Reduce boot-up memory use of V8.

test/cctest/test-heap.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 
 #include <stdlib.h>
 
 #include "v8.h"
 
 #include "execution.h"
 #include "factory.h"
 #include "macro-assembler.h"
 #include "global-handles.h"
@@ skipping 1218 matching lines @@
   InitializeVM();
   HEAP->EnsureHeapIsIterable();
   intptr_t size_of_objects_1 = HEAP->SizeOfObjects();
   HeapIterator iterator;
   intptr_t size_of_objects_2 = 0;
   for (HeapObject* obj = iterator.next();
        obj != NULL;
        obj = iterator.next()) {
     size_of_objects_2 += obj->Size();
   }
-  // Delta must be within 5% of the larger result.
-  // TODO(gc): Tighten this up by distinguishing between byte
-  // arrays that are real and those that merely mark free space
-  // on the heap.
+  // Delta must be within 1% of the larger result.
   if (size_of_objects_1 > size_of_objects_2) {
     intptr_t delta = size_of_objects_1 - size_of_objects_2;
     PrintF("Heap::SizeOfObjects: %" V8_PTR_PREFIX "d, "
            "Iterator: %" V8_PTR_PREFIX "d, "
            "delta: %" V8_PTR_PREFIX "d\n",
            size_of_objects_1, size_of_objects_2, delta);
-    CHECK_GT(size_of_objects_1 / 20, delta);
+    CHECK_GT(size_of_objects_1 / 100, delta);
   } else {
     intptr_t delta = size_of_objects_2 - size_of_objects_1;
     PrintF("Heap::SizeOfObjects: %" V8_PTR_PREFIX "d, "
            "Iterator: %" V8_PTR_PREFIX "d, "
            "delta: %" V8_PTR_PREFIX "d\n",
            size_of_objects_1, size_of_objects_2, delta);
     CHECK_GT(size_of_objects_2 / 20, delta);
   }
 }
 
@@ skipping 305 matching lines @@
     v8::HandleScope scope;
     v8::Handle<v8::Object> global = v8::Context::GetCurrent()->Global();
     v8::Handle<v8::Function> g =
         v8::Handle<v8::Function>::Cast(global->Get(v8_str("g")));
     g->Call(global, 0, NULL);
   }
 
   HEAP->incremental_marking()->set_should_hurry(true);
   HEAP->CollectGarbage(OLD_POINTER_SPACE);
 }