--- a/src/hotspot/share/runtime/safepoint.cpp	Thu Feb 28 09:43:23 2019 +0800
+++ b/src/hotspot/share/runtime/safepoint.cpp	Wed Mar 06 11:15:16 2019 +0100
@@ -1121,6 +1121,7 @@
 jlong SafepointTracing::_last_safepoint_sync_time_ns = 0;
 jlong SafepointTracing::_last_safepoint_cleanup_time_ns = 0;
 jlong SafepointTracing::_last_safepoint_end_time_ns = 0;
+jlong SafepointTracing::_last_safepoint_end_time_epoch_ms = 0;
 jlong SafepointTracing::_last_app_time_ns = 0;
 int SafepointTracing::_nof_threads = 0;
 int SafepointTracing::_nof_running = 0;
@@ -1133,6 +1134,8 @@
 void SafepointTracing::init() {
   // Application start
   _last_safepoint_end_time_ns = os::javaTimeNanos();
+  // amount of time since epoch
+  _last_safepoint_end_time_epoch_ms = os::javaTimeMillis();
 }
 
 // Helper method to print the header.
@@ -1232,6 +1235,8 @@
 
 void SafepointTracing::end() {
   _last_safepoint_end_time_ns = os::javaTimeNanos();
+  // amount of time since epoch
+  _last_safepoint_end_time_epoch_ms = os::javaTimeMillis();
 
   if (_max_sync_time < (_last_safepoint_sync_time_ns - _last_safepoint_begin_time_ns)) {
     _max_sync_time = _last_safepoint_sync_time_ns - _last_safepoint_begin_time_ns;

--- a/src/hotspot/share/runtime/safepoint.hpp	Thu Feb 28 09:43:23 2019 +0800
+++ b/src/hotspot/share/runtime/safepoint.hpp	Wed Mar 06 11:15:16 2019 +0100
@@ -240,6 +240,8 @@
   static jlong _last_safepoint_sync_time_ns;
   static jlong _last_safepoint_cleanup_time_ns;
   static jlong _last_safepoint_end_time_ns;
+  // amount of ms since epoch
+  static jlong _last_safepoint_end_time_epoch_ms;
   // Relative
   static jlong _last_app_time_ns;
 
@@ -268,8 +270,8 @@
     return (os::javaTimeNanos() - _last_safepoint_end_time_ns) / (NANOUNITS / MILLIUNITS);
   }
 
-  static jlong end_of_last_safepoint_ms() {
-    return _last_safepoint_end_time_ns / (NANOUNITS / MILLIUNITS);
+  static jlong end_of_last_safepoint_epoch_ms() {
+    return _last_safepoint_end_time_epoch_ms;
   }
 
   static jlong start_of_safepoint() {

--- a/src/hotspot/share/runtime/tieredThresholdPolicy.cpp	Thu Feb 28 09:43:23 2019 +0800
+++ b/src/hotspot/share/runtime/tieredThresholdPolicy.cpp	Wed Mar 06 11:15:16 2019 +0100
@@ -479,7 +479,7 @@
 
   // We don't update the rate if we've just came out of a safepoint.
   // delta_s is the time since last safepoint in milliseconds.
-  jlong delta_s = t - SafepointTracing::end_of_last_safepoint_ms();
+  jlong delta_s = t - SafepointTracing::end_of_last_safepoint_epoch_ms();
   jlong delta_t = t - (m->prev_time() != 0 ? m->prev_time() : start_time()); // milliseconds since the last measurement
   // How many events were there since the last time?
   int event_count = m->invocation_count() + m->backedge_count();
@@ -504,7 +504,7 @@
 // Check if this method has been stale from a given number of milliseconds.
 // See select_task().
 bool TieredThresholdPolicy::is_stale(jlong t, jlong timeout, Method* m) {
-  jlong delta_s = t - SafepointTracing::end_of_last_safepoint_ms();
+  jlong delta_s = t - SafepointTracing::end_of_last_safepoint_epoch_ms();
   jlong delta_t = t - m->prev_time();
   if (delta_t > timeout && delta_s > timeout) {
     int event_count = m->invocation_count() + m->backedge_count();