--- a/hotspot/src/share/vm/runtime/mutexLocker.hpp	Fri Apr 02 12:10:08 2010 -0400
+++ b/hotspot/src/share/vm/runtime/mutexLocker.hpp	Mon Apr 05 12:19:22 2010 -0400
@@ -63,6 +63,7 @@
 extern Monitor* CMark_lock;                      // used for concurrent mark thread coordination
 extern Monitor* ZF_mon;                          // used for G1 conc zero-fill.
 extern Monitor* Cleanup_mon;                     // used for G1 conc cleanup.
+extern Mutex*   CMRegionStack_lock;              // used for protecting accesses to the CM region stack
 extern Mutex*   SATB_Q_FL_lock;                  // Protects SATB Q
                                                  // buffer free list.
 extern Monitor* SATB_Q_CBL_mon;                  // Protects SATB Q