1264933 - 3.59 - 4.1% tscrollx e10s (linux64, windowsxp) regression on mozilla-inbound (v.48) push 1bdfcc34a189 (Wed Apr 13 2016)

Status: RESOLVED WONTFIX

(Core :: Panning and Zooming, defect)

Description

[Joel Maher ( :jmaher ) (UTC -8)]

Talos has detected a Firefox performance regression from push 1bdfcc34a189c1fd9a307814488b47a6c595d769. As author of one of the patches included in that push, we need your help to address this regression.

This is a list of all known regressions and improvements related to the push:
https://treeherder.mozilla.org/perf.html#/alerts?id=862

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#tscrollx

Reproducing and debugging the regression:

If you would like to re-run this Talos test on a potential fix, use try with the following syntax:
try: -b o -p linux64,win32 -u none -t svgr-e10s[Windows XP] --rebuild 5  # add "mozharness: --spsProfile" to generate profile data

(we suggest --rebuild 5 to be more confident in the results)

To run the test locally and do a more in-depth investigation, first set up a local Talos environment:
https://wiki.mozilla.lorg/Buildbot/Talos/Running#Running_locally_-_Source_Code

Then run the following command from the directory where you set up Talos:
talos --develop -e [path]/firefox -a tscrollx --e10s

Making a decision:
As the patch author we need your feedback to help us handle this regression.
*** Please let us know your plans by Tuesday, 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

[Joel Maher ( :jmaher ) (UTC -8)]

:kats, I see in https://bugzilla.mozilla.org/show_bug.cgi?id=1257641#c18, you were aware of this and believed this regression is worthwhile to take given the benefits of the patch.

Please confirm that and mark this as wontfix if that is the case.

Comment 2

[Kartikaya Gupta (email:[e-mail])]

Yup, confirmed. Thanks for staying on top of these regressions!