--- old/src/hotspot/share/runtime/globals.hpp	2019-10-17 17:28:58.000000000 -0400
+++ new/src/hotspot/share/runtime/globals.hpp	2019-10-17 17:28:57.000000000 -0400
@@ -716,11 +716,25 @@
   product(intx, MonitorBound, 0, "(Deprecated) Bound Monitor population")   \
           range(0, max_jint)                                                \
                                                                             \
+  diagnostic(bool, AsyncDeflateIdleMonitors, true,                          \
+          "Deflate idle monitors using JavaThreads and the ServiceThread.") \
+                                                                            \
+  /* notice: the max range value here is max_jint, not max_intx  */         \
+  /* because of overflow issue                                   */         \
+  diagnostic(intx, AsyncDeflationInterval, 250,                             \
+          "Async deflate idle monitors every so many milliseconds when "    \
+          "MonitorUsedDeflationThreshold is exceeded (0 is off).")          \
+          range(0, max_jint)                                                \
+                                                                            \
+  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 cleanup "    \
-                "safepoint which deflates monitors (0 is off). "            \
-                "The check is performed on GuaranteedSafepointInterval.")   \
-                range(0, 100)                                               \
+          "Percentage of used monitors before triggering deflation (0 is "  \
+          "off). The check is performed on GuaranteedSafepointInterval "    \
+          "or AsyncDeflateInterval.")                                       \
+          range(0, 100)                                                     \
                                                                             \
   experimental(intx, hashCode, 5,                                           \
                "(Unstable) select hashCode generation algorithm")           \