1569950 - 6.95 - 10.95% tscrollx (windows10-64-shippable-qr) regression on push ca1ff794e472f28f0f65cd93af158957c112dc62 (Wed July 17 2019)

Status: RESOLVED WONTFIX

(Core :: Graphics: WebRender, defect, P3)

Description

[Alexandru Ionescu (needinfo me) [:alexandrui]]

Talos has detected a Firefox performance regression from push:

https://hg.mozilla.org/integration/autoland/pushloghtml?changeset=ca1ff794e472f28f0f65cd93af158957c112dc62

As author of one of the patches included in that push, we need your help to address this regression.

Regressions:

11% tscrollx windows10-64-shippable-qr opt e10s stylo 0.77 -> 0.85
7% tscrollx windows10-64-shippable-qr opt e10s stylo 0.77 -> 0.82

You can find links to graphs and comparison views for each of the above tests at: https://treeherder.mozilla.org/perf.html#/alerts?id=22196

On the page above you can see an alert for each affected platform as well as a link to a graph showing the history of scores for this test. There is also a link to a treeherder page showing the Talos jobs in a pushlog format.

To learn more about the regressing test(s), please see: https://wiki.mozilla.org/Performance_sheriffing/Talos/Tests

For information on reproducing and debugging the regression, either on try or locally, see: https://wiki.mozilla.org/Performance_sheriffing/Talos/Running

*** Please let us know your plans within 3 business days, or the offending patch(es) will be backed out! ***

Our wiki page outlines the common responses and expectations: https://wiki.mozilla.org/Performance_sheriffing/Talos/RegressionBugsHandling

Comment 2

[Lee Salzman [:lsalzman]]

I am working on a fix for this at the moment, but until then the slight regression is okay, because it still at least improves the end-user experience by eliminating jank as it is.

Comment 3

[Lee Salzman [:lsalzman]]

Attachment: Bug 1569950 - only partially clear WR glyph caches if it is not necessary to fully clear. r?kvark

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/3b5c9358aa68
only partially clear WR glyph caches if it is not necessary to fully clear. r=kvark

Comment 5

[Bogdan Tara[:bogdan_tara | bogdant]]

https://hg.mozilla.org/mozilla-central/rev/3b5c9358aa68

Comment 6

[Alexandru Ionescu (needinfo me) [:alexandrui]]

Hi. I don't see any improvement from this push.

Comment 7

[Lee Salzman [:lsalzman]]

For now we are okay with accepting this regression as the alternative is higher memory usage and jank, so the patch still improves the user experience despite what Talos says.