--- old/src/share/vm/gc_implementation/concurrentMarkSweep/promotionInfo.hpp	2014-08-05 14:39:24.303509650 +0200
+++ new/src/share/vm/gc_implementation/concurrentMarkSweep/promotionInfo.hpp	2014-08-05 14:39:24.085108891 +0200
@@ -73,7 +73,7 @@
     } else {
       res = (PromotedObject*)(_next & next_mask);
     }
-    assert(oop(res)->is_oop_or_null(true /* ignore mark word */), "Not an oop?");
+    assert(oop(res)->is_oop_or_null(true /* ignore mark word */), err_msg("Not an oop? (" PTR_FORMAT ")", p2i(res)));
     return res;
   }
   inline void setNext(PromotedObject* x) {