*** old/src/share/vm/memory/metachunk.cpp	Fri Mar 11 01:25:33 2016
--- new/src/share/vm/memory/metachunk.cpp	Fri Mar 11 01:25:33 2016

*** 28,39 ****
--- 28,37 ----
  #include "utilities/copy.hpp"
  #include "utilities/debug.hpp"
  
  class VirtualSpaceNode;
  
  const size_t metadata_chunk_initialize = 0xf7f7f7f7;
  
  size_t Metachunk::object_alignment() {
    // Must align pointers and sizes to 8,
    // so that 64 bit types get correctly aligned.
    const size_t alignment = 8;
  

*** 56,71 ****
--- 54,64 ----
      _container(container)
  {
    _top = initial_top();
  #ifdef ASSERT
    set_is_tagged_free(false);
    size_t data_word_size = pointer_delta(end(),
                                          _top,
                                          sizeof(MetaWord));
    Copy::fill_to_words((HeapWord*)_top,
                        data_word_size,
                        metadata_chunk_initialize);
+   mangle();
  #endif
  }
  
  MetaWord* Metachunk::allocate(size_t word_size) {
    MetaWord* result = NULL;

*** 96,111 ****
--- 89,104 ----
                   used_word_size(), free_word_size());
    }
  }
  
  #ifndef PRODUCT
! void Metachunk::mangle(juint wordValue) {
!   // Mangle the payload of the chunk and not the links that
!   // Overwrite the payload of the chunk and not the links that
    // maintain list of chunks.
!   HeapWord* start = (HeapWord*)(bottom() + overhead());
!   HeapWord* start = (HeapWord*)initial_top();
    size_t size = word_size() - overhead();
!   Copy::fill_to_words(start, size, metadata_chunk_initialize);
!   Copy::fill_to_words(start, size, wordValue);
  }
  #endif // PRODUCT
  
  void Metachunk::verify() {
  #ifdef ASSERT