*** old/src/share/vm/memory/metachunk.cpp	Thu Mar 10 21:50:10 2016
--- new/src/share/vm/memory/metachunk.cpp	Thu Mar 10 21:50:10 2016

*** 96,111 ****
--- 96,119 ----
                   used_word_size(), free_word_size());
    }
  }
  
  #ifndef PRODUCT
! void Metachunk::mangle() {
! static void overwrite_chunk_payload(Metachunk* chunk, juint wordValue) {
    // Mangle the payload of the chunk and not the links that
    // maintain list of chunks.
!   HeapWord* start = (HeapWord*)(chunk->bottom() + chunk->overhead());
!   size_t size = chunk->word_size() - chunk->overhead();
!   Copy::fill_to_words(start, size, metadata_chunk_initialize);
!   Copy::fill_to_words(start, size, wordValue);
+ }
+ 
+ void Metachunk::mangle() {
+   overwrite_chunk_payload(this, metadata_chunk_initialize);
+ }
+ 
+ void Metachunk::zap() {
+   overwrite_chunk_payload(this, badMetaWordVal);
  }
  #endif // PRODUCT
  
  void Metachunk::verify() {
  #ifdef ASSERT