--- a/hotspot/src/share/vm/services/diagnosticCommand.cpp	Mon Jun 20 22:02:20 2016 -0700
+++ b/hotspot/src/share/vm/services/diagnosticCommand.cpp	Tue Jun 21 09:19:53 2016 +0200
@@ -413,6 +413,7 @@
 }
 
 void HeapInfoDCmd::execute(DCmdSource source, TRAPS) {
+  MutexLocker hl(Heap_lock);
   Universe::heap()->print_on(output());
 }