Talos has detected a Firefox performance regression from push: https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=5ed5a088c7820c83ef3894b6067bc32dee483257&tochange=810204c29a4dec573c0070293792e95843d650b1 As author of one of the patches included in that push, we need your help to address this regression. Regressions: 5% about_preferences_basic linux64 pgo e10s stylo 133.63 -> 140.17 4% about_preferences_basic windows10-64 pgo e10s stylo202.15 -> 210.07 4% about_preferences_basic osx-10-10 opt e10s stylo 209.20 -> 216.83 3% about_preferences_basic linux64 opt e10s stylo 146.85 -> 151.01 Improvements: 5% tsvgx windows7-32 pgo e10s stylo 393.39 -> 372.32 5% tsvgx windows7-32 opt e10s stylo 462.23 -> 439.94 You can find links to graphs and comparison views for each of the above tests at: https://treeherder.mozilla.org/perf.html#/alerts?id=12274 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

:k88hudson Please look over these perf regressions, as they seem related to bug 1417155. I think the perf improvements are related to another bug; will come back with more details on that.

I think this regression might be expected since I have added a new panel/section to about:preferences, but I will look into eliminating other possibilities

I talked to :rwood (the author of this test) and he agreed this regression is expected since the test loads all about:preferences categories at once and there is now additional category to load. We also agreed that adding about:preferences#home to the test would be a good idea