When adjusting page's live bytes counter from the mutator adjust owners unswept free bytes counter.

src/spaces.cc

 // Copyright 2011 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 631 matching lines @@
 void MemoryAllocator::ReportStatistics() {
   float pct = static_cast<float>(capacity_ - size_) / capacity_;
   PrintF("  capacity: %" V8_PTR_PREFIX "d"
              ", used: %" V8_PTR_PREFIX "d"
              ", available: %%%d\n\n",
          capacity_, size_, static_cast<int>(pct*100));
 }
 #endif
 
 // -----------------------------------------------------------------------------
+// MemoryChunk implementation
+
+void MemoryChunk::IncrementLiveBytesFromMutator(Address address, int by) {
+  MemoryChunk* chunk = MemoryChunk::FromAddress(address);
+  if (!chunk->InNewSpace()) {

[Michael Starzinger, 2012/01/18 09:12:18]

We need an additional check here to make sure that the page was elected for lazy
sweeping and isn't just being incrementally marked.

[Vyacheslav Egorov (Chromium), 2012/01/18 09:22:49]

Yeah, thanks for catching it. Somehow I lost this check along the road.

+    static_cast<PagedSpace*>(chunk->owner())->IncrementUnsweptFreeBytes(-by);
+  }
+  chunk->IncrementLiveBytes(by);
+}
+
+// -----------------------------------------------------------------------------
 // PagedSpace implementation
 
 PagedSpace::PagedSpace(Heap* heap,
                        intptr_t max_capacity,
                        AllocationSpace id,
                        Executability executable)
     : Space(heap, id, executable),
       free_list_(this),
       was_swept_conservatively_(false),
       first_unswept_page_(Page::FromAddress(NULL)),
@@ skipping 1846 matching lines @@
   LargePage* previous = NULL;
   LargePage* current = first_page_;
   while (current != NULL) {
     HeapObject* object = current->GetObject();
     // Can this large page contain pointers to non-trivial objects.  No other
     // pointer object is this big.
     bool is_pointer_object = object->IsFixedArray();
     MarkBit mark_bit = Marking::MarkBitFrom(object);
     if (mark_bit.Get()) {
       mark_bit.Clear();
-      MemoryChunk::IncrementLiveBytes(object->address(), -object->Size());
+      MemoryChunk::IncrementLiveBytesFromGC(object->address(), -object->Size());
       previous = current;
       current = current->next_page();
     } else {
       LargePage* page = current;
       // Cut the chunk out from the chunk list.
       current = current->next_page();
       if (previous == NULL) {
         first_page_ = current;
       } else {
         previous->set_next_page(current);
@@ skipping 134 matching lines @@
     object->ShortPrint();
     PrintF("\n");
   }
   printf(" --------------------------------------\n");
   printf(" Marked: %x, LiveCount: %x\n", mark_size, LiveBytes());
 }
 
 #endif  // DEBUG
 
 } }  // namespace v8::internal