Exponentially increase incremental marking factor each 512 steps.

src/incremental-marking.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 21 matching lines @@
 #include "code-stubs.h"
 
 namespace v8 {
 namespace internal {
 
 IncrementalMarking::State IncrementalMarking::state_ = STOPPED;
 MarkingStack IncrementalMarking::marking_stack_;
 
 double IncrementalMarking::steps_took_ = 0;
 int IncrementalMarking::steps_count_ = 0;
+intptr_t IncrementalMarking::allocation_marking_factor_ = 0;
 
 static intptr_t allocated = 0;
 
 class IncrementalMarkingMarkingVisitor : public ObjectVisitor {
  public:
   void VisitPointer(Object** p) {
     MarkObjectByPointer(p);
   }
 
   void VisitPointers(Object** start, Object** end) {
@@ skipping 162 matching lines @@
   Address new_space_high = Heap::new_space()->ToSpaceHigh();
   Marking::ClearRange(new_space_low,
                       static_cast<int>(new_space_high - new_space_low));
 
   ClearMarkbits();
 
 #ifdef DEBUG
   VerifyMarkbitsAreClean();
 #endif
 
+  Heap::new_space()->LowerInlineAllocationLimit(kAllocatedThreshold);
+
   // Mark strong roots grey.
   IncrementalMarkingRootMarkingVisitor visitor;
   Heap::IterateStrongRoots(&visitor, VISIT_ONLY_STRONG);
 
   // Ready to start incremental marking.
   if (FLAG_trace_incremental_marking) {
     PrintF("[IncrementalMarking] Running\n");
   }
 }
 
@@ skipping 91 matching lines @@
       FLAG_incremental_marking_steps) {
     allocated += allocated_bytes;
 
     if (allocated >= kAllocatedThreshold) {
       double start = 0;
 
       if (FLAG_trace_incremental_marking || FLAG_trace_gc) {
         start = OS::TimeCurrentMillis();
       }
 
-      intptr_t bytes_to_process = allocated * kAllocationMarkingFactor;
+      intptr_t bytes_to_process = allocated * allocation_marking_factor_;
       int count = 0;
 
       Map* filler_map = Heap::one_pointer_filler_map();
       while (!marking_stack_.is_empty() && bytes_to_process > 0) {
         HeapObject* obj = marking_stack_.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) {
           ASSERT(IsGrey(Marking::MarkBitFrom(obj)));
           int size = obj->SizeFromMap(map);
           bytes_to_process -= size;
           MarkBit map_mark_bit = Marking::MarkBitFromOldSpace(map);
           if (IsWhite(map_mark_bit)) WhiteToGreyAndPush(map, map_mark_bit);
           // TODO(gc) switch to static visitor instead of normal visitor.
           obj->IterateBody(map->instance_type(), size, &marking_visitor);
           MarkBit obj_mark_bit = Marking::MarkBitFrom(obj);
           MarkBlack(obj_mark_bit);
         }
         count++;
       }
       allocated = 0;
       if (marking_stack_.is_empty()) MarkingComplete();
       if (FLAG_trace_incremental_marking || FLAG_trace_gc) {
         double end = OS::TimeCurrentMillis();
         steps_took_ += (end - start);
-        steps_count_++;
+      }
+
+      steps_count_++;
+
+      if ((steps_count_ % kAllocationMarkingFactorSpeedupInterval) == 0) {
+        allocation_marking_factor_ *= kAllocationMarkingFactorSpeedup;
       }
     }
   }
 }
 
 
 } }  // namespace v8::internal