--- old/src/share/vm/gc/g1/g1CollectedHeap.cpp	2015-11-12 09:44:34.567698175 +0100
+++ new/src/share/vm/gc/g1/g1CollectedHeap.cpp	2015-11-12 09:44:34.459693962 +0100
@@ -3561,6 +3561,9 @@
             }
           }
         }
+        guarantee(hrrs.n_yielded() == r->rem_set()->occupied(),
+                  "Remembered set hash maps out of sync, cur: " SIZE_FORMAT " entries, next: " SIZE_FORMAT " entries",
+                  hrrs.n_yielded(), r->rem_set()->occupied());
         r->rem_set()->clear_locked();
       }
       assert(r->rem_set()->is_empty(), "At this point any humongous candidate remembered set must be empty.");
@@ -3848,6 +3851,11 @@
 
         evacuation_info.set_collectionset_regions(g1_policy()->cset_region_length());
 
+        // Make sure the remembered sets are up to date. This needs to be
+        // done before register_humongous_regions_with_cset(), otherwise
+        // we might miss some entries that need to be handled.
+        g1_rem_set()->cleanupHRRS();
+
         register_humongous_regions_with_cset();
 
         assert(check_cset_fast_test(), "Inconsistency in the InCSetState table.");