Talos has detected a Firefox performance regression from push 4c229ab19c49. 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=910 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 -u none -t svgr,svgr-e10s --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:tsvgr_opacity (add --e10s to run tests in e10s mode) 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(es) will be backed out! *** Our wiki page outlines the common responses and expectations: https://wiki.mozilla.org/Buildbot/Talos/RegressionBugsHandling

I did a lot of retriggers and it looks as though we have the one regression, here is a compare view to support it: https://treeherder.mozilla.org/perf.html#/compare?originalProject=mozilla-inbound&originalRevision=cb9908e330d1&newProject=mozilla-inbound&newRevision=4c229ab19c49&framework=1 :mattwoodrow, can you help figure out if we can reduce/remove this regression or get an explanation for it?

As I mentioned in bug 852754 comment 38, this regression is the inverse of the Talos improvement detected in bug 852754 comment 33: The improvement was due to a bug, and bug 1263480 fixed that bug, so we're back to the old numbers.

apologies for overlooking that- thanks for being patient and resolving this.