Sample allocation rate in memory reducer.

src/heap/memory-reducer.cc

 // Copyright 2015 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/memory-reducer.h"
 
 #include "src/flags.h"
 #include "src/heap/heap.h"
 #include "src/utils.h"
 #include "src/v8.h"
 
 namespace v8 {
 namespace internal {
 
 const int MemoryReducer::kLongDelayMs = 5000;
 const int MemoryReducer::kShortDelayMs = 500;
 const int MemoryReducer::kWatchdogDelayMs = 100000;
 const int MemoryReducer::kMaxNumberOfGCs = 3;
 
 MemoryReducer::TimerTask::TimerTask(MemoryReducer* memory_reducer)
     : CancelableTask(memory_reducer->heap()->isolate()),
       memory_reducer_(memory_reducer) {}
 
 
 void MemoryReducer::TimerTask::RunInternal() {
   Heap* heap = memory_reducer_->heap();
   Event event;
+  double time_ms = heap->MonotonicallyIncreasingTimeInMs();
+  heap->tracer()->SampleAllocation(time_ms, heap->NewSpaceAllocationCounter(),
+                                   heap->OldGenerationAllocationCounter());
   event.type = kTimer;
-  event.time_ms = heap->MonotonicallyIncreasingTimeInMs();
+  event.time_ms = time_ms;
   event.low_allocation_rate = heap->HasLowAllocationRate();
   event.can_start_incremental_gc =
       heap->incremental_marking()->IsStopped() &&
       heap->incremental_marking()->CanBeActivated();
   memory_reducer_->NotifyTimer(event);
 }
 
 
 void MemoryReducer::NotifyTimer(const Event& event) {
   DCHECK_EQ(kTimer, event.type);
@@ skipping 153 matching lines @@
   auto timer_task = new MemoryReducer::TimerTask(this);
   V8::GetCurrentPlatform()->CallDelayedOnForegroundThread(
       isolate, timer_task, (delay_ms + kSlackMs) / 1000.0);
 }
 
 
 void MemoryReducer::TearDown() { state_ = State(kDone, 0, 0, 0.0); }
 
 }  // internal
 }  // v8