Fix intermittent failure in ReleaseOverReservedPages on x64.

src/mark-compact.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 613 matching lines @@
     COMPACT_FREE_LISTS,
     REDUCE_MEMORY_FOOTPRINT
   };
 
   CompactionMode mode = COMPACT_FREE_LISTS;
 
   intptr_t reserved = number_of_pages * space->AreaSize();
   intptr_t over_reserved = reserved - space->SizeOfObjects();
   static const intptr_t kFreenessThreshold = 50;
 
-  if (over_reserved >= 2 * space->AreaSize()) {
+  if (over_reserved >= 2 * space->AreaSize() ||
+      (reduce_memory_footprint_ && over_reserved >= space->AreaSize())) {

[Michael Starzinger, 2012/08/10 13:03:14]

Can we merge these two conditions into the two following if statements?

if (reduce_memory_footprint_ && over_reserved >= space->AreaSize()) {
  ...
}

if (over_reserved > reserved / 3 && over_reserved >= 2 * space->AreaSize()) {
  ...
}

     // If reduction of memory footprint was requested, we are aggressive
     // about choosing pages to free.  We expect that half-empty pages
     // are easier to compact so slightly bump the limit.
     if (reduce_memory_footprint_) {
       mode = REDUCE_MEMORY_FOOTPRINT;
       max_evacuation_candidates += 2;
     }
 
     // If over-usage is very high (more than a third of the space), we
     // try to free all mostly empty pages.  We expect that almost empty
@@ skipping 3562 matching lines @@
   while (buffer != NULL) {
     SlotsBuffer* next_buffer = buffer->next();
     DeallocateBuffer(buffer);
     buffer = next_buffer;
   }
   *buffer_address = NULL;
 }
 
 
 } }  // namespace v8::internal