Talos has detected a Firefox performance regression from push: https://hg.mozilla.org/integration/autoland/pushloghtml?changeset=90b00e89e83e5eb07baf20dc55a8a141d8f242af As author of one of the patches included in that push, we need your help to address this regression. Regressions: 9% tps linux64 pgo e10s stylo 9.61 -> 10.44 6% sessionrestore linux64 pgo e10s stylo 295.04 -> 313.50 6% sessionrestore windows10-64 pgo e10s stylo 281.75 -> 298.17 6% sessionrestore windows10-64 opt e10s stylo 309.25 -> 327.25 5% sessionrestore windows7-32 pgo e10s stylo 290.75 -> 305.75 5% sessionrestore_no_auto_restore windows10-64 opt e10s stylo 332.08 -> 349.00 5% sessionrestore_no_auto_restore windows10-64-qr opt e10s stylo 335.12 -> 352.08 5% tps linux64-qr opt e10s stylo 9.22 -> 9.67 5% tps windows10-64 opt e10s stylo 10.83 -> 11.35 5% sessionrestore linux64 opt e10s stylo 323.17 -> 338.50 5% sessionrestore windows10-64-qr opt e10s stylo 317.12 -> 331.75 5% sessionrestore_no_auto_restore windows10-64 pgo e10s stylo 304.67 -> 318.58 4% sessionrestore_no_auto_restore linux64 opt e10s stylo 340.79 -> 355.42 4% sessionrestore_no_auto_restore linux64 pgo e10s stylo 316.92 -> 330.00 4% sessionrestore_no_auto_restore windows7-32 pgo e10s stylo 310.58 -> 323.25 4% sessionrestore_no_auto_restore windows7-32 opt e10s stylo 335.17 -> 348.00 4% sessionrestore windows7-32 opt e10s stylo 317.08 -> 328.50 You can find links to graphs and comparison views for each of the above tests at: https://treeherder.mozilla.org/perf.html#/alerts?id=16728 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

This is the result of converting out bootstrap addon to a WebExtension. We hope to make improvements in the beta cycle, but it's possible this is the new cost of business for system addons.

For the record, I think we recovered most of the sessionrestore regressions here: https://bugzilla.mozilla.org/show_bug.cgi?id=1498027#c7