Remove high promotion mode

src/heap/heap.cc

Index: src/heap/heap.cc
diff --git a/src/heap/heap.cc b/src/heap/heap.cc
index 3340a0fd384a3cdf8bb9e11a90b00f9f00b3b249..0740a13c092c372810db746a655aa714ff6e8007 100644
--- a/src/heap/heap.cc
+++ b/src/heap/heap.cc
@@ -115,12 +115,8 @@ Heap::Heap()
       gc_safe_size_of_old_object_(NULL),
       total_regexp_code_generated_(0),
       tracer_(this),
-      new_space_high_promotion_mode_active_(false),
-      gathering_lifetime_feedback_(0),
       high_survival_rate_period_length_(0),
       promoted_objects_size_(0),
-      low_survival_rate_period_length_(0),
-      survival_rate_(0),
       promotion_ratio_(0),
       semi_space_copied_object_size_(0),
       previous_semi_space_copied_object_size_(0),
@@ -129,8 +125,6 @@ Heap::Heap()
       nodes_copied_in_new_space_(0),
       nodes_promoted_(0),
       maximum_size_scavenges_(0),
-      previous_survival_rate_trend_(Heap::STABLE),
-      survival_rate_trend_(Heap::STABLE),
       max_gc_pause_(0.0),
       total_gc_time_ms_(0.0),
       max_alive_after_gc_(0),
@@ -1200,24 +1194,6 @@ void Heap::UpdateSurvivalStatistics(int start_new_space_size) {
   } else {
     high_survival_rate_period_length_ = 0;
   }
-
-  if (survival_rate < kYoungSurvivalRateLowThreshold) {
-    low_survival_rate_period_length_++;
-  } else {
-    low_survival_rate_period_length_ = 0;
-  }
-
-  double survival_rate_diff = survival_rate_ - survival_rate;
-
-  if (survival_rate_diff > kYoungSurvivalRateAllowedDeviation) {
-    set_survival_rate_trend(DECREASING);
-  } else if (survival_rate_diff < -kYoungSurvivalRateAllowedDeviation) {
-    set_survival_rate_trend(INCREASING);
-  } else {
-    set_survival_rate_trend(STABLE);
-  }
-
-  survival_rate_ = survival_rate;
 }
 
 bool Heap::PerformGarbageCollection(
@@ -1275,16 +1251,8 @@ bool Heap::PerformGarbageCollection(
     Scavenge();
   }
 
-  bool deopted = ProcessPretenuringFeedback();
+  ProcessPretenuringFeedback();
   UpdateSurvivalStatistics(start_new_space_size);
-
-  // When pretenuring is collecting new feedback, we do not shrink the new space
-  // right away.
-  if (deopted) {
-    RecordDeoptForPretenuring();
-  } else {
-    ConfigureNewGenerationSize();
-  }
   ConfigureInitialOldGenerationSize();
 
   isolate_->counters()->objs_since_last_young()->Set(0);
@@ -1509,8 +1477,7 @@ void Heap::CheckNewSpaceExpansionCriteria() {
       survived_since_last_expansion_ = 0;
     }
   } else if (new_space_.TotalCapacity() < new_space_.MaximumCapacity() &&
-             survived_since_last_expansion_ > new_space_.TotalCapacity() &&
-             !new_space_high_promotion_mode_active_) {
+             survived_since_last_expansion_ > new_space_.TotalCapacity()) {
     // Grow the size of new space if there is room to grow, and enough data
     // has survived scavenge since the last expansion.
     new_space_.Grow();
@@ -2664,48 +2631,6 @@ void Heap::ConfigureInitialOldGenerationSize() {
 }
 
 
-void Heap::ConfigureNewGenerationSize() {
-  bool still_gathering_lifetime_data = gathering_lifetime_feedback_ != 0;
-  if (gathering_lifetime_feedback_ != 0) gathering_lifetime_feedback_--;
-  if (!new_space_high_promotion_mode_active_ &&
-      new_space_.TotalCapacity() == new_space_.MaximumCapacity() &&
-      IsStableOrIncreasingSurvivalTrend() && IsHighSurvivalRate()) {
-    // Stable high survival rates even though young generation is at
-    // maximum capacity indicates that most objects will be promoted.
-    // To decrease scavenger pauses and final mark-sweep pauses, we
-    // have to limit maximal capacity of the young generation.
-    if (still_gathering_lifetime_data) {
-      if (FLAG_trace_gc) {
-        PrintPID(
-            "Postpone entering high promotion mode as optimized pretenuring "
-            "code is still being generated\n");
-      }
-    } else {
-      new_space_high_promotion_mode_active_ = true;
-      if (FLAG_trace_gc) {
-        PrintPID("Limited new space size due to high promotion rate: %d MB\n",
-                 new_space_.InitialTotalCapacity() / MB);
-      }
-    }
-  } else if (new_space_high_promotion_mode_active_ &&
-             IsStableOrDecreasingSurvivalTrend() && IsLowSurvivalRate()) {
-    // Decreasing low survival rates might indicate that the above high
-    // promotion mode is over and we should allow the young generation
-    // to grow again.
-    new_space_high_promotion_mode_active_ = false;
-    if (FLAG_trace_gc) {
-      PrintPID("Unlimited new space size due to low promotion rate: %d MB\n",
-               new_space_.MaximumCapacity() / MB);
-    }
-  }
-
-  if (new_space_high_promotion_mode_active_ &&
-      new_space_.TotalCapacity() > new_space_.InitialTotalCapacity()) {
-    new_space_.Shrink();
-  }
-}
-
-
 AllocationResult Heap::AllocatePartialMap(InstanceType instance_type,
                                           int instance_size) {
   Object* result = nullptr;