--- old/src/hotspot/share/runtime/mutexLocker.cpp	2017-10-31 13:44:25.459651157 -0700
+++ new/src/hotspot/share/runtime/mutexLocker.cpp	2017-10-31 13:44:25.099652597 -0700
@@ -125,6 +125,7 @@
 Monitor* RedefineClasses_lock         = NULL;
 
 Monitor* HeapMonitor_lock             = NULL;
+Monitor* HeapMonitorStorage_lock      = NULL;
 
 #if INCLUDE_TRACE
 Mutex*   JfrStacktrace_lock           = NULL;
@@ -276,7 +277,8 @@
   def(PeriodicTask_lock            , PaddedMonitor, nonleaf+5,   true,  Monitor::_safepoint_check_sometimes);
   def(RedefineClasses_lock         , PaddedMonitor, nonleaf+5,   true,  Monitor::_safepoint_check_always);
 
-  def(HeapMonitor_lock             , PaddedMonitor, leaf,        true,  Monitor::_safepoint_check_always);
+  def(HeapMonitorStorage_lock      , PaddedMonitor, nonleaf,     true,  Monitor::_safepoint_check_always);
+  def(HeapMonitor_lock             , PaddedMonitor, nonleaf+1,   true,  Monitor::_safepoint_check_always);
 
   if (WhiteBoxAPI) {
     def(Compilation_lock           , PaddedMonitor, leaf,        false, Monitor::_safepoint_check_never);