Talos has detected a Firefox performance regression from push:

https://hg.mozilla.org/integration/autoland/pushloghtml?changeset=54c0b12443edcbc5df3328ee7772345325bac70e

As author of one of the patches included in that push, we need your help to address this regression.

Regressions:

9% sessionrestore linux64 pgo e10s stylo 319.88 -> 349.50
5% sessionrestore_no_auto_restore windows10-64 pgo e10s stylo 302.33 -> 318.58
5% sessionrestore windows10-64 pgo e10s stylo 297.54 -> 312.75
4% sessionrestore_no_auto_restore windows7-32 pgo e10s stylo 311.96 -> 325.17
4% sessionrestore windows7-32 pgo e10s stylo 308.21 -> 320.00
4% sessionrestore_no_auto_restore linux64-pgo-qr opt e10s stylo 846.75 -> 878.08

Improvements:

3% ts_paint windows7-32 pgo e10s stylo 321.12 -> 312.92
2% ts_paint_webext windows10-64-pgo-qr opt e10s stylo 324.50 -> 317.00

You can find links to graphs and comparison views for each of the above tests at: https://treeherder.mozilla.org/perf.html#/alerts?id=19747

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/Performance_sheriffing/Talos/Tests

For information on reproducing and debugging the regression, either on try or locally, see: https://wiki.mozilla.org/Performance_sheriffing/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/Performance_sheriffing/Talos/RegressionBugsHandling

I noticed bug 827976 got backed out.
We should close this bug as invalid.

And also update alert 19747's state by clicking on "Marked as backed out" on it.

See also bug 1531520 which changes the talos test so that this apparent regression (which seems to actually be an improvement) will no longer be reported.

Yeah, these changes were the expected improvements and regressions from bug 827976. Once it relands, we should see the Improvements listed here again, and no longer see the sessionrestore regressions, as the meaning of that test got changed by bug 1531520.

So I think we can mark this bug as a wontfix or a duplicate of bug 1531520

(In reply to :Felipe Gomes (needinfo me!) from comment #4)

Yeah, these changes were the expected improvements and regressions from bug 827976. Once it relands, we should see the Improvements listed here again, and no longer see the sessionrestore regressions, as the meaning of that test got changed by bug 1531520.

So I think we can mark this bug as a wontfix or a duplicate of bug 1531520.

I see your point of view. I've decided to mark it INVALID because we don't usually file bugs for already backed out patches.
We only record such things in Perfherder.
Thanks for providing these insights!