Try reducing and balance GC callback stack sizes.

Source/platform/heap/CallbackStack.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CallbackStack_h
 #define CallbackStack_h
 
 #include "platform/heap/ThreadState.h"
 
 namespace blink {
 
 // The CallbackStack contains all the visitor callbacks used to trace and mark
 // objects. A specific CallbackStack instance contains at most bufferSize elements.
 // If more space is needed a new CallbackStack instance is created and chained
 // together with the former instance. I.e. a logical CallbackStack can be made of
 // multiple chained CallbackStack object instances.
 class CallbackStack {
 public:
+
+    // Callback stacks are extensible, chaining blocks together. However,
+    // all but the first block are deleted when 'popped empty', so it
+    // is in our interest to not spill over into additional blocks too
+    // often. The block sizes used here tries to reflect that -- plentiful
+    // for 'typical' GCs, but not wasting too much slop either in the
+    // initial block.
+    enum BlockSizes {
+        MarkingStackBlockSize = 8192,
+        WeakCallbackStackBlockSize = 2048,
+        PostMarkingStackBlockSize = 1024,
+        EphemeronCallbackStackBlockSize = 1024,
+    };
+
     class Item {
     public:
         Item() { }
         Item(void* object, VisitorCallback callback)
             : m_object(object)
             , m_callback(callback)
         {
         }
         void* object() { return m_object; }
         VisitorCallback callback() { return m_callback; }
         void call(Visitor* visitor) { m_callback(visitor, m_object); }
 
     private:
         void* m_object;
         VisitorCallback m_callback;
     };
 
-    CallbackStack();
+    CallbackStack(unsigned blockSize);
     ~CallbackStack();
 
     void clear();
 
     Item* allocateEntry();
     Item* pop();
 
     bool isEmpty() const;
 
     void invokeEphemeronCallbacks(Visitor*);
 
 #if ENABLE(ASSERT)
     bool hasCallbackForObject(const void*);
 #endif
 
-    static const size_t blockSize = 8192;
-
 private:
     class Block {
     public:
-        explicit Block(Block* next)
-            : m_limit(&(m_buffer[blockSize]))
-            , m_current(&(m_buffer[0]))
-            , m_next(next)
-        {
-            clearUnused();
-        }
+        Block(Block* next, unsigned blockSize);
 
         ~Block()
         {
             clearUnused();
+            delete m_buffer;
         }
 
         void clear();
 
         Block* next() const { return m_next; }
         void setNext(Block* next) { m_next = next; }
 
         bool isEmptyBlock() const
         {
             return m_current == &(m_buffer[0]);
         }
 
-        size_t size() const
-        {
-            return blockSize - (m_limit - m_current);
-        }
-
         Item* allocateEntry()
         {
             if (LIKELY(m_current < m_limit))
                 return m_current++;
             return 0;
         }
 
         Item* pop()
         {
             if (UNLIKELY(isEmptyBlock()))
                 return 0;
             return --m_current;
         }
 
         void invokeEphemeronCallbacks(Visitor*);
 #if ENABLE(ASSERT)
         bool hasCallbackForObject(const void*);
 #endif
 
     private:
         void clearUnused();
 
-        Item m_buffer[blockSize];
+        Item* m_buffer;
         Item* m_limit;
         Item* m_current;
         Block* m_next;
+#if ENABLE(ASSERT)
+        unsigned m_blockSize;
+#endif
     };
 
     Item* popSlow();
     Item* allocateEntrySlow();
     void invokeOldestCallbacks(Block*, Block*, Visitor*);
     bool hasJustOneBlock() const;
-    void swap(CallbackStack* other);
 
     Block* m_first;
     Block* m_last;
+    unsigned m_blockSize;
 };
 
 ALWAYS_INLINE CallbackStack::Item* CallbackStack::allocateEntry()
 {
     Item* item = m_first->allocateEntry();
     if (LIKELY(!!item))
         return item;
 
     return allocateEntrySlow();
 }
 
 ALWAYS_INLINE CallbackStack::Item* CallbackStack::pop()
 {
     Item* item = m_first->pop();
     if (LIKELY(!!item))
         return item;
 
     return popSlow();
 }
 
 } // namespace blink
 
 #endif // CallbackStack_h