Talos has detected a Firefox performance regression from push:

https://hg.mozilla.org/integration/autoland/pushloghtml?changeset=88a27dc859b9e45ae9510c4c20822bf6d085d5f5

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

Regressions:

13% sessionrestore_no_auto_restore linux64 pgo e10s stylo 337.17 -> 380.44

You can find links to graphs and comparison views for each of the above tests at: https://treeherder.mozilla.org/perf.html#/alerts?id=19656

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

Bug 1527066 generated a performance regression
:catlee can you take a look?

I'm not sure how bug 1527066 is implicated in this alert. The pushlog doesn't seem to reference it? The patch only impacted logging from the test harness, not anything in product.

The alert from comment 0 can now be visualized here: https://treeherder.mozilla.org/perf.html#/alerts?id=19690

I wonder if there's some PGO specific issue going on here. I re-ran a bunch of jobs on inbound from around the same time, and they also show a similar regression, but not to the same degree.

I've tried to retrigger the builds to see if it's something PGO specific, but I can't figure out how to get Talos jobs to run on the new builds.

(In reply to Chris AtLee [:catlee] from comment #4)

I've tried to retrigger the builds to see if it's something PGO specific, but I can't figure out how to get Talos jobs to run on the new builds.

Can you share some links to see where you tried this? Maybe :jmaher can be of assistance here.

(In reply to Chris AtLee [:catlee] from comment #4)

I wonder if there's some PGO specific issue going on here. I re-ran a bunch of jobs on inbound from around the same time, and they also show a similar regression, but not to the same degree.

This turned out to be true. In less than 2 days, the regression disappeared. I agree this was a PGO specific issue.