Re-land: Distinguish beween final incremental mark-compact and full mark-compact event in IdleNotif…

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

 // Copyright 2014 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/gc-idle-time-handler.h"
 #include "src/heap/gc-tracer.h"
 #include "src/utils.h"
 
 namespace v8 {
 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;
 const double GCIdleTimeHandler::kHighContextDisposalRate = 100;
 
 
 void GCIdleTimeAction::Print() {
   switch (type) {
     case DONE:
       PrintF("done");
@@ skipping 53 matching lines @@
   if (marking_step_size > kMaximumMarkingStepSize)
     return kMaximumMarkingStepSize;
 
   return static_cast<size_t>(marking_step_size * kConservativeTimeRatio);
 }
 
 
 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;
   }
   size_t result = size_of_objects / mark_compact_speed_in_bytes_per_ms;
   return Min(result, kMaxMarkCompactTimeInMs);
 }
 
 
+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,
     size_t new_space_allocation_throughput_in_bytes_per_ms) {
   size_t new_space_allocation_limit =
       kMaxFrameRenderingIdleTime * scavenge_speed_in_bytes_per_ms;
 
   // If the limit is larger than the new space size, then scavenging used to be
   // really fast. We can take advantage of the whole new space.
   if (new_space_allocation_limit > new_space_size) {
@@ skipping 35 matching lines @@
 }
 
 
 bool GCIdleTimeHandler::ShouldDoContextDisposalMarkCompact(
     bool context_disposed, double contexts_disposal_rate) {
   return context_disposed && contexts_disposal_rate > 0 &&
          contexts_disposal_rate < kHighContextDisposalRate;
 }
 
 
+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
 // a full GC.
 // (2) If the new space is almost full and we can affort a Scavenge or if the
 // next Scavenge will very likely take long, then a Scavenge is performed.
 // (3) If there is currently no MarkCompact idle round going on, we start a
 // new idle round if enough garbage was created. Otherwise we do not perform
 // garbage collection to keep system utilization low.
 // (4) If incremental marking is done, we perform a full garbage collection
@@ skipping 62 matching lines @@
   if (heap_state.incremental_marking_stopped &&
       !heap_state.can_start_incremental_marking) {
     return GCIdleTimeAction::Nothing();
   }
   size_t step_size = EstimateMarkingStepSize(
       idle_time_in_ms, heap_state.incremental_marking_speed_in_bytes_per_ms);
   return GCIdleTimeAction::IncrementalMarking(step_size);
 }
 }
 }