--- old/src/share/vm/code/codeCache.cpp	2017-07-25 14:10:54.721617073 +0200
+++ new/src/share/vm/code/codeCache.cpp	2017-07-25 14:10:54.593617077 +0200
@@ -732,6 +732,13 @@
   debug_only(verify_perm_nmethods(NULL));
 }
 
+void CodeCache::register_scavenge_root_nmethod(nmethod* nm) {
+  assert_locked_or_safepoint(CodeCache_lock);
+  if (!nm->on_scavenge_root_list() && nm->detect_scavenge_root_oops()) {
+    add_scavenge_root_nmethod(nm);
+  }
+}
+
 void CodeCache::add_scavenge_root_nmethod(nmethod* nm) {
   assert_locked_or_safepoint(CodeCache_lock);
 
--- old/src/share/vm/code/codeCache.hpp	2017-07-25 14:10:55.349617051 +0200
+++ new/src/share/vm/code/codeCache.hpp	2017-07-25 14:10:55.241617054 +0200
@@ -181,6 +181,9 @@
   static void scavenge_root_nmethods_do(CodeBlobToOopClosure* f);
 
   static nmethod* scavenge_root_nmethods()            { return _scavenge_root_nmethods; }
+  // register_scavenge_root_nmethod() conditionally adds the nmethod to the list
+  // if it is not already on the list and has a scavengeable root
+  static void register_scavenge_root_nmethod(nmethod* nm);
   static void add_scavenge_root_nmethod(nmethod* nm);
   static void drop_scavenge_root_nmethod(nmethod* nm);
 
--- old/src/share/vm/gc/g1/g1CollectedHeap.cpp	2017-07-25 14:10:55.977617029 +0200
+++ new/src/share/vm/gc/g1/g1CollectedHeap.cpp	2017-07-25 14:10:55.857617033 +0200
@@ -2458,10 +2458,6 @@
   return _cmThread->request_concurrent_phase(phase);
 }
 
-void G1CollectedHeap::verify_nmethod_roots(nmethod* nmethod) {
-
-}
-
 class PrintRegionClosure: public HeapRegionClosure {
   outputStream* _st;
 public:
--- old/src/share/vm/gc/g1/g1CollectedHeap.hpp	2017-07-25 14:10:56.741617002 +0200
+++ new/src/share/vm/gc/g1/g1CollectedHeap.hpp	2017-07-25 14:10:56.613617007 +0200
@@ -1389,6 +1389,8 @@
   // Unregister the given nmethod from the G1 heap.
   virtual void unregister_nmethod(nmethod* nm);
 
+  virtual void verify_nmethod_roots(nmethod* nmethod) {}
+
   // Free up superfluous code root memory.
   void purge_code_root_memory();
 
@@ -1436,8 +1438,6 @@
   virtual const char* const* concurrent_phases() const;
   virtual bool request_concurrent_phase(const char* phase);
 
-  void verify_nmethod_roots(nmethod* nmethod);
-
   // The methods below are here for convenience and dispatch the
   // appropriate method depending on value of the given VerifyOption
   // parameter. The values for that parameter, and their meanings,
--- old/src/share/vm/gc/parallel/parallelScavengeHeap.cpp	2017-07-25 14:10:57.421616978 +0200
+++ new/src/share/vm/gc/parallel/parallelScavengeHeap.cpp	2017-07-25 14:10:57.277616983 +0200
@@ -23,6 +23,7 @@
  */
 
 #include "precompiled.hpp"
+#include "code/codeCache.hpp"
 #include "gc/parallel/adjoiningGenerations.hpp"
 #include "gc/parallel/adjoiningVirtualSpaces.hpp"
 #include "gc/parallel/cardTableExtension.hpp"
@@ -671,3 +672,11 @@
   }
 }
 #endif
+
+void ParallelScavengeHeap::register_nmethod(nmethod* nm) {
+  CodeCache::register_scavenge_root_nmethod(nm);
+}
+
+void ParallelScavengeHeap::verify_nmethod_roots(nmethod* nmethod) {
+  nmethod->verify_scavenge_root_oops();
+}
--- old/src/share/vm/gc/parallel/parallelScavengeHeap.hpp	2017-07-25 14:10:57.993616959 +0200
+++ new/src/share/vm/gc/parallel/parallelScavengeHeap.hpp	2017-07-25 14:10:57.885616962 +0200
@@ -135,6 +135,8 @@
   // generational collectors that means during a collection of
   // the young gen.
   virtual bool is_scavengable(const void* addr);
+  virtual void register_nmethod(nmethod* nm);
+  virtual void verify_nmethod_roots(nmethod* nmethod);
 
   size_t max_capacity() const;
 
--- old/src/share/vm/gc/shared/collectedHeap.cpp	2017-07-25 14:10:58.717616933 +0200
+++ new/src/share/vm/gc/shared/collectedHeap.cpp	2017-07-25 14:10:58.589616938 +0200
@@ -137,9 +137,6 @@
 
 void CollectedHeap::register_nmethod(nmethod* nm) {
   assert_locked_or_safepoint(CodeCache_lock);
-  if (!nm->on_scavenge_root_list() && nm->detect_scavenge_root_oops()) {
-    CodeCache::add_scavenge_root_nmethod(nm);
-  }
 }
 
 void CollectedHeap::unregister_nmethod(nmethod* nm) {
--- old/src/share/vm/gc/shared/collectedHeap.hpp	2017-07-25 14:10:59.385616910 +0200
+++ new/src/share/vm/gc/shared/collectedHeap.hpp	2017-07-25 14:10:59.273616914 +0200
@@ -393,8 +393,6 @@
 
   virtual size_t max_tlab_size() const;
 
-  virtual void verify_nmethod_roots(nmethod* nmethod);
-
   // An estimate of the maximum allocation that could be performed
   // for thread-local allocation buffers without triggering any
   // collection or expansion activity.
@@ -573,6 +571,7 @@
   // Override with specific mechanism for each specialized heap type.
   virtual void register_nmethod(nmethod* nm);
   virtual void unregister_nmethod(nmethod* nm);
+  virtual void verify_nmethod_roots(nmethod* nmethod);
 
   void trace_heap_before_gc(const GCTracer* gc_tracer);
   void trace_heap_after_gc(const GCTracer* gc_tracer);
--- old/src/share/vm/gc/shared/genCollectedHeap.cpp	2017-07-25 14:10:59.953616890 +0200
+++ new/src/share/vm/gc/shared/genCollectedHeap.cpp	2017-07-25 14:10:59.853616894 +0200
@@ -1315,3 +1315,11 @@
   }
 #endif
 }
+
+void GenCollectedHeap::register_nmethod(nmethod* nm) {
+  CodeCache::register_scavenge_root_nmethod(nm);
+}
+
+void GenCollectedHeap::verify_nmethod_roots(nmethod* nmethod) {
+  nmethod->verify_scavenge_root_oops();
+}
--- old/src/share/vm/gc/shared/genCollectedHeap.hpp	2017-07-25 14:11:00.445616873 +0200
+++ new/src/share/vm/gc/shared/genCollectedHeap.hpp	2017-07-25 14:11:00.333616877 +0200
@@ -227,6 +227,8 @@
   virtual bool is_scavengable(const void* addr) {
     return is_in_young((oop)addr);
   }
+  virtual void register_nmethod(nmethod* nm);
+  virtual void verify_nmethod_roots(nmethod* nmethod);
 
   // Iteration functions.
   void oop_iterate_no_header(OopClosure* cl);