Up the initial promotion limit to 5 pages, since the old space has a minimum

src/heap.h

 // Copyright 2011 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 1203 matching lines @@
   inline bool OldGenerationPromotionLimitReached() {
     return (PromotedSpaceSize() + PromotedExternalMemorySize())
            > old_gen_promotion_limit_;
   }
 
   inline intptr_t OldGenerationSpaceAvailable() {
     return old_gen_allocation_limit_ -
            (PromotedSpaceSize() + PromotedExternalMemorySize());
   }
 
-  static const intptr_t kMinimumPromotionLimit =
-      2 * (Page::kPageSize > MB ? Page::kPageSize : MB);
+  static const intptr_t kMinimumPromotionLimit = 5 * Page::kPageSize;
   static const intptr_t kMinimumAllocationLimit =
       8 * (Page::kPageSize > MB ? Page::kPageSize : MB);
 
   // When we sweep lazily we initially guess that there is no garbage on the
   // heap and set the limits for the next GC accordingly.  As we sweep we find
   // out that some of the pages contained garbage and we have to adjust
   // downwards the size of the heap.  This means the limits that control the
   // timing of the next GC also need to be adjusted downwards.
   void LowerOldGenLimits(intptr_t adjustment) {
     size_of_old_gen_at_last_old_space_gc_ -= adjustment;
@@ skipping 1210 matching lines @@
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(PathTracer);
 };
 #endif  // DEBUG || LIVE_OBJECT_LIST
 
 } }  // namespace v8::internal
 
 #undef HEAP
 
 #endif  // V8_HEAP_H_