Use more conservative average promotion ratio for initial heap size.

src/heap/gc-tracer.cc

Index: src/heap/gc-tracer.cc
diff --git a/src/heap/gc-tracer.cc b/src/heap/gc-tracer.cc
index a35872dc47e1380311f19d1415a22292505169db..d46ed239c99ce5e9cc3f56d253be10f0fb157ffe 100644
--- a/src/heap/gc-tracer.cc
+++ b/src/heap/gc-tracer.cc
@@ -31,8 +31,8 @@ GCTracer::ContextDisposalEvent::ContextDisposalEvent(double time) {
 }
 
 
-GCTracer::SurvivalEvent::SurvivalEvent(double survival_rate) {
-  survival_rate_ = survival_rate;
+GCTracer::PromotionEvent::PromotionEvent(double promotion_ratio) {
+  promotion_ratio_ = promotion_ratio;
 }
 
 
@@ -257,8 +257,8 @@ void GCTracer::AddContextDisposalTime(double 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));
 }
 
 
@@ -372,9 +372,9 @@ void GCTracer::PrintNVP() const {
   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());
@@ -570,25 +570,25 @@ double GCTracer::ContextDisposalRateInMilliseconds() const {
 }
 
 
-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