--- old/src/hotspot/share/runtime/globals.hpp	2019-05-02 15:05:18.334391257 -0400
+++ new/src/hotspot/share/runtime/globals.hpp	2019-05-02 15:05:17.850391274 -0400
@@ -823,6 +823,9 @@
   product(intx, MonitorBound, 0, "Bound Monitor population")                \
           range(0, max_jint)                                                \
                                                                             \
+  diagnostic(bool, AsyncDeflateIdleMonitors, true,                          \
+          "Deflate idle monitors using JavaThreads and the ServiceThread.") \
+                                                                            \
   experimental(intx, MonitorUsedDeflationThreshold, 90,                     \
                 "Percentage of used monitors before triggering cleanup "    \
                 "safepoint which deflates monitors (0 is off). "            \