diff -r 90821b72481b -r bd2023eeea0a hotspot/src/share/vm/compiler/oopMap.hpp
--- a/hotspot/src/share/vm/compiler/oopMap.hpp	Tue Jul 21 21:33:44 2009 -0700
+++ b/hotspot/src/share/vm/compiler/oopMap.hpp	Wed Jul 22 15:48:51 2009 -0700
@@ -233,6 +233,10 @@
   int heap_size() const;
   void copy_to(address addr);
 
+  // Methods oops_do() and all_do() filter out NULL oops and
+  // oop == Universe::narrow_oop_base() before passing oops
+  // to closures.
+
   // Iterates through frame for a compiled method
   static void oops_do            (const frame* fr,
                                   const RegisterMap* reg_map, OopClosure* f);