[heap] Don't use black pages for map, code and, lo space. Instead color objects black.

src/heap/spaces.cc

 // Copyright 2011 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.
 
 #include "src/heap/spaces.h"
 
 #include "src/base/bits.h"
 #include "src/base/platform/platform.h"
 #include "src/full-codegen/full-codegen.h"
 #include "src/heap/slot-set.h"
@@ skipping 1165 matching lines @@
       size, this, executable());
   if (p == NULL) return false;
 
   AccountCommitted(static_cast<intptr_t>(p->size()));
 
   // Pages created during bootstrapping may contain immortal immovable objects.
   if (!heap()->deserialization_complete()) p->MarkNeverEvacuate();
 
   // When incremental marking was activated, old generation pages are allocated
   // black.
-  if (heap()->incremental_marking()->black_allocation()) {
+  if (heap()->incremental_marking()->black_allocation() &&
+      identity() != CODE_SPACE && identity() != MAP_SPACE) {

[ulan, 2016/04/06 16:44:43]

Let's whitelist instead of blacklist, identity() == OLD_SPACE

[Hannes Payer (out of office), 2016/04/06 21:24:39]

Done.

     Bitmap::SetAllBits(p);
     p->SetFlag(Page::BLACK_PAGE);
     if (FLAG_trace_incremental_marking) {
       PrintIsolate(heap()->isolate(), "Added black page %p\n", p);
     }
   }
 
   DCHECK(Capacity() <= heap()->MaxOldGenerationSize());
 
   p->InsertAfter(anchor_.prev_page());
@@ skipping 1697 matching lines @@
   uintptr_t base = reinterpret_cast<uintptr_t>(page) / MemoryChunk::kAlignment;
   uintptr_t limit = base + (page->size() - 1) / MemoryChunk::kAlignment;
   for (uintptr_t key = base; key <= limit; key++) {
     HashMap::Entry* entry = chunk_map_.LookupOrInsert(
         reinterpret_cast<void*>(key), static_cast<uint32_t>(key));
     DCHECK(entry != NULL);
     entry->value = page;
   }
 
   HeapObject* object = page->GetObject();
-  if (heap()->incremental_marking()->black_allocation()) {
-    MarkBit mark_bit = Marking::MarkBitFrom(object);
-    Marking::MarkBlack(mark_bit);
-    page->SetFlag(Page::BLACK_PAGE);
-  }
   MSAN_ALLOCATED_UNINITIALIZED_MEMORY(object->address(), object_size);
 
   if (Heap::ShouldZapGarbage()) {
     // Make the object consistent so the heap can be verified in OldSpaceStep.
     // We only need to do this in debug builds or if verify_heap is on.
     reinterpret_cast<Object**>(object->address())[0] =
         heap()->fixed_array_map();
     reinterpret_cast<Object**>(object->address())[1] = Smi::FromInt(0);
   }
 
@@ skipping 216 matching lines @@
     object->ShortPrint();
     PrintF("\n");
   }
   printf(" --------------------------------------\n");
   printf(" Marked: %x, LiveCount: %x\n", mark_size, LiveBytes());
 }
 
 #endif  // DEBUG
 }  // namespace internal
 }  // namespace v8