1611800 - 11.18 - 61.89% glterrain / tart / tscrollx (windows10-64-shippable-qr) regression on push cd2634c753b9b955aafc290d57f0cbcdf9fab688 (Fri January 24 2020)

Status: RESOLVED WONTFIX

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

Description

[Florin Strugariu [:Bebe]]

Talos has detected a Firefox performance regression from push:

https://hg.mozilla.org/integration/autoland/pushloghtml?changeset=cd2634c753b9b955aafc290d57f0cbcdf9fab688

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

Regressions:

62% glterrain windows10-64-shippable-qr opt e10s stylo 1.08 -> 1.74
34% tscrollx windows10-64-shippable-qr opt e10s stylo 0.82 -> 1.09
23% tscrollx windows10-64-shippable-qr opt e10s stylo 0.85 -> 1.05
11% tart windows10-64-shippable-qr opt e10s stylo 2.79 -> 3.10

You can find links to graphs and comparison views for each of the above tests at: https://treeherder.mozilla.org/perf.html#/alerts?id=24805

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/TestEngineering/Performance/Talos

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

Comment 1

[Sotaro Ikeda [:sotaro]]

Regression of glterrain was already accepted by :jgilbert at Bug 1595437 Comment 13 . Another regression became smaller than Bug 1603083 . By enabling native compositor by Bug 1592509, total performance becomes better.

:gw, can you comment to this bug?

Comment 2

[Glenn Watson [:gw]]

Yes, we can mark this as WONTFIX, for now at least.

The glterrain one has been discussed with jgilbert. The other ones are large % values, but very small in terms of overall frame budget in ms - we believe this is due to higher overhead in DC at lower resolutions.

It's possible in future we may be able to improve these, but we want to keep DC enabled and the reported regressions are not a problem.

Comment 3

[Marian Raiciof [:marauder]]

Thanks for the updates!