Distinguish beween final incremental mark-compact and full mark-compact event in IdleNotification.

BUG=

Review URL: https://codereview.chromium.org/727323004

Cr-Commit-Position: refs/heads/master@{#25501}

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

@@ -11,6 +11,7 @@ namespace internal {
 
 const double GCIdleTimeHandler::kConservativeTimeRatio = 0.9;
 const size_t GCIdleTimeHandler::kMaxMarkCompactTimeInMs = 1000;
+const size_t GCIdleTimeHandler::kMaxFinalIncrementalMarkCompactTimeInMs = 1000;
 const size_t GCIdleTimeHandler::kMinTimeForFinalizeSweeping = 100;
 const int GCIdleTimeHandler::kMaxMarkCompactsInIdleRound = 7;
 const int GCIdleTimeHandler::kIdleScavengeThreshold = 5;
@@ -84,8 +85,7 @@ size_t GCIdleTimeHandler::EstimateMarkingStepSize(
 size_t GCIdleTimeHandler::EstimateMarkCompactTime(
     size_t size_of_objects, size_t mark_compact_speed_in_bytes_per_ms) {
   // TODO(hpayer): Be more precise about the type of mark-compact event. It
-  // makes a huge difference if it is incremental or non-incremental and if
-  // compaction is happening.
+  // makes a huge difference if compaction is happening.
   if (mark_compact_speed_in_bytes_per_ms == 0) {
     mark_compact_speed_in_bytes_per_ms = kInitialConservativeMarkCompactSpeed;
   }
@@ -94,6 +94,19 @@ size_t GCIdleTimeHandler::EstimateMarkCompactTime(
 }
 
 
+size_t GCIdleTimeHandler::EstimateFinalIncrementalMarkCompactTime(
+    size_t size_of_objects,
+    size_t final_incremental_mark_compact_speed_in_bytes_per_ms) {
+  if (final_incremental_mark_compact_speed_in_bytes_per_ms == 0) {
+    final_incremental_mark_compact_speed_in_bytes_per_ms =
+        kInitialConservativeFinalIncrementalMarkCompactSpeed;
+  }
+  size_t result =
+      size_of_objects / final_incremental_mark_compact_speed_in_bytes_per_ms;
+  return Min(result, kMaxFinalIncrementalMarkCompactTimeInMs);
+}
+
+
 bool GCIdleTimeHandler::ShouldDoScavenge(
     size_t idle_time_in_ms, size_t new_space_size, size_t used_new_space_size,
     size_t scavenge_speed_in_bytes_per_ms,
@@ -149,6 +162,16 @@ bool GCIdleTimeHandler::ShouldDoContextDisposalMarkCompact(
 }
 
 
+bool GCIdleTimeHandler::ShouldDoFinalIncrementalMarkCompact(
+    size_t idle_time_in_ms, size_t size_of_objects,
+    size_t final_incremental_mark_compact_speed_in_bytes_per_ms) {
+  return idle_time_in_ms >=
+         EstimateFinalIncrementalMarkCompactTime(
+             size_of_objects,
+             final_incremental_mark_compact_speed_in_bytes_per_ms);
+}
+
+
 // The following logic is implemented by the controller:
 // (1) If we don't have any idle time, do nothing, unless a context was
 // disposed, incremental marking is stopped, and the heap is small. Then do

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

@@ -92,9 +92,18 @@ class GCIdleTimeHandler {
   // conservative lower bound for the mark-compact speed.
   static const size_t kInitialConservativeMarkCompactSpeed = 2 * MB;
 
+  // If we haven't recorded any final incremental mark-compact events yet, we
+  // use conservative lower bound for the mark-compact speed.
+  static const size_t kInitialConservativeFinalIncrementalMarkCompactSpeed =
+      2 * MB;
+
   // Maximum mark-compact time returned by EstimateMarkCompactTime.
   static const size_t kMaxMarkCompactTimeInMs;
 
+  // Maximum final incremental mark-compact time returned by
+  // EstimateFinalIncrementalMarkCompactTime.
+  static const size_t kMaxFinalIncrementalMarkCompactTimeInMs;
+
   // Minimum time to finalize sweeping phase. The main thread may wait for
   // sweeper threads.
   static const size_t kMinTimeForFinalizeSweeping;
@@ -128,6 +137,7 @@ class GCIdleTimeHandler {
     bool sweeping_in_progress;
     size_t mark_compact_speed_in_bytes_per_ms;
     size_t incremental_marking_speed_in_bytes_per_ms;
+    size_t final_incremental_mark_compact_speed_in_bytes_per_ms;
     size_t scavenge_speed_in_bytes_per_ms;
     size_t used_new_space_size;
     size_t new_space_capacity;
@@ -158,6 +168,9 @@ class GCIdleTimeHandler {
   static size_t EstimateMarkCompactTime(
       size_t size_of_objects, size_t mark_compact_speed_in_bytes_per_ms);
 
+  static size_t EstimateFinalIncrementalMarkCompactTime(
+      size_t size_of_objects, size_t mark_compact_speed_in_bytes_per_ms);
+
   static bool ShouldDoMarkCompact(size_t idle_time_in_ms,
                                   size_t size_of_objects,
                                   size_t mark_compact_speed_in_bytes_per_ms);
@@ -165,6 +178,10 @@ class GCIdleTimeHandler {
   static bool ShouldDoContextDisposalMarkCompact(bool context_disposed,
                                                  double contexts_disposal_rate);
 
+  static bool ShouldDoFinalIncrementalMarkCompact(
+      size_t idle_time_in_ms, size_t size_of_objects,
+      size_t final_incremental_mark_compact_speed_in_bytes_per_ms);
+
   static bool ShouldDoScavenge(
       size_t idle_time_in_ms, size_t new_space_size, size_t used_new_space_size,
       size_t scavenger_speed_in_bytes_per_ms,

src/heap/gc-tracer.cc

@@ -68,6 +68,7 @@ const char* GCTracer::Event::TypeName(bool short_name) const {
         return "Scavenge";
       }
     case MARK_COMPACTOR:
+    case INCREMENTAL_MARK_COMPACTOR:
       if (short_name) {
         return "ms";
       } else {
@@ -96,7 +97,7 @@ GCTracer::GCTracer(Heap* heap)
       new_space_top_after_gc_(0) {
   current_ = Event(Event::START, NULL, NULL);
   current_.end_time = base::OS::TimeCurrentMillis();
-  previous_ = previous_mark_compactor_event_ = current_;
+  previous_ = previous_incremental_mark_compactor_event_ = current_;
 }
 
 
@@ -110,13 +111,18 @@ void GCTracer::Start(GarbageCollector collector, const char* gc_reason,
         reinterpret_cast<intptr_t>((heap_->new_space()->top()) -
                                    new_space_top_after_gc_));
   }
-  if (current_.type == Event::MARK_COMPACTOR)
-    previous_mark_compactor_event_ = current_;
+  if (current_.type == Event::INCREMENTAL_MARK_COMPACTOR)
+    previous_incremental_mark_compactor_event_ = current_;
 
   if (collector == SCAVENGER) {
     current_ = Event(Event::SCAVENGER, gc_reason, collector_reason);
-  } else {
-    current_ = Event(Event::MARK_COMPACTOR, gc_reason, collector_reason);
+  } else if (collector == MARK_COMPACTOR) {
+    if (heap_->incremental_marking()->IsMarking()) {
+      current_ =
+          Event(Event::INCREMENTAL_MARK_COMPACTOR, gc_reason, collector_reason);
+    } else {
+      current_ = Event(Event::MARK_COMPACTOR, gc_reason, collector_reason);
+    }
   }
 
   current_.start_time = start_time;
@@ -164,21 +170,30 @@ void GCTracer::Stop() {
         current_.cumulative_pure_incremental_marking_duration -
         previous_.cumulative_pure_incremental_marking_duration;
     scavenger_events_.push_front(current_);
-  } else {
+  } else if (current_.type == Event::INCREMENTAL_MARK_COMPACTOR) {
     current_.incremental_marking_steps =
         current_.cumulative_incremental_marking_steps -
-        previous_mark_compactor_event_.cumulative_incremental_marking_steps;
+        previous_incremental_mark_compactor_event_
+            .cumulative_incremental_marking_steps;
     current_.incremental_marking_bytes =
         current_.cumulative_incremental_marking_bytes -
-        previous_mark_compactor_event_.cumulative_incremental_marking_bytes;
+        previous_incremental_mark_compactor_event_
+            .cumulative_incremental_marking_bytes;
     current_.incremental_marking_duration =
         current_.cumulative_incremental_marking_duration -
-        previous_mark_compactor_event_.cumulative_incremental_marking_duration;
+        previous_incremental_mark_compactor_event_
+            .cumulative_incremental_marking_duration;
     current_.pure_incremental_marking_duration =
         current_.cumulative_pure_incremental_marking_duration -
-        previous_mark_compactor_event_
+        previous_incremental_mark_compactor_event_
             .cumulative_pure_incremental_marking_duration;
     longest_incremental_marking_step_ = 0.0;
+    incremental_mark_compactor_events_.push_front(current_);
+  } else {
+    DCHECK(current_.incremental_marking_bytes == 0);
+    DCHECK(current_.incremental_marking_duration == 0);
+    DCHECK(current_.pure_incremental_marking_duration == 0);
+    DCHECK(longest_incremental_marking_step_ == 0.0);
     mark_compactor_events_.push_front(current_);
   }
 
@@ -381,15 +396,15 @@ double GCTracer::MeanIncrementalMarkingDuration() const {
 
   // We haven't completed an entire round of incremental marking, yet.
   // Use data from GCTracer instead of data from event buffers.
-  if (mark_compactor_events_.empty()) {
+  if (incremental_mark_compactor_events_.empty()) {
     return cumulative_incremental_marking_duration_ /
            cumulative_incremental_marking_steps_;
   }
 
   int steps = 0;
   double durations = 0.0;
-  EventBuffer::const_iterator iter = mark_compactor_events_.begin();
-  while (iter != mark_compactor_events_.end()) {
+  EventBuffer::const_iterator iter = incremental_mark_compactor_events_.begin();
+  while (iter != incremental_mark_compactor_events_.end()) {
     steps += iter->incremental_marking_steps;
     durations += iter->incremental_marking_duration;
     ++iter;
@@ -404,11 +419,12 @@ double GCTracer::MeanIncrementalMarkingDuration() const {
 double GCTracer::MaxIncrementalMarkingDuration() const {
   // We haven't completed an entire round of incremental marking, yet.
   // Use data from GCTracer instead of data from event buffers.
-  if (mark_compactor_events_.empty()) return longest_incremental_marking_step_;
+  if (incremental_mark_compactor_events_.empty())
+    return longest_incremental_marking_step_;
 
   double max_duration = 0.0;
-  EventBuffer::const_iterator iter = mark_compactor_events_.begin();
-  while (iter != mark_compactor_events_.end())
+  EventBuffer::const_iterator iter = incremental_mark_compactor_events_.begin();
+  while (iter != incremental_mark_compactor_events_.end())
     max_duration = Max(iter->longest_incremental_marking_step, max_duration);
 
   return max_duration;
@@ -420,15 +436,15 @@ intptr_t GCTracer::IncrementalMarkingSpeedInBytesPerMillisecond() const {
 
   // We haven't completed an entire round of incremental marking, yet.
   // Use data from GCTracer instead of data from event buffers.
-  if (mark_compactor_events_.empty()) {
+  if (incremental_mark_compactor_events_.empty()) {
     return static_cast<intptr_t>(cumulative_incremental_marking_bytes_ /
                                  cumulative_pure_incremental_marking_duration_);
   }
 
   intptr_t bytes = 0;
   double durations = 0.0;
-  EventBuffer::const_iterator iter = mark_compactor_events_.begin();
-  while (iter != mark_compactor_events_.end()) {
+  EventBuffer::const_iterator iter = incremental_mark_compactor_events_.begin();
+  while (iter != incremental_mark_compactor_events_.end()) {
     bytes += iter->incremental_marking_bytes;
     durations += iter->pure_incremental_marking_duration;
     ++iter;
@@ -462,8 +478,24 @@ intptr_t GCTracer::MarkCompactSpeedInBytesPerMillisecond() const {
   EventBuffer::const_iterator iter = mark_compactor_events_.begin();
   while (iter != mark_compactor_events_.end()) {
     bytes += iter->start_object_size;
-    durations += iter->end_time - iter->start_time +
-                 iter->pure_incremental_marking_duration;
+    durations += iter->end_time - iter->start_time;
+    ++iter;
+  }
+
+  if (durations == 0.0) return 0;
+
+  return static_cast<intptr_t>(bytes / durations);
+}
+
+
+intptr_t GCTracer::FinalIncrementalMarkCompactSpeedInBytesPerMillisecond()
+    const {
+  intptr_t bytes = 0;
+  double durations = 0.0;
+  EventBuffer::const_iterator iter = incremental_mark_compactor_events_.begin();
+  while (iter != incremental_mark_compactor_events_.end()) {
+    bytes += iter->start_object_size;
+    durations += iter->end_time - iter->start_time;
     ++iter;
   }
 

src/heap/gc-tracer.h

@@ -160,7 +160,12 @@ class GCTracer {
 
   class Event {
    public:
-    enum Type { SCAVENGER = 0, MARK_COMPACTOR = 1, START = 2 };
+    enum Type {
+      SCAVENGER = 0,
+      MARK_COMPACTOR = 1,
+      INCREMENTAL_MARK_COMPACTOR = 2,
+      START = 3
+    };
 
     // Default constructor leaves the event uninitialized.
     Event() {}
@@ -211,7 +216,8 @@ class GCTracer {
 
     // Incremental marking steps since
     // - last event for SCAVENGER events
-    // - last MARK_COMPACTOR event for MARK_COMPACTOR events
+    // - last INCREMENTAL_MARK_COMPACTOR event for INCREMENTAL_MARK_COMPACTOR
+    // events
     int incremental_marking_steps;
 
     // Bytes marked since creation of tracer (value at start of event).
@@ -219,7 +225,8 @@ class GCTracer {
 
     // Bytes marked since
     // - last event for SCAVENGER events
-    // - last MARK_COMPACTOR event for MARK_COMPACTOR events
+    // - last INCREMENTAL_MARK_COMPACTOR event for INCREMENTAL_MARK_COMPACTOR
+    // events
     intptr_t incremental_marking_bytes;
 
     // Cumulative duration of incremental marking steps since creation of
@@ -228,7 +235,8 @@ class GCTracer {
 
     // Duration of incremental marking steps since
     // - last event for SCAVENGER events
-    // - last MARK_COMPACTOR event for MARK_COMPACTOR events
+    // - last INCREMENTAL_MARK_COMPACTOR event for INCREMENTAL_MARK_COMPACTOR
+    // events
     double incremental_marking_duration;
 
     // Cumulative pure duration of incremental marking steps since creation of
@@ -237,7 +245,8 @@ class GCTracer {
 
     // Duration of pure incremental marking steps since
     // - last event for SCAVENGER events
-    // - last MARK_COMPACTOR event for MARK_COMPACTOR events
+    // - last INCREMENTAL_MARK_COMPACTOR event for INCREMENTAL_MARK_COMPACTOR
+    // events
     double pure_incremental_marking_duration;
 
     // Longest incremental marking step since start of marking.
@@ -316,6 +325,12 @@ class GCTracer {
     return MaxDuration(mark_compactor_events_);
   }
 
+  // Compute the mean duration of the last incremental mark compactor
+  // events. Returns 0 if no events have been recorded.
+  double MeanIncrementalMarkCompactorDuration() const {
+    return MeanDuration(incremental_mark_compactor_events_);
+  }
+
   // Compute the mean step duration of the last incremental marking round.
   // Returns 0 if no incremental marking round has been completed.
   double MeanIncrementalMarkingDuration() const;
@@ -332,10 +347,15 @@ class GCTracer {
   // Returns 0 if no events have been recorded.
   intptr_t ScavengeSpeedInBytesPerMillisecond() const;
 
-  // Compute the max mark-sweep speed in bytes/millisecond.
+  // Compute the average mark-sweep speed in bytes/millisecond.
   // Returns 0 if no events have been recorded.
   intptr_t MarkCompactSpeedInBytesPerMillisecond() const;
 
+  // Compute the average incremental mark-sweep finalize speed in
+  // bytes/millisecond.
+  // Returns 0 if no events have been recorded.
+  intptr_t FinalIncrementalMarkCompactSpeedInBytesPerMillisecond() const;
+
   // Allocation throughput in the new space in bytes/millisecond.
   // Returns 0 if no events have been recorded.
   intptr_t NewSpaceAllocationThroughputInBytesPerMillisecond() const;
@@ -361,6 +381,16 @@ class GCTracer {
   // Compute the max duration of the events in the given ring buffer.
   double MaxDuration(const EventBuffer& events) const;
 
+  void ClearMarkCompactStatistics() {
+    cumulative_incremental_marking_steps_ = 0;
+    cumulative_incremental_marking_bytes_ = 0;
+    cumulative_incremental_marking_duration_ = 0;
+    cumulative_pure_incremental_marking_duration_ = 0;
+    longest_incremental_marking_step_ = 0;
+    cumulative_marking_duration_ = 0;
+    cumulative_sweeping_duration_ = 0;
+  }
+
   // Pointer to the heap that owns this tracer.
   Heap* heap_;
 
@@ -371,8 +401,8 @@ class GCTracer {
   // Previous tracer event.
   Event previous_;
 
-  // Previous MARK_COMPACTOR event.
-  Event previous_mark_compactor_event_;
+  // Previous INCREMENTAL_MARK_COMPACTOR event.
+  Event previous_incremental_mark_compactor_event_;
 
   // RingBuffers for SCAVENGER events.
   EventBuffer scavenger_events_;
@@ -380,6 +410,9 @@ class GCTracer {
   // RingBuffers for MARK_COMPACTOR events.
   EventBuffer mark_compactor_events_;
 
+  // RingBuffers for INCREMENTAL_MARK_COMPACTOR events.
+  EventBuffer incremental_mark_compactor_events_;
+
   // RingBuffer for allocation events.
   AllocationEventBuffer allocation_events_;
 

src/heap/heap.cc

@@ -4374,12 +4374,12 @@ void Heap::IdleMarkCompact(const char* message) {
 
 void Heap::TryFinalizeIdleIncrementalMarking(
     size_t idle_time_in_ms, size_t size_of_objects,
-    size_t mark_compact_speed_in_bytes_per_ms) {
+    size_t final_incremental_mark_compact_speed_in_bytes_per_ms) {
   if (incremental_marking()->IsComplete() ||
       (mark_compact_collector()->IsMarkingDequeEmpty() &&
-       gc_idle_time_handler_.ShouldDoMarkCompact(
+       gc_idle_time_handler_.ShouldDoFinalIncrementalMarkCompact(
            idle_time_in_ms, size_of_objects,
-           mark_compact_speed_in_bytes_per_ms))) {
+           final_incremental_mark_compact_speed_in_bytes_per_ms))) {
     IdleMarkCompact("idle notification: finalize incremental");
   }
 }
@@ -4414,6 +4414,9 @@ bool Heap::IdleNotification(int idle_time_in_ms) {
       static_cast<size_t>(tracer()->MarkCompactSpeedInBytesPerMillisecond());
   heap_state.incremental_marking_speed_in_bytes_per_ms = static_cast<size_t>(
       tracer()->IncrementalMarkingSpeedInBytesPerMillisecond());
+  heap_state.final_incremental_mark_compact_speed_in_bytes_per_ms =
+      static_cast<size_t>(
+          tracer()->FinalIncrementalMarkCompactSpeedInBytesPerMillisecond());
   heap_state.scavenge_speed_in_bytes_per_ms =
       static_cast<size_t>(tracer()->ScavengeSpeedInBytesPerMillisecond());
   heap_state.used_new_space_size = new_space_.Size();
@@ -4444,7 +4447,7 @@ bool Heap::IdleNotification(int idle_time_in_ms) {
       if (remaining_idle_time_in_ms > 0) {
         TryFinalizeIdleIncrementalMarking(
             remaining_idle_time_in_ms, heap_state.size_of_objects,
-            heap_state.mark_compact_speed_in_bytes_per_ms);
+            heap_state.final_incremental_mark_compact_speed_in_bytes_per_ms);
       }
       break;
     }

test/unittests/heap/gc-idle-time-handler-unittest.cc

@@ -180,6 +180,20 @@ TEST_F(GCIdleTimeHandlerTest, DontDoMarkCompact) {
 }
 
 
+TEST_F(GCIdleTimeHandlerTest, ShouldDoFinalIncrementalMarkCompact) {
+  size_t idle_time_in_ms = 16;
+  EXPECT_TRUE(GCIdleTimeHandler::ShouldDoFinalIncrementalMarkCompact(
+      idle_time_in_ms, 0, 0));
+}
+
+
+TEST_F(GCIdleTimeHandlerTest, DontDoFinalIncrementalMarkCompact) {
+  size_t idle_time_in_ms = 1;
+  EXPECT_FALSE(GCIdleTimeHandler::ShouldDoFinalIncrementalMarkCompact(
+      idle_time_in_ms, kSizeOfObjects, kMarkingSpeed));
+}
+
+
 TEST_F(GCIdleTimeHandlerTest, ContextDisposeLowRate) {
   GCIdleTimeHandler::HeapState heap_state = DefaultHeapState();
   heap_state.contexts_disposed = 1;