Oilpan: Scale up the number of marking threads according to available processors

Source/platform/heap/Heap.cpp

 /*
  * Copyright (C) 2013 Google Inc. 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
@@ skipping 2123 matching lines @@
     s_markingStack = new CallbackStack();
     s_postMarkingCallbackStack = new CallbackStack();
     s_weakCallbackStack = new CallbackStack();
     s_ephemeronStack = new CallbackStack();
     s_heapDoesNotContainCache = new HeapDoesNotContainCache();
     s_markingVisitor = new MarkingVisitor(s_markingStack);
     s_freePagePool = new FreePagePool();
     s_orphanedPagePool = new OrphanedPagePool();
     s_markingThreads = new Vector<OwnPtr<blink::WebThread> >();
     if (blink::Platform::current()) {
-        // FIXME: We should let the amount of threads scale with the
-        // amount of processors in the system instead of hardcoding
-        // it.
+        int processors = blink::Platform::current()->numberOfProcessors();
+        int numberOfMarkingThreads = std::min(processors, maxNumberOfMarkingThreads);
         for (int i = 0; i < numberOfMarkingThreads; i++)
-            s_markingThreads->append(adoptPtr(blink::Platform::current()->createThread("Blink Heap Marker Thread")));
+            s_markingThreads->append(adoptPtr(blink::Platform::current()->createThread("Blink GC Marking Thread")));
     }
 }
 
 void Heap::shutdown()
 {
     s_shutdownCalled = true;
     ThreadState::shutdownHeapIfNecessary();
 }
 
 void Heap::doShutdown()
@@ skipping 734 matching lines @@
 CallbackStack* Heap::s_weakCallbackStack;
 CallbackStack* Heap::s_ephemeronStack;
 HeapDoesNotContainCache* Heap::s_heapDoesNotContainCache;
 bool Heap::s_shutdownCalled = false;
 bool Heap::s_lastGCWasConservative = false;
 FreePagePool* Heap::s_freePagePool;
 OrphanedPagePool* Heap::s_orphanedPagePool;
 Heap::RegionTree* Heap::s_regionTree = 0;
 
 }