--- old/src/share/vm/gc_implementation/g1/g1GCPhaseTimes.cpp	2015-02-17 09:48:40.067475325 +0100
+++ new/src/share/vm/gc_implementation/g1/g1GCPhaseTimes.cpp	2015-02-17 09:48:40.007473582 +0100
@@ -29,6 +29,7 @@
 #include "gc_implementation/g1/g1Log.hpp"
 #include "gc_implementation/g1/g1StringDedup.hpp"
 #include "runtime/atomic.inline.hpp"
+#include "g1CollectedHeap.hpp"
 
 // Helper class for avoiding interleaved logging
 class LineBuffer: public StackObj {
@@ -145,6 +146,7 @@
   for (uint i = 0; i < _length; i++) {
     _data[i] = (T)_uninitialized;
   }
+  _has_new_data = true;
 }
 
 template <class T>
@@ -158,10 +160,12 @@
 
 #endif
 
-G1GCPhaseTimes::G1GCPhaseTimes(uint max_gc_threads) :
+G1GCPhaseTimes::G1GCPhaseTimes(uint max_gc_threads, uint num_ext_root_scan_phases) :
   _max_gc_threads(max_gc_threads),
+  _num_ext_root_scan_phases(num_ext_root_scan_phases),
   _last_gc_worker_start_times_ms(_max_gc_threads, "%.1lf", false),
   _last_ext_root_scan_times_ms(_max_gc_threads, "%.1lf"),
+  _last_ext_root_scan_phase_times_ms(NULL),
   _last_satb_filtering_times_ms(_max_gc_threads, "%.1lf"),
   _last_update_rs_times_ms(_max_gc_threads, "%.1lf"),
   _last_update_rs_processed_buffers(_max_gc_threads, "%d"),
@@ -179,6 +183,21 @@
   _cur_string_dedup_table_fixup_worker_times_ms(_max_gc_threads, "%.1lf")
 {
   assert(max_gc_threads > 0, "Must have some GC threads");
+  if (track_ext_root_scan_phases()) {
+    _last_ext_root_scan_phase_times_ms = NEW_C_HEAP_ARRAY(WorkerDataArray<double>*, num_ext_root_scan_phases, mtGC);
+    for (uint i = 0; i < num_ext_root_scan_phases; i++) {
+      _last_ext_root_scan_phase_times_ms[i] = new WorkerDataArray<double>(_max_gc_threads, "%.1lf");
+    }
+  }
+}
+
+G1GCPhaseTimes::~G1GCPhaseTimes() {
+  if (track_ext_root_scan_phases()) {
+    for (uint i = 0; i < _num_ext_root_scan_phases; i++) {
+      delete _last_ext_root_scan_phase_times_ms[i];
+    }
+    FREE_C_HEAP_ARRAY(WorkerDataArray<double>*, _last_ext_root_scan_phase_times_ms);
+  }
 }
 
 void G1GCPhaseTimes::note_gc_start(uint active_gc_threads) {
@@ -203,6 +222,9 @@
   _last_redirty_logged_cards_time_ms.reset();
   _last_redirty_logged_cards_processed_cards.reset();
 
+  for (uint i = 0; i < _num_ext_root_scan_phases; i++) {
+    _last_ext_root_scan_phase_times_ms[i]->reset();
+  }
 }
 
 void G1GCPhaseTimes::note_gc_end() {
@@ -295,6 +317,12 @@
   print_stats(1, "Parallel Time", _cur_collection_par_time_ms, _active_gc_threads);
   _last_gc_worker_start_times_ms.print(2, "GC Worker Start (ms)");
   _last_ext_root_scan_times_ms.print(2, "Ext Root Scanning (ms)");
+  if (track_ext_root_scan_phases()) {
+    for (uint i = 0; i < _num_ext_root_scan_phases; i++) {
+      WorkerDataArray<double>* data = _last_ext_root_scan_phase_times_ms[i];
+      data->print(3, G1CollectedHeap::ext_roots_task_string(i));
+    }
+  }
   if (_last_satb_filtering_times_ms.sum() > 0.0) {
     _last_satb_filtering_times_ms.print(2, "SATB Filtering (ms)");
   }