Bug 155595 - Set the WebContent process's main thread QoS to USER-INTERACTIVE
Summary: Set the WebContent process's main thread QoS to USER-INTERACTIVE
Status: RESOLVED FIXED
Alias: None
Product: WebKit
Classification: Unclassified
Component: WebKit2 (show other bugs)
Version: WebKit Nightly Build
Hardware: Unspecified Unspecified
: P2 Normal
Assignee: Chris Dumez
URL:
Keywords: InRadar
Depends on:
Blocks:
 
Reported: 2016-03-17 12:51 PDT by Chris Dumez
Modified: 2016-03-17 13:47 PDT (History)
7 users (show)

See Also:

Attachments
Patch (4.97 KB, patch)
2016-03-17 12:58 PDT, Chris Dumez 		no flags Details | Formatted Diff | Diff
Patch (4.97 KB, patch)
2016-03-17 13:08 PDT, Chris Dumez 		no flags Details | Formatted Diff | Diff
Show Obsolete (1) View All Add an attachment (proposed patch, testcase, etc.)

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Description Chris Dumez 2016-03-17 12:51:16 PDT 
Set the WebContent process's main thread QoS to USER-INTERACTIVE instead of USER-INITIATED to match the UIProcess's main thread QoS. The WebContent process main thread is drawing UI and the policy is to use USER-INTERACTIVE QoS in such case.
Comment 1 Chris Dumez 2016-03-17 12:51:37 PDT 
rdar://problem/22534965
Comment 2 Chris Dumez 2016-03-17 12:58:50 PDT 
Created attachment 274316 [details]
Patch
Comment 3 Chris Dumez 2016-03-17 13:08:02 PDT 
Created attachment 274320 [details]
Patch
Comment 4 Antti Koivisto 2016-03-17 13:17:26 PDT 
We have deliberately used lower priority for web thread/process so it doesn't make scrolling choppy. How have you verified this is not a problem anymore?
Comment 5 Chris Dumez 2016-03-17 13:18:33 PDT 
(In reply to comment #4)
> We have deliberately used lower priority for web thread/process so it
> doesn't make scrolling choppy. How have you verified this is not a problem
> anymore

We now use the same QoS but the WebContent process still has lower relative priority than the scrolling thread to mitigate the issue as explained in the ChangeLog.
Comment 6 Chris Dumez 2016-03-17 13:23:11 PDT 
(In reply to comment #5)
> (In reply to comment #4)
> > We have deliberately used lower priority for web thread/process so it
> > doesn't make scrolling choppy. How have you verified this is not a problem
> > anymore
> 
> We now use the same QoS but the WebContent process still has lower relative
> priority than the scrolling thread to mitigate the issue as explained in the
> ChangeLog.

About the verification, scrolling on nytimes.com does not look visibly choppier and I was counting on ScrollPerf to let us know if there is a regression on this front.
Comment 7 Antti Koivisto 2016-03-17 13:43:37 PDT 
Comment on attachment 274320 [details]
Patch

Ok!
Comment 8 Chris Dumez 2016-03-17 13:47:01 PDT 
Comment on attachment 274320 [details]
Patch

Clearing flags on attachment: 274320

Committed r198350: <http://trac.webkit.org/changeset/198350>
Comment 9 Chris Dumez 2016-03-17 13:47:08 PDT 
All reviewed patches have been landed.  Closing bug.