--- a/hotspot/src/share/vm/code/nmethod.cpp	Wed Sep 23 23:56:15 2009 -0700
+++ b/hotspot/src/share/vm/code/nmethod.cpp	Wed Sep 23 23:57:44 2009 -0700
@@ -1558,13 +1558,12 @@
 // the (strong) marking phase, and then again when walking
 // the code cache contents during the weak roots processing
 // phase. The two uses are distinguished by means of the
-// do_nmethods() method in the closure "f" below -- which
-// answers "yes" in the first case, and "no" in the second
+// 'do_strong_roots_only' flag, which is true in the first
 // case. We want to walk the weak roots in the nmethod
 // only in the second case. The weak roots in the nmethod
 // are the oops in the ExceptionCache and the InlineCache
 // oops.
-void nmethod::oops_do(OopClosure* f) {
+void nmethod::oops_do(OopClosure* f, bool do_strong_roots_only) {
   // make sure the oops ready to receive visitors
   assert(!is_zombie() && !is_unloaded(),
          "should not call follow on zombie or unloaded nmethod");
@@ -1582,7 +1581,7 @@
 
   // Compiled code
   f->do_oop((oop*) &_method);
-  if (!f->do_nmethods()) {
+  if (!do_strong_roots_only) {
     // weak roots processing phase -- update ExceptionCache oops
     ExceptionCache* ec = exception_cache();
     while(ec != NULL) {

--- a/hotspot/src/share/vm/code/nmethod.hpp	Wed Sep 23 23:56:15 2009 -0700
+++ b/hotspot/src/share/vm/code/nmethod.hpp	Wed Sep 23 23:57:44 2009 -0700
@@ -490,7 +490,8 @@
 
   void preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map,
                                      OopClosure* f);
-  void oops_do(OopClosure* f);
+  virtual void oops_do(OopClosure* f) { oops_do(f, false); }
+  void         oops_do(OopClosure* f, bool do_strong_roots_only);
   bool detect_scavenge_root_oops();
   void verify_scavenge_root_oops() PRODUCT_RETURN;
 

--- a/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/cmsOopClosures.hpp	Wed Sep 23 23:56:15 2009 -0700
+++ b/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/cmsOopClosures.hpp	Wed Sep 23 23:57:44 2009 -0700
@@ -47,13 +47,10 @@
  private:
   const MemRegion _span;
   CMSBitMap*      _bitMap;
-  const bool      _should_do_nmethods;
  protected:
   DO_OOP_WORK_DEFN
  public:
-  MarkRefsIntoClosure(MemRegion span, CMSBitMap* bitMap,
-                      bool should_do_nmethods);
-  bool should_do_nmethods() { return _should_do_nmethods; }
+  MarkRefsIntoClosure(MemRegion span, CMSBitMap* bitMap);
   virtual void do_oop(oop* p);
   virtual void do_oop(narrowOop* p);
   inline void do_oop_nv(oop* p)       { MarkRefsIntoClosure::do_oop_work(p); }
@@ -71,13 +68,11 @@
   const MemRegion _span;
   CMSBitMap*      _verification_bm;
   CMSBitMap*      _cms_bm;
-  const bool      _should_do_nmethods;
  protected:
   DO_OOP_WORK_DEFN
  public:
   MarkRefsIntoVerifyClosure(MemRegion span, CMSBitMap* verification_bm,
-                            CMSBitMap* cms_bm, bool should_do_nmethods);
-  bool should_do_nmethods() { return _should_do_nmethods; }
+                            CMSBitMap* cms_bm);
   virtual void do_oop(oop* p);
   virtual void do_oop(narrowOop* p);
   inline void do_oop_nv(oop* p)       { MarkRefsIntoVerifyClosure::do_oop_work(p); }
@@ -268,7 +263,6 @@
   inline void do_oop_nv(oop* p)       { Par_MarkRefsIntoAndScanClosure::do_oop_work(p); }
   inline void do_oop_nv(narrowOop* p) { Par_MarkRefsIntoAndScanClosure::do_oop_work(p); }
   bool do_header() { return true; }
-  virtual const bool do_nmethods() const { return true; }
   // When ScanMarkedObjectsAgainClosure is used,
   // it passes [Par_]MarkRefsIntoAndScanClosure to oop_oop_iterate(),
   // and this delegation is used.

--- a/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp	Wed Sep 23 23:56:15 2009 -0700
+++ b/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp	Wed Sep 23 23:57:44 2009 -0700
@@ -2852,7 +2852,7 @@
   GenCollectedHeap* gch = GenCollectedHeap::heap();
 
   // Mark from roots one level into CMS
-  MarkRefsIntoClosure notOlder(_span, verification_mark_bm(), true /* nmethods */);
+  MarkRefsIntoClosure notOlder(_span, verification_mark_bm());
   gch->rem_set()->prepare_for_younger_refs_iterate(false); // Not parallel.
 
   gch->gen_process_strong_roots(_cmsGen->level(),
@@ -2904,7 +2904,7 @@
 
   // Mark from roots one level into CMS
   MarkRefsIntoVerifyClosure notOlder(_span, verification_mark_bm(),
-                                     markBitMap(), true /* nmethods */);
+                                     markBitMap());
   gch->rem_set()->prepare_for_younger_refs_iterate(false); // Not parallel.
   gch->gen_process_strong_roots(_cmsGen->level(),
                                 true,   // younger gens are roots
@@ -3490,8 +3490,10 @@
   FalseClosure falseClosure;
   // In the case of a synchronous collection, we will elide the
   // remark step, so it's important to catch all the nmethod oops
-  // in this step; hence the last argument to the constrcutor below.
-  MarkRefsIntoClosure notOlder(_span, &_markBitMap, !asynch /* nmethods */);
+  // in this step.
+  // The final 'true' flag to gen_process_strong_roots will ensure this.
+  // If 'async' is true, we can relax the nmethod tracing.
+  MarkRefsIntoClosure notOlder(_span, &_markBitMap);
   GenCollectedHeap* gch = GenCollectedHeap::heap();
 
   verify_work_stacks_empty();
@@ -6441,10 +6443,9 @@
 // generation then this will lose younger_gen cards!
 
 MarkRefsIntoClosure::MarkRefsIntoClosure(
-  MemRegion span, CMSBitMap* bitMap, bool should_do_nmethods):
+  MemRegion span, CMSBitMap* bitMap):
     _span(span),
-    _bitMap(bitMap),
-    _should_do_nmethods(should_do_nmethods)
+    _bitMap(bitMap)
 {
     assert(_ref_processor == NULL, "deliberately left NULL");
     assert(_bitMap->covers(_span), "_bitMap/_span mismatch");
@@ -6465,12 +6466,11 @@
 
 // A variant of the above, used for CMS marking verification.
 MarkRefsIntoVerifyClosure::MarkRefsIntoVerifyClosure(
-  MemRegion span, CMSBitMap* verification_bm, CMSBitMap* cms_bm,
-  bool should_do_nmethods):
+  MemRegion span, CMSBitMap* verification_bm, CMSBitMap* cms_bm):
     _span(span),
     _verification_bm(verification_bm),
-    _cms_bm(cms_bm),
-    _should_do_nmethods(should_do_nmethods) {
+    _cms_bm(cms_bm)
+{
     assert(_ref_processor == NULL, "deliberately left NULL");
     assert(_verification_bm->covers(_span), "_verification_bm/_span mismatch");
 }

--- a/hotspot/src/share/vm/gc_implementation/shared/markSweep.hpp	Wed Sep 23 23:56:15 2009 -0700
+++ b/hotspot/src/share/vm/gc_implementation/shared/markSweep.hpp	Wed Sep 23 23:57:44 2009 -0700
@@ -64,7 +64,6 @@
    public:
     virtual void do_oop(oop* p);
     virtual void do_oop(narrowOop* p);
-    virtual const bool do_nmethods() const { return true; }
     virtual const bool should_remember_mdo() const { return true; }
     virtual void remember_mdo(DataLayout* p) { MarkSweep::revisit_mdo(p); }
   };

--- a/hotspot/src/share/vm/memory/iterator.cpp	Wed Sep 23 23:56:15 2009 -0700
+++ b/hotspot/src/share/vm/memory/iterator.cpp	Wed Sep 23 23:57:44 2009 -0700
@@ -68,8 +68,8 @@
   }
 }
 
-void CodeBlobToOopClosure::do_newly_marked_nmethod(CodeBlob* cb) {
-  cb->oops_do(_cl);
+void CodeBlobToOopClosure::do_newly_marked_nmethod(nmethod* nm) {
+  nm->oops_do(_cl, /*do_strong_roots_only=*/ true);
 }
 
 void CodeBlobToOopClosure::do_code_blob(CodeBlob* cb) {

--- a/hotspot/src/share/vm/memory/iterator.hpp	Wed Sep 23 23:56:15 2009 -0700
+++ b/hotspot/src/share/vm/memory/iterator.hpp	Wed Sep 23 23:57:44 2009 -0700
@@ -25,6 +25,7 @@
 // The following classes are C++ `closures` for iterating over objects, roots and spaces
 
 class CodeBlob;
+class nmethod;
 class ReferenceProcessor;
 class DataLayout;
 
@@ -70,9 +71,6 @@
   virtual const bool should_remember_mdo() const { return false; }
   virtual void remember_mdo(DataLayout* v) { /* do nothing */ }
 
-  // If "true", invoke on nmethods (when scanning compiled frames).
-  virtual const bool do_nmethods() const { return false; }
-
   // The methods below control how object iterations invoking this closure
   // should be performed:
 
@@ -190,7 +188,7 @@
 class MarkingCodeBlobClosure : public CodeBlobClosure {
  public:
   // Called for each code blob, but at most once per unique blob.
-  virtual void do_newly_marked_nmethod(CodeBlob* cb) = 0;
+  virtual void do_newly_marked_nmethod(nmethod* nm) = 0;
 
   virtual void do_code_blob(CodeBlob* cb);
     // = { if (!nmethod(cb)->test_set_oops_do_mark())  do_newly_marked_nmethod(cb); }
@@ -213,7 +211,7 @@
   OopClosure* _cl;
   bool _do_marking;
 public:
-  virtual void do_newly_marked_nmethod(CodeBlob* cb);
+  virtual void do_newly_marked_nmethod(nmethod* cb);
     // = { cb->oops_do(_cl); }
   virtual void do_code_blob(CodeBlob* cb);
     // = { if (_do_marking)  super::do_code_blob(cb); else cb->oops_do(_cl); }