diff -r 1ee412f7fec9 -r 39b01ab7035a src/share/vm/runtime/thread.hpp
--- a/src/share/vm/runtime/thread.hpp	Wed Oct 07 19:01:55 2009 -0400
+++ b/src/share/vm/runtime/thread.hpp	Fri Oct 16 02:05:46 2009 -0700
@@ -684,8 +684,13 @@
   methodOop     _callee_target;
 
   // Oop results of VM runtime calls
-  oop           _vm_result;                      // Used to pass back an oop result into Java code, GC-preserved
-  oop           _vm_result_2;                    // Used to pass back an oop result into Java code, GC-preserved
+  oop           _vm_result;    // Used to pass back an oop result into Java code, GC-preserved
+  oop           _vm_result_2;  // Used to pass back an oop result into Java code, GC-preserved
+
+  // See ReduceInitialCardMarks: this holds the precise space interval of
+  // the most recent slow path allocation for which compiled code has
+  // elided card-marks for performance along the fast-path.
+  MemRegion     _deferred_card_mark;
 
   MonitorChunk* _monitor_chunks;                 // Contains the off stack monitors
                                                  // allocated during deoptimization
@@ -1082,6 +1087,9 @@
   oop  vm_result_2() const                       { return _vm_result_2; }
   void set_vm_result_2  (oop x)                  { _vm_result_2   = x; }
 
+  MemRegion deferred_card_mark() const           { return _deferred_card_mark; }
+  void set_deferred_card_mark(MemRegion mr)      { _deferred_card_mark = mr;   }
+
   // Exception handling for compiled methods
   oop      exception_oop() const                 { return _exception_oop; }
   int      exception_stack_size() const          { return _exception_stack_size; }