--- a/hotspot/src/share/vm/gc/g1/g1CollectedHeap.hpp	Thu Dec 10 14:24:26 2015 +0000
+++ b/hotspot/src/share/vm/gc/g1/g1CollectedHeap.hpp	Wed Dec 09 16:05:24 2015 +0100
@@ -573,6 +573,9 @@
   void register_old_region_with_cset(HeapRegion* r) {
     _in_cset_fast_test.set_in_old(r->hrm_index());
   }
+  inline void register_ext_region_with_cset(HeapRegion* r) {
+    _in_cset_fast_test.set_ext(r->hrm_index());
+  }
   void clear_in_cset(const HeapRegion* hr) {
     _in_cset_fast_test.clear(hr);
   }