--- old/src/share/vm/gc/shared/cardGeneration.cpp	2015-10-21 17:28:35.000000000 +0200
+++ new/src/share/vm/gc/shared/cardGeneration.cpp	2015-10-21 17:28:35.000000000 +0200
@@ -352,7 +352,6 @@
 }
 
 void CardGeneration::younger_refs_iterate(OopsInGenClosure* blk, uint n_threads) {
-  blk->set_generation(this);
+  blk->assert_generation(this);
   younger_refs_in_space_iterate(space(), blk, n_threads);
-  blk->reset_generation();
 }