--- a/hotspot/src/share/vm/memory/referenceProcessor.hpp	Thu Sep 16 13:45:55 2010 -0700
+++ b/hotspot/src/share/vm/memory/referenceProcessor.hpp	Mon Sep 20 14:38:38 2010 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2008, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -85,8 +85,10 @@
 
   // The discovered ref lists themselves
 
-  // The MT'ness degree of the queues below
+  // The active MT'ness degree of the queues below
   int             _num_q;
+  // The maximum MT'ness degree of the queues below
+  int             _max_num_q;
   // Arrays of lists of oops, one per thread
   DiscoveredList* _discoveredSoftRefs;
   DiscoveredList* _discoveredWeakRefs;
@@ -95,6 +97,7 @@
 
  public:
   int num_q()                            { return _num_q; }
+  void set_mt_degree(int v)              { _num_q = v; }
   DiscoveredList* discovered_soft_refs() { return _discoveredSoftRefs; }
   static oop  sentinel_ref()             { return _sentinelRef; }
   static oop* adr_sentinel_ref()         { return &_sentinelRef; }
@@ -244,6 +247,7 @@
     _bs(NULL),
     _is_alive_non_header(NULL),
     _num_q(0),
+    _max_num_q(0),
     _processing_is_mt(false),
     _next_id(0)
   {}
@@ -312,6 +316,9 @@
   void weak_oops_do(OopClosure* f);       // weak roots
   static void oops_do(OopClosure* f);     // strong root(s)
 
+  // Balance each of the discovered lists.
+  void balance_all_queues();
+
   // Discover a Reference object, using appropriate discovery criteria
   bool discover_reference(oop obj, ReferenceType rt);