--- old/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp	2014-12-12 02:18:53.846000000 -0500
+++ new/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp	2014-12-12 02:18:53.739000000 -0500
@@ -1608,14 +1608,13 @@
 
   // If the collection is being acquired from the background
   // collector, there may be references on the discovered
-  // references lists that have NULL referents (being those
-  // that were concurrently cleared by a mutator) or
-  // that are no longer active (having been enqueued concurrently
-  // by the mutator).
-  // Scrub the list of those references because Mark-Sweep-Compact
-  // code assumes referents are not NULL and that all discovered
-  // Reference objects are active.
-  ref_processor()->clean_up_discovered_references();
+  // references lists.  Abandon those references, since some
+  // of them may have become unreachable due to later mutator
+  // activity, and the compacting collector we're about to run
+  // won't see them as live.
+  ref_processor()->disable_discovery();
+  ref_processor()->abandon_partial_discovery();
+  ref_processor()->verify_no_references_recorded();
 
   if (first_state > Idling) {
     save_heap_summary();
@@ -1681,7 +1680,7 @@
   ReferenceProcessorMTDiscoveryMutator rp_mut_discovery(ref_processor(), false);
 
   ref_processor()->set_enqueuing_is_done(false);
-  ref_processor()->enable_discovery(false /*verify_disabled*/, false /*check_no_refs*/);
+  ref_processor()->enable_discovery();
   ref_processor()->setup_policy(clear_all_soft_refs);
   // If an asynchronous collection finishes, the _modUnionTable is
   // all clear.  If we are assuming the collection from an asynchronous
@@ -2998,7 +2997,7 @@
                     Mutex::_no_safepoint_check_flag);
     checkpointRootsInitialWork();
     // enable ("weak") refs discovery
-    rp->enable_discovery(true /*verify_disabled*/, true /*check_no_refs*/);
+    rp->enable_discovery();
     _collectorState = Marking;
   }
   SpecializationStats::print();