--- old/src/share/vm/gc_implementation/g1/heapRegionSeq.cpp	2014-08-28 09:58:55.450344577 +0200
+++ new/src/share/vm/gc_implementation/g1/heapRegionSeq.cpp	2014-08-28 09:58:55.370347396 +0200
@@ -217,8 +217,12 @@
 
 void HeapRegionSeq::iterate(HeapRegionClosure* blk) const {
   uint len = max_length();
+  iterate_range(blk, 0, len);
+}
 
-  for (uint i = 0; i < len; i++) {
+void HeapRegionSeq::iterate_range(HeapRegionClosure* blk, uint start, uint end) const {
+  assert(start <= end && end <= max_length(), "Invalid range.");
+  for (uint i = start; i < end; i++) {
     if (!is_available(i)) {
       continue;
     }