Reland Shrink initial old generation size based on new space survival rate.

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/v8.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/base/bits.h"
 #include "src/base/once.h"
@@ skipping 45 matching lines @@
       amount_of_external_allocated_memory_at_last_global_gc_(0),
       isolate_(NULL),
       code_range_size_(0),
       // semispace_size_ should be a power of 2 and old_generation_size_ should
       // be a multiple of Page::kPageSize.
       reserved_semispace_size_(8 * (kPointerSize / 4) * MB),
       max_semi_space_size_(8 * (kPointerSize / 4) * MB),
       initial_semispace_size_(Page::kPageSize),
       target_semispace_size_(Page::kPageSize),
       max_old_generation_size_(700ul * (kPointerSize / 4) * MB),
+      initial_old_generation_size_(max_old_generation_size_ / 2),
+      old_generation_size_configured_(false),
       max_executable_size_(256ul * (kPointerSize / 4) * MB),
       // Variables set based on semispace_size_ and old_generation_size_ in
       // ConfigureHeap.
       // Will be 4 * reserved_semispace_size_ to ensure that young
       // generation can be aligned to its size.
       maximum_committed_(0),
       survived_since_last_expansion_(0),
       survived_last_scavenge_(0),
       sweep_generation_(0),
       always_allocate_scope_depth_(0),
@@ skipping 14 matching lines @@
       allocations_count_(0),
       raw_allocations_hash_(0),
       dump_allocations_hash_countdown_(FLAG_dump_allocations_digest_at_alloc),
       ms_count_(0),
       gc_count_(0),
       remembered_unmapped_pages_index_(0),
       unflattened_strings_length_(0),
 #ifdef DEBUG
       allocation_timeout_(0),
 #endif  // DEBUG
-      old_generation_allocation_limit_(kMinimumOldGenerationAllocationLimit),
+      old_generation_allocation_limit_(initial_old_generation_size_),
       old_gen_exhausted_(false),
       inline_allocation_disabled_(false),
       store_buffer_rebuilder_(store_buffer()),
       hidden_string_(NULL),
       gc_safe_size_of_old_object_(NULL),
       total_regexp_code_generated_(0),
       tracer_(this),
       high_survival_rate_period_length_(0),
       promoted_objects_size_(0),
-      promotion_rate_(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),
       total_gc_time_ms_(0.0),
       max_alive_after_gc_(0),
       min_in_mutator_(kMaxInt),
       marking_time_(0.0),
@@ skipping 304 matching lines @@
 
 #ifdef VERIFY_HEAP
     if (FLAG_verify_heap) {
       Verify();
     }
 #endif
   }
 
   // Reset GC statistics.
   promoted_objects_size_ = 0;
+  previous_semi_space_copied_object_size_ = semi_space_copied_object_size_;
   semi_space_copied_object_size_ = 0;
   nodes_died_in_new_space_ = 0;
   nodes_copied_in_new_space_ = 0;
   nodes_promoted_ = 0;
 
   UpdateMaximumCommitted();
 
 #ifdef DEBUG
   DCHECK(!AllowHeapAllocation::IsAllowed() && gc_state_ == NOT_IN_GC);
 
@@ skipping 583 matching lines @@
       NormalizedMapCache::cast(cache)->Clear();
     }
     context = Context::cast(context)->get(Context::NEXT_CONTEXT_LINK);
   }
 }
 
 
 void Heap::UpdateSurvivalStatistics(int start_new_space_size) {
   if (start_new_space_size == 0) return;
 
-  promotion_rate_ = (static_cast<double>(promoted_objects_size_) /
-                     static_cast<double>(start_new_space_size) * 100);
+  promotion_ratio_ = (static_cast<double>(promoted_objects_size_) /
+                      static_cast<double>(start_new_space_size) * 100);
+
+  if (previous_semi_space_copied_object_size_ > 0) {
+    promotion_rate_ =
+        (static_cast<double>(promoted_objects_size_) /
+         static_cast<double>(previous_semi_space_copied_object_size_) * 100);
+  } 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_rate_ + semi_space_copied_rate_;
+  double survival_rate = promotion_ratio_ + semi_space_copied_rate_;
+  tracer()->AddSurvivalRate(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) {
@@ skipping 37 matching lines @@
   if (collector == MARK_COMPACTOR) {
     // Perform mark-sweep with optional compaction.
     MarkCompact();
     sweep_generation_++;
     // Temporarily set the limit for case when PostGarbageCollectionProcessing
     // allocates and triggers GC. The real limit is set at after
     // PostGarbageCollectionProcessing.
     old_generation_allocation_limit_ =
         OldGenerationAllocationLimit(PromotedSpaceSizeOfObjects(), 0);
     old_gen_exhausted_ = false;
+    old_generation_size_configured_ = true;
   } else {
     Scavenge();
   }
 
   UpdateSurvivalStatistics(start_new_space_size);
+  ConfigureInitialOldGenerationSize();
 
   isolate_->counters()->objs_since_last_young()->Set(0);
 
   // Callbacks that fire after this point might trigger nested GCs and
   // restart incremental marking, the assertion can't be moved down.
   DCHECK(collector == SCAVENGER || incremental_marking()->IsStopped());
 
   gc_post_processing_depth_++;
   {
     AllowHeapAllocation allow_allocation;
@@ skipping 1215 matching lines @@
 
 void Heap::ScavengeObjectSlow(HeapObject** p, HeapObject* object) {
   SLOW_DCHECK(object->GetIsolate()->heap()->InFromSpace(object));
   MapWord first_word = object->map_word();
   SLOW_DCHECK(!first_word.IsForwardingAddress());
   Map* map = first_word.ToMap();
   map->GetHeap()->DoScavengeObject(map, p, object);
 }
 
 
+void Heap::ConfigureInitialOldGenerationSize() {
+  if (!old_generation_size_configured_ && tracer()->SurvivalEventsRecorded()) {
+    old_generation_allocation_limit_ =
+        Max(kMinimumOldGenerationAllocationLimit,
+            static_cast<intptr_t>(
+                static_cast<double>(initial_old_generation_size_) *
+                (tracer()->AverageSurvivalRate() / 100)));
+  }
+}
+
+
 AllocationResult Heap::AllocatePartialMap(InstanceType instance_type,
                                           int instance_size) {
   Object* result;
   AllocationResult allocation = AllocateRaw(Map::kSize, MAP_SPACE, MAP_SPACE);
   if (!allocation.To(&result)) return allocation;
 
   // Map::cast cannot be used due to uninitialized map field.
   reinterpret_cast<Map*>(result)->set_map(raw_unchecked_meta_map());
   reinterpret_cast<Map*>(result)->set_instance_type(instance_type);
   reinterpret_cast<Map*>(result)->set_instance_size(instance_size);
@@ skipping 2792 matching lines @@
   if (FLAG_semi_space_growth_factor < 2) {
     FLAG_semi_space_growth_factor = 2;
   }
 
   // The old generation is paged and needs at least one page for each space.
   int paged_space_count = LAST_PAGED_SPACE - FIRST_PAGED_SPACE + 1;
   max_old_generation_size_ =
       Max(static_cast<intptr_t>(paged_space_count * Page::kPageSize),
           max_old_generation_size_);
 
+  if (FLAG_initial_old_space_size > 0) {
+    initial_old_generation_size_ = FLAG_initial_old_space_size * MB;
+  } else {
+    initial_old_generation_size_ = max_old_generation_size_ / 2;
+  }
+  old_generation_allocation_limit_ = initial_old_generation_size_;
+
   // We rely on being able to allocate new arrays in paged spaces.
   DCHECK(Page::kMaxRegularHeapObjectSize >=
          (JSArray::kSize +
           FixedArray::SizeFor(JSObject::kInitialMaxFastElementArray) +
           AllocationMemento::kSize));
 
   code_range_size_ = code_range_size * MB;
 
   configured_ = true;
   return true;
@@ skipping 1229 matching lines @@
       static_cast<int>(object_sizes_last_time_[index]));
   CODE_AGE_LIST_COMPLETE(ADJUST_LAST_TIME_OBJECT_COUNT)
 #undef ADJUST_LAST_TIME_OBJECT_COUNT
 
   MemCopy(object_counts_last_time_, object_counts_, sizeof(object_counts_));
   MemCopy(object_sizes_last_time_, object_sizes_, sizeof(object_sizes_));
   ClearObjectStats();
 }
 }
 }  // namespace v8::internal