Slow down incremental marking on main thread when idle notification is active.

src/heap/incremental-marking.cc

 // 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.
 
 #include "src/v8.h"
 
 #include "src/heap/incremental-marking.h"
 
 #include "src/code-stubs.h"
 #include "src/compilation-cache.h"
@@ skipping 862 matching lines @@
   }
 
   allocated_ += allocated_bytes;
 
   if (marking == DO_NOT_FORCE_MARKING && allocated_ < kAllocatedThreshold &&
       write_barriers_invoked_since_last_step_ <
           kWriteBarriersInvokedThreshold) {
     return 0;
   }
 
+  // If an idle notification happened recently, we delay marking steps.
+  if (marking == DO_NOT_FORCE_MARKING &&
+      heap_->RecentIdleNotifcationHappened()) {
+    return 0;
+  }
+
   if (state_ == MARKING && no_marking_scope_depth_ > 0) return 0;
 
   intptr_t bytes_processed = 0;
   {
     HistogramTimerScope incremental_marking_scope(
         heap_->isolate()->counters()->gc_incremental_marking());
     double start = base::OS::TimeCurrentMillis();
 
     // 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
@@ skipping 76 matching lines @@
 void IncrementalMarking::IncrementIdleMarkingDelayCounter() {
   idle_marking_delay_counter_++;
 }
 
 
 void IncrementalMarking::ClearIdleMarkingDelayCounter() {
   idle_marking_delay_counter_ = 0;
 }
 }
 }  // namespace v8::internal