--- a/src/hotspot/share/gc/shenandoah/shenandoahTraversalGC.cpp	Thu May 16 15:45:46 2019 +0100
+++ b/src/hotspot/share/gc/shenandoah/shenandoahTraversalGC.cpp	Thu May 16 19:07:31 2019 +0200
@@ -556,11 +556,6 @@
 }
 
 void ShenandoahTraversalGC::concurrent_traversal_collection() {
-  {
-    MutexLocker ml(ClassLoaderDataGraph_lock);
-    ClassLoaderDataGraph::clear_claimed_marks();
-  }
-
   ShenandoahGCPhase phase_work(ShenandoahPhaseTimings::conc_traversal);
   if (!_heap->cancelled_gc()) {
     uint nworkers = _heap->workers()->active_workers();