--- a/hotspot/src/share/vm/gc/g1/concurrentMark.hpp	Mon Dec 21 14:09:21 2015 +0000
+++ b/hotspot/src/share/vm/gc/g1/concurrentMark.hpp	Fri Dec 18 08:17:30 2015 -0800
@@ -353,6 +353,9 @@
   // time of remark.
   volatile bool           _concurrent_marking_in_progress;
 
+  // Keep track of whether we have started concurrent phase or not.
+  bool                    _concurrent_phase_started;
+
   // All of these times are in ms
   NumberSeq _init_times;
   NumberSeq _remark_times;
@@ -516,6 +519,9 @@
     _concurrent_marking_in_progress = false;
   }
 
+  void register_concurrent_phase_start(const char* title);
+  void register_concurrent_phase_end();
+
   void update_accum_task_vtime(int i, double vtime) {
     _accum_task_vtime[i] += vtime;
   }