Bug 189738

Summary: REGRESSION(r235917): 2% regression in Dromaeo CSS selector on MacBookPro11,4
Product: WebKit Reporter: Ryosuke Niwa <rniwa>
Component: DOMAssignee: Ryosuke Niwa <rniwa>
Status: RESOLVED FIXED    
Severity: Normal CC: cdumez, koivisto, webkit-bug-importer, ysuzuki
Priority: P2 Keywords: InRadar
Version: WebKit Nightly Build   
Hardware: Unspecified   
OS: Unspecified   
Bug Depends on: 166748    
Bug Blocks:    
Attachments:
Description Flags
Fixes the bug
none
Patch for landing none

Description Ryosuke Niwa 2018-09-19 02:09:20 PDT 
https://trac.webkit.org/changeset/235917 introduced ~27% regression in nth-child(~) tests and 2% regression for the total Dromaeo css selector tests.
Comment 1 Radar WebKit Bug Importer 2018-09-19 02:09:45 PDT 
<rdar://problem/44595527>
Comment 2 Ryosuke Niwa 2018-09-19 02:14:47 PDT 
Created attachment 350099 [details]
Fixes the bug
Comment 3 Yusuke Suzuki 2018-09-19 02:40:26 PDT 
Comment on attachment 350099 [details]
Fixes the bug

r=me with one more fix.
I think generateNthLastChildParentCheckAndRelationUpdate has the same issue too.
Comment 4 Ryosuke Niwa 2018-09-19 12:37:31 PDT 
(In reply to Yusuke Suzuki from comment #3)
> Comment on attachment 350099 [details]
> Fixes the bug
> 
> r=me with one more fix.
> I think generateNthLastChildParentCheckAndRelationUpdate has the same issue
> too.

Good catch! Thanks for the review.
Comment 5 Ryosuke Niwa 2018-09-19 12:37:52 PDT 
Created attachment 350143 [details]
Patch for landing
Comment 6 Ryosuke Niwa 2018-09-19 12:38:09 PDT 
Comment on attachment 350143 [details]
Patch for landing

Wait for EWS.
Comment 7 Ryosuke Niwa 2018-09-19 15:31:20 PDT 
Committed r236228: <https://trac.webkit.org/changeset/236228>
Comment 8 Yusuke Suzuki 2018-09-19 22:39:45 PDT 
Nice, it seems the regression is recovered. https://perf.webkit.org/v3/#/charts?since=1536816937999&paneList=((19-31)-(19-39)-(19-36))