Title: [117127] branches/safari-536-branch/Source/_javascript_Core
Diff
Modified: branches/safari-536-branch/Source/_javascript_Core/ChangeLog (117126 => 117127)
--- branches/safari-536-branch/Source/_javascript_Core/ChangeLog 2012-05-15 19:56:51 UTC (rev 117126)
+++ branches/safari-536-branch/Source/_javascript_Core/ChangeLog 2012-05-15 19:58:17 UTC (rev 117127)
@@ -1,5 +1,49 @@
2012-05-15 Lucas Forschler <[email protected]>
+ Merge 116484
+
+ 2012-05-08 Mark Hahnenberg <[email protected]>
+
+ Heap should not continually allocate new pages in steady state
+ https://bugs.webkit.org/show_bug.cgi?id=85936
+
+ Reviewed by Geoff Garen.
+
+ Currently, in steady state (i.e. a constant amount of live GC
+ memory with a constant rate of allocation) assuming we've just
+ finished a collection with X live blocks in CopiedSpace, we
+ increase our working set by X blocks in CopiedSpace with each
+ collection we perform. This is due to the fact that we allocate
+ until we run out of free blocks to use in the Heap before we
+ consider whether we should run a collection.
+
+ In the longer term, this issue will be mostly resolved by
+ implementing quick release for the CopiedSpace. In the shorter
+ term, we should change our policy to check whether we should
+ allocate before trying to use a free block from the Heap. We
+ can change our policy to something more appropriate once we
+ have implemented quick release.
+
+ This change should also have the convenient side effect of
+ reducing the variance in GC-heavy tests (e.g. v8-splay) due
+ to fact that we are doing less VM allocation during copying
+ collection. Overall, this patch is performance neutral across
+ the benchmarks we track.
+
+ * heap/CopiedSpace.cpp:
+ (JSC::CopiedSpace::getFreshBlock): Shuffle the request from the BlockAllocator
+ around so that we only do it if the block request must succeed
+ i.e. after we've already checked whether we should do a collection.
+ * heap/MarkedAllocator.cpp:
+ (JSC::MarkedAllocator::allocateSlowCase): Ditto.
+ (JSC::MarkedAllocator::allocateBlock): We no longer have a failure mode in this
+ function because by the time we've called it, we've already checked whether we
+ should run a collection so there's no point in returning null.
+ * heap/MarkedAllocator.h: Removing old arguments from function declaration.
+ (MarkedAllocator):
+
+2012-05-15 Lucas Forschler <[email protected]>
+
Merge 116372
2012-05-07 Oliver Hunt <[email protected]>
Modified: branches/safari-536-branch/Source/_javascript_Core/heap/CopiedSpace.cpp (117126 => 117127)
--- branches/safari-536-branch/Source/_javascript_Core/heap/CopiedSpace.cpp 2012-05-15 19:56:51 UTC (rev 117126)
+++ branches/safari-536-branch/Source/_javascript_Core/heap/CopiedSpace.cpp 2012-05-15 19:58:17 UTC (rev 117127)
@@ -212,10 +212,10 @@
CheckedBoolean CopiedSpace::getFreshBlock(AllocationEffort allocationEffort, CopiedBlock** outBlock)
{
CopiedBlock* block = 0;
- if (HeapBlock* heapBlock = m_heap->blockAllocator().allocate())
- block = new (NotNull, heapBlock) CopiedBlock(heapBlock->m_allocation);
- else if (allocationEffort == AllocationMustSucceed) {
- if (!allocateNewBlock(&block)) {
+ if (allocationEffort == AllocationMustSucceed) {
+ if (HeapBlock* heapBlock = m_heap->blockAllocator().allocate())
+ block = new (NotNull, heapBlock) CopiedBlock(heapBlock->m_allocation);
+ else if (!allocateNewBlock(&block)) {
*outBlock = 0;
ASSERT_NOT_REACHED();
return false;
Modified: branches/safari-536-branch/Source/_javascript_Core/heap/MarkedAllocator.cpp (117126 => 117127)
--- branches/safari-536-branch/Source/_javascript_Core/heap/MarkedAllocator.cpp 2012-05-15 19:56:51 UTC (rev 117126)
+++ branches/safari-536-branch/Source/_javascript_Core/heap/MarkedAllocator.cpp 2012-05-15 19:58:17 UTC (rev 117127)
@@ -68,44 +68,30 @@
if (LIKELY(result != 0))
return result;
- AllocationEffort allocationEffort;
-
- if (m_heap->shouldCollect())
- allocationEffort = AllocationCanFail;
- else
- allocationEffort = AllocationMustSucceed;
-
- MarkedBlock* block = allocateBlock(allocationEffort);
- if (block) {
- addBlock(block);
- void* result = tryAllocate();
- ASSERT(result);
- return result;
+ if (m_heap->shouldCollect()) {
+ m_heap->collect(Heap::DoNotSweep);
+
+ result = tryAllocate();
+ if (result)
+ return result;
}
-
- m_heap->collect(Heap::DoNotSweep);
-
- result = tryAllocate();
-
- if (result)
- return result;
-
+
ASSERT(!m_heap->shouldCollect());
- addBlock(allocateBlock(AllocationMustSucceed));
-
+ MarkedBlock* block = allocateBlock();
+ ASSERT(block);
+ addBlock(block);
+
result = tryAllocate();
ASSERT(result);
return result;
}
-MarkedBlock* MarkedAllocator::allocateBlock(AllocationEffort allocationEffort)
+MarkedBlock* MarkedAllocator::allocateBlock()
{
MarkedBlock* block = static_cast<MarkedBlock*>(m_heap->blockAllocator().allocate());
if (block)
block = MarkedBlock::recycle(block, m_heap, m_cellSize, m_cellsNeedDestruction);
- else if (allocationEffort == AllocationCanFail)
- return 0;
else
block = MarkedBlock::create(m_heap, m_cellSize, m_cellsNeedDestruction);
Modified: branches/safari-536-branch/Source/_javascript_Core/heap/MarkedAllocator.h (117126 => 117127)
--- branches/safari-536-branch/Source/_javascript_Core/heap/MarkedAllocator.h 2012-05-15 19:56:51 UTC (rev 117126)
+++ branches/safari-536-branch/Source/_javascript_Core/heap/MarkedAllocator.h 2012-05-15 19:58:17 UTC (rev 117127)
@@ -41,7 +41,7 @@
JS_EXPORT_PRIVATE void* allocateSlowCase();
void* tryAllocate();
void* tryAllocateHelper();
- MarkedBlock* allocateBlock(AllocationEffort);
+ MarkedBlock* allocateBlock();
MarkedBlock::FreeList m_freeList;
MarkedBlock* m_currentBlock;
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