Bug 186736

Summary:	JITThunks wastes 106KB of HashTable capacity on cnn.com
Product:	WebKit	Reporter:	Simon Fraser (smfr) <simon.fraser>
Component:	JavaScriptCore	Assignee:	Nobody <webkit-unassigned>
Status:	RESOLVED DUPLICATE
Severity:	Normal	CC:	bfulgham, 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 12:31:57 PDT

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

Wasted capacity: 106528 bytes (used 24544 of 131072 bytes, utilization: 18.73%) - 1 allocations
1   0x11623be95 WTF::HashTable<std::__1::tuple<JSC::TaggedNativeFunction, JSC::TaggedNativeFunction, WTF::String>, WTF::KeyValuePair<std::__1::tuple<JSC::TaggedNativeFunction, JSC::TaggedNativeFunction, WTF::String>, JSC::Weak<JSC::NativeExecutable> >, WTF::KeyValuePairKeyExtractor<WTF::KeyValuePair<std::__1::tuple<JSC::TaggedNativeFunction, JSC::TaggedNativeFunction, WTF::String>, JSC::Weak<JSC::NativeExecutable> > >, JSC::JITThunks::HostFunctionHash, WTF::HashMap<std::__1::tuple<JSC::TaggedNativeFunction, JSC::TaggedNativeFunction, WTF::String>, JSC::Weak<JSC::NativeExecutable>, JSC::JITThunks::HostFunctionHash, JSC::JITThunks::HostFunctionHashTrait, WTF::HashTraits<JSC::Weak<JSC::NativeExecutable> > >::KeyValuePairTraits, JSC::JITThunks::HostFunctionHashTrait>::HashTable()
2   0x11623be75 WTF::HashMap<std::__1::tuple<JSC::TaggedNativeFunction, JSC::TaggedNativeFunction, WTF::String>, JSC::Weak<JSC::NativeExecutable>, JSC::JITThunks::HostFunctionHash, JSC::JITThunks::HostFunctionHashTrait, WTF::HashTraits<JSC::Weak<JSC::NativeExecutable> > >::HashMap()
3   0x11623be55 WTF::HashMap<std::__1::tuple<JSC::TaggedNativeFunction, JSC::TaggedNativeFunction, WTF::String>, JSC::Weak<JSC::NativeExecutable>, JSC::JITThunks::HostFunctionHash, JSC::JITThunks::HostFunctionHashTrait, WTF::HashTraits<JSC::Weak<JSC::NativeExecutable> > >::HashMap()
4   0x116233661 JSC::JITThunks::JITThunks()
5   0x116233725 JSC::JITThunks::JITThunks()
6   0x1166be558 JSC::VM::VM(JSC::VM::VMType, JSC::HeapType)
7   0x1166c1d51 JSC::VM::VM(JSC::VM::VMType, JSC::HeapType)
8   0x1166c5406 JSC::VM::create(JSC::HeapType)

Comment 1 Radar WebKit Bug Importer 2018-06-16 12:32:19 PDT

<rdar://problem/41189174>

Comment 2 Simon Fraser (smfr) 2018-06-16 12:44:19 PDT

On nytimes.com:

Wasted capacity: 98176 bytes (used 32896 of 131072 bytes, utilization: 25.10%) - 1 allocations
1   0x11623be95 WTF::HashTable<std::__1::tuple<JSC::TaggedNativeFunction, JSC::TaggedNativeFunction, WTF::String>, WTF::KeyValuePair<std::__1::tuple<JSC::TaggedNativeFunction, JSC::TaggedNativeFunction, WTF::String>, JSC::Weak<JSC::NativeExecutable> >, WTF::KeyValuePairKeyExtractor<WTF::KeyValuePair<std::__1::tuple<JSC::TaggedNativeFunction, JSC::TaggedNativeFunction, WTF::String>, JSC::Weak<JSC::NativeExecutable> > >, JSC::JITThunks::HostFunctionHash, WTF::HashMap<std::__1::tuple<JSC::TaggedNativeFunction, JSC::TaggedNativeFunction, WTF::String>, JSC::Weak<JSC::NativeExecutable>, JSC::JITThunks::HostFunctionHash, JSC::JITThunks::HostFunctionHashTrait, WTF::HashTraits<JSC::Weak<JSC::NativeExecutable> > >::KeyValuePairTraits, JSC::JITThunks::HostFunctionHashTrait>::HashTable()
2   0x11623be75 WTF::HashMap<std::__1::tuple<JSC::TaggedNativeFunction, JSC::TaggedNativeFunction, WTF::String>, JSC::Weak<JSC::NativeExecutable>, JSC::JITThunks::HostFunctionHash, JSC::JITThunks::HostFunctionHashTrait, WTF::HashTraits<JSC::Weak<JSC::NativeExecutable> > >::HashMap()
3   0x11623be55 WTF::HashMap<std::__1::tuple<JSC::TaggedNativeFunction, JSC::TaggedNativeFunction, WTF::String>, JSC::Weak<JSC::NativeExecutable>, JSC::JITThunks::HostFunctionHash, JSC::JITThunks::HostFunctionHashTrait, WTF::HashTraits<JSC::Weak<JSC::NativeExecutable> > >::HashMap()
4   0x116233661 JSC::JITThunks::JITThunks()
5   0x116233725 JSC::JITThunks::JITThunks()
6   0x1166be558 JSC::VM::VM(JSC::VM::VMType, JSC::HeapType)
7   0x1166c1d51 JSC::VM::VM(JSC::VM::VMType, JSC::HeapType)
8   0x1166c5406 JSC::VM::create(JSC::HeapType)

Comment 3 Yusuke Suzuki 2020-02-29 01:19:38 PST

Note that we recently compacted this into 1/4 size.

Comment 4 Yusuke Suzuki 2020-02-29 01:19:54 PST

https://bugs.webkit.org/show_bug.cgi?id=207715

Comment 5 Brent Fulgham 2022-02-12 19:52:15 PST


*** This bug has been marked as a duplicate of bug 207715 ***