Removed IdleGlobalGC and just perform IdleNotification when incremental marking is on.

src/heap.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/accessors.h"
 #include "src/api.h"
 #include "src/base/once.h"
 #include "src/base/utils/random-number-generator.h"
@@ skipping 4236 matching lines @@
     gc_count_at_last_idle_gc_ = gc_count_;
     if (uncommit) {
       new_space_.Shrink();
       UncommitFromSpace();
     }
   }
 }
 
 
 bool Heap::IdleNotification(int hint) {
+  // If incremental marking is off, we do not perform idle notification.
+  if (!FLAG_incremental_marking) return true;

[jochen (gone - plz use gerrit), 2014/07/28 13:11:13]

why not return false (meaning "no need to call again"?)

[Hannes Payer (out of office), 2014/07/28 13:56:49]

Return true means that "we are done".

+
   // Hints greater than this value indicate that
   // the embedder is requesting a lot of GC work.
   const int kMaxHint = 1000;
   const int kMinHintForIncrementalMarking = 10;
   // Minimal hint that allows to do full GC.
   const int kMinHintForFullGC = 100;
   intptr_t size_factor = Min(Max(hint, 20), kMaxHint) / 4;
   // The size factor is in range [5..250]. The numbers here are chosen from
   // experiments. If you changes them, make sure to test with
   // chrome/performance_ui_tests --gtest_filter="GeneralMixMemoryTest.*
@@ skipping 16 matching lines @@
       AdvanceIdleIncrementalMarking(step_size);
     }
 
     // After context disposal there is likely a lot of garbage remaining, reset
     // the idle notification counters in order to trigger more incremental GCs
     // on subsequent idle notifications.
     StartIdleRound();
     return false;
   }
 
-  if (!FLAG_incremental_marking || isolate_->serializer_enabled()) {
-    return IdleGlobalGC();
-  }
-
   // By doing small chunks of GC work in each IdleNotification,
   // perform a round of incremental GCs and after that wait until
   // the mutator creates enough garbage to justify a new round.
   // An incremental GC progresses as follows:
   // 1. many incremental marking steps,
   // 2. one old space mark-sweep-compact,
   // Use mark-sweep-compact events to count incremental GCs in a round.
 
   if (mark_sweeps_since_idle_round_started_ >= kMaxMarkSweepsInIdleRound) {
     if (EnoughGarbageSinceLastIdleRound()) {
@@ skipping 34 matching lines @@
   // the sweepter threads here.
   if (hint >= kMinHintForFullGC &&
       mark_compact_collector()->sweeping_in_progress()) {
     mark_compact_collector()->EnsureSweepingCompleted();
   }
 
   return false;
 }
 
 
-bool Heap::IdleGlobalGC() {
-  static const int kIdlesBeforeScavenge = 4;
-  static const int kIdlesBeforeMarkSweep = 7;
-  static const int kIdlesBeforeMarkCompact = 8;
-  static const int kMaxIdleCount = kIdlesBeforeMarkCompact + 1;
-  static const unsigned int kGCsBetweenCleanup = 4;
-
-  if (!last_idle_notification_gc_count_init_) {
-    last_idle_notification_gc_count_ = gc_count_;
-    last_idle_notification_gc_count_init_ = true;
-  }
-
-  bool uncommit = true;
-  bool finished = false;
-
-  // Reset the number of idle notifications received when a number of
-  // GCs have taken place. This allows another round of cleanup based
-  // on idle notifications if enough work has been carried out to
-  // provoke a number of garbage collections.
-  if (gc_count_ - last_idle_notification_gc_count_ < kGCsBetweenCleanup) {
-    number_idle_notifications_ =
-        Min(number_idle_notifications_ + 1, kMaxIdleCount);
-  } else {
-    number_idle_notifications_ = 0;
-    last_idle_notification_gc_count_ = gc_count_;
-  }
-
-  if (number_idle_notifications_ == kIdlesBeforeScavenge) {
-    CollectGarbage(NEW_SPACE, "idle notification");
-    new_space_.Shrink();
-    last_idle_notification_gc_count_ = gc_count_;
-  } else if (number_idle_notifications_ == kIdlesBeforeMarkSweep) {
-    // Before doing the mark-sweep collections we clear the
-    // compilation cache to avoid hanging on to source code and
-    // generated code for cached functions.
-    isolate_->compilation_cache()->Clear();
-
-    CollectAllGarbage(kReduceMemoryFootprintMask, "idle notification");
-    new_space_.Shrink();
-    last_idle_notification_gc_count_ = gc_count_;
-
-  } else if (number_idle_notifications_ == kIdlesBeforeMarkCompact) {
-    CollectAllGarbage(kReduceMemoryFootprintMask, "idle notification");
-    new_space_.Shrink();
-    last_idle_notification_gc_count_ = gc_count_;
-    number_idle_notifications_ = 0;
-    finished = true;
-  } else if (number_idle_notifications_ > kIdlesBeforeMarkCompact) {
-    // If we have received more than kIdlesBeforeMarkCompact idle
-    // notifications we do not perform any cleanup because we don't
-    // expect to gain much by doing so.
-    finished = true;
-  }
-
-  if (uncommit) UncommitFromSpace();
-
-  return finished;
-}
-
-
 #ifdef DEBUG
 
 void Heap::Print() {
   if (!HasBeenSetUp()) return;
   isolate()->PrintStack(stdout);
   AllSpaces spaces(this);
   for (Space* space = spaces.next(); space != NULL; space = spaces.next()) {
     space->Print();
   }
 }
@@ skipping 1809 matching lines @@
       static_cast<int>(object_sizes_last_time_[index]));
   CODE_AGE_LIST_COMPLETE(ADJUST_LAST_TIME_OBJECT_COUNT)
 #undef ADJUST_LAST_TIME_OBJECT_COUNT
 
   MemCopy(object_counts_last_time_, object_counts_, sizeof(object_counts_));
   MemCopy(object_sizes_last_time_, object_sizes_, sizeof(object_sizes_));
   ClearObjectStats();
 }
 
 } }  // namespace v8::internal