Changeset 96432 in webkit for trunk/Source/JavaScriptCore/heap

Timestamp:

Sep 30, 2011, 3:23:33 PM (14 years ago)

Author:

[email protected]

Message:

2011-09-30 Oliver Hunt <​[email protected]>

Need a sensible GGC policy

Reviewed by Geoff Garen.

This replaces the existing random collection policy
with a deterministic policy based on nursery size.

• heap/AllocationSpace.cpp: (JSC::AllocationSpace::allocateSlowCase):
• heap/Heap.cpp: (JSC::Heap::Heap): (JSC::Heap::markRoots): (JSC::Heap::collect):
• heap/Heap.h:
• heap/MarkedSpace.cpp: (JSC::MarkedSpace::MarkedSpace): (JSC::MarkedSpace::resetAllocator):
• heap/MarkedSpace.h: (JSC::MarkedSpace::nurseryWaterMark): (JSC::MarkedSpace::allocate):

Location:

trunk/Source/JavaScriptCore/heap

Files:

• AllocationSpace.cpp (modified) (1 diff)
• Heap.cpp (modified) (6 diffs)
• Heap.h (modified) (2 diffs)
• MarkedSpace.cpp (modified) (2 diffs)
• MarkedSpace.h (modified) (4 diffs)

trunk/Source/JavaScriptCore/heap/AllocationSpace.cpp

@@ -56 +56 @@
     AllocationEffort allocationEffort;
     
-    if (m_markedSpace.waterMark() < m_markedSpace.highWaterMark() || !m_heap->m_isSafeToCollect)
+    if ((
+#if ENABLE(GGC)
+         m_markedSpace.nurseryWaterMark() < m_heap->m_minBytesPerCycle
+#else
+         m_markedSpace.waterMark() < m_markedSpace.highWaterMark()
+#endif
+         ) || !m_heap->m_isSafeToCollect)
         allocationEffort = AllocationMustSucceed;
     else

trunk/Source/JavaScriptCore/heap/Heap.cpp

@@ -215 +215 @@
     : m_heapSize(heapSize)
     , m_minBytesPerCycle(heapSizeForHint(heapSize))
+    , m_lastFullGCSize(0)
     , m_operationInProgress(NoOperation)
     , m_objectSpace(this)
@@ -454 +455 @@
 }
 
-void Heap::markRoots()
-{
+void Heap::markRoots(bool fullGC)
+{
+    UNUSED_PARAM(fullGC);
     ASSERT(isValidThreadState(m_globalData));
     if (m_operationInProgress != NoOperation)
@@ -474 +476 @@
 #if ENABLE(GGC)
     MarkedBlock::DirtyCellVector dirtyCells;
-    // Until we have a sensible policy we just random choose to perform
-    // young generation collections 90% of the time.
-    if (WTF::randomNumber() > 0.1)
+    if (!fullGC)
         m_objectSpace.gatherDirtyCells(dirtyCells);
     else
@@ -487 +487 @@
 
 #if ENABLE(GGC)
-    for (size_t i = 0; i < dirtyObjectCount; i++) {
+    size_t dirtyCellCount = dirtyCells.size();
+    for (size_t i = 0; i < dirtyCellCount; i++) {
         heapRootVisitor.visitChildren(dirtyCells[i]);
         visitor.drain();
@@ -600 +601 @@
     ASSERT(m_isSafeToCollect);
     JAVASCRIPTCORE_GC_BEGIN();
-    
+    bool fullGC = sweepToggle == DoSweep;
+    if (!fullGC)
+        fullGC = (capacity() > 4 * m_lastFullGCSize);  
     canonicalizeCellLivenessData();
-    markRoots();
+
+    markRoots(fullGC);
 
     harvestWeakReferences();
@@ -622 +626 @@
     // new bytes allocated) proportion, and seems to work well in benchmarks.
     size_t proportionalBytes = 2 * size();
+    if (fullGC)
+        m_lastFullGCSize = proportionalBytes / 2;
+    
     m_objectSpace.setHighWaterMark(max(proportionalBytes, m_minBytesPerCycle));
     JAVASCRIPTCORE_GC_END();

trunk/Source/JavaScriptCore/heap/Heap.h

@@ -145 +145 @@
 
         void clearMarks();
-        void markRoots();
+        void markRoots(bool fullGC);
         void markProtectedObjects(HeapRootVisitor&);
         void markTempSortVectors(HeapRootVisitor&);
@@ -165 +165 @@
         const HeapSize m_heapSize;
         const size_t m_minBytesPerCycle;
+        size_t m_lastFullGCSize;
         
         OperationInProgress m_operationInProgress;

trunk/Source/JavaScriptCore/heap/MarkedSpace.cpp

@@ -33 +33 @@
 MarkedSpace::MarkedSpace(Heap* heap)
     : m_waterMark(0)
+    , m_nurseryWaterMark(0)
     , m_highWaterMark(0)
     , m_heap(heap)
@@ -64 +65 @@
 {
     m_waterMark = 0;
+    m_nurseryWaterMark = 0;
 
     for (size_t cellSize = preciseStep; cellSize <= preciseCutoff; cellSize += preciseStep)

trunk/Source/JavaScriptCore/heap/MarkedSpace.h

@@ -73 +73 @@
     size_t waterMark();
     size_t highWaterMark();
+    size_t nurseryWaterMark();
     void setHighWaterMark(size_t);
 
@@ -92 +93 @@
     FixedArray<SizeClass, impreciseCount> m_impreciseSizeClasses;
     size_t m_waterMark;
+    size_t m_nurseryWaterMark;
     size_t m_highWaterMark;
     Heap* m_heap;
@@ -104 +106 @@
 {
     return m_highWaterMark;
+}
+
+inline size_t MarkedSpace::nurseryWaterMark()
+{
+    return m_nurseryWaterMark;
 }
 
@@ -127 +134 @@
             if (firstFreeCell)
                 break;
-
+            m_nurseryWaterMark += block->capacity() - block->size();
             m_waterMark += block->capacity();
             block->didConsumeFreeList();