[heap] Remove black pages and use black areas instead.

src/heap/incremental-marking.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_HEAP_INCREMENTAL_MARKING_H_
 #define V8_HEAP_INCREMENTAL_MARKING_H_
 
 #include "src/cancelable-task.h"
 #include "src/execution.h"
 #include "src/heap/heap.h"
@@ skipping 191 matching lines @@
 
   void ClearIdleMarkingDelayCounter();
 
   bool IsIdleMarkingDelayCounterLimitReached();
 
   static void MarkObject(Heap* heap, HeapObject* object);
 
   static void TransferMark(Heap* heap, Address old_start, Address new_start);
 
   // Returns true if the transferred color is black.
-  INLINE(static bool TransferColor(HeapObject* from, HeapObject* to)) {
-    if (Page::FromAddress(to->address())->IsFlagSet(Page::BLACK_PAGE))
-      return true;
+  INLINE(static void TransferColor(HeapObject* from, HeapObject* to,
+                                   int size)) {
     MarkBit from_mark_bit = ObjectMarking::MarkBitFrom(from);
     MarkBit to_mark_bit = ObjectMarking::MarkBitFrom(to);
+
+    if (Marking::IsBlack(to_mark_bit)) {
+      DCHECK(to->GetHeap()->incremental_marking()->black_allocation());
+      return;
+    }
+
     DCHECK(Marking::IsWhite(to_mark_bit));
     if (from_mark_bit.Get()) {
       to_mark_bit.Set();
       if (from_mark_bit.Next().Get()) {
         to_mark_bit.Next().Set();
-        return true;
+        MemoryChunk::IncrementLiveBytesFromGC(to, size);

[ulan, 2016/07/19 13:23:32]

This side-effect of the function is unexpected. Why not do it on call-site?

[Hannes Payer (out of office), 2016/07/19 14:42:53]

As discussed offline. I will do this change in a separate CL. Together with
decreasing liveness and adding a higher-level marking operation that also takes
care of live bytes.

       }
     }
-    return false;
   }
 
   void IterateBlackObject(HeapObject* object);
 
   Heap* heap() const { return heap_; }
 
   IncrementalMarkingJob* incremental_marking_job() {
     return &incremental_marking_job_;
   }
 
@@ skipping 87 matching lines @@
   GCRequestType request_type_;
 
   IncrementalMarkingJob incremental_marking_job_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(IncrementalMarking);
 };
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_INCREMENTAL_MARKING_H_