1189161 - 5-11.5% Linux 32/Win* tsvgr_opacity/tps regression on Mozilla-Inbound-Non-PGO on July 29, 2015 from push 82fc23b5d5b8

Status: RESOLVED WONTFIX

(Testing :: Talos, defect)

Description

[Vaibhav (:vaibhav1994)]

Talos has detected a Firefox performance regression from the commit 82fc23b5d5b8 in bug 1183604.  We need you to address this regression.

This is a list of all known regressions and improvements related to your bug:
http://alertmanager.allizom.org:8080/alerts.html?rev=82fc23b5d5b8&showAll=1

On the page above you can see Talos 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, please see: https://wiki.mozilla.org/Buildbot/Talos/Tests#tps

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 linux,win64,win32 -u none -t g2  # add "mozharness: --spsProfile" to generate profile data

To run the test locally and do a more in-depth investigation, first set up a local Talos environment:
https://wiki.mozilla.org/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 tps

Making a decision:
As the patch author we need your feedback to help us handle this regression.
*** Please let us know your plans by Monday, or the offending patch will be backed out! ***

Our wiki page oulines the common responses and expectations:
https://wiki.mozilla.org/Buildbot/Talos/RegressionBugsHandling

Comment 1

[Vaibhav (:vaibhav1994)]

Joel, needinfo-ing you since you were the reviewer of the patch. SVG, ROW Opacity from the graph: http://graphs.mozilla.org/graph.html#tests=[[225,132,33],[225,131,33]]&sel=none&displayrange=30&datatype=geo looks like an improvement has been removed due to bug 1186956

However, Talos Page Switch graph: http://graphs.mozilla.org/graph.html#tests=[[329,132,31],[329,131,31]]&sel=none&displayrange=30&datatype=geo looks like it has regressed more than levels before the improvement. I have retriggered some tests on inbound to get more data - https://treeherder.mozilla.org/#/jobs?repo=mozilla-inbound&fromchange=3d882ef61333&tochange=39fba4322e8a&filter-searchStr=Windows%208%2064-bit%20mozilla-inbound%20talos%20g2

Comment 2

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

thanks for looking into this, yes it looks like a valid regression.  For tps, we are making major changes to that test, so for now, I would like to ignore that- especially on windows.

I really don't like the svg opacity on linux regression, nor the damp on pgo.

The problem here is this is fixing a series of other regression, I need to dig into what wins we had before fixing and see how much of this is expected.