Change age-mark to not expect pages to be in increasing order.

src/heap-inl.h

 // 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 274 matching lines @@
 bool Heap::OldGenerationAllocationLimitReached() {
   if (!incremental_marking()->IsStopped()) return false;
   return OldGenerationSpaceAvailable() < 0;
 }
 
 
 bool Heap::ShouldBePromoted(Address old_address, int object_size) {
   // An object should be promoted if:
   // - the object has survived a scavenge operation or
   // - to space is already 25% full.
-  // TODO(gc): Do something about age-mark in paged new-space.
-  return old_address < new_space_.age_mark()
-      || (new_space_.Size() + object_size) >= (new_space_.Capacity() >> 2);
+  NewSpacePage* page = NewSpacePage::FromAddress(old_address);
+  Address age_mark = new_space_.age_mark();
+  bool below_mark = page->IsFlagSet(MemoryChunk::NEW_SPACE_BELOW_AGE_MARK) &&
+      (!page->ContainsLimit(age_mark) || old_address < age_mark);
+  return below_mark ||
+      (new_space_.Size() + object_size) >= (new_space_.Capacity() >> 2);
 }
 
 
 void Heap::RecordWrite(Address address, int offset) {
   if (!InNewSpace(address)) store_buffer_.Mark(address + offset);
 }
 
 
 void Heap::RecordWrites(Address address, int start, int len) {
   if (!InNewSpace(address)) {
@@ skipping 381 matching lines @@
 
 
 Heap* _inline_get_heap_() {
   return HEAP;
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_INL_H_