--- a/src/hotspot/share/jfr/periodic/sampling/jfrThreadSampler.cpp	Thu Sep 12 11:35:02 2019 +0200
+++ b/src/hotspot/share/jfr/periodic/sampling/jfrThreadSampler.cpp	Sat Sep 14 13:03:44 2019 +0200
@@ -522,7 +522,7 @@
     elapsedTimer sample_time;
     sample_time.start();
     {
-      MutexLocker tlock(Threads_lock, Mutex::_no_safepoint_check_flag);
+      MutexLocker tlock(Threads_lock);
       ThreadsListHandle tlh;
       // Resolve a sample session relative start position index into the thread list array.
       // In cases where the last sampled thread is NULL or not-NULL but stale, find_index() returns -1.