--- old/src/hotspot/share/runtime/globals.hpp	2019-10-17 17:31:36.000000000 -0400
+++ new/src/hotspot/share/runtime/globals.hpp	2019-10-17 17:31:35.000000000 -0400
@@ -726,8 +726,9 @@
           "MonitorUsedDeflationThreshold is exceeded (0 is off).")          \
           range(0, max_jint)                                                \
                                                                             \
-  diagnostic(bool, CheckMonitorLists, false,                                \
-          "Sanity check the lock free ObjectMonitor lists.")                \
+  diagnostic_pd(bool, HandshakeAfterDeflateIdleMonitors,                    \
+          "Handshake with all JavaThreads after async deflating idle "      \
+          "monitors to force threads to leave C2 monitor code.")            \
                                                                             \
   experimental(intx, MonitorUsedDeflationThreshold, 90,                     \
           "Percentage of used monitors before triggering deflation (0 is "  \