--- a/hotspot/src/share/vm/gc_implementation/g1/heapRegion.cpp	Tue Jan 10 20:02:41 2012 +0100
+++ b/hotspot/src/share/vm/gc_implementation/g1/heapRegion.cpp	Tue Jan 10 18:58:13 2012 -0500
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2011, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2012, 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
@@ -575,6 +575,40 @@
   oops_in_mr_iterate(MemRegion(bottom(), saved_mark_word()), cl);
 }
 
+void HeapRegion::note_self_forwarding_removal_start(bool during_initial_mark,
+                                                    bool during_conc_mark) {
+  // We always recreate the prev marking info and we'll explicitly
+  // mark all objects we find to be self-forwarded on the prev
+  // bitmap. So all objects need to be below PTAMS.
+  _prev_top_at_mark_start = top();
+  _prev_marked_bytes = 0;
+
+  if (during_initial_mark) {
+    // During initial-mark, we'll also explicitly mark all objects
+    // we find to be self-forwarded on the next bitmap. So all
+    // objects need to be below NTAMS.
+    _next_top_at_mark_start = top();
+    set_top_at_conc_mark_count(bottom());
+    _next_marked_bytes = 0;
+  } else if (during_conc_mark) {
+    // During concurrent mark, all objects in the CSet (including
+    // the ones we find to be self-forwarded) are implicitly live.
+    // So all objects need to be above NTAMS.
+    _next_top_at_mark_start = bottom();
+    set_top_at_conc_mark_count(bottom());
+    _next_marked_bytes = 0;
+  }
+}
+
+void HeapRegion::note_self_forwarding_removal_end(bool during_initial_mark,
+                                                  bool during_conc_mark,
+                                                  size_t marked_bytes) {
+  assert(0 <= marked_bytes && marked_bytes <= used(),
+         err_msg("marked: "SIZE_FORMAT" used: "SIZE_FORMAT,
+                 marked_bytes, used()));
+  _prev_marked_bytes = marked_bytes;
+}
+
 HeapWord*
 HeapRegion::object_iterate_mem_careful(MemRegion mr,
                                                  ObjectClosure* cl) {