Use more conservative average promotion ratio for initial heap size.

src/heap/gc-tracer.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/v8.h"
 
 #include "src/heap/gc-tracer.h"
 
 namespace v8 {
 namespace internal {
@@ skipping 13 matching lines @@
   duration_ = duration;
   allocation_in_bytes_ = allocation_in_bytes;
 }
 
 
 GCTracer::ContextDisposalEvent::ContextDisposalEvent(double time) {
   time_ = time;
 }
 
 
-GCTracer::SurvivalEvent::SurvivalEvent(double survival_rate) {
-  survival_rate_ = survival_rate;
+GCTracer::PromotionEvent::PromotionEvent(double promotion_ratio) {
+  promotion_ratio_ = promotion_ratio;
 }
 
 
 GCTracer::Event::Event(Type type, const char* gc_reason,
                        const char* collector_reason)
     : type(type),
       gc_reason(gc_reason),
       collector_reason(collector_reason),
       start_time(0.0),
       end_time(0.0),
@@ skipping 204 matching lines @@
                                          intptr_t allocation_in_bytes) {
   allocation_events_.push_front(AllocationEvent(duration, allocation_in_bytes));
 }
 
 
 void GCTracer::AddContextDisposalTime(double time) {
   context_disposal_events_.push_front(ContextDisposalEvent(time));
 }
 
 
-void GCTracer::AddSurvivalRate(double survival_rate) {
-  survival_events_.push_front(SurvivalEvent(survival_rate));
+void GCTracer::AddPromotionRatio(double promotion_ratio) {
+  promotion_events_.push_front(PromotionEvent(promotion_ratio));
 }
 
 
 void GCTracer::AddIncrementalMarkingStep(double duration, intptr_t bytes) {
   cumulative_incremental_marking_steps_++;
   cumulative_incremental_marking_bytes_ += bytes;
   cumulative_incremental_marking_duration_ += duration;
   longest_incremental_marking_step_ =
       Max(longest_incremental_marking_step_, duration);
   cumulative_marking_duration_ += duration;
@@ skipping 93 matching lines @@
   intptr_t allocated_since_last_gc =
       current_.start_object_size - previous_.end_object_size;
   PrintF("allocated=%" V8_PTR_PREFIX "d ", allocated_since_last_gc);
   PrintF("promoted=%" V8_PTR_PREFIX "d ", heap_->promoted_objects_size_);
   PrintF("semi_space_copied=%" V8_PTR_PREFIX "d ",
          heap_->semi_space_copied_object_size_);
   PrintF("nodes_died_in_new=%d ", heap_->nodes_died_in_new_space_);
   PrintF("nodes_copied_in_new=%d ", heap_->nodes_copied_in_new_space_);
   PrintF("nodes_promoted=%d ", heap_->nodes_promoted_);
   PrintF("promotion_ratio=%.1f%% ", heap_->promotion_ratio_);
+  PrintF("average_promotion_ratio=%.1f%% ", AveragePromotionRatio());
   PrintF("promotion_rate=%.1f%% ", heap_->promotion_rate_);
   PrintF("semi_space_copy_rate=%.1f%% ", heap_->semi_space_copied_rate_);
-  PrintF("average_survival_rate%.1f%% ", AverageSurvivalRate());
   PrintF("new_space_allocation_throughput=%" V8_PTR_PREFIX "d ",
          NewSpaceAllocationThroughputInBytesPerMillisecond());
   PrintF("context_disposal_rate=%.1f ", ContextDisposalRateInMilliseconds());
 
   if (current_.type == Event::SCAVENGER) {
     PrintF("steps_count=%d ", current_.incremental_marking_steps);
     PrintF("steps_took=%.1f ", current_.incremental_marking_duration);
     PrintF("scavenge_throughput=%" V8_PTR_PREFIX "d ",
            ScavengeSpeedInBytesPerMillisecond());
   } else {
@@ skipping 175 matching lines @@
       context_disposal_events_.begin();
   while (iter != context_disposal_events_.end()) {
     end = iter->time_;
     ++iter;
   }
 
   return (begin - end) / context_disposal_events_.size();
 }
 
 
-double GCTracer::AverageSurvivalRate() const {
-  if (survival_events_.size() == 0) return 0.0;
+double GCTracer::AveragePromotionRatio() const {
+  if (promotion_events_.size() == 0) return 0.0;
 
   double sum_of_rates = 0.0;
-  SurvivalEventBuffer::const_iterator iter = survival_events_.begin();
-  while (iter != survival_events_.end()) {
-    sum_of_rates += iter->survival_rate_;
+  PromotionEventBuffer::const_iterator iter = promotion_events_.begin();
+  while (iter != promotion_events_.end()) {
+    sum_of_rates += iter->promotion_ratio_;
     ++iter;
   }
 
-  return sum_of_rates / static_cast<double>(survival_events_.size());
+  return sum_of_rates / static_cast<double>(promotion_events_.size());
 }
 
 
 bool GCTracer::SurvivalEventsRecorded() const {
-  return survival_events_.size() > 0;
+  return promotion_events_.size() > 0;
 }
 
 
-void GCTracer::ResetSurvivalEvents() { survival_events_.reset(); }
+void GCTracer::ResetSurvivalEvents() { promotion_events_.reset(); }
 }
 }  // namespace v8::internal