Reland of "[heap] Switch to 500k pages"

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index f5bece0a11fbe08d16a563fda13cc60f9891e786..2c260534959f26fd15e4d80b2286bdf34b25cbef 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -4712,6 +4712,7 @@ class FreeSpace: public HeapObject {
   // Size is smi tagged when it is stored.
   static const int kSizeOffset = HeapObject::kHeaderSize;
   static const int kNextOffset = POINTER_SIZE_ALIGN(kSizeOffset + kPointerSize);
+  static const int kSize = kNextOffset + kPointerSize;
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(FreeSpace);
@@ -10466,12 +10467,12 @@ class JSArray: public JSObject {
   static const int kLengthOffset = JSObject::kHeaderSize;
   static const int kSize = kLengthOffset + kPointerSize;
 
-  // 600 * KB is the Page::kMaxRegularHeapObjectSize defined in spaces.h which
+  // 400 * KB is the Page::kMaxRegularHeapObjectSize defined in spaces.h which

[Hannes Payer (out of office), 2016/08/10 21:17:35]

Why not 300?

[Michael Lippautz, 2016/08/11 09:48:11]

Crankshaft (and esp hydrogen stubs) don't check for kMaxRegularHeapObjectSize at
all places. The problem is more involved, as the stubs often require objects to
be allocated in new space to avoid write barriers.

Since those stubs are already deprecated and in the process of being move to
turbo fan we just mitigate it by staying at 400 (which will not trigger a case).
This is merely a problem with our verification, as allocating a large object in
new space works like expected (except that it should not go there ;)).

Turbofan already suffers from similar issues: tracking bug: chromium:636391

   // we do not want to include in objects.h
   // Note that Page::kMaxRegularHeapObjectSize has to be in sync with
   // kInitialMaxFastElementArray which is checked in a DCHECK in heap.cc.
   static const int kInitialMaxFastElementArray =
-      (600 * KB - FixedArray::kHeaderSize - kSize - AllocationMemento::kSize) /
+      (400 * KB - FixedArray::kHeaderSize - kSize - AllocationMemento::kSize) /
       kPointerSize;
 
  private: