--- old/src/share/vm/gc/g1/g1ConcurrentMark.hpp	2016-09-13 11:46:16.606138946 +0200
+++ new/src/share/vm/gc/g1/g1ConcurrentMark.hpp	2016-09-13 11:46:16.452134151 +0200
@@ -190,7 +190,7 @@
   // NULL if out of memory.
   OopChunk* allocate_new_chunk();
 
-  size_t volatile _chunks_in_chunk_list;
+  volatile size_t _chunks_in_chunk_list;
 
   volatile bool _out_of_memory;
 
@@ -200,6 +200,12 @@
   // list is empty.
   OopChunk* remove_chunk_from_list(OopChunk* volatile* list); 
 
+  void add_chunk_to_chunk_list(OopChunk* elem);
+  void add_chunk_to_free_list(OopChunk* elem);
+
+  OopChunk* remove_chunk_from_chunk_list();
+  OopChunk* remove_chunk_from_free_list();
+
   bool  _should_expand;
 
   // Resizes the mark stack to the given new capacity. Releases any previous
@@ -229,8 +235,8 @@
   bool par_pop_chunk(oop* buffer);
 
   // Return whether the chunk list is empty. Racy due to unsynchronized access to 
-  // _chunks_in_chunk_list.
-  bool is_empty() const { return _chunks_in_chunk_list == 0; }
+  // _chunk_list.
+  bool is_empty() const { return _chunk_list == NULL; }
 
   size_t capacity() const  { return _chunk_capacity; }