Bug 219677

Summary: REGRESSION(r268886): Page load time performance regression
Product: WebKit Reporter: Per Arne Vollan <pvollan>
Component: WebKit Misc.Assignee: Noam Rosenthal <noam>
Status: RESOLVED FIXED    
Severity: Normal CC: ap, bfulgham, calvaris, cgarcia, darin, dean_johnson, ews-watchlist, gustavo, menard, nham, pnormand, pvollan, vjaquez, webkit-bug-importer
Priority: P2 Keywords: InRadar
Version: WebKit Nightly Build   
Hardware: Unspecified   
OS: Unspecified   
Attachments:
Description Flags
Patch none

Description Per Arne Vollan 2020-12-09 04:44:55 PST
The commit r268886 introduced a page load time regression on iOS. In particular, loading nytimes and facebook seems to be slower.
Comment 1 Per Arne Vollan 2020-12-09 04:45:47 PST
<rdar://problem/71543823>
Comment 2 Noam Rosenthal 2020-12-09 04:54:00 PST
How was the regression tested? Bisecting? Reverting? What is the metric for page load time?
Comment 3 Noam Rosenthal 2020-12-13 00:04:26 PST
I have a speculation on how to fix it, working on a patch.
Comment 4 Noam Rosenthal 2020-12-14 00:33:37 PST
Created attachment 416140 [details]
Patch
Comment 5 Per Arne Vollan 2020-12-14 01:39:20 PST
(In reply to Noam Rosenthal from comment #3)
> I have a speculation on how to fix it, working on a patch.

Great, thanks! I can test this patch.
Comment 6 Noam Rosenthal 2020-12-14 03:36:14 PST
(In reply to Per Arne Vollan from comment #5)
> (In reply to Noam Rosenthal from comment #3)
> > I have a speculation on how to fix it, working on a patch.
> 
> Great, thanks! I can test this patch.
Thanks!
Let me know if there's a way I can test it myself :)
Comment 7 Per Arne Vollan 2020-12-15 06:11:57 PST
(In reply to Noam Rosenthal from comment #6)
> (In reply to Per Arne Vollan from comment #5)
> > (In reply to Noam Rosenthal from comment #3)
> > > I have a speculation on how to fix it, working on a patch.
> > 
> > Great, thanks! I can test this patch.
> Thanks!
> Let me know if there's a way I can test it myself :)

It looks like this patch recovers all, or most of the initial regression. Great work!
Comment 8 EWS 2020-12-15 09:30:58 PST
Committed r270845: <https://trac.webkit.org/changeset/270845>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 416140 [details].