We have detected a build metrics regression from push:

https://hg.mozilla.org/integration/autoland/pushloghtml?changeset=e913585fdb4bdd73946b5e357c78da7221a71a53

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

Regressions:

300KBytes installer size linux64 pgo 69,616,919.58 -> 69,906,754.42
200KBytes installer size windows2012-32 pgo 67,036,780.50 -> 67,294,900.08
200KBytes installer size windows2012-64 pgo 69,725,203.25 -> 69,984,312.42
200KBytes installer size linux32 pgo 69,706,460.67 -> 69,952,071.83
200KBytes installer size osx-cross opt 76,423,131.25 -> 76,668,593.92

You can find links to graphs and comparison views for each of the above tests at: https://treeherder.mozilla.org/perf.html#/alerts?id=19909

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 jobs in a pushlog format.

To learn more about the regressing test(s), please see: https://developer.mozilla.org/en-US/docs/Mozilla/Performance/Automated_Performance_Testing_and_Sheriffing/Build_Metrics

*** Please let us know your plans within 3 business days, or the offending patch(es) will be backed out! ***

See Bug 1533662 Comment 1

You could use this bug also for logging optimization efforts. But if you file a separate bug for that, please link it against this one.

Clearing up regression bugs that have since shipped to users. It looks like there are some potential optimisation efforts in bug 1534996, but I don't think it makes sense to keep this bug open.