[heap] Change LO space limit to 512k - page header

src/heap/spaces.h

 // Copyright 2011 the V8 project 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 V8_HEAP_SPACES_H_
 #define V8_HEAP_SPACES_H_
 
 #include <list>
 #include <memory>
 #include <unordered_set>
@@ skipping 698 matching lines @@
       static_cast<intptr_t>(MemoryChunk::POINTERS_TO_HERE_ARE_INTERESTING) |
       static_cast<intptr_t>(MemoryChunk::POINTERS_FROM_HERE_ARE_INTERESTING);
 
   // Maximum object size that gets allocated into regular pages. Objects larger
   // than that size are allocated in large object space and are never moved in
   // memory. This also applies to new space allocation, since objects are never
   // migrated from new space to large object space. Takes double alignment into
   // account.
   // TODO(hpayer): This limit should be way smaller but we currently have
   // short living objects >256K.
-  static const int kMaxRegularHeapObjectSize = 600 * KB;
+  static const int kMaxRegularHeapObjectSize = 512 * KB - Page::kHeaderSize;
 
   static inline Page* ConvertNewToOld(Page* old_page, PagedSpace* new_owner);
 
   // Returns the page containing a given address. The address ranges
   // from [page_addr .. page_addr + kPageSize[. This only works if the object
   // is in fact in a page.
   static Page* FromAddress(Address addr) {
     return reinterpret_cast<Page*>(OffsetFrom(addr) & ~kPageAlignmentMask);
   }
 
@@ skipping 2301 matching lines @@
     count = 0;
   }
   // Must be small, since an iteration is used for lookup.
   static const int kMaxComments = 64;
 };
 #endif
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_SPACES_H_