Reland "Make more GCs in idle notification handler."

src/heap.cc

 // Copyright 2012 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 134 matching lines @@
       last_gc_end_timestamp_(0.0),
       marking_time_(0.0),
       sweeping_time_(0.0),
       store_buffer_(this),
       marking_(this),
       incremental_marking_(this),
       number_idle_notifications_(0),
       last_idle_notification_gc_count_(0),
       last_idle_notification_gc_count_init_(false),
       mark_sweeps_since_idle_round_started_(0),
-      ms_count_at_last_idle_notification_(0),
       gc_count_at_last_idle_gc_(0),
       scavenges_since_last_idle_round_(kIdleScavengeThreshold),
       gcs_since_last_deopt_(0),
 #ifdef VERIFY_HEAP
       no_weak_embedded_maps_verification_scope_depth_(0),
 #endif
       promotion_queue_(this),
       configured_(false),
       chunks_queued_for_free_(NULL),
       relocation_mutex_(NULL) {
@@ skipping 5686 matching lines @@
                               IncrementalMarking::NO_GC_VIA_STACK_GUARD);
 
   if (incremental_marking()->IsComplete()) {
     bool uncommit = false;
     if (gc_count_at_last_idle_gc_ == gc_count_) {
       // No GC since the last full GC, the mutator is probably not active.
       isolate_->compilation_cache()->Clear();
       uncommit = true;
     }
     CollectAllGarbage(kNoGCFlags, "idle notification: finalize incremental");
+    mark_sweeps_since_idle_round_started_++;
     gc_count_at_last_idle_gc_ = gc_count_;
     if (uncommit) {
       new_space_.Shrink();
       UncommitFromSpace();
     }
   }
 }
 
 
 bool Heap::IdleNotification(int hint) {
   // Hints greater than this value indicate that
   // the embedder is requesting a lot of GC work.
   const int kMaxHint = 1000;
+  const int kMinHint = 10;

[Hannes Payer (out of office), 2013/06/14 11:48:58]

Can we call that kMinHintForIncrementalMarking? This would be in sync with
kMinHintForFullGC.

[ulan, 2013/06/14 14:24:20]

Done.

   // 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.*
   intptr_t step_size =
       size_factor * IncrementalMarking::kAllocatedThreshold;
 
   if (contexts_disposed_ > 0) {
@@ skipping 42 matching lines @@
   }
 
   if (mark_sweeps_since_idle_round_started_ >= kMaxMarkSweepsInIdleRound) {
     if (EnoughGarbageSinceLastIdleRound()) {
       StartIdleRound();
     } else {
       return true;
     }
   }
 
-  int new_mark_sweeps = ms_count_ - ms_count_at_last_idle_notification_;
-  mark_sweeps_since_idle_round_started_ += new_mark_sweeps;
-  ms_count_at_last_idle_notification_ = ms_count_;
-
   int remaining_mark_sweeps = kMaxMarkSweepsInIdleRound -
                               mark_sweeps_since_idle_round_started_;
 
-  if (remaining_mark_sweeps <= 0) {
-    FinishIdleRound();
-    return true;
-  }
-
   if (incremental_marking()->IsStopped()) {
     // If there are no more than two GCs left in this idle round and we are
     // allowed to do a full GC, then make those GCs full in order to compact
     // the code space.
     // TODO(ulan): Once we enable code compaction for incremental marking,
     // we can get rid of this special case and always start incremental marking.
     if (remaining_mark_sweeps <= 2 && hint >= kMinHintForFullGC) {
       CollectAllGarbage(kReduceMemoryFootprintMask,
                         "idle notification: finalize idle round");
-    } else {
+      mark_sweeps_since_idle_round_started_++;
+    } else if (hint > kMinHint) {
       incremental_marking()->Start();
     }
   }
-  if (!incremental_marking()->IsStopped()) {
+  if (!incremental_marking()->IsStopped() && hint > kMinHint) {
     AdvanceIdleIncrementalMarking(step_size);
   }
+
+  if (mark_sweeps_since_idle_round_started_ >= kMaxMarkSweepsInIdleRound) {
+    FinishIdleRound();
+    return true;
+  }
+
   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;
@@ skipping 2095 matching lines @@
   if (FLAG_parallel_recompilation) {
     heap_->relocation_mutex_->Lock();
 #ifdef DEBUG
     heap_->relocation_mutex_locked_by_optimizer_thread_ =
         heap_->isolate()->optimizing_compiler_thread()->IsOptimizerThread();
 #endif  // DEBUG
   }
 }
 
 } }  // namespace v8::internal