--- a/src/hotspot/share/runtime/thread.cpp	Tue Sep 25 11:24:59 2018 +0800
+++ b/src/hotspot/share/runtime/thread.cpp	Mon Sep 24 22:12:07 2018 -0700
@@ -1953,13 +1953,9 @@
   // between JNI-acquired and regular Java monitors. We can only see
   // regular Java monitors here if monitor enter-exit matching is broken.
   //
-  // Optionally release any monitors for regular JavaThread exits. This
-  // is provided as a work around for any bugs in monitor enter-exit
-  // matching. This can be expensive so it is not enabled by default.
-  //
   // ensure_join() ignores IllegalThreadStateExceptions, and so does
   // ObjectSynchronizer::release_monitors_owned_by_thread().
-  if (exit_type == jni_detach || ObjectMonitor::Knob_ExitRelease) {
+  if (exit_type == jni_detach) {
     // Sanity check even though JNI DetachCurrentThread() would have
     // returned JNI_ERR if there was a Java frame. JavaThread exit
     // should be done executing Java code by the time we get here.