Revert trunk to bleeding_edge at r12484

src/incremental-marking.cc

 // Copyright 2012 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 26 matching lines @@
 
 namespace v8 {
 namespace internal {
 
 
 IncrementalMarking::IncrementalMarking(Heap* heap)
     : heap_(heap),
       state_(STOPPED),
       marking_deque_memory_(NULL),
       marking_deque_memory_committed_(false),
+      marker_(this, heap->mark_compact_collector()),
       steps_count_(0),
       steps_took_(0),
       longest_step_(0.0),
       old_generation_space_available_at_start_of_incremental_(0),
       old_generation_space_used_at_start_of_incremental_(0),
       steps_count_since_last_gc_(0),
       steps_took_since_last_gc_(0),
       should_hurry_(false),
-      marking_speed_(0),
+      allocation_marking_factor_(0),
       allocated_(0),
       no_marking_scope_depth_(0) {
 }
 
 
 void IncrementalMarking::TearDown() {
   delete marking_deque_memory_;
 }
 
 
 void IncrementalMarking::RecordWriteSlow(HeapObject* obj,
                                          Object** slot,
                                          Object* value) {
   if (BaseRecordWrite(obj, slot, value) && slot != NULL) {
     MarkBit obj_bit = Marking::MarkBitFrom(obj);
     if (Marking::IsBlack(obj_bit)) {
       // Object is not going to be rescanned we need to record the slot.
       heap_->mark_compact_collector()->RecordSlot(
           HeapObject::RawField(obj, 0), slot, value);
     }
   }
 }
 
 
 void IncrementalMarking::RecordWriteFromCode(HeapObject* obj,
                                              Object* value,
                                              Isolate* isolate) {
   ASSERT(obj->IsHeapObject());
+
+  // Fast cases should already be covered by RecordWriteStub.
+  ASSERT(value->IsHeapObject());
+  ASSERT(!value->IsHeapNumber());
+  ASSERT(!value->IsString() ||
+         value->IsConsString() ||
+         value->IsSlicedString());
+  ASSERT(Marking::IsWhite(Marking::MarkBitFrom(HeapObject::cast(value))));
+
   IncrementalMarking* marking = isolate->heap()->incremental_marking();
   ASSERT(!marking->is_compacting_);
-
-  MemoryChunk* chunk = MemoryChunk::FromAddress(obj->address());
-  int counter = chunk->write_barrier_counter();
-  if (counter < (MemoryChunk::kWriteBarrierCounterGranularity / 2)) {
-    marking->write_barriers_invoked_since_last_step_ +=
-        MemoryChunk::kWriteBarrierCounterGranularity -
-            chunk->write_barrier_counter();
-    chunk->set_write_barrier_counter(
-        MemoryChunk::kWriteBarrierCounterGranularity);
-  }
-
   marking->RecordWrite(obj, NULL, value);
 }
 
 
 void IncrementalMarking::RecordWriteForEvacuationFromCode(HeapObject* obj,
                                                           Object** slot,
                                                           Isolate* isolate) {
-  ASSERT(obj->IsHeapObject());
   IncrementalMarking* marking = isolate->heap()->incremental_marking();
   ASSERT(marking->is_compacting_);
-
-  MemoryChunk* chunk = MemoryChunk::FromAddress(obj->address());
-  int counter = chunk->write_barrier_counter();
-  if (counter < (MemoryChunk::kWriteBarrierCounterGranularity / 2)) {
-    marking->write_barriers_invoked_since_last_step_ +=
-        MemoryChunk::kWriteBarrierCounterGranularity -
-            chunk->write_barrier_counter();
-    chunk->set_write_barrier_counter(
-        MemoryChunk::kWriteBarrierCounterGranularity);
-  }
-
   marking->RecordWrite(obj, slot, *slot);
 }
 
 
 void IncrementalMarking::RecordCodeTargetPatch(Code* host,
                                                Address pc,
                                                HeapObject* value) {
   if (IsMarking()) {
     RelocInfo rinfo(pc, RelocInfo::CODE_TARGET, 0, host);
     RecordWriteIntoCode(host, &rinfo, value);
@@ skipping 55 matching lines @@
 
     table_.Register(kVisitSharedFunctionInfo, &VisitSharedFunctionInfo);
 
     table_.Register(kVisitJSFunction, &VisitJSFunction);
 
     table_.Register(kVisitJSRegExp, &VisitJSRegExp);
   }
 
   static void VisitJSWeakMap(Map* map, HeapObject* object) {
     Heap* heap = map->GetHeap();
-    Object** start_slot =
-        HeapObject::RawField(object, JSWeakMap::kPropertiesOffset);
     VisitPointers(heap,
-                  start_slot,
-                  start_slot,
+                  HeapObject::RawField(object, JSWeakMap::kPropertiesOffset),
                   HeapObject::RawField(object, JSWeakMap::kSize));
   }
 
   static void VisitSharedFunctionInfo(Map* map, HeapObject* object) {
     Heap* heap = map->GetHeap();
     SharedFunctionInfo* shared = SharedFunctionInfo::cast(object);
     if (shared->ic_age() != heap->global_ic_age()) {
       shared->ResetForNewContext(heap->global_ic_age());
     }
     FixedBodyVisitor<IncrementalMarkingMarkingVisitor,
                      SharedFunctionInfo::BodyDescriptor,
                      void>::Visit(map, object);
   }
 
-  static const int kScanningChunk = 32 * 1024;
-
-  static int VisitHugeArray(FixedArray* array) {
-    Heap* heap = array->GetHeap();
-    MemoryChunk* chunk = MemoryChunk::FromAddress(array->address());
-    Object** start_slot = array->data_start();
-    int length = array->length();
-
-    if (chunk->owner()->identity() != LO_SPACE) {
-      VisitPointers(heap, start_slot, start_slot, start_slot + length);
-      return length;
-    }
-
-    int from =
-        chunk->IsPartiallyScanned() ? chunk->PartiallyScannedProgress() : 0;
-    int to = Min(from + kScanningChunk, length);
-
-    VisitPointers(heap, start_slot, start_slot + from, start_slot + to);
-
-    if (to == length) {
-      // If it went from black to grey while it was waiting for the next bit to
-      // be scanned then we have to start the scan again.
-      MarkBit mark_bit = Marking::MarkBitFrom(array);
-      if (!Marking::IsBlack(mark_bit)) {
-        ASSERT(Marking::IsGrey(mark_bit));
-        chunk->SetPartiallyScannedProgress(0);
-      } else {
-        chunk->SetCompletelyScanned();
-      }
-    } else {
-      chunk->SetPartiallyScannedProgress(to);
-    }
-    return to - from;
-  }
-
   static inline void VisitJSFunction(Map* map, HeapObject* object) {
     Heap* heap = map->GetHeap();
     // Iterate over all fields in the body but take care in dealing with
     // the code entry and skip weak fields.
-    Object** start_slot =
-        HeapObject::RawField(object, JSFunction::kPropertiesOffset);
     VisitPointers(heap,
-                  start_slot,
-                  start_slot,
+                  HeapObject::RawField(object, JSFunction::kPropertiesOffset),
                   HeapObject::RawField(object, JSFunction::kCodeEntryOffset));
     VisitCodeEntry(heap, object->address() + JSFunction::kCodeEntryOffset);
     VisitPointers(heap,
-                  start_slot,
                   HeapObject::RawField(object,
                       JSFunction::kCodeEntryOffset + kPointerSize),
                   HeapObject::RawField(object,
                       JSFunction::kNonWeakFieldsEndOffset));
   }
 
   INLINE(static void VisitPointer(Heap* heap, Object** p)) {
     Object* obj = *p;
     if (obj->NonFailureIsHeapObject()) {
       heap->mark_compact_collector()->RecordSlot(p, p, obj);
       MarkObject(heap, obj);
     }
   }
 
-  INLINE(static void VisitPointers(Heap* heap,
-                                   Object** anchor,
-                                   Object** start,
-                                   Object** end)) {
+  INLINE(static void VisitPointers(Heap* heap, Object** start, Object** end)) {
     for (Object** p = start; p < end; p++) {
       Object* obj = *p;
       if (obj->NonFailureIsHeapObject()) {
-        heap->mark_compact_collector()->RecordSlot(anchor, p, obj);
+        heap->mark_compact_collector()->RecordSlot(start, p, obj);
         MarkObject(heap, obj);
       }
     }
   }
 
-  // Marks the object grey and pushes it on the marking stack.
   INLINE(static void MarkObject(Heap* heap, Object* obj)) {
     HeapObject* heap_object = HeapObject::cast(obj);
     MarkBit mark_bit = Marking::MarkBitFrom(heap_object);
     if (mark_bit.data_only()) {
       if (heap->incremental_marking()->MarkBlackOrKeepGrey(mark_bit)) {
         MemoryChunk::IncrementLiveBytesFromGC(heap_object->address(),
                                               heap_object->Size());
       }
     } else if (Marking::IsWhite(mark_bit)) {
       heap->incremental_marking()->WhiteToGreyAndPush(heap_object, mark_bit);
     }
   }
-
-  // Marks the object black without pushing it on the marking stack.
-  // Returns true if object needed marking and false otherwise.
-  INLINE(static bool MarkObjectWithoutPush(Heap* heap, Object* obj)) {
-    HeapObject* heap_object = HeapObject::cast(obj);
-    MarkBit mark_bit = Marking::MarkBitFrom(heap_object);
-    if (Marking::IsWhite(mark_bit)) {
-      mark_bit.Set();
-      MemoryChunk::IncrementLiveBytesFromGC(heap_object->address(),
-                                            heap_object->Size());
-      return true;
-    }
-    return false;
-  }
 };
 
 
 class IncrementalMarkingRootMarkingVisitor : public ObjectVisitor {
  public:
   IncrementalMarkingRootMarkingVisitor(Heap* heap,
                                        IncrementalMarking* incremental_marking)
       : heap_(heap),
         incremental_marking_(incremental_marking) {
   }
@@ skipping 349 matching lines @@
       }
     } else if (obj->map() != filler_map) {
       // Skip one word filler objects that appear on the
       // stack when we perform in place array shift.
       array[new_top] = obj;
       new_top = ((new_top + 1) & mask);
       ASSERT(new_top != marking_deque_.bottom());
 #ifdef DEBUG
         MarkBit mark_bit = Marking::MarkBitFrom(obj);
         ASSERT(Marking::IsGrey(mark_bit) ||
-               (obj->IsFiller() && Marking::IsWhite(mark_bit)) ||
-               MemoryChunk::FromAddress(obj->address())->IsPartiallyScanned());
+               (obj->IsFiller() && Marking::IsWhite(mark_bit)));
 #endif
     }
   }
   marking_deque_.set_top(new_top);
 
   steps_took_since_last_gc_ = 0;
   steps_count_since_last_gc_ = 0;
   longest_step_ = 0.0;
 }
 
 
 void IncrementalMarking::Hurry() {
   if (state() == MARKING) {
     double start = 0.0;
     if (FLAG_trace_incremental_marking) {
       PrintF("[IncrementalMarking] Hurry\n");
       start = OS::TimeCurrentMillis();
     }
     // TODO(gc) hurry can mark objects it encounters black as mutator
     // was stopped.
     Map* filler_map = heap_->one_pointer_filler_map();
     Map* native_context_map = heap_->native_context_map();
-    do {
-      while (!marking_deque_.IsEmpty()) {
-        HeapObject* obj = marking_deque_.Pop();
+    while (!marking_deque_.IsEmpty()) {
+      HeapObject* obj = marking_deque_.Pop();
 
-        // Explicitly skip one word fillers. Incremental markbit patterns are
-        // correct only for objects that occupy at least two words.
-        Map* map = obj->map();
-        if (map == filler_map) {
-          continue;
-        } else if (map == native_context_map) {
-          // Native contexts have weak fields.
-          IncrementalMarkingMarkingVisitor::VisitNativeContext(map, obj);
-          ASSERT(!Marking::IsBlack(Marking::MarkBitFrom(obj)));
-          MemoryChunk::IncrementLiveBytesFromGC(obj->address(), obj->Size());
-        } else if (map->instance_type() == FIXED_ARRAY_TYPE &&
-          FixedArray::cast(obj)->length() >
-                IncrementalMarkingMarkingVisitor::kScanningChunk) {
-          MarkBit map_mark_bit = Marking::MarkBitFrom(map);
-          if (Marking::IsWhite(map_mark_bit)) {
-            WhiteToGreyAndPush(map, map_mark_bit);
-          }
-          MarkBit mark_bit = Marking::MarkBitFrom(obj);
-          if (!Marking::IsBlack(mark_bit)) {
-            MemoryChunk::IncrementLiveBytesFromGC(obj->address(), obj->Size());
-          } else {
-            ASSERT(
-                MemoryChunk::FromAddress(obj->address())->IsPartiallyScanned());
-          }
-          IncrementalMarkingMarkingVisitor::VisitHugeArray(
-                FixedArray::cast(obj));
-         } else {
-          MarkBit map_mark_bit = Marking::MarkBitFrom(map);
-          if (Marking::IsWhite(map_mark_bit)) {
-            WhiteToGreyAndPush(map, map_mark_bit);
-          }
-          IncrementalMarkingMarkingVisitor::IterateBody(map, obj);
-          ASSERT(!Marking::IsBlack(Marking::MarkBitFrom(obj)));
-          MemoryChunk::IncrementLiveBytesFromGC(obj->address(), obj->Size());
+      // Explicitly skip one word fillers. Incremental markbit patterns are
+      // correct only for objects that occupy at least two words.
+      Map* map = obj->map();
+      if (map == filler_map) {
+        continue;
+      } else if (map == native_context_map) {
+        // Native contexts have weak fields.
+        IncrementalMarkingMarkingVisitor::VisitNativeContext(map, obj);
+      } else if (map->instance_type() == MAP_TYPE) {
+        Map* map = Map::cast(obj);
+        heap_->ClearCacheOnMap(map);
+
+        // When map collection is enabled we have to mark through map's
+        // transitions and back pointers in a special way to make these links
+        // weak.  Only maps for subclasses of JSReceiver can have transitions.
+        STATIC_ASSERT(LAST_TYPE == LAST_JS_RECEIVER_TYPE);
+        if (FLAG_collect_maps &&
+            map->instance_type() >= FIRST_JS_RECEIVER_TYPE) {
+          marker_.MarkMapContents(map);
+        } else {
+          IncrementalMarkingMarkingVisitor::VisitPointers(
+              heap_,
+              HeapObject::RawField(map, Map::kPointerFieldsBeginOffset),
+              HeapObject::RawField(map, Map::kPointerFieldsEndOffset));
         }
+      } else {
+        MarkBit map_mark_bit = Marking::MarkBitFrom(map);
+        if (Marking::IsWhite(map_mark_bit)) {
+          WhiteToGreyAndPush(map, map_mark_bit);
+        }
+        IncrementalMarkingMarkingVisitor::IterateBody(map, obj);
+      }
 
-        MarkBit mark_bit = Marking::MarkBitFrom(obj);
-        Marking::MarkBlack(mark_bit);
-      }
-      state_ = COMPLETE;
-      if (FLAG_trace_incremental_marking) {
-        double end = OS::TimeCurrentMillis();
-        PrintF("[IncrementalMarking] Complete (hurry), spent %d ms.\n",
-               static_cast<int>(end - start));
-      }
-      MarkCompactCollector::ProcessLargePostponedArrays(heap_, &marking_deque_);
-    } while (!marking_deque_.IsEmpty());
+      MarkBit mark_bit = Marking::MarkBitFrom(obj);
+      ASSERT(!Marking::IsBlack(mark_bit));
+      Marking::MarkBlack(mark_bit);
+      MemoryChunk::IncrementLiveBytesFromGC(obj->address(), obj->Size());
+    }
+    state_ = COMPLETE;
+    if (FLAG_trace_incremental_marking) {
+      double end = OS::TimeCurrentMillis();
+      PrintF("[IncrementalMarking] Complete (hurry), spent %d ms.\n",
+             static_cast<int>(end - start));
+    }
   }
 
   if (FLAG_cleanup_code_caches_at_gc) {
     PolymorphicCodeCache* poly_cache = heap_->polymorphic_code_cache();
     Marking::GreyToBlack(Marking::MarkBitFrom(poly_cache));
     MemoryChunk::IncrementLiveBytesFromGC(poly_cache->address(),
                                           PolymorphicCodeCache::kSize);
   }
 
   Object* context = heap_->native_contexts_list();
@@ skipping 79 matching lines @@
                               CompletionAction action) {
   if (heap_->gc_state() != Heap::NOT_IN_GC ||
       !FLAG_incremental_marking ||
       !FLAG_incremental_marking_steps ||
       (state_ != SWEEPING && state_ != MARKING)) {
     return;
   }
 
   allocated_ += allocated_bytes;
 
-  if (allocated_ < kAllocatedThreshold &&
-      write_barriers_invoked_since_last_step_ <
-          kWriteBarriersInvokedThreshold) {
-    return;
-  }
+  if (allocated_ < kAllocatedThreshold) return;
 
   if (state_ == MARKING && no_marking_scope_depth_ > 0) return;
 
-  // The marking speed is driven either by the allocation rate or by the rate
-  // at which we are having to check the color of objects in the write barrier.
-  // It is possible for a tight non-allocating loop to run a lot of write
-  // barriers before we get here and check them (marking can only take place on
-  // allocation), so to reduce the lumpiness we don't use the write barriers
-  // invoked since last step directly to determine the amount of work to do.
-  intptr_t bytes_to_process =
-      marking_speed_ * Max(allocated_, kWriteBarriersInvokedThreshold);
-  allocated_ = 0;
-  write_barriers_invoked_since_last_step_ = 0;
-
+  intptr_t bytes_to_process = allocated_ * allocation_marking_factor_;
   bytes_scanned_ += bytes_to_process;
 
   double start = 0;
 
   if (FLAG_trace_incremental_marking || FLAG_trace_gc) {
     start = OS::TimeCurrentMillis();
   }
 
   if (state_ == SWEEPING) {
     if (heap_->AdvanceSweepers(static_cast<int>(bytes_to_process))) {
       bytes_scanned_ = 0;
       StartMarking(PREVENT_COMPACTION);
     }
   } else if (state_ == MARKING) {
     Map* filler_map = heap_->one_pointer_filler_map();
     Map* native_context_map = heap_->native_context_map();
-    while (true) {
-      while (!marking_deque_.IsEmpty() && bytes_to_process > 0) {
-        HeapObject* obj = marking_deque_.Pop();
+    while (!marking_deque_.IsEmpty() && bytes_to_process > 0) {
+      HeapObject* obj = marking_deque_.Pop();
 
-        // Explicitly skip one word fillers. Incremental markbit patterns are
-        // correct only for objects that occupy at least two words.
-        Map* map = obj->map();
-        if (map == filler_map) continue;
+      // Explicitly skip one word fillers. Incremental markbit patterns are
+      // correct only for objects that occupy at least two words.
+      Map* map = obj->map();
+      if (map == filler_map) continue;
 
-        int size = obj->SizeFromMap(map);
-        MarkBit map_mark_bit = Marking::MarkBitFrom(map);
-        if (Marking::IsWhite(map_mark_bit)) {
-          WhiteToGreyAndPush(map, map_mark_bit);
+      int size = obj->SizeFromMap(map);
+      bytes_to_process -= size;
+      MarkBit map_mark_bit = Marking::MarkBitFrom(map);
+      if (Marking::IsWhite(map_mark_bit)) {
+        WhiteToGreyAndPush(map, map_mark_bit);
+      }
+
+      // TODO(gc) switch to static visitor instead of normal visitor.
+      if (map == native_context_map) {
+        // Native contexts have weak fields.
+        Context* ctx = Context::cast(obj);
+
+        // We will mark cache black with a separate pass
+        // when we finish marking.
+        MarkObjectGreyDoNotEnqueue(ctx->normalized_map_cache());
+
+        IncrementalMarkingMarkingVisitor::VisitNativeContext(map, ctx);
+      } else if (map->instance_type() == MAP_TYPE) {
+        Map* map = Map::cast(obj);
+        heap_->ClearCacheOnMap(map);
+
+        // When map collection is enabled we have to mark through map's
+        // transitions and back pointers in a special way to make these links
+        // weak.  Only maps for subclasses of JSReceiver can have transitions.
+        STATIC_ASSERT(LAST_TYPE == LAST_JS_RECEIVER_TYPE);
+        if (FLAG_collect_maps &&
+            map->instance_type() >= FIRST_JS_RECEIVER_TYPE) {
+          marker_.MarkMapContents(map);
+        } else {
+          IncrementalMarkingMarkingVisitor::VisitPointers(
+              heap_,
+              HeapObject::RawField(map, Map::kPointerFieldsBeginOffset),
+              HeapObject::RawField(map, Map::kPointerFieldsEndOffset));
         }
+      } else {
+        IncrementalMarkingMarkingVisitor::IterateBody(map, obj);
+      }
 
-        // TODO(gc) switch to static visitor instead of normal visitor.
-        if (map == native_context_map) {
-          // Native contexts have weak fields.
-          Context* ctx = Context::cast(obj);
+      MarkBit obj_mark_bit = Marking::MarkBitFrom(obj);
+      SLOW_ASSERT(Marking::IsGrey(obj_mark_bit) ||
+                  (obj->IsFiller() && Marking::IsWhite(obj_mark_bit)));
+      Marking::MarkBlack(obj_mark_bit);
+      MemoryChunk::IncrementLiveBytesFromGC(obj->address(), size);
+    }
+    if (marking_deque_.IsEmpty()) MarkingComplete(action);
+  }
 
-          // We will mark cache black with a separate pass
-          // when we finish marking.
-          MarkObjectGreyDoNotEnqueue(ctx->normalized_map_cache());
-
-          IncrementalMarkingMarkingVisitor::VisitNativeContext(map, ctx);
-          bytes_to_process -= size;
-          SLOW_ASSERT(Marking::IsGrey(Marking::MarkBitFrom(obj)));
-          MemoryChunk::IncrementLiveBytesFromGC(obj->address(), size);
-        } else if (map->instance_type() == FIXED_ARRAY_TYPE &&
-          FixedArray::cast(obj)->length() >
-              IncrementalMarkingMarkingVisitor::kScanningChunk) {
-          SLOW_ASSERT(
-              Marking::IsGrey(Marking::MarkBitFrom(obj)) ||
-              MemoryChunk::FromAddress(obj->address())->IsPartiallyScanned());
-          bytes_to_process -=
-              IncrementalMarkingMarkingVisitor::VisitHugeArray(
-                  FixedArray::cast(obj));
-          MarkBit obj_mark_bit = Marking::MarkBitFrom(obj);
-          if (!Marking::IsBlack(obj_mark_bit)) {
-            MemoryChunk::IncrementLiveBytesFromGC(obj->address(), size);
-          }
-         } else {
-          IncrementalMarkingMarkingVisitor::IterateBody(map, obj);
-          bytes_to_process -= size;
-          SLOW_ASSERT(
-              Marking::IsGrey(Marking::MarkBitFrom(obj)) ||
-              (obj->IsFiller() && Marking::IsWhite(Marking::MarkBitFrom(obj))));
-          MemoryChunk::IncrementLiveBytesFromGC(obj->address(), size);
-        }
-
-        MarkBit obj_mark_bit = Marking::MarkBitFrom(obj);
-        Marking::MarkBlack(obj_mark_bit);
-      }
-      if (marking_deque_.IsEmpty()) {
-        MarkCompactCollector::ProcessLargePostponedArrays(heap_,
-                                                          &marking_deque_);
-        if (marking_deque_.IsEmpty()) {
-          MarkingComplete(action);
-          break;
-         }
-       } else {
-        ASSERT(bytes_to_process <= 0);
-        break;
-       }
-    }
-  }
+  allocated_ = 0;
 
   steps_count_++;
   steps_count_since_last_gc_++;
 
   bool speed_up = false;
 
-  if ((steps_count_ % kMarkingSpeedAccellerationInterval) == 0) {
+  if ((steps_count_ % kAllocationMarkingFactorSpeedupInterval) == 0) {
     if (FLAG_trace_gc) {
       PrintPID("Speed up marking after %d steps\n",
-               static_cast<int>(kMarkingSpeedAccellerationInterval));
+               static_cast<int>(kAllocationMarkingFactorSpeedupInterval));
     }
     speed_up = true;
   }
 
   bool space_left_is_very_small =
       (old_generation_space_available_at_start_of_incremental_ < 10 * MB);
 
   bool only_1_nth_of_space_that_was_available_still_left =
-      (SpaceLeftInOldSpace() * (marking_speed_ + 1) <
+      (SpaceLeftInOldSpace() * (allocation_marking_factor_ + 1) <
           old_generation_space_available_at_start_of_incremental_);
 
   if (space_left_is_very_small ||
       only_1_nth_of_space_that_was_available_still_left) {
     if (FLAG_trace_gc) PrintPID("Speed up marking because of low space left\n");
     speed_up = true;
   }
 
   bool size_of_old_space_multiplied_by_n_during_marking =
       (heap_->PromotedTotalSize() >
-       (marking_speed_ + 1) *
+       (allocation_marking_factor_ + 1) *
            old_generation_space_used_at_start_of_incremental_);
   if (size_of_old_space_multiplied_by_n_during_marking) {
     speed_up = true;
     if (FLAG_trace_gc) {
       PrintPID("Speed up marking because of heap size increase\n");
     }
   }
 
   int64_t promoted_during_marking = heap_->PromotedTotalSize()
       - old_generation_space_used_at_start_of_incremental_;
-  intptr_t delay = marking_speed_ * MB;
+  intptr_t delay = allocation_marking_factor_ * MB;
   intptr_t scavenge_slack = heap_->MaxSemiSpaceSize();
 
   // We try to scan at at least twice the speed that we are allocating.
   if (promoted_during_marking > bytes_scanned_ / 2 + scavenge_slack + delay) {
     if (FLAG_trace_gc) {
       PrintPID("Speed up marking because marker was not keeping up\n");
     }
     speed_up = true;
   }
 
   if (speed_up) {
     if (state_ != MARKING) {
       if (FLAG_trace_gc) {
         PrintPID("Postponing speeding up marking until marking starts\n");
       }
     } else {
-      marking_speed_ += kMarkingSpeedAccellerationInterval;
-      marking_speed_ = static_cast<int>(
-          Min(kMaxMarkingSpeed,
-              static_cast<intptr_t>(marking_speed_ * 1.3)));
+      allocation_marking_factor_ += kAllocationMarkingFactorSpeedup;
+      allocation_marking_factor_ = static_cast<int>(
+          Min(kMaxAllocationMarkingFactor,
+              static_cast<intptr_t>(allocation_marking_factor_ * 1.3)));
       if (FLAG_trace_gc) {
-        PrintPID("Marking speed increased to %d\n", marking_speed_);
+        PrintPID("Marking speed increased to %d\n", allocation_marking_factor_);
       }
     }
   }
 
   if (FLAG_trace_incremental_marking || FLAG_trace_gc) {
     double end = OS::TimeCurrentMillis();
     double delta = (end - start);
     longest_step_ = Max(longest_step_, delta);
     steps_took_ += delta;
     steps_took_since_last_gc_ += delta;
   }
 }
 
 
 void IncrementalMarking::ResetStepCounters() {
   steps_count_ = 0;
   steps_took_ = 0;
   longest_step_ = 0.0;
   old_generation_space_available_at_start_of_incremental_ =
       SpaceLeftInOldSpace();
   old_generation_space_used_at_start_of_incremental_ =
       heap_->PromotedTotalSize();
   steps_count_since_last_gc_ = 0;
   steps_took_since_last_gc_ = 0;
   bytes_rescanned_ = 0;
-  marking_speed_ = kInitialMarkingSpeed;
+  allocation_marking_factor_ = kInitialAllocationMarkingFactor;
   bytes_scanned_ = 0;
-  write_barriers_invoked_since_last_step_ = 0;
 }
 
 
 int64_t IncrementalMarking::SpaceLeftInOldSpace() {
   return heap_->MaxOldGenerationSize() - heap_->PromotedSpaceSizeOfObjects();
 }
 
 } }  // namespace v8::internal