--- old/src/share/vm/gc/shared/workgroup.hpp	2016-04-06 17:17:39.206383842 +0200
+++ new/src/share/vm/gc/shared/workgroup.hpp	2016-04-06 17:17:39.106383841 +0200
@@ -285,9 +285,9 @@
 // enumeration type.
 
 class SubTasksDone: public CHeapObj<mtInternal> {
-  uint* _tasks;
+  volatile uint* _tasks;
   uint _n_tasks;
-  uint _threads_completed;
+  volatile uint _threads_completed;
 #ifdef ASSERT
   volatile uint _claimed;
 #endif