Don't unlink evacuation candidates before sweeping, move them to the end of their list of pages.

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 564 matching lines @@
   MemoryChunk* other_next = other->next_chunk();
 
   set_next_chunk(other_next);
   set_prev_chunk(other);
   other_next->set_prev_chunk(this);
   other->set_next_chunk(this);
 }
 
 
 void MemoryChunk::Unlink() {
-  if (!InNewSpace() && IsFlagSet(SCAN_ON_SCAVENGE)) {
-    heap_->decrement_scan_on_scavenge_pages();
-    ClearFlag(SCAN_ON_SCAVENGE);
-  }
   MemoryChunk* next_element = next_chunk();
   MemoryChunk* prev_element = prev_chunk();
   next_element->set_prev_chunk(prev_element);
   prev_element->set_next_chunk(next_element);
   set_prev_chunk(NULL);
   set_next_chunk(NULL);
 }
 
 
 MemoryChunk* MemoryAllocator::AllocateChunk(intptr_t reserve_area_size,
@@ skipping 347 matching lines @@
 // -----------------------------------------------------------------------------
 // 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),
-      unswept_free_bytes_(0) {
+      unswept_free_bytes_(0),
+      end_of_unswept_pages_(NULL) {
   if (id == CODE_SPACE) {
     area_size_ = heap->isolate()->memory_allocator()->
         CodePageAreaSize();
   } else {
     area_size_ = Page::kPageSize - Page::kObjectStartOffset;
   }
   max_capacity_ = (RoundDown(max_capacity, Page::kPageSize) / Page::kPageSize)
       * AreaSize();
   accounting_stats_.Clear();
 
@@ skipping 152 matching lines @@
     page->ResetFreeListStatistics();
   }
 }
 
 
 void PagedSpace::IncreaseCapacity(int size) {
   accounting_stats_.ExpandSpace(size);
 }
 
 
-void PagedSpace::ReleasePage(Page* page, bool unlink) {
+void PagedSpace::ReleasePage(Page* page) {
   ASSERT(page->LiveBytes() == 0);
   ASSERT(AreaSize() == page->area_size());
 
   if (page->WasSwept()) {
     intptr_t size = free_list_.EvictFreeListItems(page);
     accounting_stats_.AllocateBytes(size);
     ASSERT_EQ(AreaSize(), static_cast<int>(size));
   } else {
     DecreaseUnsweptFreeBytes(page);
   }
 
-  // TODO(hpayer): This check is just used for debugging purpose and
-  // should be removed or turned into an assert after investigating the
-  // crash in concurrent sweeping.
-  CHECK(!free_list_.ContainsPageFreeListItems(page));
+  if (page->IsFlagSet(MemoryChunk::SCAN_ON_SCAVENGE)) {
+    heap()->decrement_scan_on_scavenge_pages();
+    page->ClearFlag(MemoryChunk::SCAN_ON_SCAVENGE);
+  }
+
+  ASSERT(!free_list_.ContainsPageFreeListItems(page));
 
   if (Page::FromAllocationTop(allocation_info_.top()) == page) {
     allocation_info_.set_top(NULL);
     allocation_info_.set_limit(NULL);
   }
 
-  if (unlink) {
-    page->Unlink();
-  }
+  page->Unlink();
   if (page->IsFlagSet(MemoryChunk::CONTAINS_ONLY_DATA)) {
     heap()->isolate()->memory_allocator()->Free(page);
   } else {
     heap()->QueueMemoryChunkForFree(page);
   }
 
   ASSERT(Capacity() > 0);
   accounting_stats_.ShrinkSpace(AreaSize());
 }
 
@@ skipping 1990 matching lines @@
     object->ShortPrint();
     PrintF("\n");
   }
   printf(" --------------------------------------\n");
   printf(" Marked: %x, LiveCount: %x\n", mark_size, LiveBytes());
 }
 
 #endif  // DEBUG
 
 } }  // namespace v8::internal