--- old/src/hotspot/share/runtime/objectMonitor.hpp	2019-08-28 15:04:00.598957364 -0400
+++ new/src/hotspot/share/runtime/objectMonitor.hpp	2019-08-28 15:04:00.410957371 -0400
@@ -159,19 +159,13 @@
     Old
   } AllocationState;
   AllocationState _allocation_state;
- public:
-  ObjectMonitor* _next_om;          // Next ObjectMonitor* linkage
- private:
   // Separate _header and _owner on different cache lines since both can
   // have busy multi-threaded access. _header, _object and _allocation_state
   // are set at initial inflation. _object and _allocation_state don't
   // change until deflation so _object and _allocation_state are good
-  // choices to share the cache line with _header. _next_om shares _header's
-  // cache line for pre-monitor list historical reasons. _next_om only
-  // changes if the next ObjectMonitor is deflated.
+  // choices to share the cache line with _header.
   DEFINE_PAD_MINUS_SIZE(0, OM_CACHE_LINE_SIZE, sizeof(volatile markWord) +
-                        sizeof(void* volatile) + sizeof(AllocationState) +
-                        sizeof(ObjectMonitor*));
+                        sizeof(void* volatile) + sizeof(AllocationState));
   // Used by async deflation as a marker in the _owner field:
   #define DEFLATER_MARKER reinterpret_cast<void*>(-1)
  protected:                         // protected for JvmtiRawMonitor
@@ -186,6 +180,12 @@
                         sizeof(volatile jlong));
   volatile jint _ref_count;         // ref count for ObjectMonitor* and used by the async deflation
                                     // protocol. See ObjectSynchronizer::deflate_monitor_using_JT().
+ private:
+  // Separate _ref_count and _next_om on different cache lines since
+  // both can have busy multi-threaded access.
+  DEFINE_PAD_MINUS_SIZE(2, OM_CACHE_LINE_SIZE, sizeof(volatile jint));
+ public:                            // for static synchronizer.cpp access:
+  ObjectMonitor* volatile _next_om;  // Next ObjectMonitor* linkage
  protected:                         // protected for JvmtiRawMonitor
   volatile intptr_t _recursions;    // recursion count, 0 for first entry
   ObjectWaiter* volatile _EntryList;  // Threads blocked on entry or reentry.
@@ -210,6 +210,7 @@
   volatile int _WaitSetLock;        // protects Wait Queue - simple spinlock
 
  public:
+  volatile int visit_marker;
   static void Initialize();
 
   // Only perform a PerfData operation if the PerfData object has been