Speed up incremental marking if the heap size doubled

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 25 matching lines @@
 namespace internal {
 
 
 IncrementalMarking::IncrementalMarking(Heap* heap)
     : heap_(heap),
       state_(STOPPED),
       marking_deque_memory_(NULL),
       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),
       allocation_marking_factor_(0),
       allocated_(0) {
 }
 
 
 void IncrementalMarking::TearDown() {
   delete marking_deque_memory_;
@@ skipping 520 matching lines @@
       }
     }
     if (marking_deque_.IsEmpty()) MarkingComplete();
   }
 
   allocated_ = 0;
 
   steps_count_++;
   steps_count_since_last_gc_++;
 
-  if ((steps_count_ % kAllocationMarkingFactorSpeedupInterval) == 0) {
+  bool speed_up = false;
+
+  if (old_generation_space_available_at_start_of_incremental_ < 10 * MB ||
+      SpaceLeftInOldSpace() <
+          old_generation_space_available_at_start_of_incremental_ >> 1) {
+    // Half of the space that was available is gone while we were
+    // incrementally marking.
+    speed_up = true;
+    old_generation_space_available_at_start_of_incremental_ =
+        SpaceLeftInOldSpace();
+  }
+
+  if (heap_->PromotedTotalSize() >
+      old_generation_space_used_at_start_of_incremental_ << 1) {
+    // Size of old space doubled while we were incrementally marking.
+    speed_up = true;
+    old_generation_space_used_at_start_of_incremental_ =
+        heap_->PromotedTotalSize();
+  }
+
+  if ((steps_count_ % kAllocationMarkingFactorSpeedupInterval) == 0 &&
+      allocation_marking_factor_ < kMaxAllocationMarkingFactor) {
+    speed_up = true;
+  }
+
+  if (speed_up && 0) {
     allocation_marking_factor_ += kAllocationMarkingFactorSpeedup;
     allocation_marking_factor_ =
         static_cast<int>(allocation_marking_factor_ * 1.3);
     if (FLAG_trace_gc) {
       PrintF("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;
+  allocation_marking_factor_ = kInitialAllocationMarkingFactor;
+}
+
+
+int64_t IncrementalMarking::SpaceLeftInOldSpace() {
+  return heap_->MaxOldGenerationSize() - heap_->PromotedSpaceSize();
+}
+
 } }  // namespace v8::internal