186733 2018-06-16 12:28:12 -0700 ensurePropertyReplacementWatchpointSet wastes 308KB of HashTable capacity on cnn.com 2018-06-16 12:33:47 -0700 1 1 1 Unclassified WebKit JavaScriptCore WebKit Nightly Build Unspecified Unspecified NEW InRadar P2 Normal --- 1 simon.fraser webkit-unassigned keith_miller saam simon.fraser webkit-bug-importer oldest_to_newest 1433782 0 simon.fraser 2018-06-16 12:28:12 -0700 Using tooling from bug 186698, loading can and running "notifyutil -p com.apple.WebKit.dumpHashTableCapacity" shows: Wasted capacity: 168032 bytes (used 34720 of 202752 bytes, utilization: 17.12%) - 1441 allocations 1 0x116684e05 WTF::HashTable<int, WTF::KeyValuePair<int, WTF::RefPtr<JSC::WatchpointSet, WTF::DumbPtrTraits<JSC::WatchpointSet> > >, WTF::KeyValuePairKeyExtractor<WTF::KeyValuePair<int, WTF::RefPtr<JSC::WatchpointSet, WTF::DumbPtrTraits<JSC::WatchpointSet> > > >, WTF::IntHash<int>, WTF::HashMap<int, WTF::RefPtr<JSC::WatchpointSet, WTF::DumbPtrTraits<JSC::WatchpointSet> >, WTF::IntHash<int>, WTF::UnsignedWithZeroKeyHashTraits<int>, WTF::HashTraits<WTF::RefPtr<JSC::WatchpointSet, WTF::DumbPtrTraits<JSC::WatchpointSet> > > >::KeyValuePairTraits, WTF::UnsignedWithZeroKeyHashTraits<int> >::HashTable() 2 0x116684de5 WTF::HashMap<int, WTF::RefPtr<JSC::WatchpointSet, WTF::DumbPtrTraits<JSC::WatchpointSet> >, WTF::IntHash<int>, WTF::UnsignedWithZeroKeyHashTraits<int>, WTF::HashTraits<WTF::RefPtr<JSC::WatchpointSet, WTF::DumbPtrTraits<JSC::WatchpointSet> > > >::HashMap() 3 0x116684dc5 WTF::HashMap<int, WTF::RefPtr<JSC::WatchpointSet, WTF::DumbPtrTraits<JSC::WatchpointSet> >, WTF::IntHash<int>, WTF::UnsignedWithZeroKeyHashTraits<int>, WTF::HashTraits<WTF::RefPtr<JSC::WatchpointSet, WTF::DumbPtrTraits<JSC::WatchpointSet> > > >::HashMap() 4 0x1166754f2 JSC::Structure::ensurePropertyReplacementWatchpointSet(JSC::VM&, int) 5 0x1157cf3af JSC::PropertyCondition::isWatchableWhenValid(JSC::Structure*, JSC::PropertyCondition::WatchabilityEffort) const 6 0x1157cf510 JSC::PropertyCondition::isWatchable(JSC::Structure*, JSC::JSObject*, JSC::PropertyCondition::WatchabilityEffort) const 7 0x1157bdca0 JSC::ObjectPropertyCondition::isWatchable(JSC::Structure*, JSC::PropertyCondition::WatchabilityEffort) const 8 0x1157bb17b JSC::ObjectPropertyCondition::isWatchable(JSC::PropertyCondition::WatchabilityEffort) const 1433783 1 webkit-bug-importer 2018-06-16 12:28:35 -0700 <rdar://problem/41189144> 1433786 2 simon.fraser 2018-06-16 12:29:58 -0700 Also this code path: Wasted capacity: 140416 bytes (used 44928 of 185344 bytes, utilization: 24.24%) - 1018 allocations 1 0x116684e05 WTF::HashTable<int, WTF::KeyValuePair<int, WTF::RefPtr<JSC::WatchpointSet, WTF::DumbPtrTraits<JSC::WatchpointSet> > >, WTF::KeyValuePairKeyExtractor<WTF::KeyValuePair<int, WTF::RefPtr<JSC::WatchpointSet, WTF::DumbPtrTraits<JSC::WatchpointSet> > > >, WTF::IntHash<int>, WTF::HashMap<int, WTF::RefPtr<JSC::WatchpointSet, WTF::DumbPtrTraits<JSC::WatchpointSet> >, WTF::IntHash<int>, WTF::UnsignedWithZeroKeyHashTraits<int>, WTF::HashTraits<WTF::RefPtr<JSC::WatchpointSet, WTF::DumbPtrTraits<JSC::WatchpointSet> > > >::KeyValuePairTraits, WTF::UnsignedWithZeroKeyHashTraits<int> >::HashTable() 2 0x116684de5 WTF::HashMap<int, WTF::RefPtr<JSC::WatchpointSet, WTF::DumbPtrTraits<JSC::WatchpointSet> >, WTF::IntHash<int>, WTF::UnsignedWithZeroKeyHashTraits<int>, WTF::HashTraits<WTF::RefPtr<JSC::WatchpointSet, WTF::DumbPtrTraits<JSC::WatchpointSet> > > >::HashMap() 3 0x116684dc5 WTF::HashMap<int, WTF::RefPtr<JSC::WatchpointSet, WTF::DumbPtrTraits<JSC::WatchpointSet> >, WTF::IntHash<int>, WTF::UnsignedWithZeroKeyHashTraits<int>, WTF::HashTraits<WTF::RefPtr<JSC::WatchpointSet, WTF::DumbPtrTraits<JSC::WatchpointSet> > > >::HashMap() 4 0x1166754f2 JSC::Structure::ensurePropertyReplacementWatchpointSet(JSC::VM&, int) 5 0x116675b58 JSC::Structure::didCachePropertyReplacement(JSC::VM&, int) 6 0x11626c20a llint_slow_path_put_by_id 7 0x11531710f llint_entry 8 0x11531b8d6 llint_entry 1433796 3 simon.fraser 2018-06-16 12:33:47 -0700 Also: Wasted capacity: 67888 bytes (used 18000 of 85888 bytes, utilization: 20.96%) - 551 allocations 1 0x116684e05 WTF::HashTable<int, WTF::KeyValuePair<int, WTF::RefPtr<JSC::WatchpointSet, WTF::DumbPtrTraits<JSC::WatchpointSet> > >, WTF::KeyValuePairKeyExtractor<WTF::KeyValuePair<int, WTF::RefPtr<JSC::WatchpointSet, WTF::DumbPtrTraits<JSC::WatchpointSet> > > >, WTF::IntHash<int>, WTF::HashMap<int, WTF::RefPtr<JSC::WatchpointSet, WTF::DumbPtrTraits<JSC::WatchpointSet> >, WTF::IntHash<int>, WTF::UnsignedWithZeroKeyHashTraits<int>, WTF::HashTraits<WTF::RefPtr<JSC::WatchpointSet, WTF::DumbPtrTraits<JSC::WatchpointSet> > > >::KeyValuePairTraits, WTF::UnsignedWithZeroKeyHashTraits<int> >::HashTable() 2 0x116684de5 WTF::HashMap<int, WTF::RefPtr<JSC::WatchpointSet, WTF::DumbPtrTraits<JSC::WatchpointSet> >, WTF::IntHash<int>, WTF::UnsignedWithZeroKeyHashTraits<int>, WTF::HashTraits<WTF::RefPtr<JSC::WatchpointSet, WTF::DumbPtrTraits<JSC::WatchpointSet> > > >::HashMap() 3 0x116684dc5 WTF::HashMap<int, WTF::RefPtr<JSC::WatchpointSet, WTF::DumbPtrTraits<JSC::WatchpointSet> >, WTF::IntHash<int>, WTF::UnsignedWithZeroKeyHashTraits<int>, WTF::HashTraits<WTF::RefPtr<JSC::WatchpointSet, WTF::DumbPtrTraits<JSC::WatchpointSet> > > >::HashMap() 4 0x1166754f2 JSC::Structure::ensurePropertyReplacementWatchpointSet(JSC::VM&, int) 5 0x1156e0cb3 JSC::Structure::startWatchingPropertyForReplacements(JSC::VM&, int) 6 0x11624959d JSC::tryCacheGetByID(JSC::ExecState*, JSC::JSValue, JSC::Identifier const&, JSC::PropertySlot const&, JSC::StructureStubInfo&, JSC::GetByIDKind) 7 0x116247627 JSC::repatchGetByID(JSC::ExecState*, JSC::JSValue, JSC::Identifier const&, JSC::PropertySlot const&, JSC::StructureStubInfo&, JSC::GetByIDKind) 8 0x116226f97 operationGetByIdOptimize::$_1::operator()(bool, JSC::PropertySlot&) const