Perform full GC in background idle notification.

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"
@@ skipping 77 matching lines @@
 
 
 void MemoryReducer::NotifyBackgroundIdleNotification(const Event& event) {
   DCHECK_EQ(kBackgroundIdleNotification, event.type);
   Action old_action = state_.action;
   int old_started_gcs = state_.started_gcs;
   state_ = Step(state_, event);
   if (old_action == kWait && state_.action == kWait &&
       old_started_gcs + 1 == state_.started_gcs) {
     DCHECK(heap()->incremental_marking()->IsStopped());
-    DCHECK(FLAG_incremental_marking);
-    heap()->StartIdleIncrementalMarking();
-    if (FLAG_trace_gc_verbose) {
-      PrintIsolate(heap()->isolate(),
-                   "Memory reducer: started GC #%d"
-                   " (background idle)\n",
-                   state_.started_gcs);
-    }
+    heap()->CollectAllGarbage(Heap::kReduceMemoryFootprintMask,

[Hannes Payer (out of office), 2015/08/03 19:11:39]

Let's leave a comment here why we do a full GCs. Or actually a TODO, it may be
beneficial to incremental marking here.

[ulan, 2015/08/04 11:26:21]

Done.

+                              "memory reducer background GC");
   }
 }
 
 
 bool MemoryReducer::WatchdogGC(const State& state, const Event& event) {
   return state.last_gc_time_ms != 0 &&
          event.time_ms > state.last_gc_time_ms + kWatchdogDelayMs;
 }
 
 
@@ skipping 70 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