We have detected a build metrics regression from push: https://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?changeset=5afa32a16a2f7ebbd8bf19e49efc50832110980d As author of one of the patches included in that push, we need your help to address this regression. Regressions: 12% build times windows2012-64 debug static-analysis taskcluster-c4.4xlarge 2,157.82 -> 2,418.85 7% build times windows2012-64 opt static-analysis taskcluster-c4.4xlarge 2,740.23 -> 2,944.31 You can find links to graphs and comparison views for each of the above tests at: https://treeherder.mozilla.org/perf.html#/alerts?id=11068 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

Very likely to be an out-of-tree infrastructure change, which caused this.

#taskcluster didn't seem to think there were any AMI deploys last week. This /might/ be Amazon patching the underlying hosts for spectre and meltdown :/

(In reply to Gregory Szorc [:gps] from comment #2) > #taskcluster didn't seem to think there were any AMI deploys last week. > > This /might/ be Amazon patching the underlying hosts for spectre and > meltdown :/ Sounds reasonable.

actually this would affect ALL versions of Firefox, not just firefox 59

Marking all versions as affected based on comment 4.

:gps' comment [1] in bug 1429319 made me check this bug too. Turns out the build times here have also returned to normal. == Change summary for alert #11208 (as of Wed, 17 Jan 2018 10:56:51 GMT) == Improvements: 7% build times windows2012-64 debug static-analysis taskcluster-c4.4xlarge 2,271.50 -> 2,119.95 1% build times windows2012-64 opt static-analysis taskcluster-c4.4xlarge 2,749.36 -> 2,725.16 For up to date results, see: https://treeherder.mozilla.org/perf.html#/alerts?id=11208 Marking this bug as resolved. [1] https://bugzilla.mozilla.org/show_bug.cgi?id=1429319#c4