1347602 - 15.97 - 20.97% tresize (windows7-32, windows8-64) regression on push 7e35e5f2b9dfb5539598e67e3b08502e111be353 (Mon Mar 13 2017)

Status: RESOLVED DUPLICATE of bug 1347545

(Firefox :: Security, defect)

Description

[Robert Wood [:rwood]]

Talos has detected a Firefox performance regression from push 7e35e5f2b9dfb5539598e67e3b08502e111be353. As author of one of the patches included in that push, we need your help to address this regression.

Regressions:

 21%  tresize windows8-64 pgo      10.22 -> 12.36
 16%  tresize windows7-32 pgo      9.13 -> 10.59


You can find links to graphs and comparison views for each of the above tests at: https://treeherder.mozilla.org/perf.html#/alerts?id=5442

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

[Johann Hofmann [:johannh]]

It's highly unlikely that this patch was the cause of the regression, sorry. The patch replaces an unneeded function in a test file with a utility function. I don't see how this would cause a performance hit in the application.

That's all from my side, I'm not sure how to help you with this. Please redirect to the correct cause.

Comment 2

[William Lachance (:wlach)]

Looking at the graphs, this test went bimodal after bug 1346644 landed, that is almost certainly the root cause here. Let's dupe this to the already-filed bug 1347545 tracking that.