--- old/src/share/vm/gc/shenandoah/shenandoahConcurrentThread.cpp	2017-03-13 09:18:23.159587851 -0400
+++ new/src/share/vm/gc/shenandoah/shenandoahConcurrentThread.cpp	2017-03-13 09:18:23.098587952 -0400
@@ -87,6 +87,7 @@
   GCIdMark gc_id_mark;
   TraceCollectorStats tcs(heap->monitoring_support()->concurrent_collection_counters());
   TraceMemoryManagerStats tmms(false, GCCause::_no_cause_specified);
+  ShenandoahWorkGang* workers = heap->workers();
 
   // Start initial mark under STW:
   {
@@ -105,10 +106,9 @@
   // Continue concurrent mark:
   {
     // Setup workers for concurrent marking phase
-    WorkGang* workers = heap->workers();
     uint n_workers = ShenandoahCollectorPolicy::calc_workers_for_conc_marking(workers->active_workers(),
       Threads::number_of_non_daemon_threads());
-    ShenandoahWorkerScope scope(workers, n_workers);
+    ShenandoahWorkerSessionScope scope(workers, n_workers, ShenandoahWorkerSessionScope::Concurrent);
 
     GCTraceTime(Info, gc) time("Concurrent marking", gc_timer, GCCause::_no_gc, true);
     TraceCollectorStats tcs(heap->monitoring_support()->concurrent_collection_counters());
@@ -154,10 +154,9 @@
   // Continue concurrent evacuation:
   {
     // Setup workers for concurrent evacuation phase
-    WorkGang* workers = heap->workers();
     uint n_workers = ShenandoahCollectorPolicy::calc_workers_for_conc_evacuation(workers->active_workers(),
       Threads::number_of_non_daemon_threads());
-    ShenandoahWorkerScope scope(workers, n_workers);
+    ShenandoahWorkerSessionScope scope(workers, n_workers, ShenandoahWorkerSessionScope::Concurrent);
 
     GCTraceTime(Info, gc) time("Concurrent evacuation ", gc_timer, GCCause::_no_gc, true);
     TraceCollectorStats tcs(heap->monitoring_support()->concurrent_collection_counters());
@@ -170,7 +169,6 @@
   {
     GCTraceTime(Info, gc) time("Concurrent reset bitmaps", gc_timer, GCCause::_no_gc);
     heap->shenandoahPolicy()->record_phase_start(ShenandoahCollectorPolicy::reset_bitmaps);
-    WorkGang* workers = heap->workers();
     ShenandoahPushWorkerScope scope(workers, heap->max_workers());
     heap->reset_next_mark_bitmap(workers);
     heap->shenandoahPolicy()->record_phase_end(ShenandoahCollectorPolicy::reset_bitmaps);