Introduce a new growth criterion for the new space behind a flag

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 52 matching lines @@
       initial_semispace_size_(Page::kPageSize),
       target_semispace_size_(Page::kPageSize),
       max_old_generation_size_(700ul * (kPointerSize / 4) * MB),
       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),
       contexts_disposed_(0),
       global_ic_age_(0),
       flush_monomorphic_ics_(false),
       scan_on_scavenge_pages_(0),
       new_space_(this),
       old_pointer_space_(NULL),
       old_data_space_(NULL),
       code_space_(NULL),
@@ skipping 1211 matching lines @@
 
     HeapObjectIterator data_it(heap->old_data_space());
     for (HeapObject* object = data_it.Next(); object != NULL;
          object = data_it.Next())
       object->Iterate(&v);
 }
 #endif  // VERIFY_HEAP
 
 
 void Heap::CheckNewSpaceExpansionCriteria() {
-  if (new_space_.TotalCapacity() < new_space_.MaximumCapacity() &&
-      survived_since_last_expansion_ > new_space_.TotalCapacity()) {
-    // Grow the size of new space if there is room to grow, enough data
-    // has survived scavenge since the last expansion and we are not in
-    // high promotion mode.
+  if (FLAG_experimental_new_space_growth_heuristic) {
+    if (new_space_.TotalCapacity() < new_space_.MaximumCapacity() &&
+        survived_last_scavenge_ * 100 / new_space_.TotalCapacity() >= 10) {
+      // Grow the size of new space if there is room to grow, and more than 10%
+      // have survived the last scavenge.
+      new_space_.Grow();
+      survived_since_last_expansion_ = 0;
+    }
+  } else if (new_space_.TotalCapacity() < new_space_.MaximumCapacity() &&
+             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();
     survived_since_last_expansion_ = 0;
   }
 }
 
 
 static bool IsUnscavengedHeapObject(Heap* heap, Object** p) {
   return heap->InNewSpace(*p) &&
          !HeapObject::cast(*p)->map_word().IsForwardingAddress();
 }
@@ skipping 4993 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