--- a/src/hotspot/share/gc/cms/cmsHeap.cpp	Mon Oct 16 23:23:27 2017 -0700
+++ b/src/hotspot/share/gc/cms/cmsHeap.cpp	Tue Oct 17 08:51:55 2017 +0200
@@ -134,6 +134,14 @@
   ConcurrentMarkSweepThread::cmst()->stop();
 }
 
+void CMSHeap::safepoint_synchronize_begin() {
+  ConcurrentMarkSweepThread::synchronize(false);
+}
+
+void CMSHeap::safepoint_synchronize_end() {
+  ConcurrentMarkSweepThread::desynchronize(false);
+}
+
 void CMSHeap::cms_process_roots(StrongRootsScope* scope,
                                 bool young_gen_as_roots,
                                 ScanningOption so,