--- a/src/share/vm/memory/cardTableModRefBS.hpp	Tue Aug 19 10:50:27 2014 +0200
+++ b/src/share/vm/memory/cardTableModRefBS.hpp	Thu Aug 21 11:47:10 2014 +0200
@@ -96,12 +96,12 @@
   // The declaration order of these const fields is important; see the
   // constructor before changing.
   const MemRegion _whole_heap;       // the region covered by the card table
-  const size_t    _guard_index;      // index of very last element in the card
+  size_t          _guard_index;      // index of very last element in the card
                                      // table; it is set to a guard value
                                      // (last_card) and should never be modified
-  const size_t    _last_valid_index; // index of the last valid element
+  size_t          _last_valid_index; // index of the last valid element
   const size_t    _page_size;        // page size used when mapping _byte_map
-  const size_t    _byte_map_size;    // in bytes
+  size_t          _byte_map_size;    // in bytes
   jbyte*          _byte_map;         // the card marking array
 
   int _cur_covered_regions;
@@ -123,7 +123,12 @@
  protected:
   // Initialization utilities; covered_words is the size of the covered region
   // in, um, words.
-  inline size_t cards_required(size_t covered_words);
+  inline size_t cards_required(size_t covered_words) {
+    // Add one for a guard card, used to detect errors.
+    const size_t words = align_size_up(covered_words, card_size_in_words);
+    return words / card_size_in_words + 1;
+  }
+
   inline size_t compute_byte_map_size();
 
   // Finds and return the index of the region, if any, to which the given
@@ -137,7 +142,7 @@
   int find_covering_region_containing(HeapWord* addr);
 
   // Resize one of the regions covered by the remembered set.
-  void resize_covered_region(MemRegion new_region);
+  virtual void resize_covered_region(MemRegion new_region);
 
   // Returns the leftmost end of a committed region corresponding to a
   // covered region before covered region "ind", or else "NULL" if "ind" is
@@ -282,6 +287,8 @@
   CardTableModRefBS(MemRegion whole_heap, int max_covered_regions);
   ~CardTableModRefBS();
 
+  virtual void initialize();
+
   // *** Barrier set functions.
 
   bool has_write_ref_pre_barrier() { return false; }