1369004 - 10.14 - 16.93% tp5o_webext Main_RSS / tp5o_webext Private Bytes (windows7-32) regression on push 8429360d3050f174202a1a8133489b6f7291348f (Wed May 31 2017)

Status: RESOLVED FIXED

(Core :: Gecko Profiler, defect)

Description

[Ionuț Goldan [:igoldan]]

Talos has detected a Firefox performance regression from push:

https://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?changeset=8429360d3050f174202a1a8133489b6f7291348f

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

Regressions:

 17%  tp5o_webext Private Bytes windows7-32 opt e10s     150,255,886.02 -> 175,699,268.91
 10%  tp5o_webext Main_RSS windows7-32 opt e10s          125,110,238.83 -> 137,791,636.73


You can find links to graphs and comparison views for each of the above tests at: https://treeherder.mozilla.org/perf.html#/alerts?id=6955

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]]

:njn could you look over this issue and confirm it? PGO on windows7 builds look affected, but their alerts will come later.

linux64 *may* also be affected by this or a previous change, but I can't really tell now, as I'm waiting for extra data points.

Comment 2

[Markus Stange [:mstange]]

This is an extremely surprising regression range. Has the backout of bug 1347274 has fixed the memory regression?
I'd say that bug 1366316 is the more likely candidate to have caused this.

Comment 3

[Markus Stange [:mstange]]

(In reply to Markus Stange [:mstange] from comment #2)
> This is an extremely surprising regression range. Has the backout of bug
> 1347274 has fixed the memory regression?
> I'd say that bug 1366316 is the more likely candidate to have caused this.

The backout has indeed fixed the regression, according to bug 1347274 comment 38. Weird!