Use smaller heap growing factor in idle notification to start incremental marking when there is idle time >16ms.

BUG=chromium:477323
LOG=y

Review URL: https://codereview.chromium.org/1090963002

Cr-Commit-Position: refs/heads/master@{#27897}

src/heap/gc-idle-time-handler.h

@@ -119,9 +119,12 @@ class GCIdleTimeHandler {
   static const int kIdleScavengeThreshold;
 
   // This is the maximum scheduled idle time. Note that it can be more than
-  // 16 ms when there is currently no rendering going on.
+  // 16.66 ms when there is currently no rendering going on.
   static const size_t kMaxScheduledIdleTime = 50;
 
+  // The maximum idle time when frames are rendered is 16.66ms.
+  static const size_t kMaxFrameRenderingIdleTime = 17;
+
   // We conservatively assume that in the next kTimeUntilNextIdleEvent ms
   // no idle notification happens.
   static const size_t kTimeUntilNextIdleEvent = 100;

src/heap/heap.cc

@@ -1131,8 +1131,7 @@ bool Heap::PerformGarbageCollection(
     // Temporarily set the limit for case when PostGarbageCollectionProcessing
     // allocates and triggers GC. The real limit is set at after
     // PostGarbageCollectionProcessing.
-    old_generation_allocation_limit_ =
-        OldGenerationAllocationLimit(PromotedSpaceSizeOfObjects(), 0);
+    SetOldGenerationAllocationLimit(PromotedSpaceSizeOfObjects(), 0);
     old_gen_exhausted_ = false;
     old_generation_size_configured_ = true;
   } else {
@@ -1166,8 +1165,8 @@ bool Heap::PerformGarbageCollection(
     // Register the amount of external allocated memory.
     amount_of_external_allocated_memory_at_last_global_gc_ =
         amount_of_external_allocated_memory_;
-    old_generation_allocation_limit_ = OldGenerationAllocationLimit(
-        PromotedSpaceSizeOfObjects(), freed_global_handles);
+    SetOldGenerationAllocationLimit(PromotedSpaceSizeOfObjects(),
+                                    freed_global_handles);
     // We finished a marking cycle. We can uncommit the marking deque until
     // we start marking again.
     mark_compact_collector_.UncommitMarkingDeque();
@@ -4548,7 +4547,7 @@ bool Heap::TryFinalizeIdleIncrementalMarking(
 
 bool Heap::WorthActivatingIncrementalMarking() {
   return incremental_marking()->IsStopped() &&
-         incremental_marking()->WorthActivating() && NextGCIsLikelyToBeFull();
+         incremental_marking()->ShouldActivate();
 }
 
 
@@ -4573,6 +4572,7 @@ bool Heap::IdleNotification(double deadline_in_seconds) {
       static_cast<double>(base::Time::kMillisecondsPerSecond);
   HistogramTimerScope idle_notification_scope(
       isolate_->counters()->gc_idle_notification());
+  double idle_time_in_ms = deadline_in_ms - MonotonicallyIncreasingTimeInMs();
 
   GCIdleTimeHandler::HeapState heap_state;
   heap_state.contexts_disposed = contexts_disposed_;
@@ -4581,8 +4581,15 @@ bool Heap::IdleNotification(double deadline_in_seconds) {
   heap_state.size_of_objects = static_cast<size_t>(SizeOfObjects());
   heap_state.incremental_marking_stopped = incremental_marking()->IsStopped();
   // TODO(ulan): Start incremental marking only for large heaps.
+  intptr_t limit = old_generation_allocation_limit_;
+  if (static_cast<size_t>(idle_time_in_ms) >
+      GCIdleTimeHandler::kMaxFrameRenderingIdleTime) {
+    limit = idle_old_generation_allocation_limit_;
+  }
+
   heap_state.can_start_incremental_marking =
-      incremental_marking()->ShouldActivate() && FLAG_incremental_marking &&
+      incremental_marking()->WorthActivating() &&
+      NextGCIsLikelyToBeFull(limit) && FLAG_incremental_marking &&
       !mark_compact_collector()->sweeping_in_progress();
   heap_state.sweeping_in_progress =
       mark_compact_collector()->sweeping_in_progress();
@@ -4603,7 +4610,6 @@ bool Heap::IdleNotification(double deadline_in_seconds) {
       static_cast<size_t>(
           tracer()->NewSpaceAllocationThroughputInBytesPerMillisecond());
 
-  double idle_time_in_ms = deadline_in_ms - MonotonicallyIncreasingTimeInMs();
   GCIdleTimeAction action =
       gc_idle_time_handler_.Compute(idle_time_in_ms, heap_state);
   isolate()->counters()->gc_idle_time_allotted_in_ms()->AddSample(
@@ -5192,21 +5198,37 @@ int64_t Heap::PromotedExternalMemorySize() {
 }
 
 
-intptr_t Heap::OldGenerationAllocationLimit(intptr_t old_gen_size,
-                                            int freed_global_handles) {
+intptr_t Heap::CalculateOldGenerationAllocationLimit(double factor,
+                                                     intptr_t old_gen_size) {
+  CHECK(factor > 1.0);
+  CHECK(old_gen_size > 0);
+  intptr_t limit = static_cast<intptr_t>(old_gen_size * factor);
+  limit = Max(limit, kMinimumOldGenerationAllocationLimit);
+  limit += new_space_.Capacity();
+  intptr_t halfway_to_the_max = (old_gen_size + max_old_generation_size_) / 2;
+  return Min(limit, halfway_to_the_max);
+}
+
+
+void Heap::SetOldGenerationAllocationLimit(intptr_t old_gen_size,
+                                           int freed_global_handles) {
   const int kMaxHandles = 1000;
   const int kMinHandles = 100;
-  double min_factor = 1.1;
+  const double min_factor = 1.1;
   double max_factor = 4;
+  const double idle_max_factor = 1.5;
   // We set the old generation growing factor to 2 to grow the heap slower on
   // memory-constrained devices.
   if (max_old_generation_size_ <= kMaxOldSpaceSizeMediumMemoryDevice) {
     max_factor = 2;
   }
+
   // If there are many freed global handles, then the next full GC will
   // likely collect a lot of garbage. Choose the heap growing factor
   // depending on freed global handles.
   // TODO(ulan, hpayer): Take into account mutator utilization.
+  // TODO(hpayer): The idle factor could make the handles heuristic obsolete.
+  // Look into that.
   double factor;
   if (freed_global_handles <= kMinHandles) {
     factor = max_factor;
@@ -5225,11 +5247,10 @@ intptr_t Heap::OldGenerationAllocationLimit(intptr_t old_gen_size,
     factor = min_factor;
   }
 
-  intptr_t limit = static_cast<intptr_t>(old_gen_size * factor);
-  limit = Max(limit, kMinimumOldGenerationAllocationLimit);
-  limit += new_space_.Capacity();
-  intptr_t halfway_to_the_max = (old_gen_size + max_old_generation_size_) / 2;
-  return Min(limit, halfway_to_the_max);
+  old_generation_allocation_limit_ =
+      CalculateOldGenerationAllocationLimit(factor, old_gen_size);
+  idle_old_generation_allocation_limit_ = CalculateOldGenerationAllocationLimit(
+      Min(factor, idle_max_factor), old_gen_size);
 }
 
 

src/heap/heap.h

@@ -634,6 +634,10 @@ class Heap {
   // Returns of size of all objects residing in the heap.
   intptr_t SizeOfObjects();
 
+  intptr_t old_generation_allocation_limit() const {
+    return old_generation_allocation_limit_;
+  }
+
   // Return the starting address and a mask for the new space.  And-masking an
   // address with the mask will result in the start address of the new space
   // for all addresses in either semispace.
@@ -1120,8 +1124,14 @@ class Heap {
   static const int kMaxExecutableSizeHugeMemoryDevice =
       256 * kPointerMultiplier;
 
-  intptr_t OldGenerationAllocationLimit(intptr_t old_gen_size,
-                                        int freed_global_handles);
+  // Calculates the allocation limit based on a given growing factor and a
+  // given old generation size.
+  intptr_t CalculateOldGenerationAllocationLimit(double factor,
+                                                 intptr_t old_gen_size);
+
+  // Sets the allocation limit to trigger the next full garbage collection.
+  void SetOldGenerationAllocationLimit(intptr_t old_gen_size,
+                                       int freed_global_handles);
 
   // Indicates whether inline bump-pointer allocation has been disabled.
   bool inline_allocation_disabled() { return inline_allocation_disabled_; }
@@ -1231,13 +1241,12 @@ class Heap {
     survived_since_last_expansion_ += survived;
   }
 
-  inline bool NextGCIsLikelyToBeFull() {
+  inline bool NextGCIsLikelyToBeFull(intptr_t limit) {
     if (FLAG_gc_global) return true;
 
     if (FLAG_stress_compaction && (gc_count_ & 1) != 0) return true;
 
-    intptr_t adjusted_allocation_limit =
-        old_generation_allocation_limit_ - new_space_.Capacity();
+    intptr_t adjusted_allocation_limit = limit - new_space_.Capacity();
 
     if (PromotedTotalSize() >= adjusted_allocation_limit) return true;
 
@@ -1640,6 +1649,10 @@ class Heap {
   // generation and on every allocation in large object space.
   intptr_t old_generation_allocation_limit_;
 
+  // The allocation limit when there is >16.66ms idle time in the idle time
+  // handler.
+  intptr_t idle_old_generation_allocation_limit_;
+
   // Indicates that an allocation has failed in the old generation since the
   // last GC.
   bool old_gen_exhausted_;

src/heap/incremental-marking.cc

@@ -387,7 +387,9 @@ void IncrementalMarking::ActivateIncrementalWriteBarrier() {
 
 
 bool IncrementalMarking::ShouldActivate() {
-  return WorthActivating() && heap_->NextGCIsLikelyToBeFull();
+  return WorthActivating() &&
+         heap_->NextGCIsLikelyToBeFull(
+             heap_->old_generation_allocation_limit());
 }