Bug 186725

Summary:	InferredTypeTable wastes 2MB of HashTable capacity on cnn.com
Product:	WebKit	Reporter:	Simon Fraser (smfr) <simon.fraser>
Component:	JavaScriptCore	Assignee:	Nobody <webkit-unassigned>
Status:	RESOLVED CONFIGURATION CHANGED
Severity:	Normal	CC:	keith_miller, saam, simon.fraser, webkit-bug-importer, ysuzuki
Priority:	P2	Keywords:	InRadar
Version:	WebKit Nightly Build
Hardware:	Unspecified
OS:	Unspecified
See Also:	https://bugs.webkit.org/show_bug.cgi?id=190906

Description Simon Fraser (smfr) 2018-06-16 12:17:54 PDT

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

Wasted capacity: 1 998 144 bytes (used 904640 of 2902784 bytes, utilization: 31.16%) - 8209 allocations
1   0x116495945 WTF::HashTable<WTF::RefPtr<WTF::UniquedStringImpl, WTF::DumbPtrTraits<WTF::UniquedStringImpl> >, WTF::KeyValuePair<WTF::RefPtr<WTF::UniquedStringImpl, WTF::DumbPtrTraits<WTF::UniquedStringImpl> >, JSC::WriteBarrier<JSC::InferredType, WTF::DumbPtrTraits<JSC::InferredType> > >, WTF::KeyValuePairKeyExtractor<WTF::KeyValuePair<WTF::RefPtr<WTF::UniquedStringImpl, WTF::DumbPtrTraits<WTF::UniquedStringImpl> >, JSC::WriteBarrier<JSC::InferredType, WTF::DumbPtrTraits<JSC::InferredType> > > >, JSC::IdentifierRepHash, WTF::HashMap<WTF::RefPtr<WTF::UniquedStringImpl, WTF::DumbPtrTraits<WTF::UniquedStringImpl> >, JSC::WriteBarrier<JSC::InferredType, WTF::DumbPtrTraits<JSC::InferredType> >, JSC::IdentifierRepHash, WTF::HashTraits<WTF::RefPtr<WTF::UniquedStringImpl, WTF::DumbPtrTraits<WTF::UniquedStringImpl> > >, WTF::HashTraits<JSC::WriteBarrier<JSC::InferredType, WTF::DumbPtrTraits<JSC::InferredType> > > >::KeyValuePairTraits, WTF::HashTraits<WTF::RefPtr<WTF::UniquedStringImpl, WTF::DumbPtrTraits<WTF::UniquedStringImpl> > > >::HashTable()
2   0x116495925 WTF::HashMap<WTF::RefPtr<WTF::UniquedStringImpl, WTF::DumbPtrTraits<WTF::UniquedStringImpl> >, JSC::WriteBarrier<JSC::InferredType, WTF::DumbPtrTraits<JSC::InferredType> >, JSC::IdentifierRepHash, WTF::HashTraits<WTF::RefPtr<WTF::UniquedStringImpl, WTF::DumbPtrTraits<WTF::UniquedStringImpl> > >, WTF::HashTraits<JSC::WriteBarrier<JSC::InferredType, WTF::DumbPtrTraits<JSC::InferredType> > > >::HashMap()
3   0x116489b15 WTF::HashMap<WTF::RefPtr<WTF::UniquedStringImpl, WTF::DumbPtrTraits<WTF::UniquedStringImpl> >, JSC::WriteBarrier<JSC::InferredType, WTF::DumbPtrTraits<JSC::InferredType> >, JSC::IdentifierRepHash, WTF::HashTraits<WTF::RefPtr<WTF::UniquedStringImpl, WTF::DumbPtrTraits<WTF::UniquedStringImpl> > >, WTF::HashTraits<JSC::WriteBarrier<JSC::InferredType, WTF::DumbPtrTraits<JSC::InferredType> > > >::HashMap()
4   0x116489aea JSC::InferredTypeTable::InferredTypeTable(JSC::VM&)
5   0x11648894d JSC::InferredTypeTable::InferredTypeTable(JSC::VM&)
6   0x1164888d1 JSC::InferredTypeTable::create(JSC::VM&)
7   0x116675e46 JSC::Structure::willStoreValueSlow(JSC::VM&, JSC::PropertyName, JSC::JSValue, bool, JSC::InferredTypeTable::StoredPropertyAge)
8   0x11536b938 JSC::Structure::willStoreValueForNewTransition(JSC::VM&, JSC::PropertyName, JSC::JSValue, bool)

Comment 1 Radar WebKit Bug Importer 2018-06-16 12:18:17 PDT

<rdar://problem/41189073>

Comment 2 Yusuke Suzuki 2019-01-29 22:27:12 PST

InferredTypeTable is now removed :)