Bug 197745

Summary: REGRESSION (r241734): 1% slower PLT on iPad
Product: WebKit Reporter: Daniel Bates <dbates>
Component: WebKit Misc.Assignee: Daniel Bates <dbates>
Status: RESOLVED FIXED    
Severity: Normal CC: bfulgham, pvollan, webkit-bug-importer
Priority: P2 Keywords: InRadar, PlatformOnly, Regression
Version: WebKit Local Build   
Hardware: iPhone / iPad   
OS: iOS 12   
See Also: https://bugs.webkit.org/show_bug.cgi?id=197746
Bug Depends on: 192824    
Bug Blocks: 190571    
Attachments:
Description Flags
Patch none

Daniel Bates
Reported 2019-05-09 11:15:57 PDT
When building with USE(UIKIT_KEYBOARD_ADDITIONS) enabled and following r241734 we now always request a keyboard when WKContentView becomes first responder as we have one key event handling code path. As it turns out this is expensive enough the cause an ~1% slowdown in PLT on iPad.
Attachments
Patch (3.22 KB, patch)
2019-05-09 11:42 PDT, Daniel Bates 		no flags
DetailsFormatted DiffDiff
View All Add attachment proposed patch, testcase, etc.
Daniel Bates
Comment 1 2019-05-09 11:28:36 PDT
Have a patch that regains the ~1% loss by lazily requesting keyboard instantiation immediately only if we have a hardware keyboard attached. Better fix is to be even lazier: only on first hardware keydown. We'll do this in another bug to spread out the risk and because we (Apple) wants this fix sooner. See bug #197746.
Daniel Bates
Comment 2 2019-05-09 11:41:35 PDT
<rdar://problem/50457731>
Daniel Bates
Comment 3 2019-05-09 11:42:24 PDT
Created attachment 369503 [details] Patch
Per Arne Vollan
Comment 4 2019-05-09 11:54:51 PDT
Comment on attachment 369503 [details] Patch Great work, Dan! R=me.
Daniel Bates
Comment 5 2019-05-09 11:58:48 PDT
Comment on attachment 369503 [details] Patch Clearing flags on attachment: 369503 Committed r245148: <https://trac.webkit.org/changeset/245148>
Daniel Bates
Comment 6 2019-05-09 11:58:50 PDT
All reviewed patches have been landed. Closing bug.
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