[heap] New heuristics for incremental marking step size.

src/heap/heap.cc

 // Copyright 2012 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/heap.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/ast/context-slot-cache.h"
 #include "src/base/bits.h"
@@ skipping 97 matching lines @@
       ms_count_(0),
       gc_count_(0),
       remembered_unmapped_pages_index_(0),
 #ifdef DEBUG
       allocation_timeout_(0),
 #endif  // DEBUG
       old_generation_allocation_limit_(initial_old_generation_size_),
       inline_allocation_disabled_(false),
       total_regexp_code_generated_(0),
       tracer_(nullptr),
-      high_survival_rate_period_length_(0),
       promoted_objects_size_(0),
       promotion_ratio_(0),
       semi_space_copied_object_size_(0),
       previous_semi_space_copied_object_size_(0),
       semi_space_copied_rate_(0),
       nodes_died_in_new_space_(0),
       nodes_copied_in_new_space_(0),
       nodes_promoted_(0),
       maximum_size_scavenges_(0),
       max_gc_pause_(0.0),
@@ skipping 1140 matching lines @@
   } else {
     promotion_rate_ = 0;
   }
 
   semi_space_copied_rate_ =
       (static_cast<double>(semi_space_copied_object_size_) /
        static_cast<double>(start_new_space_size) * 100);
 
   double survival_rate = promotion_ratio_ + semi_space_copied_rate_;
   tracer()->AddSurvivalRatio(survival_rate);
-  if (survival_rate > kYoungSurvivalRateHighThreshold) {
-    high_survival_rate_period_length_++;
-  } else {
-    high_survival_rate_period_length_ = 0;
-  }
 }
 
 bool Heap::PerformGarbageCollection(
     GarbageCollector collector, const v8::GCCallbackFlags gc_callback_flags) {
   int freed_global_handles = 0;
 
   if (collector != SCAVENGER) {
     PROFILE(isolate_, CodeMovingGCEvent());
   }
 
@@ skipping 16 matching lines @@
       VMState<EXTERNAL> state(isolate_);
       HandleScope handle_scope(isolate_);
       CallGCPrologueCallbacks(gc_type, kNoGCCallbackFlags);
     }
   }
 
   EnsureFromSpaceIsCommitted();
 
   int start_new_space_size = Heap::new_space()->SizeAsInt();
 
-  if (IsHighSurvivalRate()) {
-    // We speed up the incremental marker if it is running so that it
-    // does not fall behind the rate of promotion, which would cause a
-    // constantly growing old space.
-    incremental_marking()->NotifyOfHighPromotionRate();
-  }
-
   {
     Heap::PretenuringScope pretenuring_scope(this);
 
     if (collector == MARK_COMPACTOR) {
       UpdateOldGenerationAllocationCounter();
       // Perform mark-sweep with optional compaction.
       MarkCompact();
       old_generation_size_configured_ = true;
       // This should be updated before PostGarbageCollectionProcessing, which
       // can cause another GC. Take into account the objects promoted during GC.
@@ skipping 5219 matching lines @@
 }
 
 
 // static
 int Heap::GetStaticVisitorIdForMap(Map* map) {
   return StaticVisitorBase::GetVisitorId(map);
 }
 
 }  // namespace internal
 }  // namespace v8