--- old/src/hotspot/share/gc/z/zRootsIterator.cpp	2019-12-09 22:12:12.534575578 +0100
+++ new/src/hotspot/share/gc/z/zRootsIterator.cpp	2019-12-09 22:12:12.330572357 +0100
@@ -139,23 +139,23 @@
   }
 }
 
-class ZRootsIteratorCodeBlobClosure : public CodeBlobToOopClosure {
+class ZRootsIteratorCodeBlobClosure : public CodeBlobClosure {
 private:
-  BarrierSetNMethod* const _bs;
-  const bool               _disarm_nmethods;
+  ZRootsIteratorClosure* const _cl;
+  const bool                   _should_disarm_nmethods;
 
 public:
-  ZRootsIteratorCodeBlobClosure(OopClosure* cl, bool disarm_nmethods) :
-    CodeBlobToOopClosure(cl, true /* fix_relocations */),
-    _bs(BarrierSet::barrier_set()->barrier_set_nmethod()),
-    _disarm_nmethods(disarm_nmethods) {}
+  ZRootsIteratorCodeBlobClosure(ZRootsIteratorClosure* cl) :
+    _cl(cl),
+    _should_disarm_nmethods(cl->should_disarm_nmethods()) {}
 
   virtual void do_code_blob(CodeBlob* cb) {
     nmethod* const nm = cb->as_nmethod_or_null();
     if (nm != NULL && nm->oops_do_try_claim()) {
-      CodeBlobToOopClosure::do_code_blob(cb);
-      if (_disarm_nmethods) {
-        _bs->disarm(nm);
+      ZNMethod::nmethod_oops_do(nm, _cl);
+      assert(ZNMethod::is_armed(nm) == _should_disarm_nmethods, "Invalid state");
+      if (_should_disarm_nmethods) {
+        ZNMethod::disarm(nm);
       }
     }
   }
@@ -164,23 +164,20 @@
 class ZRootsIteratorThreadClosure : public ThreadClosure {
 private:
   ZRootsIteratorClosure* const _cl;
-  const bool                   _disarm_nmethods;
 
 public:
-  ZRootsIteratorThreadClosure(ZRootsIteratorClosure* cl, bool disarm_nmethods) :
-      _cl(cl),
-      _disarm_nmethods(disarm_nmethods) {}
+  ZRootsIteratorThreadClosure(ZRootsIteratorClosure* cl) :
+      _cl(cl) {}
 
   virtual void do_thread(Thread* thread) {
-    ZRootsIteratorCodeBlobClosure code_cl(_cl, _disarm_nmethods);
+    ZRootsIteratorCodeBlobClosure code_cl(_cl);
     thread->oops_do(_cl, ClassUnloading ? &code_cl : NULL);
     _cl->do_thread(thread);
   }
 };
 
-ZRootsIterator::ZRootsIterator(bool visit_jvmti_weak_export, bool disarm_nmethods) :
+ZRootsIterator::ZRootsIterator(bool visit_jvmti_weak_export) :
     _visit_jvmti_weak_export(visit_jvmti_weak_export),
-    _disarm_nmethods(disarm_nmethods),
     _universe(this),
     _object_synchronizer(this),
     _management(this),
@@ -248,7 +245,7 @@
 void ZRootsIterator::do_threads(ZRootsIteratorClosure* cl) {
   ZStatTimer timer(ZSubPhasePauseRootsThreads);
   ResourceMark rm;
-  ZRootsIteratorThreadClosure thread_cl(cl, _disarm_nmethods);
+  ZRootsIteratorThreadClosure thread_cl(cl);
   Threads::possibly_parallel_threads_do(true, &thread_cl);
 }