1401483 - 17.19 - 40.24% sessionrestore_many_windows (windows10-64, windows7-32) regression on push 8ec345b71a6e775d9ba65b2e770f98253492b8a9 (Tue Sep 19 2017)

Status: RESOLVED WONTFIX

(Core :: Networking: Cache, defect, P3)

Description

[Ionuț Goldan [:igoldan]]

Talos has detected a Firefox performance regression from push:

https://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?changeset=8ec345b71a6e775d9ba65b2e770f98253492b8a9

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

Regressions:

 40%  sessionrestore_many_windows windows10-64 pgo e10s     2,484.83 -> 3,484.75
 17%  sessionrestore_many_windows windows7-32 pgo e10s      2,987.71 -> 3,501.33


You can find links to graphs and comparison views for each of the above tests at: https://treeherder.mozilla.org/perf.html#/alerts?id=9545

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]]

Michal, I filed this bug to keep track of the status of enabling RCWN and better triage the perf alerts.

Comment 2

[Jim Mathies [:jimm]]

Can we get some detail on what this bug is all about?

Comment 3

[Ionuț Goldan [:igoldan]]

When bug 1392841 landed, it brought big improvements noticed by sessionrestore_many_windows perf tests, until the backouts. With this bug, I'm able to watch for the stable landing of the bug, and then confirm the improvement.

Comment 4

[Gregory Pappas [:gregp]]

Closing old win7 regressions

and bug 1392841 eventually did land, which should've fixed this