-	    if (sdiff > ERTS_TIME_CORRECTION_LARGE_ADJ_DIFF)
+	    if (sdiff > time_sup.r.o.adj.large_diff)
 		new_correction.error = -ERTS_TCORR_ERR_LARGE_ADJ;
 	    else
 		new_correction.error = -ERTS_TCORR_ERR_SMALL_ADJ;
@@ -414,16 +470,16 @@ check_time_correction(void *unused)
     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)
+		|| -time_sup.r.o.adj.large_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) {
+	else if (sdiff > time_sup.r.o.adj.small_diff) {
 	    set_new_correction = 1;
-	    if (sdiff > ERTS_TIME_CORRECTION_LARGE_ADJ_DIFF)
+	    if (sdiff > time_sup.r.o.adj.large_diff)
 		new_correction.error = -ERTS_TCORR_ERR_LARGE_ADJ;
 	    else
 		new_correction.error = -ERTS_TCORR_ERR_SMALL_ADJ;
@@ -436,7 +492,7 @@ check_time_correction(void *unused)
     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)
+		|| sdiff <= time_sup.r.o.adj.large_diff)
 		set_new_correction = 0;
 	    else {
 		new_correction.error = -ERTS_TCORR_ERR_LARGE_ADJ;
@@ -444,9 +500,9 @@ check_time_correction(void *unused)
 	    }
 	    set_new_correction = 0;
 	}
-	else if (sdiff < -ERTS_TIME_CORRECTION_SMALL_ADJ_DIFF) {
+	else if (sdiff < -time_sup.r.o.adj.small_diff) {
 	    set_new_correction = 1;
-	    if (sdiff < -ERTS_TIME_CORRECTION_LARGE_ADJ_DIFF)
+	    if (sdiff < -time_sup.r.o.adj.large_diff)
 		new_correction.error = ERTS_TCORR_ERR_LARGE_ADJ;
 	    else
 		new_correction.error = ERTS_TCORR_ERR_SMALL_ADJ;
@@ -475,11 +531,13 @@ check_time_correction(void *unused)
 	    mtime_acc = ddp->acc.mon;
 	    stime_acc = ddp->acc.sys;
 
-	    avg_drift_adj = ((stime_acc - mtime_acc)*ERTS_MONOTONIC_TIME_UNIT) / mtime_acc;
+	    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;
+	    drift_adj = (((stime_diff - mtime_diff)*ERTS_MONOTONIC_TIME_UNIT)
+			 / mtime_diff);
 	    
 	    ix++;
 	    if (ix >= ERTS_DRIFT_INTERVALS)
@@ -499,10 +557,11 @@ check_time_correction(void *unused)
 	    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.
+	     * 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
@@ -512,7 +571,8 @@ check_time_correction(void *unused)
 	    }
 	    else {
 		if (ddp->dirty_counter <= 0) {
-		    drift_adj = ((stime_acc - mtime_acc)*ERTS_MONOTONIC_TIME_UNIT) / mtime_acc;
+		    drift_adj = ((stime_acc - mtime_acc)
+				 *ERTS_MONOTONIC_TIME_UNIT) / mtime_acc;
 		}
 		if (ddp->dirty_counter >= 0) {
 		    if (ddp->dirty_counter == 0) {
@@ -573,7 +633,9 @@ check_time_correction(void *unused)
 	&& time_sup.inf.c.parmon.cdata.short_check_interval) {
 	timeout = ERTS_MONOTONIC_TO_MSEC(ERTS_SHORT_TIME_CORRECTION_CHECK);
     }
-    
+
+    ERTS_PRINT_CORRECTION;
+
     if (set_new_correction) {
 	erts_smp_rwmtx_rwlock(&time_sup.inf.c.parmon.rwmtx);
 
@@ -610,6 +672,8 @@ check_time_correction(void *unused)
 		   NULL,
 		   NULL,
 		   timeout);
+
+#undef ERTS_PRINT_CORRECTION
 }
 
 #ifndef ERTS_HAVE_CORRECTED_OS_MONOTONIC
@@ -618,9 +682,9 @@ static void
 init_check_time_correction(void *unused)
 {
     ErtsMonotonicDriftData *ddp;
-    ErtsMonotonicTime old_mtime, old_stime, mtime, stime, mtime_diff, stime_diff;
+    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;
@@ -628,10 +692,7 @@ init_check_time_correction(void *unused)
     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);
+    stime = erts_os_system_time();
 
     mtime_diff = mtime - old_mtime;
     stime_diff = stime - old_stime;
@@ -663,7 +724,7 @@ init_check_time_correction(void *unused)
 #endif
 
 static ErtsMonotonicTime
-finalize_corrected_time_offset(SysTimeval *todp)
+finalize_corrected_time_offset(ErtsSystemTime *stimep)
 {
     ErtsMonotonicTime os_mtime;
     ErtsMonotonicCorrectionData cdata;
@@ -672,7 +733,7 @@ finalize_corrected_time_offset(SysTimeval *todp)
     erts_smp_rwmtx_rlock(&time_sup.inf.c.parmon.rwmtx);
 
     os_mtime = erts_os_monotonic_time();
-    sys_gettimeofday(todp);
+    *stimep = erts_os_system_time();
 
     cdata = time_sup.inf.c.parmon.cdata;
 
@@ -690,6 +751,7 @@ 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
@@ -707,15 +769,11 @@ late_init_time_correction(void)
 
 static ErtsMonotonicTime get_not_corrected_time(void)
 {
-    SysTimeval tmp_tv;
     ErtsMonotonicTime stime, mtime;
 
     erts_smp_mtx_lock(&erts_get_time_mtx);
 
-    sys_gettimeofday(&tmp_tv);
-
-    stime = ERTS_SEC_TO_MONOTONIC(tmp_tv.tv_sec);
-    stime += ERTS_USEC_TO_MONOTONIC(tmp_tv.tv_usec);
+    stime = erts_os_system_time();
 
     mtime = stime - time_sup.inf.c.not_corrected_moffset;
 
@@ -753,7 +811,7 @@ int erts_check_time_adj_support(int time_correction,
     /* User wants time correction */
 
 #ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT
-    return !time_sup.r.o.os_monotonic_disable;
+    return !time_sup.r.o.os_monotonic_time_disable;
 #else
     return 0;
 #endif
@@ -782,24 +840,35 @@ void erts_init_sys_time_sup(void)
 #endif
 
 #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;
+    time_sup.r.o.os_monotonic_time_disable
+	= !sys_init_time_res.have_os_monotonic_time;
+    time_sup.r.o.os_monotonic_time_func
+	= sys_init_time_res.os_monotonic_time_info.func;
+    time_sup.r.o.os_monotonic_time_clock_id
+	= sys_init_time_res.os_monotonic_time_info.clock_id;
+    time_sup.r.o.os_monotonic_time_locked
+	= sys_init_time_res.os_monotonic_time_info.locked_use;
+    time_sup.r.o.os_monotonic_time_resolution
+	= sys_init_time_res.os_monotonic_time_info.resolution;
+    time_sup.r.o.os_monotonic_time_extended
+	= sys_init_time_res.os_monotonic_time_info.extended;
+    time_sup.r.o.os_system_time_func
+	= sys_init_time_res.os_system_time_info.func;
+    time_sup.r.o.os_system_time_clock_id
+	= sys_init_time_res.os_system_time_info.clock_id;
+    time_sup.r.o.os_system_time_locked
+	= sys_init_time_res.os_system_time_info.locked_use;
+    time_sup.r.o.os_system_time_resolution
+	= sys_init_time_res.os_system_time_info.resolution;
 #endif
 }
 
 int 
 erts_init_time_sup(int time_correction, ErtsTimeWarpMode time_warp_mode)
 {
+    ErtsMonotonicTime resolution;
 #if !ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT
-    ErtsMonotonicTime abs_start;
+    ErtsMonotonicTime abs_native_offset, native_offset;
 #endif
 
     ASSERT(ERTS_MONOTONIC_TIME_MIN < ERTS_MONOTONIC_TIME_MAX);
@@ -822,36 +891,42 @@ erts_init_time_sup(int time_correction, ErtsTimeWarpMode time_warp_mode)
     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;
+    native_offset = time_sup.r.o.start - ERTS_MONOTONIC_TIME_UNIT;
+    native_offset = native_offset;
 #else /* ARCH_64 */
-    if (ERTS_MONOTONIC_TIME_UNIT <= 1000*1000)
-	abs_start = time_sup.r.o.start = 0;
+    if (ERTS_MONOTONIC_TIME_UNIT <= 10*1000*1000) {
+	time_sup.r.o.start = 0;
+	native_offset = -ERTS_MONOTONIC_TIME_UNIT;
+	abs_native_offset = ERTS_MONOTONIC_TIME_UNIT;
+    }
     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;
+	native_offset = time_sup.r.o.start - ERTS_MONOTONIC_TIME_UNIT;
+	abs_native_offset = -1*native_offset;
     }
 #endif
 
-    time_sup.r.o.start_offset.native = time_sup.r.o.start;
+    time_sup.r.o.start_offset.native = (time_sup.r.o.start
+					- ERTS_MONOTONIC_TIME_UNIT);
     time_sup.r.o.start_offset.nsec = (ErtsMonotonicTime)
-	erts_time_unit_conversion((Uint64) abs_start,
+	erts_time_unit_conversion((Uint64) abs_native_offset,
 				  (Uint32) ERTS_MONOTONIC_TIME_UNIT,
 				  (Uint32) 1000*1000*1000);
     time_sup.r.o.start_offset.usec = (ErtsMonotonicTime)
-	erts_time_unit_conversion((Uint64) abs_start,
+	erts_time_unit_conversion((Uint64) abs_native_offset,
 				  (Uint32) ERTS_MONOTONIC_TIME_UNIT,
 				  (Uint32) 1000*1000);
     time_sup.r.o.start_offset.msec = (ErtsMonotonicTime)
-	erts_time_unit_conversion((Uint64) abs_start,
+	erts_time_unit_conversion((Uint64) abs_native_offset,
 				  (Uint32) ERTS_MONOTONIC_TIME_UNIT,
 				  (Uint32) 1000);
     time_sup.r.o.start_offset.sec = (ErtsMonotonicTime)
-	erts_time_unit_conversion((Uint64) abs_start,
+	erts_time_unit_conversion((Uint64) abs_native_offset,
 				  (Uint32) ERTS_MONOTONIC_TIME_UNIT,
 				  (Uint32) 1);
-    if (time_sup.r.o.start < 0) {
+    if (native_offset < 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;
@@ -860,13 +935,37 @@ erts_init_time_sup(int time_correction, ErtsTimeWarpMode time_warp_mode)
 
 #endif
 
+    resolution = time_sup.r.o.os_monotonic_time_resolution;
+    if (resolution > time_sup.r.o.os_system_time_resolution)
+	resolution = time_sup.r.o.os_system_time_resolution;
+
+    time_sup.r.o.adj.large_diff = erts_time_sup__.r.o.monotonic_time_unit;
+    time_sup.r.o.adj.large_diff *= 50;
+    time_sup.r.o.adj.large_diff /= resolution;
+    if (time_sup.r.o.adj.large_diff < ERTS_USEC_TO_MONOTONIC(500))
+	time_sup.r.o.adj.large_diff = ERTS_USEC_TO_MONOTONIC(500);
+    time_sup.r.o.adj.small_diff = time_sup.r.o.adj.large_diff/10;
+
+#ifdef ERTS_TIME_CORRECTION_PRINT
+    fprintf(stderr, "start         = %lld\n\r", (long long) ERTS_MONOTONIC_TIME_START);
+    fprintf(stderr, "native offset = %lld\n\r", (long long) ERTS_MONOTONIC_OFFSET_NATIVE);
+    fprintf(stderr, "nsec offset   = %lld\n\r", (long long) ERTS_MONOTONIC_OFFSET_NSEC);
+    fprintf(stderr, "usec offset   = %lld\n\r", (long long) ERTS_MONOTONIC_OFFSET_USEC);
+    fprintf(stderr, "msec offset   = %lld\n\r", (long long) ERTS_MONOTONIC_OFFSET_MSEC);
+    fprintf(stderr, "sec offset    = %lld\n\r", (long long) ERTS_MONOTONIC_OFFSET_SEC);
+    fprintf(stderr, "large diff    = %lld usec\r\n",
+	    (long long) ERTS_MONOTONIC_TO_USEC(time_sup.r.o.adj.large_diff));
+    fprintf(stderr, "small diff    = %lld usec\r\n",
+	    (long long) ERTS_MONOTONIC_TO_USEC(time_sup.r.o.adj.small_diff));
+#endif
+
     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)
+    if (time_sup.r.o.os_monotonic_time_disable)
 	time_sup.r.o.correction = 0;
 
     if (time_sup.r.o.correction) {
@@ -874,10 +973,10 @@ erts_init_time_sup(int time_correction, ErtsTimeWarpMode time_warp_mode)
 	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.inf.c.sinit = erts_os_system_time();
 	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);
+	offset = time_sup.inf.c.sinit;
+	offset -= ERTS_MONOTONIC_TIME_UNIT;
 	init_time_offset(offset);
 
 	rwmtx_opts.type = ERTS_SMP_RWMTX_TYPE_EXTREMELY_FREQUENT_READ;
@@ -889,15 +988,12 @@ erts_init_time_sup(int time_correction, ErtsTimeWarpMode time_warp_mode)
 	cdatap = &time_sup.inf.c.parmon.cdata;
     
 #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.sys = time_sup.inf.c.sinit;
 	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.erl_mtime = ERTS_MONOTONIC_TIME_UNIT;
 	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;
@@ -910,9 +1006,8 @@ erts_init_time_sup(int time_correction, ErtsTimeWarpMode time_warp_mode)
     {
 	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;
+	stime = time_sup.inf.c.sinit = erts_os_system_time();
+	offset = stime - ERTS_MONOTONIC_TIME_UNIT;
 	time_sup.inf.c.not_corrected_moffset = offset;
 	init_time_offset(offset);
 	time_sup.f.c.last_not_corrected_time = 0;
@@ -937,6 +1032,7 @@ erts_late_init_time_sup(void)
     if (time_sup.r.o.get_time == get_corrected_time)
 	late_init_time_correction();
 #endif
+    erts_late_sys_init_time();
 }
 
 ErtsTimeWarpMode erts_time_warp_mode(void)
@@ -987,17 +1083,12 @@ erts_finalize_time_offset(void)
 
 	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);
+		ErtsMonotonicTime stime = erts_os_system_time();
 
 		mtime = stime - time_sup.inf.c.not_corrected_moffset;
 
@@ -1016,11 +1107,9 @@ erts_finalize_time_offset(void)
 	    }
 #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;
-
+		ErtsSystemTime stime;
+		mtime = finalize_corrected_time_offset(&stime);
+		new_offset = stime - mtime;
 	    }
 #endif
 	    new_offset = ERTS_MONOTONIC_TO_USEC(new_offset);
@@ -1515,13 +1604,16 @@ erts_get_monotonic_time(void)
 void
 get_sys_now(Uint* megasec, Uint* sec, Uint* microsec)
 {
-    SysTimeval now;
-    
-    sys_gettimeofday(&now);
-    
-    *megasec = (Uint) (now.tv_sec / 1000000);
-    *sec = (Uint) (now.tv_sec % 1000000);
-    *microsec = (Uint) (now.tv_usec);
+    ErtsSystemTime stime = erts_os_system_time();
+    ErtsSystemTime ms, s, us;
+
+    us = ERTS_MONOTONIC_TO_USEC(stime);
+    s = us / (1000*1000);
+    ms = s / (1000*1000);
+
+    *megasec = (Uint) ms;
+    *sec = (Uint) (s - ms*(1000*1000));
+    *microsec = (Uint) (us - s*(1000*1000));
 }
 
 #ifdef HAVE_ERTS_NOW_CPU
@@ -1737,7 +1829,7 @@ make_time_val(Process *c_p, ErtsMonotonicTime time_val)
 Eterm
 erts_get_monotonic_start_time(struct process *c_p)
 {
-    return make_time_val(c_p, ERTS_MONOTONIC_OFFSET_NATIVE);
+    return make_time_val(c_p, ERTS_MONOTONIC_TIME_START);
 }
 
 static Eterm
@@ -1747,27 +1839,31 @@ bld_monotonic_time_source(Uint **hpp, Uint *szp, Sint64 os_mtime)
     return NIL;
 #else
     int i = 0;
-    Eterm k[5];
-    Eterm v[5];
+    Eterm k[6];
+    Eterm v[6];
 
-    if (time_sup.r.o.os_monotonic_disable)
+    if (time_sup.r.o.os_monotonic_time_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);
+    v[i++] = erts_bld_atom(hpp, szp,
+			   time_sup.r.o.os_monotonic_time_func);
 
-    if (time_sup.r.o.os_monotonic_clock_id) {
+    if (time_sup.r.o.os_monotonic_time_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);
+	v[i++] = erts_bld_atom(hpp, szp,
+			       time_sup.r.o.os_monotonic_time_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, "resolution");
+    v[i++] = erts_bld_uint64(hpp, szp,
+			     time_sup.r.o.os_monotonic_time_resolution);
+
+    k[i] = erts_bld_atom(hpp, szp, "extended");
+    v[i++] = time_sup.r.o.os_monotonic_time_extended ? am_yes : am_no;
 
     k[i] = erts_bld_atom(hpp, szp, "parallel");
-    v[i++] = time_sup.r.o.os_monotonic_locked ? am_no : am_yes;
+    v[i++] = time_sup.r.o.os_monotonic_time_locked ? am_no : am_yes;
 
     k[i] = erts_bld_atom(hpp, szp, "time");
     v[i++] = erts_bld_sint64(hpp, szp, os_mtime);
@@ -1783,7 +1879,7 @@ erts_monotonic_time_source(struct process *c_p)
     Eterm *hp = NULL;
     Sint64 os_mtime = 0;
 #ifdef ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT
-    if (!time_sup.r.o.os_monotonic_disable)
+    if (!time_sup.r.o.os_monotonic_time_disable)
 	os_mtime = (Sint64) erts_os_monotonic_time();
 #endif
 
@@ -1793,6 +1889,49 @@ erts_monotonic_time_source(struct process *c_p)
     return bld_monotonic_time_source(&hp, NULL, os_mtime);
 }
 
+static Eterm
+bld_system_time_source(Uint **hpp, Uint *szp, Sint64 os_stime)
+{
+    int i = 0;
+    Eterm k[5];
+    Eterm v[5];
+
+    k[i] = erts_bld_atom(hpp, szp, "function");
+    v[i++] = erts_bld_atom(hpp, szp,
+			   time_sup.r.o.os_system_time_func);
+
+    if (time_sup.r.o.os_system_time_clock_id) {
+	k[i] = erts_bld_atom(hpp, szp, "clock_id");
+	v[i++] = erts_bld_atom(hpp, szp,
+			       time_sup.r.o.os_system_time_clock_id);
+    }
+
+    k[i] = erts_bld_atom(hpp, szp, "resolution");
+    v[i++] = erts_bld_uint64(hpp, szp,
+			     time_sup.r.o.os_system_time_resolution);
+
+    k[i] = erts_bld_atom(hpp, szp, "parallel");
+    v[i++] = am_yes;
+
+    k[i] = erts_bld_atom(hpp, szp, "time");
+    v[i++] = erts_bld_sint64(hpp, szp, os_stime);
+
+    return erts_bld_2tup_list(hpp, szp, (Sint) i, k, v);
+}
+
+Eterm
+erts_system_time_source(struct process *c_p)
+{
+    Uint hsz = 0;
+    Eterm *hp = NULL;
+    Sint64 os_stime = (Sint64) erts_os_system_time();
+
+    bld_system_time_source(NULL, &hsz, os_stime);
+    if (hsz)
+	hp = HAlloc(c_p, hsz);
+    return bld_system_time_source(&hp, NULL, os_stime);
+}
+
 
 #include "bif.h"
 
@@ -1967,21 +2106,13 @@ BIF_RETTYPE timestamp_0(BIF_ALIST_0)
 
 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);
+    ErtsSystemTime stime = erts_os_system_time();
     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);
+    ErtsSystemTime stime = erts_os_system_time();
     BIF_RET(time_unit_conversion(BIF_P, BIF_ARG_1, stime, 0));
 }
 
diff --git a/erts/emulator/beam/sys.h b/erts/emulator/beam/sys.h
index a0f35fef1b..251b39508f 100644
--- a/erts/emulator/beam/sys.h
+++ b/erts/emulator/beam/sys.h
@@ -710,7 +710,7 @@ typedef enum {
 } ErtsTimeWarpMode;
 
 typedef struct {
-    int have_os_monotonic;
+    int have_os_monotonic_time;
     ErtsMonotonicTime os_monotonic_time_unit;
     ErtsMonotonicTime sys_clock_resolution;
     struct {
@@ -718,7 +718,14 @@ typedef struct {
 	char *func;
 	char *clock_id;
 	int locked_use;
-    } os_monotonic_info;
+	int extended;
+    } os_monotonic_time_info;
+    struct {
+	Uint64 resolution;
+	char *func;
+	char *clock_id;
+	int locked_use;
+    } os_system_time_info;
 } ErtsSysInitTimeResult;
 
 #define ERTS_SYS_INIT_TIME_RESULT_INITER \
@@ -726,13 +733,13 @@ typedef struct {
 
 extern void erts_init_sys_time_sup(void);
 extern void sys_init_time(ErtsSysInitTimeResult *);
+extern void erts_late_sys_init_time(void);
 extern void erts_deliver_time(void);
 extern void erts_time_remaining(SysTimeval *);
 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);
-
 ERTS_GLB_INLINE int erts_block_fpe(void);
 ERTS_GLB_INLINE void erts_unblock_fpe(int);
 
diff --git a/erts/emulator/beam/time.c b/erts/emulator/beam/time.c
index 9f997e1d0b..3dfd3f79d4 100644
--- a/erts/emulator/beam/time.c
+++ b/erts/emulator/beam/time.c
@@ -524,6 +524,7 @@ erts_set_timer(ErlTimer *p, ErlTimeoutProc timeout,
 	tiw->nto++;
 	tiw->at_once.nto++;
 	*tiw->at_once.tail = p;
+	tiw->at_once.tail = &p->next;
 	p->next = NULL;
 	p->timeout_pos = timeout_pos;
 	timeout_time = ERTS_CLKTCKS_TO_MONOTONIC(timeout_pos);
diff --git a/erts/emulator/sys/common/erl_os_monotonic_time_extender.c b/erts/emulator/sys/common/erl_os_monotonic_time_extender.c
new file mode 100644
index 0000000000..f3633b7267
--- /dev/null
+++ b/erts/emulator/sys/common/erl_os_monotonic_time_extender.c
@@ -0,0 +1,88 @@
+/*
+ * %CopyrightBegin%
+ * 
+ * Copyright Ericsson AB 2015. 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 "erl_os_monotonic_time_extender.h"
+
+#ifdef USE_THREADS
+
+static void *os_monotonic_time_extender(void *vstatep)
+{
+    ErtsOsMonotonicTimeExtendState *state = (ErtsOsMonotonicTimeExtendState *) vstatep;
+    long sleep_time = state->check_interval*1000;
+    Uint32 (*raw_os_mtime)(void) = state->raw_os_monotonic_time;
+    Uint32 last_msb = 0;
+
+    while (1) {
+	Uint32 msb = (*raw_os_mtime)() & (((Uint32) 1) << 31);
+
+	if (msb != last_msb) {
+	    int ix = ((int) (last_msb >> 31)) & 1;
+	    Uint32 xtnd = (Uint32) erts_atomic32_read_nob(&state->extend[ix]);
+	    erts_atomic32_set_nob(&state->extend[ix], (erts_aint32_t) (xtnd + 1));
+	    last_msb = msb;
+	}
+	erts_milli_sleep(sleep_time);
+    }
+
+    erl_exit(ERTS_ABORT_EXIT, "os_monotonic_time_extender thread terminating");
+    return NULL;
+}
+
+static erts_tid_t os_monotonic_extender_tid;
+#endif
+
+void
+erts_init_os_monotonic_time_extender(ErtsOsMonotonicTimeExtendState *statep,
+				     Uint32 (*raw_os_monotonic_time)(void),
+				     int check_seconds)
+{
+#ifdef USE_THREADS
+    statep->raw_os_monotonic_time = raw_os_monotonic_time;
+    erts_atomic32_init_nob(&statep->extend[0], (erts_aint32_t) 0);
+    erts_atomic32_init_nob(&statep->extend[1], (erts_aint32_t) 0);
+    statep->check_interval = check_seconds;
+
+#else
+    statep->extend[0] = (Uint32) 0;
+    statep->extend[1] = (Uint32) 0;
+    statep->last_msb = (ErtsMonotonicTime) 0;
+#endif
+}
+
+void
+erts_late_init_os_monotonic_time_extender(ErtsOsMonotonicTimeExtendState *statep)
+{
+#ifdef USE_THREADS
+    erts_thr_opts_t thr_opts = ERTS_THR_OPTS_DEFAULT_INITER;
+    thr_opts.detached = 1;
+    thr_opts.suggested_stack_size = 4;
+
+#if 0
+    thr_opts.name = "os_monotonic_time_extender";
+#endif
+
+    erts_thr_create(&os_monotonic_extender_tid,
+		    os_monotonic_time_extender,
+		    (void*) statep,
+		    &thr_opts);
+#endif
+}
diff --git a/erts/emulator/sys/common/erl_os_monotonic_time_extender.h b/erts/emulator/sys/common/erl_os_monotonic_time_extender.h
new file mode 100644
index 0000000000..0f9e7c86ae
--- /dev/null
+++ b/erts/emulator/sys/common/erl_os_monotonic_time_extender.h
@@ -0,0 +1,65 @@
+/*
+ * %CopyrightBegin%
+ * 
+ * Copyright Ericsson AB 2015. All Rights Reserved.
+ * 
+ * The contents of this file are subject to the Erlang Public License,
+ * Version 1.1, (the "License"); you may not use this file except in
+ * compliance with the License. You should have received a copy of the
+ * Erlang Public License along with this software. If not, it can be
+ * retrieved online at http://www.erlang.org/.
+ * 
+ * Software distributed under the License is distributed on an "AS IS"
+ * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+ * the License for the specific language governing rights and limitations
+ * under the License.
+ * 
+ * %CopyrightEnd%
+ */
+
+#ifndef ERL_OS_MONOTONIC_TIME_EXTENDER_H__
+#define ERL_OS_MONOTONIC_TIME_EXTENDER_H__
+
+#include "sys.h"
+#include "erl_threads.h"
+
+typedef struct {
+#ifdef USE_THREADS
+    Uint32 (*raw_os_monotonic_time)(void);
+    erts_atomic32_t extend[2];
+    int check_interval;
+#else
+    Uint32 extend[2];
+    ErtsMonotonicTime last_msb;
+#endif
+} ErtsOsMonotonicTimeExtendState;
+
+#ifdef USE_THREADS
+#  define ERTS_CHK_EXTEND_OS_MONOTONIC_TIME(S, RT) ((void) 1)
+#  define ERTS_EXTEND_OS_MONOTONIC_TIME(S, RT)				\
+    ((((ErtsMonotonicTime)						\
+       erts_atomic32_read_nob(&((S)->extend[((int) ((RT) >> 31)) & 1]))) \
+      << 32)								\
+     + (RT))
+#else
+#  define ERTS_CHK_EXTEND_OS_MONOTONIC_TIME(S, RT)			\
+    do {								\
+	Uint32 msb__ = (RT) & (((Uint32) 1) << 31);			\
+	if (msb__ != (S)->last_msb) {					\
+	    int ix__ = ((int) ((S)->last_msb >> 31)) & 1;		\
+	    (S)->extend[ix__]++;					\
+	    (S)->last_msb = msb;					\
+	}								\
+    } while (0)
+#  define ERTS_EXTEND_OS_MONOTONIC_TIME(S, RT)				\
+    ((((ErtsMonotonicTime) (S)->extend[((int) ((RT) >> 31)) & 1]) << 32) + (RT))
+#endif
+
+void
+erts_init_os_monotonic_time_extender(ErtsOsMonotonicTimeExtendState *statep,
+				     Uint32 (*raw_os_monotonic_time)(void),
+				     int check_seconds);
+void
+erts_late_init_os_monotonic_time_extender(ErtsOsMonotonicTimeExtendState *statep);
+
+#endif
diff --git a/erts/emulator/sys/unix/erl_unix_sys.h b/erts/emulator/sys/unix/erl_unix_sys.h
index 46d0b8dc9b..aa158390d6 100644
--- a/erts/emulator/sys/unix/erl_unix_sys.h
+++ b/erts/emulator/sys/unix/erl_unix_sys.h
@@ -161,12 +161,18 @@ typedef struct tms SysTimes;
 
 #if SIZEOF_LONG == 8
 typedef long ErtsMonotonicTime;
+typedef long ErtsSysHrTime;
 #elif SIZEOF_LONG_LONG == 8
 typedef long long ErtsMonotonicTime;
+typedef long long ErtsSysHrTime;
 #else
 #error No signed 64-bit type found...
 #endif
 
+typedef ErtsMonotonicTime ErtsSystemTime;
+
+ErtsSystemTime erts_os_system_time(void);
+
 #define ERTS_MONOTONIC_TIME_MIN (((ErtsMonotonicTime) 1) << 63)
 #define ERTS_MONOTONIC_TIME_MAX (~ERTS_MONOTONIC_TIME_MIN)
 
@@ -201,17 +207,15 @@ ErtsMonotonicTime erts_os_monotonic_time(void);
 #elif defined(OS_MONOTONIC_TIME_USING_GETHRTIME)
 
 #define erts_os_monotonic() ((ErtsMonotonicTime) gethrtime())
+#define erts_sys_hrtime() ((ErtsSysHrTime) gethrtime())
 
 #elif defined(OS_MONOTONIC_TIME_USING_MACH_CLOCK_GET_TIME) \
     || defined(OS_MONOTONIC_TIME_USING_TIMES)
 
 #if defined(OS_MONOTONIC_TIME_USING_TIMES)
+/* Time unit determined at runtime... */
 #  undef ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT
-#  define ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT (1000*1000)
-#  define ERTS_HAVE_ERTS_OS_TIME_OFFSET_FINALIZE 1
-void erts_os_time_offset_finalize(void);
-#  define ERTS_HAVE_ERTS_OS_MONOTONIC_TIME_INIT
-void erts_os_monotonic_time_init(void);
+#  define ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT 0
 #endif
 
 ErtsMonotonicTime erts_os_monotonic_time(void);
@@ -224,6 +228,15 @@ ErtsMonotonicTime erts_os_monotonic_time(void);
 
 #endif
 
+/*
+ * erts_sys_hrtime() is the highest resolution
+ * time function found. Time unit is nano-seconds.
+ * It may or may not be monotonic.
+ */
+#ifndef erts_sys_hrtime
+extern ErtsSysHrTime erts_sys_hrtime(void);
+#endif
+
 struct erts_sys_time_read_only_data__ {
 #ifdef ERTS_OS_MONOTONIC_INLINE_FUNC_PTR_CALL__
     ErtsMonotonicTime (*os_monotonic_time)(void);
diff --git a/erts/emulator/sys/unix/sys.c b/erts/emulator/sys/unix/sys.c
index f1c785890c..7d52650a70 100644
--- a/erts/emulator/sys/unix/sys.c
+++ b/erts/emulator/sys/unix/sys.c
@@ -556,18 +556,18 @@ erts_sys_pre_init(void)
 
     erts_thr_init(&eid);
 
-#endif /* USE_THREADS */
-
-    erts_init_sys_time_sup();
-
-#ifdef USE_THREADS
-
     report_exit_list = NULL;
 
 #ifdef ERTS_ENABLE_LOCK_COUNT
     erts_lcnt_init();
 #endif
 
+#endif /* USE_THREADS */
+
+    erts_init_sys_time_sup();
+
+#ifdef USE_THREADS
+
 #if CHLDWTHR || defined(ERTS_SMP)
     erts_mtx_init(&chld_stat_mtx, "child_status");
 #endif
diff --git a/erts/emulator/sys/unix/sys_time.c b/erts/emulator/sys/unix/sys_time.c
index 9fdb1930b7..d6591a8296 100644
--- a/erts/emulator/sys/unix/sys_time.c
+++ b/erts/emulator/sys/unix/sys_time.c
@@ -33,6 +33,7 @@
 
 #include "sys.h"
 #include "global.h"
+#include "erl_os_monotonic_time_extender.h"
 
 #ifdef NO_SYSCONF
 #  define TICKS_PER_SEC()	HZ
@@ -55,36 +56,19 @@
 
 #undef ERTS_SYS_TIME_INTERNAL_STATE_WRITE_FREQ__
 #undef ERTS_SYS_TIME_INTERNAL_STATE_READ_ONLY__
+#undef ERTS_SYS_TIME_INTERNAL_STATE_READ_MOSTLY__
 
 #if defined(OS_MONOTONIC_TIME_USING_TIMES)
 
-#define ERTS_WRAP_SYS_TIMES 1
-#define ERTS_SYS_TIME_INTERNAL_STATE_WRITE_FREQ__
-#define ERTS_SYS_TIME_INTERNAL_STATE_READ_ONLY__
-
-/*
- * Not sure there is a need to use times() anymore, perhaps drop
- * support for this soon...
- *
- * sys_times() might need to be wrapped and the values shifted (right)
- * a bit to cope with faster ticks, 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
-static clock_t sys_times_wrap(void);
-#define KERNEL_TICKS() (sys_times_wrap() &  \
-			((1UL << ((sizeof(clock_t) * 8) - 1)) - 1)) 
-#define ERTS_KERNEL_TICK_TO_USEC(TCKS) (((TCKS)*(1000*1000)) \
-					/ internal_state.r.o.ticks_per_sec_wrap)
-#else
+static Uint32
+get_tick_count(void)
+{
+    struct tms unused;
+    return (Uint32) times(&unused);
+}
 
-#define KERNEL_TICKS() (sys_times(&internal_state.w.f.dummy_tms) &  \
-			((1UL << ((sizeof(clock_t) * 8) - 1)) - 1)) 
-#define ERTS_KERNEL_TICK_TO_USEC(TCKS) (((TCKS)*(1000*1000))/SYS_CLK_TCK)
-#endif
+#define ERTS_SYS_TIME_INTERNAL_STATE_READ_ONLY__
+#define ERTS_SYS_TIME_INTERNAL_STATE_READ_MOSTLY__
 
 #endif
 
@@ -101,16 +85,23 @@ ErtsSysTimeData__ erts_sys_time_data__ erts_align_attribute(ERTS_CACHE_LINE_SIZE
 
 #define ERTS_SYS_TIME_INTERNAL_STATE_WRITE_FREQ__
 
-ErtsMonotonicTime clock_gettime_monotonic_raw(void);
-ErtsMonotonicTime clock_gettime_monotonic_verified(void);
+static ErtsMonotonicTime clock_gettime_monotonic_raw(void);
+static ErtsMonotonicTime clock_gettime_monotonic_verified(void);
 
 #endif /* defined(__linux__) && defined(OS_MONOTONIC_TIME_USING_CLOCK_GETTIME) */
 
 #ifdef ERTS_SYS_TIME_INTERNAL_STATE_READ_ONLY__
 struct sys_time_internal_state_read_only__ {
 #if defined(OS_MONOTONIC_TIME_USING_TIMES)
-    int ticks_bsr;
-    int ticks_per_sec_wrap;
+    int times_shift;
+#endif
+};
+#endif
+
+#ifdef ERTS_SYS_TIME_INTERNAL_STATE_READ_MOSTLY__
+struct sys_time_internal_state_read_mostly__ {
+#if defined(OS_MONOTONIC_TIME_USING_TIMES)
+    ErtsOsMonotonicTimeExtendState os_mtime_xtnd;
 #endif
 };
 #endif
@@ -121,15 +112,6 @@ struct sys_time_internal_state_write_freq__ {
 #if defined(__linux__) && defined(OS_MONOTONIC_TIME_USING_CLOCK_GETTIME)
     ErtsMonotonicTime last_delivered;
 #endif
-#if defined(OS_MONOTONIC_TIME_USING_TIMES)
-    ErtsMonotonicTime last_tick_count;
-    ErtsMonotonicTime last_tick_wrap_count;
-    ErtsMonotonicTime last_tick_monotonic_time;
-    ErtsMonotonicTime last_timeofday_usec;
-#ifndef ERTS_WRAP_SYS_TIMES 
-    SysTimes dummy_tms;
-#endif
-#endif
 };
 #endif
 
@@ -144,6 +126,14 @@ static struct {
 		     * ASSUMED_CACHE_LINE_SIZE];
     } r;
 #endif
+#ifdef ERTS_SYS_TIME_INTERNAL_STATE_READ_MOSTLY__
+    union {
+	struct sys_time_internal_state_read_mostly__ m;
+	char align__[(((sizeof(struct sys_time_internal_state_read_mostly__) - 1)
+		       / ASSUMED_CACHE_LINE_SIZE) + 1)
+		     * ASSUMED_CACHE_LINE_SIZE];
+    } wr;
+#endif
 #ifdef ERTS_SYS_TIME_INTERNAL_STATE_WRITE_FREQ__
     union {
 	struct sys_time_internal_state_write_freq__ f;
@@ -160,46 +150,46 @@ sys_init_time(ErtsSysInitTimeResult *init_resp)
 {
 #if !defined(ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT)
 
-    init_resp->have_os_monotonic = 0;
+    init_resp->have_os_monotonic_time = 0;
 
 #else /* defined(ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT) */
 
     int major, minor, build, vsn;
 
-    init_resp->os_monotonic_info.resolution = (Uint64) 1000*1000*1000;
+    init_resp->os_monotonic_time_info.resolution = (Uint64) 1000*1000*1000;
 #if defined(HAVE_CLOCK_GETRES) && defined(MONOTONIC_CLOCK_ID)
     {
 	struct timespec ts;
-	if (clock_getres(MONOTONIC_CLOCK_ID, &ts) == 0
-	    && ts.tv_sec == 0 && ts.tv_nsec != 0) {
-	    init_resp->os_monotonic_info.resolution /= ts.tv_nsec;
+	if (clock_getres(MONOTONIC_CLOCK_ID, &ts) == 0) {
+	    if (ts.tv_sec == 0 && ts.tv_nsec != 0)
+		init_resp->os_monotonic_time_info.resolution /= ts.tv_nsec;
+	    else if (ts.tv_sec >= 1)
+		init_resp->os_monotonic_time_info.resolution = 1;
 	}
     }
 #endif
 
 #ifdef MONOTONIC_CLOCK_ID_STR
-    init_resp->os_monotonic_info.clock_id = MONOTONIC_CLOCK_ID_STR;
+    init_resp->os_monotonic_time_info.clock_id = MONOTONIC_CLOCK_ID_STR;
 #else
-    init_resp->os_monotonic_info.clock_id = NULL;
+    init_resp->os_monotonic_time_info.clock_id = NULL;
 #endif
 
-    init_resp->os_monotonic_info.locked_use = 0;
+    init_resp->os_monotonic_time_info.locked_use = 0;
 
 #if defined(OS_MONOTONIC_TIME_USING_CLOCK_GETTIME)
-    init_resp->os_monotonic_info.func = "clock_gettime";
+    init_resp->os_monotonic_time_info.func = "clock_gettime";
 #elif defined(OS_MONOTONIC_TIME_USING_MACH_CLOCK_GET_TIME)
-    init_resp->os_monotonic_info.func = "clock_get_time";
+    init_resp->os_monotonic_time_info.func = "clock_get_time";
 #elif defined(OS_MONOTONIC_TIME_USING_GETHRTIME)
-    init_resp->os_monotonic_info.func = "gethrtime";
+    init_resp->os_monotonic_time_info.func = "gethrtime";
 #elif defined(OS_MONOTONIC_TIME_USING_TIMES)
-    init_resp->os_monotonic_info.func = "times";
-    init_resp->os_monotonic_info.locked_use = 1;
-    init_resp->os_monotonic_info.resolution = TICKS_PER_SEC();
+    init_resp->os_monotonic_time_info.func = "times";
 #else
 # error Unknown erts_os_monotonic_time() implementation
 #endif
 
-    init_resp->have_os_monotonic = 1;
+    init_resp->have_os_monotonic_time = 1;
 
     os_version(&major, &minor, &build);
 
@@ -222,7 +212,7 @@ sys_init_time(ErtsSysInitTimeResult *init_resp)
 			  "os_monotonic_time");
 	internal_state.w.f.last_delivered
 	    = clock_gettime_monotonic_raw();
-	init_resp->os_monotonic_info.locked_use = 1;
+	init_resp->os_monotonic_time_info.locked_use = 1;
     }
 #else /* !(defined(__linux__) && defined(OS_MONOTONIC_TIME_USING_CLOCK_GETTIME)) */
     {
@@ -239,7 +229,7 @@ sys_init_time(ErtsSysInitTimeResult *init_resp)
 #if defined(HAVE_SYSCONF) && defined(_SC_NPROCESSORS_CONF)
 		if (sysconf(_SC_NPROCESSORS_CONF) > 1)
 #endif
-		    init_resp->have_os_monotonic = 0;
+		    init_resp->have_os_monotonic_time = 0;
 	    }
 	}
     }
@@ -247,7 +237,9 @@ sys_init_time(ErtsSysInitTimeResult *init_resp)
 
 #endif /* defined(ERTS_HAVE_OS_MONOTONIC_TIME_SUPPORT) */
 
+#ifdef ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT
     init_resp->os_monotonic_time_unit = ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT;
+#endif
     init_resp->sys_clock_resolution = SYS_CLOCK_RESOLUTION;
 
     /* 
@@ -258,38 +250,171 @@ sys_init_time(ErtsSysInitTimeResult *init_resp)
 	erl_exit(ERTS_ABORT_EXIT, "Can't get clock ticks/sec\n");
     
 #if defined(OS_MONOTONIC_TIME_USING_TIMES)
+#if ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT
+#  error Time unit is supposed to be determined at runtime...
+#endif
+    {
+	ErtsMonotonicTime resolution = erts_sys_time_data__.r.o.ticks_per_sec;
+	ErtsMonotonicTime time_unit = resolution;
+	int shift = 0;
 
-    if (erts_sys_time_data__.r.o.ticks_per_sec >= 1000) {
-	/* Workaround for beta linux kernels, need to be done in runtime
-	   to make erlang run on both 2.4 and 2.5 kernels. In the future, 
-	   the kernel ticks might as 
-	   well be used as a high res timer instead, but that's for when the 
-	   majority uses kernels with HZ == 1024 */
-	internal_state.r.o.ticks_bsr = 3;
-    } else {
-	internal_state.r.o.ticks_bsr = 0;
+	while (time_unit < 1000*1000) {
+	    time_unit <<= 1;
+	    shift++;
+	}
+
+	init_resp->os_monotonic_time_info.resolution = resolution;
+	init_resp->os_monotonic_time_unit = time_unit;
+	init_resp->os_monotonic_time_info.extended = 1;
+	internal_state.r.o.times_shift = shift;
+
+	erts_init_os_monotonic_time_extender(&internal_state.wr.m.os_mtime_xtnd,
+					     get_tick_count,
+					     (1 << 29) / resolution);
     }
+#endif /* defined(OS_MONOTONIC_TIME_USING_TIMES) */
 
-    internal_state.r.o.ticks_per_sec_wrap
-	= (erts_sys_time_data__.r.o.ticks_per_sec
-	   >> internal_state.r.o.ticks_bsr);
+#ifdef WALL_CLOCK_ID_STR
+    init_resp->os_system_time_info.clock_id = WALL_CLOCK_ID_STR;
+#else
+    init_resp->os_system_time_info.clock_id = NULL;
+#endif
 
-    erts_smp_mtx_init(&internal_state.w.f.mtx, "os_monotonic_time");
-    internal_state.w.f.last_tick_count = KERNEL_TICKS();
-    internal_state.w.f.last_tick_wrap_count = 0;    
-    internal_state.w.f.last_tick_monotonic_time
-	= ERTS_KERNEL_TICK_TO_USEC(internal_state.w.f.last_tick_count);
+    init_resp->os_system_time_info.locked_use = 0;
+    init_resp->os_system_time_info.resolution = (Uint64) 1000*1000*1000;
+#if defined(HAVE_CLOCK_GETRES) && defined(WALL_CLOCK_ID)
     {
-	SysTimeval tv;
-	sys_gettimeofday(&tv);
-	internal_state.w.f.last_timeofday_usec = tv.tv_sec*(1000*1000);
-	internal_state.w.f.last_timeofday_usec += tv.tv_usec;
+	struct timespec ts;
+	if (clock_getres(WALL_CLOCK_ID, &ts) == 0) {
+	    if (ts.tv_sec == 0 && ts.tv_nsec != 0)
+		init_resp->os_system_time_info.resolution /= ts.tv_nsec;
+	    else if (ts.tv_sec >= 1)
+		init_resp->os_system_time_info.resolution = 1;
+	}
     }
+#endif
 
-#endif /* defined(OS_MONOTONIC_TIME_USING_TIMES) */
+#if defined(OS_SYSTEM_TIME_USING_CLOCK_GETTIME)
+    init_resp->os_system_time_info.func = "clock_gettime";
+#elif defined(OS_SYSTEM_TIME_USING_MACH_CLOCK_GET_TIME)
+    init_resp->os_system_time_info.func = "clock_get_time";
+#elif defined(OS_SYSTEM_TIME_GETTIMEOFDAY)
+    init_resp->os_system_time_info.func = "gettimeofday";    
+    init_resp->os_system_time_info.resolution = 1000*1000;
+    init_resp->os_system_time_info.clock_id = NULL;
+#else
+#  error Missing erts_os_system_time() implmenentation
+#endif
+
+}
+
+void
+erts_late_sys_init_time(void)
+{
+#if defined(OS_MONOTONIC_TIME_USING_TIMES)
+    erts_late_init_os_monotonic_time_extender(&internal_state.wr.m.os_mtime_xtnd);
+#endif
+}
+
+static ERTS_INLINE ErtsSystemTime
+adj_stime_time_unit(ErtsSystemTime stime, Uint32 res)
+{
+    if (res == ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT)
+	return stime;
+    if (res == (Uint32) 1000*1000*1000
+	&& ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT == 1000*1000)
+	return stime/1000;
+    if (res == (Uint32) 1000*1000
+	&& ERTS_COMPILE_TIME_MONOTONIC_TIME_UNIT == 1000*1000*1000)
+	return stime*1000;
+    return ((ErtsSystemTime)
+	    erts_time_unit_conversion(stime,
+				      (Uint32) res,
+				      (Uint32) ERTS_MONOTONIC_TIME_UNIT));
+}
+
+#if defined(OS_SYSTEM_TIME_USING_CLOCK_GETTIME)
 
+ErtsSystemTime
+erts_os_system_time(void)
+{
+    ErtsSystemTime stime;
+    struct timespec ts;
+
+    if (clock_gettime(WALL_CLOCK_ID,&ts) != 0) {
+	int err = errno;
+	char *errstr = err ? strerror(err) : "unknown";
+	erl_exit(ERTS_ABORT_EXIT,
+		 "clock_gettime(%s, _) failed: %s (%d)\n",
+		 WALL_CLOCK_ID_STR, errstr, err);
+
+    }
+
+    stime = (ErtsSystemTime) ts.tv_sec;
+    stime *= (ErtsSystemTime) 1000*1000*1000;
+    stime += (ErtsSystemTime) ts.tv_nsec;
+    return adj_stime_time_unit(stime, (Uint32) 1000*1000*1000);
 }
 
+#elif defined(OS_SYSTEM_TIME_USING_MACH_CLOCK_GET_TIME)
+
+ErtsSystemTime
+erts_os_system_time(void)
+{
+    ErtsSystemTime stime;
+    kern_return_t res;
+    clock_serv_t clk_srv;
+    mach_timespec_t time_spec;
+    int err;
+
+    host_get_clock_service(mach_host_self(),
+			   WALL_CLOCK_ID,
+			   &clk_srv);
+    errno = 0;
+    res = clock_get_time(clk_srv, &time_spec);
+    err = errno;
+    mach_port_deallocate(mach_task_self(), clk_srv);
+    if (res != KERN_SUCCESS) {
+	char *errstr = err ? strerror(err) : "unknown";
+	erl_exit(ERTS_ABORT_EXIT,
+		 "clock_get_time(%s, _) failed: %s (%d)\n",
+		 MONOTONIC_CLOCK_ID_STR, errstr, err);
+    }
+
+    stime = (ErtsSystemTime) time_spec.tv_sec;
+    stime *= (ErtsSystemTime) 1000*1000*1000;
+    stime += (ErtsSystemTime) time_spec.tv_nsec;
+
+    return adj_stime_time_unit(stime, (Uint32) 1000*1000*1000);
+}
+
+#elif defined(OS_SYSTEM_TIME_GETTIMEOFDAY)
+
+ErtsSystemTime
+erts_os_system_time(void)
+{
+    ErtsSystemTime stime;
+    struct timeval tv;
+
+    if (gettimeofday(&tv, NULL) != 0) {
+	int err = errno;
+	char *errstr = err ? strerror(err) : "unknown";
+	erl_exit(ERTS_ABORT_EXIT,
+		 "gettimeofday(_, NULL) failed: %s (%d)\n",
+		 errstr, err);
+    }
+
+    stime = (ErtsSystemTime) tv.tv_sec;
+    stime *= (ErtsSystemTime) 1000*1000;
+    stime += (ErtsSystemTime) tv.tv_usec;
+
+    return adj_stime_time_unit(stime, (Uint32) 1000*1000);
+}
+
+#else
+#  error Missing erts_os_system_time() implmenentation
+#endif
+
 #if defined(OS_MONOTONIC_TIME_USING_CLOCK_GETTIME)
 
 static ERTS_INLINE ErtsMonotonicTime
@@ -314,7 +439,7 @@ clock_gettime_monotonic(void)
 
 #if defined(__linux__)
 
-ErtsMonotonicTime clock_gettime_monotonic_verified(void)
+static ErtsMonotonicTime clock_gettime_monotonic_verified(void)
 {
     ErtsMonotonicTime mtime;
 
@@ -330,7 +455,7 @@ ErtsMonotonicTime clock_gettime_monotonic_verified(void)
     return mtime;
 }
 
-ErtsMonotonicTime clock_gettime_monotonic_raw(void)
+static ErtsMonotonicTime clock_gettime_monotonic_raw(void)
 {
     return clock_gettime_monotonic();
 }
@@ -344,6 +469,12 @@ ErtsMonotonicTime erts_os_monotonic_time(void)
 
 #endif /* !defined(__linux__) */
 
+ErtsSysHrTime
+erts_sys_hrtime(void)
+{
+    return (ErtsSysHrTime) clock_gettime_monotonic();
+}
+
 #elif defined(OS_MONOTONIC_TIME_USING_MACH_CLOCK_GET_TIME)
 
 #include <mach/clock.h>
@@ -377,91 +508,47 @@ ErtsMonotonicTime erts_os_monotonic_time(void)
     return mtime;
 }
 
-#elif defined(OS_MONOTONIC_TIME_USING_TIMES)
-
-static clock_t sys_times_wrap(void)
-{
-    SysTimes dummy;
-    clock_t result = (sys_times(&dummy) >> internal_state.r.o.ticks_bsr);
-    return result;
-}
-
-void
-erts_os_time_offset_finalize(void)
+ErtsSysHrTime
+erts_sys_hrtime(void)
 {
-    erts_smp_mtx_lock(&internal_state.w.f.mtx);
-    internal_state.w.f.last_tick_wrap_count = 0;
-    erts_smp_mtx_unlock(&internal_state.w.f.mtx);
+    return (ErtsSysHrTime) erts_os_monotonic_time();
 }
 
-#define ERTS_TIME_EXCEED_TICK_LIMIT(SYS_TIME, TCK_TIME)			\
-    (((Uint64) (SYS_TIME)) - (((Uint64) (TCK_TIME))			\
-			      - ERTS_KERNEL_TICK_TO_USEC(1))		\
-     > ERTS_KERNEL_TICK_TO_USEC(2))
+#elif defined(OS_MONOTONIC_TIME_USING_TIMES)
 
-/* Returns monotonic time in micro seconds */
 ErtsMonotonicTime
 erts_os_monotonic_time(void)
 {
-    SysTimeval tv;
-    ErtsMonotonicTime res;
-    ErtsMonotonicTime tick_count;
-    ErtsMonotonicTime tick_count_usec;
-    ErtsMonotonicTime tick_monotonic_time;
-    ErtsMonotonicTime timeofday_usec;
-    ErtsMonotonicTime timeofday_diff_usec;
-
-    erts_smp_mtx_lock(&internal_state.w.f.mtx);
-
-    tick_count = (ErtsMonotonicTime) KERNEL_TICKS();
-    sys_gettimeofday(&tv);
-
-    if (internal_state.w.f.last_tick_count > tick_count) {
-	internal_state.w.f.last_tick_wrap_count
-	    += (((ErtsMonotonicTime) 1) << ((sizeof(clock_t) * 8) - 1));
-    }
-    internal_state.w.f.last_tick_count = tick_count;
-    tick_count += internal_state.w.f.last_tick_wrap_count;
-
-    tick_count_usec = ERTS_KERNEL_TICK_TO_USEC(tick_count);
-
-    timeofday_usec = (ErtsMonotonicTime) tv.tv_sec*(1000*1000);
-    timeofday_usec += (ErtsMonotonicTime) tv.tv_usec;
-    timeofday_diff_usec = timeofday_usec;
-    timeofday_diff_usec -= internal_state.w.f.last_timeofday_usec;
-    internal_state.w.f.last_timeofday_usec = timeofday_usec;
-
-    if (timeofday_diff_usec < 0) {
-	/* timeofday jumped backwards use tick count only... */
-	tick_monotonic_time = tick_count_usec;
-    }
-    else {
-	/* Use time diff from of timeofday if not off by too much... */
-	tick_monotonic_time = internal_state.w.f.last_tick_monotonic_time;
-	tick_monotonic_time += timeofday_diff_usec;
-
-	if (ERTS_TIME_EXCEED_TICK_LIMIT(tick_monotonic_time, tick_count_usec)) {
-	    /*
-	     * Value off by more than one tick from tick_count, i.e.
-	     * timofday leaped one way or the other. We use
-	     * tick_count_usec as is instead and unfortunately
-	     * get lousy precision.
-	     */
-	    tick_monotonic_time = tick_count_usec;
-	}
-    }
+    Uint32 ticks = get_tick_count();
+    ERTS_CHK_EXTEND_OS_MONOTONIC_TIME(&internal_state.wr.m.os_mtime_xtnd,
+				      ticks);
+    return ERTS_EXTEND_OS_MONOTONIC_TIME(&internal_state.wr.m.os_mtime_xtnd,
+					 ticks) << internal_state.r.o.times_shift;
+}
 
-    if (internal_state.w.f.last_tick_monotonic_time < tick_monotonic_time)
-	internal_state.w.f.last_tick_monotonic_time = tick_monotonic_time;
+#  define ERTS_NEED_ERTS_SYS_HRTIME_FALLBACK
 
-    res = internal_state.w.f.last_tick_monotonic_time;
+#else  /* !defined(OS_MONOTONIC_TIME_USING_TIMES) */
+/* No os-monotonic-time */
+#  define ERTS_NEED_ERTS_SYS_HRTIME_FALLBACK
+#endif
 
-    erts_smp_mtx_unlock(&internal_state.w.f.mtx);
+#ifdef ERTS_NEED_ERTS_SYS_HRTIME_FALLBACK
 
-    return res;
+ErtsSysHrTime
+erts_sys_hrtime(void)
+{
+    ErtsSysHrTime time;
+    struct timeval tv;
+    gettimeofday(&tv);
+    time = (ErtsSysHrTime) tv.tv_sec;
+    time *= (ErtsSysHrTime) 1000*1000*1000;
+    time += ((ErtsSysHrTime) tv.tv_usec)*1000;
+    return time;
 }
 
-#endif  /* !defined(OS_MONOTONIC_TIME_USING_TIMES) */
+#endif
+
 
 #ifdef HAVE_GETHRVTIME_PROCFS_IOCTL
 
diff --git a/erts/emulator/sys/win32/erl_win_sys.h b/erts/emulator/sys/win32/erl_win_sys.h
index 33aa88ab5f..9aeb460720 100644
--- a/erts/emulator/sys/win32/erl_win_sys.h
+++ b/erts/emulator/sys/win32/erl_win_sys.h
@@ -172,13 +172,19 @@ typedef long long          Sint64;
 #  endif
 
 typedef long long ErtsMonotonicTime;
+typedef long long ErtsSysHrTime;
 #else
 typedef ULONGLONG Uint64;
 typedef LONGLONG  Sint64;
 
 typedef LONGLONG ErtsMonotonicTime;
+typedef LONGLONG ErtsSysHrTime;
 #endif
 
+typedef ErtsMonotonicTime ErtsSystemTime;
+
+ErtsSystemTime erts_os_system_time(void);
+
 #define ERTS_MONOTONIC_TIME_MIN (((ErtsMonotonicTime) 1) << 63)
 #define ERTS_MONOTONIC_TIME_MAX (~ERTS_MONOTONIC_TIME_MIN)
 
@@ -187,6 +193,7 @@ typedef LONGLONG ErtsMonotonicTime;
 
 struct erts_sys_time_read_only_data__ {
     ErtsMonotonicTime (*os_monotonic_time)(void);
+    ErtsSysHrTime (*sys_hrtime)(void);
 };
 
 typedef struct {
@@ -201,6 +208,7 @@ typedef struct {
 extern ErtsSysTimeData__ erts_sys_time_data__;
 
 ERTS_GLB_INLINE ErtsMonotonicTime erts_os_monotonic_time(void);
+ERTS_GLB_INLINE ErtsSysHrTime erts_sys_hrtime(void);
 
 #if ERTS_GLB_INLINE_INCL_FUNC_DEF
 
@@ -210,6 +218,12 @@ erts_os_monotonic_time(void)
     return (*erts_sys_time_data__.r.o.os_monotonic_time)();
 }
 
+ERTS_GLB_INLINE ErtsSysHrTime
+erts_sys_hrtime(void)
+{
+    return (*erts_sys_time_data__.r.o.sys_hrtime)();
+}
+
 #endif /* ERTS_GLB_INLINE_INCL_FUNC_DEF */
 
 extern void sys_gettimeofday(SysTimeval *tv);
diff --git a/erts/emulator/sys/win32/sys_time.c b/erts/emulator/sys/win32/sys_time.c
index 3a10125c81..da9c4d2e29 100644
--- a/erts/emulator/sys/win32/sys_time.c
+++ b/erts/emulator/sys/win32/sys_time.c
@@ -25,6 +25,8 @@
 #endif
 #include "sys.h"
 #include "assert.h"
+#include "erl_os_monotonic_time_extender.h"
+#include "erl_time.h"
 
 #define LL_LITERAL(X) ERTS_I64_LITERAL(X)
 
@@ -71,6 +73,8 @@ static int days_in_month[2][13] = {
     {0,31,28,31,30,31,30,31,31,30,31,30,31},
     {0,31,29,31,30,31,30,31,31,30,31,30,31}};
 
+#define ERTS_GET_TICK_COUNT_TIME_UNIT_SHIFT 10
+
 /*
  * erts_os_monotonic_time()
  */
@@ -78,6 +82,12 @@ static int days_in_month[2][13] = {
 struct sys_time_internal_state_read_only__ {
     ULONGLONG (WINAPI *pGetTickCount64)(void);
     BOOL (WINAPI *pQueryPerformanceCounter)(LARGE_INTEGER *);
+    Sint32 pcf;
+    int using_get_tick_count_time_unit;
+};
+
+struct sys_time_internal_state_read_mostly__ {
+    ErtsOsMonotonicTimeExtendState os_mtime_xtnd;
 };
 
 struct sys_time_internal_state_write_freq__ {
@@ -94,6 +104,12 @@ __declspec(align(ASSUMED_CACHE_LINE_SIZE)) struct {
 		     * ASSUMED_CACHE_LINE_SIZE];
     } r;
     union {
+	struct sys_time_internal_state_read_mostly__ m;
+	char align__[(((sizeof(struct sys_time_internal_state_read_mostly__) - 1)
+		       / ASSUMED_CACHE_LINE_SIZE) + 1)
+		     * ASSUMED_CACHE_LINE_SIZE];
+    } wr;
+    union {
 	struct sys_time_internal_state_write_freq__ f;
 	char align__[(((sizeof(struct sys_time_internal_state_write_freq__) - 1)
 		       / ASSUMED_CACHE_LINE_SIZE) + 1)
@@ -114,29 +130,63 @@ os_monotonic_time_qpc(void)
     return (ErtsMonotonicTime) pc.QuadPart;
 }
 
+static Uint32
+get_tick_count(void)
+{
+    return (Uint32) GetTickCount();
+}
+
 static ErtsMonotonicTime
 os_monotonic_time_gtc32(void) 
 {
-    ULONGLONG res, ticks;
+    Uint32 ticks = (Uint32) GetTickCount();
+    ERTS_CHK_EXTEND_OS_MONOTONIC_TIME(&internal_state.wr.m.os_mtime_xtnd,
+				      tick_count);
+    return ERTS_EXTEND_OS_MONOTONIC_TIME(&internal_state.wr.m.os_mtime_xtnd,
+					 ticks) << 10;
+}
 
-    erts_smp_mtx_lock(&internal_state.w.f.mtime_mtx);
+static ErtsMonotonicTime
+os_monotonic_time_gtc64(void) 
+{
+    ULONGLONG ticks = (*internal_state.r.o.pGetTickCount64)();
+    return (ErtsMonotonicTime) ticks << 10;
+}
 
-    ticks = (ULONGLONG) (GetTickCount() & 0x7FFFFFFF);
-    if (ticks < internal_state.w.f.last_tick_count)
-	internal_state.w.f.wrap += (ULONGLONG) LL_LITERAL(1) << 31;
-    internal_state.w.f.last_tick_count = ticks;
-    res = ticks + internal_state.w.f.wrap;
+static ErtsSysHrTime
+sys_hrtime_qpc(void)
+{
+    LARGE_INTEGER pc;
 
-    erts_smp_mtx_unlock(&internal_state.w.f.mtime_mtx);
+    if (!(*internal_state.r.o.pQueryPerformanceCounter)(&pc))
+	erl_exit(ERTS_ABORT_EXIT, "QueryPerformanceCounter() failed\n");
 
-    return (ErtsMonotonicTime) res*1000;
+    ASSERT(pc.QuadPart > 0);
+
+    return (ErtsSysHrTime) erts_time_unit_conversion((Uint64) pc.QuadPart,
+						     internal_state.r.o.pcf,
+						     (Uint32) 1000*1000*1000);
 }
 
-static ErtsMonotonicTime
-os_monotonic_time_gtc64(void) 
+static ErtsSysHrTime
+sys_hrtime_gtc32(void)
 {
-    ULONGLONG ticks = (*internal_state.r.o.pGetTickCount64)();
-    return (ErtsMonotonicTime) ticks*1000;
+    ErtsSysHrTime time;
+    Uint32 ticks = (Uint32) GetTickCount();
+    ERTS_CHK_EXTEND_OS_MONOTONIC_TIME(&internal_state.wr.m.os_mtime_xtnd,
+				      tick_count);
+    time = (ErtsSysHrTime) ERTS_EXTEND_OS_MONOTONIC_TIME(&internal_state.wr.m.os_mtime_xtnd,
+							 ticks);
+    time *= (ErtsSysHrTime) (1000 * 1000);
+    return time;
+}
+
+static ErtsSysHrTime
+sys_hrtime_gtc64(void)
+{
+    ErtsSysHrTime time = (*internal_state.r.o.pGetTickCount64)();
+    time *= (ErtsSysHrTime) (1000*1000);
+    return time;
 }
 
 /*
@@ -147,11 +197,12 @@ void
 sys_init_time(ErtsSysInitTimeResult *init_resp)
 {
     ErtsMonotonicTime (*os_mtime_func)(void);
+    ErtsSysHrTime (*sys_hrtime_func)(void) = NULL;
     ErtsMonotonicTime time_unit;
     char kernel_dll_name[] = "kernel32";
     HMODULE module;
 
-    init_resp->os_monotonic_info.clock_id = NULL;
+    init_resp->os_monotonic_time_info.clock_id = NULL;
 
     module = GetModuleHandle(kernel_dll_name);
     if (!module) {
@@ -161,11 +212,20 @@ sys_init_time(ErtsSysInitTimeResult *init_resp)
 	internal_state.w.f.wrap = 0;
 	internal_state.w.f.last_tick_count = 0;
 
-	init_resp->os_monotonic_info.func = "GetTickCount";
-	init_resp->os_monotonic_info.locked_use = 1;
-	init_resp->os_monotonic_info.resolution = 1000;
-	time_unit = (ErtsMonotonicTime) 1000*1000;
+	init_resp->os_monotonic_time_info.func = "GetTickCount";
+	init_resp->os_monotonic_time_info.locked_use = 1;
+	/* 10-16 ms resolution according to MicroSoft documentation */
+	init_resp->os_monotonic_time_info.resolution = 100; /* 10 ms */
+	time_unit = (ErtsMonotonicTime) 1000;
+	time_unit <<= ERTS_GET_TICK_COUNT_TIME_UNIT_SHIFT;
+	internal_state.r.o.using_get_tick_count_time_unit = 1;
 	os_mtime_func = os_monotonic_time_gtc32;
+	init_resp->os_monotonic_time_info.extended = 1;
+	erts_init_os_monotonic_time_extender(&internal_state.wr.m.os_mtime_xtnd,
+					     get_tick_count,
+					     60*60*24*7); /* Check once a week */
+	if (!sys_hrtime_func)
+	    sys_hrtime_func = sys_hrtime_gtc32;
     }
     else {
 	int major, minor, build;
@@ -182,11 +242,16 @@ sys_init_time(ErtsSysInitTimeResult *init_resp)
 	    if (!internal_state.r.o.pGetTickCount64)
 		goto get_tick_count;
 
-	    init_resp->os_monotonic_info.func = "GetTickCount64";
-	    init_resp->os_monotonic_info.locked_use = 0;
-	    init_resp->os_monotonic_info.resolution = 1000;
-	    time_unit = (ErtsMonotonicTime) 1000*1000;
+	    init_resp->os_monotonic_time_info.func = "GetTickCount64";
+	    init_resp->os_monotonic_time_info.locked_use = 0;
+	    /* 10-16 ms resolution according to MicroSoft documentation */
+	    init_resp->os_monotonic_time_info.resolution = 100; /* 10 ms */
+	    time_unit = (ErtsMonotonicTime) 1000;
+	    time_unit <<= ERTS_GET_TICK_COUNT_TIME_UNIT_SHIFT;
+	    internal_state.r.o.using_get_tick_count_time_unit = 1;
 	    os_mtime_func = os_monotonic_time_gtc64;
+	    if (!sys_hrtime_func)
+		sys_hrtime_func = sys_hrtime_gtc64;
 	}
 	else { /* Vista or newer... */
 
@@ -199,40 +264,59 @@ sys_init_time(ErtsSysInitTimeResult *init_resp)
 		goto get_tick_count64;
 	    if (!(*QPF)(&pf))
 		goto get_tick_count64;
-	    /*
-	     * We only use QueryPerformanceCounter() if
-	     * its frequency is equal to, or larger than
-	     * GHz in order to ensure that the user wont
-	     * be able to observe faulty order between
-	     * values retrieved on different threads.
-	     */
-	    if (pf.QuadPart < (LONGLONG) 1000*1000*1000)
-		goto get_tick_count64;
+
 	    internal_state.r.o.pQueryPerformanceCounter
 		= ((BOOL (WINAPI *)(LARGE_INTEGER *))
 		   GetProcAddress(module, "QueryPerformanceCounter"));
 	    if (!internal_state.r.o.pQueryPerformanceCounter)
 		goto get_tick_count64;
 
-	    init_resp->os_monotonic_info.func = "QueryPerformanceCounter";
-	    init_resp->os_monotonic_info.locked_use = 0;
+	    if (pf.QuadPart < (((LONGLONG) 1) << 32)) {
+		internal_state.r.o.pcf = (Uint32) pf.QuadPart;
+		sys_hrtime_func = sys_hrtime_qpc;
+	    }
+	    
+	    /*
+	     * We only use QueryPerformanceCounter() for
+	     * os-monotonic-time if its frequency is equal
+	     * to, or larger than GHz in order to ensure
+	     * that the user wont be able to observe faulty
+	     * order between values retrieved on different threads.
+	     */
+	    if (pf.QuadPart < (LONGLONG) 1000*1000*1000)
+		goto get_tick_count64;
+
+	    init_resp->os_monotonic_time_info.func = "QueryPerformanceCounter";
+	    init_resp->os_monotonic_time_info.locked_use = 0;
 	    time_unit = (ErtsMonotonicTime) pf.QuadPart;
-	    init_resp->os_monotonic_info.resolution = time_unit;
+	    internal_state.r.o.using_get_tick_count_time_unit = 0;
+	    init_resp->os_monotonic_time_info.resolution = time_unit;
 	    os_mtime_func = os_monotonic_time_qpc;
 	}
     }
 
     erts_sys_time_data__.r.o.os_monotonic_time = os_mtime_func;
     init_resp->os_monotonic_time_unit = time_unit;
-    init_resp->have_os_monotonic = 1;
+    init_resp->have_os_monotonic_time = 1;
     init_resp->sys_clock_resolution = 1;
 
+    init_resp->os_system_time_info.func = "GetSystemTime";    
+    init_resp->os_system_time_info.clock_id = NULL;
+    init_resp->os_system_time_info.resolution = 100;
+    init_resp->os_system_time_info.locked_use = 0;
+
     if(GetTimeZoneInformation(&static_tzi) && 
        static_tzi.StandardDate.wMonth != 0 &&
        static_tzi.DaylightDate.wMonth != 0) {
 	have_static_tzi = 1;
     }
+}
 
+void
+erts_late_sys_init_time(void)
+{
+    if (erts_sys_time_data__.r.o.os_monotonic_time == os_monotonic_time_gtc32)
+	erts_late_init_os_monotonic_time_extender(&internal_state.wr.m.os_mtime_xtnd);
 }
 
 /* Returns a switchtimes for DST as UTC filetimes given data from a 
@@ -513,6 +597,37 @@ sys_gettimeofday(SysTimeval *tv)
 			 EPOCH_JULIAN_DIFF);
 }
 
+ErtsSystemTime
+erts_os_system_time(void)
+{
+    SYSTEMTIME t;
+    FILETIME ft;
+    ULARGE_INTEGER ull;
+    ErtsSystemTime stime;
+
+    GetSystemTime(&t);
+    SystemTimeToFileTime(&t, &ft);
+    FILETIME_TO_ULI(ull,ft);
+
+    /* now in 100 ns units */
+
+    stime = (ErtsSystemTime) ull.QuadPart;
+    stime -= (((ErtsSystemTime) EPOCH_JULIAN_DIFF)
+	      * ((ErtsSystemTime) (10*1000*1000)));
+    stime /= (ErtsSystemTime) (10*1000);
+
+    if (internal_state.r.o.using_get_tick_count_time_unit) {
+	stime <<= ERTS_GET_TICK_COUNT_TIME_UNIT_SHIFT;
+	return stime;
+    }
+
+    return ((ErtsSystemTime)
+	    erts_time_unit_conversion(stime,
+				      (Uint32) 1000,
+				      (Uint32) ERTS_MONOTONIC_TIME_UNIT));
+}
+
+
 clock_t 
 sys_times(SysTimes *buffer) {
     clock_t kernel_ticks = (GetTickCount() / 
diff --git a/erts/example/time_compat.erl b/erts/example/time_compat.erl
index d582117ceb..90b7fbcc80 100644
--- a/erts/example/time_compat.erl
+++ b/erts/example/time_compat.erl
@@ -240,6 +240,7 @@ system_info(Item) ->
 		time_offset ->
 		    final;
 		NotSupArg when NotSupArg == os_monotonic_time_source;
+			       NotSupArg == os_system_time_source;
 			       NotSupArg == start_time ->
 		    %% Cannot emulate this...
 		    erlang:error(notsup, [NotSupArg]);
diff --git a/erts/preloaded/ebin/erlang.beam b/erts/preloaded/ebin/erlang.beam
index 7238dabf40..7e7ac99b1c 100644
--- a/erts/preloaded/ebin/erlang.beam
+++ b/erts/preloaded/ebin/erlang.beam
diff --git a/erts/preloaded/src/erlang.erl b/erts/preloaded/src/erlang.erl
index 425b59790e..4bbad4df99 100644
--- a/erts/preloaded/src/erlang.erl
+++ b/erts/preloaded/src/erlang.erl
@@ -2537,6 +2537,7 @@ tuple_to_list(_Tuple) ->
          (nif_version) -> string();
          (otp_release) -> string();
          (os_monotonic_time_source) -> [{atom(),term()}];
+         (os_system_time_source) -> [{atom(),term()}];
          (port_count) -> non_neg_integer();
          (port_limit) -> pos_integer();
          (process_count) -> pos_integer();