Reviewers: Kasper Lund, Description: Do not use left-over space after new space alignment for other spaces. Doing so makes the max new space size influence the initial total size of the heap.
This change reduces the initial memory use of V8 by over 6MB. Please review this at http://codereview.chromium.org/202017 SVN Base: http://v8.googlecode.com/svn/branches/bleeding_edge/ Affected files: M src/heap.cc Index: src/heap.cc =================================================================== --- src/heap.cc (revision 2849) +++ src/heap.cc (working copy) @@ -3185,63 +3185,49 @@ if (!ConfigureHeapDefault()) return false; } - // Setup memory allocator and allocate an initial chunk of memory. The - // initial chunk is double the size of the new space to ensure that we can - // find a pair of semispaces that are contiguous and aligned to their size. + // Setup memory allocator and reserve a chunk of memory for new + // space. The chunk is double the size of the new space to ensure + // that we can find a pair of semispaces that are contiguous and + // aligned to their size. if (!MemoryAllocator::Setup(MaxCapacity())) return false; - void* chunk - = MemoryAllocator::ReserveInitialChunk(2 * young_generation_size_); + void* chunk = + MemoryAllocator::ReserveInitialChunk(2 * young_generation_size_); if (chunk == NULL) return false; - // Put the initial chunk of the old space at the start of the initial - // chunk, then the two new space semispaces, then the initial chunk of - // code space. Align the pair of semispaces to their size, which must be - // a power of 2. + // Align the pair of semispaces to their size, which must be a power + // of 2. ASSERT(IsPowerOf2(young_generation_size_)); - Address code_space_start = reinterpret_cast<Address>(chunk); - Address new_space_start = RoundUp(code_space_start, young_generation_size_); - Address old_space_start = new_space_start + young_generation_size_; - int code_space_size = new_space_start - code_space_start; - int old_space_size = young_generation_size_ - code_space_size; - - // Initialize new space. + Address new_space_start = + RoundUp(reinterpret_cast<byte*>(chunk), young_generation_size_); if (!new_space_.Setup(new_space_start, young_generation_size_)) return false; - // Initialize old space, set the maximum capacity to the old generation - // size. It will not contain code. + // Initialize old pointer space. old_pointer_space_ = new OldSpace(old_generation_size_, OLD_POINTER_SPACE, NOT_EXECUTABLE); if (old_pointer_space_ == NULL) return false; - if (!old_pointer_space_->Setup(old_space_start, old_space_size >> 1)) { - return false; - } + if (!old_pointer_space_->Setup(NULL, 0)) return false; + + // Initialize old data space. old_data_space_ = new OldSpace(old_generation_size_, OLD_DATA_SPACE, NOT_EXECUTABLE); if (old_data_space_ == NULL) return false; - if (!old_data_space_->Setup(old_space_start + (old_space_size >> 1), - old_space_size >> 1)) { - return false; - } + if (!old_data_space_->Setup(NULL, 0)) return false; // Initialize the code space, set its maximum capacity to the old // generation size. It needs executable memory. code_space_ = new OldSpace(old_generation_size_, CODE_SPACE, EXECUTABLE); if (code_space_ == NULL) return false; - if (!code_space_->Setup(code_space_start, code_space_size)) return false; + if (!code_space_->Setup(NULL, 0)) return false; // Initialize map space. map_space_ = new MapSpace(kMaxMapSpaceSize, MAP_SPACE); if (map_space_ == NULL) return false; - // Setting up a paged space without giving it a virtual memory range big - // enough to hold at least a page will cause it to allocate. if (!map_space_->Setup(NULL, 0)) return false; // Initialize global property cell space. cell_space_ = new CellSpace(old_generation_size_, CELL_SPACE); if (cell_space_ == NULL) return false; - // Setting up a paged space without giving it a virtual memory range big - // enough to hold at least a page will cause it to allocate. if (!cell_space_->Setup(NULL, 0)) return false; // The large object code space may contain code or data. We set the memory --~--~---------~--~----~------------~-------~--~----~ v8-dev mailing list [email protected] http://groups.google.com/group/v8-dev -~----------~----~----~----~------~----~------~--~---
