--- a/hotspot/src/share/vm/gc/g1/g1CollectedHeap.cpp	Thu Aug 06 15:49:50 2015 +0200
+++ b/hotspot/src/share/vm/gc/g1/g1CollectedHeap.cpp	Thu Aug 06 15:49:52 2015 +0200
@@ -4449,9 +4449,6 @@
   ParallelTaskTerminator _terminator;
   uint _n_workers;
 
-  Mutex _stats_lock;
-  Mutex* stats_lock() { return &_stats_lock; }
-
 public:
   G1ParTask(G1CollectedHeap* g1h, RefToScanQueueSet *task_queues, G1RootProcessor* root_processor, uint n_workers)
     : AbstractGangTask("G1 collection"),
@@ -4459,8 +4456,7 @@
       _queues(task_queues),
       _root_processor(root_processor),
       _terminator(n_workers, _queues),
-      _n_workers(n_workers),
-      _stats_lock(Mutex::leaf, "parallel G1 stats lock", true)
+      _n_workers(n_workers)
   {}
 
   RefToScanQueueSet* queues() { return _queues; }
@@ -4587,8 +4583,8 @@
       _g1h->update_surviving_young_words(pss.surviving_young_words()+1);
 
       if (PrintTerminationStats) {
-        MutexLocker x(stats_lock());
-        pss.print_termination_stats(worker_id);
+        MutexLockerEx x(ParGCRareEvent_lock, Mutex::_no_safepoint_check_flag);
+        pss.print_termination_stats();
       }
 
       assert(pss.queue_is_empty(), "should be empty");
@@ -5504,7 +5500,9 @@
     }
 
     // The individual threads will set their evac-failure closures.
-    if (PrintTerminationStats) G1ParScanThreadState::print_termination_stats_hdr();
+    if (PrintTerminationStats) {
+      G1ParScanThreadState::print_termination_stats_hdr();
+    }
 
     workers()->run_task(&g1_par_task);
     end_par_time_sec = os::elapsedTime();

--- a/hotspot/src/share/vm/gc/g1/g1ParScanThreadState.cpp	Thu Aug 06 15:49:50 2015 +0200
+++ b/hotspot/src/share/vm/gc/g1/g1ParScanThreadState.cpp	Thu Aug 06 15:49:52 2015 +0200
@@ -76,32 +76,24 @@
   FREE_C_HEAP_ARRAY(size_t, _surviving_young_words_base);
 }
 
-void
-G1ParScanThreadState::print_termination_stats_hdr(outputStream* const st)
-{
+void G1ParScanThreadState::print_termination_stats_hdr(outputStream* const st) {
   st->print_raw_cr("GC Termination Stats");
-  st->print_raw_cr("     elapsed  --strong roots-- -------termination-------"
-                   " ------waste (KiB)------");
-  st->print_raw_cr("thr     ms        ms      %        ms      %    attempts"
-                   "  total   alloc    undo");
-  st->print_raw_cr("--- --------- --------- ------ --------- ------ --------"
-                   " ------- ------- -------");
+  st->print_raw_cr("     elapsed  --strong roots-- -------termination------- ------waste (KiB)------");
+  st->print_raw_cr("thr     ms        ms      %        ms      %    attempts  total   alloc    undo");
+  st->print_raw_cr("--- --------- --------- ------ --------- ------ -------- ------- ------- -------");
 }
 
-void
-G1ParScanThreadState::print_termination_stats(int i,
-                                              outputStream* const st) const
-{
+void G1ParScanThreadState::print_termination_stats(outputStream* const st) const {
   const double elapsed_ms = elapsed_time() * 1000.0;
   const double s_roots_ms = strong_roots_time() * 1000.0;
   const double term_ms    = term_time() * 1000.0;
   size_t alloc_buffer_waste = 0;
   size_t undo_waste = 0;
   _plab_allocator->waste(alloc_buffer_waste, undo_waste);
-  st->print_cr("%3d %9.2f %9.2f %6.2f "
+  st->print_cr("%3u %9.2f %9.2f %6.2f "
                "%9.2f %6.2f " SIZE_FORMAT_W(8) " "
                SIZE_FORMAT_W(7) " " SIZE_FORMAT_W(7) " " SIZE_FORMAT_W(7),
-               i, elapsed_ms, s_roots_ms, s_roots_ms * 100 / elapsed_ms,
+               _queue_num, elapsed_ms, s_roots_ms, s_roots_ms * 100 / elapsed_ms,
                term_ms, term_ms * 100 / elapsed_ms, term_attempts(),
                (alloc_buffer_waste + undo_waste) * HeapWordSize / K,
                alloc_buffer_waste * HeapWordSize / K,

--- a/hotspot/src/share/vm/gc/g1/g1ParScanThreadState.hpp	Thu Aug 06 15:49:50 2015 +0200
+++ b/hotspot/src/share/vm/gc/g1/g1ParScanThreadState.hpp	Thu Aug 06 15:49:52 2015 +0200
@@ -139,8 +139,11 @@
     return os::elapsedTime() - _start;
   }
 
+  // Print the header for the per-thread termination statistics.
   static void print_termination_stats_hdr(outputStream* const st = gclog_or_tty);
-  void print_termination_stats(int i, outputStream* const st = gclog_or_tty) const;
+
+  // Print actual per-thread termination statistics.
+  void print_termination_stats(outputStream* const st = gclog_or_tty) const;
 
   size_t* surviving_young_words() {
     // We add on to hide entry 0 which accumulates surviving words for