Bug 186734

Summary:	FunctionCodeBlock wastes 144KB of HashTable capacity on cnn.com
Product:	WebKit	Reporter:	Simon Fraser (smfr) <simon.fraser>
Component:	JavaScriptCore	Assignee:	Nobody <webkit-unassigned>
Status:	NEW ---
Severity:	Normal	CC:	keith_miller, saam, simon.fraser, webkit-bug-importer, ysuzuki
Priority:	P2	Keywords:	InRadar
Version:	WebKit Nightly Build
Hardware:	Unspecified
OS:	Unspecified

Description Simon Fraser (smfr) 2018-06-16 12:29:06 PDT

Using tooling from bug 186698, loading can and running "notifyutil -p com.apple.WebKit.dumpHashTableCapacity" shows:

Wasted capacity: 143952 bytes (used 37488 of 181440 bytes, utilization: 20.66%) - 4780 allocations
1   0x115776625 WTF::HashTable<std::__1::tuple<JSC::Structure*, JSC::Instruction*>, WTF::KeyValuePair<std::__1::tuple<JSC::Structure*, JSC::Instruction*>, WTF::Bag<JSC::LLIntPrototypeLoadAdaptiveStructureWatchpoint, WTF::DumbPtrTraits<WTF::Private::BagNode<JSC::LLIntPrototypeLoadAdaptiveStructureWatchpoint> > > >, WTF::KeyValuePairKeyExtractor<WTF::KeyValuePair<std::__1::tuple<JSC::Structure*, JSC::Instruction*>, WTF::Bag<JSC::LLIntPrototypeLoadAdaptiveStructureWatchpoint, WTF::DumbPtrTraits<WTF::Private::BagNode<JSC::LLIntPrototypeLoadAdaptiveStructureWatchpoint> > > > >, WTF::TupleHash<JSC::Structure*, JSC::Instruction*>, WTF::HashMap<std::__1::tuple<JSC::Structure*, JSC::Instruction*>, WTF::Bag<JSC::LLIntPrototypeLoadAdaptiveStructureWatchpoint, WTF::DumbPtrTraits<WTF::Private::BagNode<JSC::LLIntPrototypeLoadAdaptiveStructureWatchpoint> > >, WTF::TupleHash<JSC::Structure*, JSC::Instruction*>, WTF::HashTraits<std::__1::tuple<JSC::Structure*, JSC::Instruction*> >, WTF::HashTraits<WTF::Bag<JSC::LLIntPrototypeLoadAdaptiveStructureWatchpoint, WTF::DumbPtrTraits<WTF::Private::BagNode<JSC::LLIntPrototypeLoadAdaptiveStructureWatchpoint> > > > >::KeyValuePairTraits, WTF::HashTraits<std::__1::tuple<JSC::Structure*, JSC::Instruction*> > >::HashTable()
2   0x115776605 WTF::HashMap<std::__1::tuple<JSC::Structure*, JSC::Instruction*>, WTF::Bag<JSC::LLIntPrototypeLoadAdaptiveStructureWatchpoint, WTF::DumbPtrTraits<WTF::Private::BagNode<JSC::LLIntPrototypeLoadAdaptiveStructureWatchpoint> > >, WTF::TupleHash<JSC::Structure*, JSC::Instruction*>, WTF::HashTraits<std::__1::tuple<JSC::Structure*, JSC::Instruction*> >, WTF::HashTraits<WTF::Bag<JSC::LLIntPrototypeLoadAdaptiveStructureWatchpoint, WTF::DumbPtrTraits<WTF::Private::BagNode<JSC::LLIntPrototypeLoadAdaptiveStructureWatchpoint> > > > >::HashMap()
3   0x11574ef25 WTF::HashMap<std::__1::tuple<JSC::Structure*, JSC::Instruction*>, WTF::Bag<JSC::LLIntPrototypeLoadAdaptiveStructureWatchpoint, WTF::DumbPtrTraits<WTF::Private::BagNode<JSC::LLIntPrototypeLoadAdaptiveStructureWatchpoint> > >, WTF::TupleHash<JSC::Structure*, JSC::Instruction*>, WTF::HashTraits<std::__1::tuple<JSC::Structure*, JSC::Instruction*> >, WTF::HashTraits<WTF::Bag<JSC::LLIntPrototypeLoadAdaptiveStructureWatchpoint, WTF::DumbPtrTraits<WTF::Private::BagNode<JSC::LLIntPrototypeLoadAdaptiveStructureWatchpoint> > > > >::HashMap()
4   0x1157504a5 JSC::CodeBlock::CodeBlock(JSC::VM*, JSC::Structure*, JSC::ScriptExecutable*, JSC::UnlinkedCodeBlock*, JSC::JSScope*, WTF::RefPtr<JSC::SourceProvider, WTF::DumbPtrTraits<JSC::SourceProvider> >&&, unsigned int, unsigned int)
5   0x11666020b JSC::FunctionCodeBlock::FunctionCodeBlock(JSC::VM*, JSC::Structure*, JSC::FunctionExecutable*, JSC::UnlinkedFunctionCodeBlock*, JSC::JSScope*, WTF::RefPtr<JSC::SourceProvider, WTF::DumbPtrTraits<JSC::SourceProvider> >&&, unsigned int, unsigned int)
6   0x11665ffa2 JSC::FunctionCodeBlock::FunctionCodeBlock(JSC::VM*, JSC::Structure*, JSC::FunctionExecutable*, JSC::UnlinkedFunctionCodeBlock*, JSC::JSScope*, WTF::RefPtr<JSC::SourceProvider, WTF::DumbPtrTraits<JSC::SourceProvider> >&&, unsigned int, unsigned int)
7   0x116659b2e JSC::FunctionCodeBlock::create(JSC::VM*, JSC::FunctionExecutable*, JSC::UnlinkedFunctionCodeBlock*, JSC::JSScope*, WTF::RefPtr<JSC::SourceProvider, WTF::DumbPtrTraits<JSC::SourceProvider> >&&, unsigned int, unsigned int)
8   0x11665967b JSC::ScriptExecutable::newCodeBlockFor(JSC::CodeSpecializationKind, JSC::JSFunction*, JSC::JSScope*, JSC::JSObject*&)

Comment 1 Radar WebKit Bug Importer 2018-06-16 12:29:37 PDT

<rdar://problem/41189150>

Comment 2 Simon Fraser (smfr) 2018-06-16 12:37:38 PDT

> 300KB on nytimes.com:

Wasted capacity: 301344 bytes (used 77088 of 378432 bytes, utilization: 20.37%) - 8369 allocations
1   0x115776625 WTF::HashTable<std::__1::tuple<JSC::Structure*, JSC::Instruction*>, WTF::KeyValuePair<std::__1::tuple<JSC::Structure*, JSC::Instruction*>, WTF::Bag<JSC::LLIntPrototypeLoadAdaptiveStructureWatchpoint, WTF::DumbPtrTraits<WTF::Private::BagNode<JSC::LLIntPrototypeLoadAdaptiveStructureWatchpoint> > > >, WTF::KeyValuePairKeyExtractor<WTF::KeyValuePair<std::__1::tuple<JSC::Structure*, JSC::Instruction*>, WTF::Bag<JSC::LLIntPrototypeLoadAdaptiveStructureWatchpoint, WTF::DumbPtrTraits<WTF::Private::BagNode<JSC::LLIntPrototypeLoadAdaptiveStructureWatchpoint> > > > >, WTF::TupleHash<JSC::Structure*, JSC::Instruction*>, WTF::HashMap<std::__1::tuple<JSC::Structure*, JSC::Instruction*>, WTF::Bag<JSC::LLIntPrototypeLoadAdaptiveStructureWatchpoint, WTF::DumbPtrTraits<WTF::Private::BagNode<JSC::LLIntPrototypeLoadAdaptiveStructureWatchpoint> > >, WTF::TupleHash<JSC::Structure*, JSC::Instruction*>, WTF::HashTraits<std::__1::tuple<JSC::Structure*, JSC::Instruction*> >, WTF::HashTraits<WTF::Bag<JSC::LLIntPrototypeLoadAdaptiveStructureWatchpoint, WTF::DumbPtrTraits<WTF::Private::BagNode<JSC::LLIntPrototypeLoadAdaptiveStructureWatchpoint> > > > >::KeyValuePairTraits, WTF::HashTraits<std::__1::tuple<JSC::Structure*, JSC::Instruction*> > >::HashTable()
2   0x115776605 WTF::HashMap<std::__1::tuple<JSC::Structure*, JSC::Instruction*>, WTF::Bag<JSC::LLIntPrototypeLoadAdaptiveStructureWatchpoint, WTF::DumbPtrTraits<WTF::Private::BagNode<JSC::LLIntPrototypeLoadAdaptiveStructureWatchpoint> > >, WTF::TupleHash<JSC::Structure*, JSC::Instruction*>, WTF::HashTraits<std::__1::tuple<JSC::Structure*, JSC::Instruction*> >, WTF::HashTraits<WTF::Bag<JSC::LLIntPrototypeLoadAdaptiveStructureWatchpoint, WTF::DumbPtrTraits<WTF::Private::BagNode<JSC::LLIntPrototypeLoadAdaptiveStructureWatchpoint> > > > >::HashMap()
3   0x11574ef25 WTF::HashMap<std::__1::tuple<JSC::Structure*, JSC::Instruction*>, WTF::Bag<JSC::LLIntPrototypeLoadAdaptiveStructureWatchpoint, WTF::DumbPtrTraits<WTF::Private::BagNode<JSC::LLIntPrototypeLoadAdaptiveStructureWatchpoint> > >, WTF::TupleHash<JSC::Structure*, JSC::Instruction*>, WTF::HashTraits<std::__1::tuple<JSC::Structure*, JSC::Instruction*> >, WTF::HashTraits<WTF::Bag<JSC::LLIntPrototypeLoadAdaptiveStructureWatchpoint, WTF::DumbPtrTraits<WTF::Private::BagNode<JSC::LLIntPrototypeLoadAdaptiveStructureWatchpoint> > > > >::HashMap()
4   0x1157504a5 JSC::CodeBlock::CodeBlock(JSC::VM*, JSC::Structure*, JSC::ScriptExecutable*, JSC::UnlinkedCodeBlock*, JSC::JSScope*, WTF::RefPtr<JSC::SourceProvider, WTF::DumbPtrTraits<JSC::SourceProvider> >&&, unsigned int, unsigned int)
5   0x11666020b JSC::FunctionCodeBlock::FunctionCodeBlock(JSC::VM*, JSC::Structure*, JSC::FunctionExecutable*, JSC::UnlinkedFunctionCodeBlock*, JSC::JSScope*, WTF::RefPtr<JSC::SourceProvider, WTF::DumbPtrTraits<JSC::SourceProvider> >&&, unsigned int, unsigned int)
6   0x11665ffa2 JSC::FunctionCodeBlock::FunctionCodeBlock(JSC::VM*, JSC::Structure*, JSC::FunctionExecutable*, JSC::UnlinkedFunctionCodeBlock*, JSC::JSScope*, WTF::RefPtr<JSC::SourceProvider, WTF::DumbPtrTraits<JSC::SourceProvider> >&&, unsigned int, unsigned int)
7   0x116659b2e JSC::FunctionCodeBlock::create(JSC::VM*, JSC::FunctionExecutable*, JSC::UnlinkedFunctionCodeBlock*, JSC::JSScope*, WTF::RefPtr<JSC::SourceProvider, WTF::DumbPtrTraits<JSC::SourceProvider> >&&, unsigned int, unsigned int)
8   0x11665967b JSC::ScriptExecutable::newCodeBlockFor(JSC::CodeSpecializationKind, JSC::JSFunction*, JSC::JSScope*, JSC::JSObject*&)