--- old/src/share/vm/gc_interface/collectedHeap.hpp	2013-08-14 15:08:48.343501618 +0200
+++ new/src/share/vm/gc_interface/collectedHeap.hpp	2013-08-14 15:08:48.063501623 +0200
@@ -605,9 +605,9 @@
   void print_heap_after_gc();
 
   // Registering and unregistering an nmethod (compiled code) with the heap.
-  // Override with specific mechanism for each specialized heap type
-  virtual void register_nmethod(nmethod* nm) {}
-  virtual void unregister_nmethod(nmethod* nm) {}
+  // Override with specific mechanism for each specialized heap type.
+  virtual void register_nmethod(nmethod* nm);
+  virtual void unregister_nmethod(nmethod* nm);
 
   void trace_heap_before_gc(GCTracer* gc_tracer);
   void trace_heap_after_gc(GCTracer* gc_tracer);