Remove shrinking of new space on compaction and only do it on idle...

src/heap.cc

 // Copyright 2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 447 matching lines @@
   EnsureFromSpaceIsCommitted();
   if (collector == MARK_COMPACTOR) {
     MarkCompact(tracer);
 
     int old_gen_size = PromotedSpaceSize();
     old_gen_promotion_limit_ =
         old_gen_size + Max(kMinimumPromotionLimit, old_gen_size / 3);
     old_gen_allocation_limit_ =
         old_gen_size + Max(kMinimumAllocationLimit, old_gen_size / 2);
     old_gen_exhausted_ = false;
-  } else {
-    Scavenge();
   }
+  Scavenge();
+
   Counters::objs_since_last_young.Set(0);
 
   PostGarbageCollectionProcessing();
 
   if (collector == MARK_COMPACTOR) {
     // Register the amount of external allocated memory.
     amount_of_external_allocated_memory_at_last_global_gc_ =
         amount_of_external_allocated_memory_;
   }
 
@@ skipping 33 matching lines @@
   MarkCompactEpilogue(is_compacting);
 
   LOG(ResourceEvent("markcompact", "end"));
 
   gc_state_ = NOT_IN_GC;
 
   Shrink();
 
   Counters::objs_since_last_full.Set(0);
   context_disposed_pending_ = false;
-
-  Scavenge();
-
-  // Shrink new space as much as possible after compacting full
-  // garbage collections.
-  if (is_compacting) new_space_.Shrink();
 }
 
 
 void Heap::MarkCompactPrologue(bool is_compacting) {
   // At any old GC clear the keyed lookup cache to enable collection of unused
   // maps.
   KeyedLookupCache::Clear();
   ContextSlotCache::Clear();
   DescriptorLookupCache::Clear();
 
@@ skipping 2260 matching lines @@
   }
 
   if (number_idle_notifications >= kIdlesBeforeCollection) {
     // The first time through we collect without forcing compaction.
     // The second time through we force compaction and quit.
     bool force_compaction =
         number_idle_notifications > kIdlesBeforeCollection;
     CollectAllGarbage(force_compaction);
     last_gc_count = gc_count_;
     if (force_compaction) {
+      // Shrink new space.
+      new_space_.Shrink();
       number_idle_notifications = 0;
       finished = true;
     }
   }
 
   // Uncommit unused memory in new space.
   Heap::UncommitFromSpace();
   return finished;
 }
 
@@ skipping 1146 matching lines @@
 #ifdef DEBUG
 bool Heap::GarbageCollectionGreedyCheck() {
   ASSERT(FLAG_gc_greedy);
   if (Bootstrapper::IsActive()) return true;
   if (disallow_allocation_failure()) return true;
   return CollectGarbage(0, NEW_SPACE);
 }
 #endif
 
 } }  // namespace v8::internal