1455523 - 61.3 - 75.67% displaylist_mutate (linux64, osx-10-10, windows10-64, windows7-32) regression on push 652cff2a5a79e299ee7d34ca0bb9703de01e98fe (Tue Apr 17 2018)

Status: RESOLVED WONTFIX

(Core :: Web Painting, defect)

Description

[Ionuț Goldan [:igoldan]]

Talos has detected a Firefox performance regression from push:

https://hg.mozilla.org/releases/mozilla-beta/pushloghtml?changeset=652cff2a5a79e299ee7d34ca0bb9703de01e98fe

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

Regressions:

 76%  displaylist_mutate windows7-32 opt e10s stylo     4,191.12 -> 7,362.65
 74%  displaylist_mutate linux64 opt e10s stylo         2,686.70 -> 4,679.81
 67%  displaylist_mutate windows10-64 opt e10s stylo    3,674.61 -> 6,152.29
 61%  displaylist_mutate osx-10-10 opt e10s stylo       6,865.82 -> 11,074.49

Improvements:

  3%  stylebench windows10-64 opt e10s stylo     70.09 -> 72.37


You can find links to graphs and comparison views for each of the above tests at: https://treeherder.mozilla.org/perf.html#/alerts?id=12805

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/Buildbot/Talos/Tests

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

Comment 1

[Ionuț Goldan [:igoldan]]

:mattwoodrow Out of the big patch that landed, bug 1454509 looks like the source of regression. Please state whether I'm right or wrong.

Assuming I got this right, I guess we simply have to accept this, right? (according to [1])

[1] https://bugzilla.mozilla.org/show_bug.cgi?id=1454509#c0

Comment 2

[Matt Woodrow (:mattwoodrow)]

Yes, unfortunately we do. Retained-dl is the source of the wins, so disabling it means we lose them. 61 will be better!