1614560 - 26.21% build times (windows2012-32) regression on push 2d6fc4d1275b96db707e197697a5a6f551a2d271 (Mon February 10 2020)

Status: RESOLVED WONTFIX

(Developer Infrastructure :: Source Code Analysis, defect)

Description

[Alexandru Ionescu (needinfo me) [:alexandrui]]

We have detected a build metrics regression from push:

https://hg.mozilla.org/integration/autoland/pushloghtml?changeset=2d6fc4d1275b96db707e197697a5a6f551a2d271

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

Regressions:

26% build times windows2012-32 opt taskcluster-c5.4xlarge 2,101.01 -> 2,651.73

You can find links to graphs and comparison views for each of the above tests at: https://treeherder.mozilla.org/perf.html#/alerts?id=24906

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! ***

Comment 1

[Mike Hommey [:glandium]]

This looks like a typical change that forces everything to be rebuilt, so this is also accompanied with a drop in sccache hit rate, which goes back up on following pushes, and it looks like the build times are back to more or less normal times now...

Comment 2

[Alexandru Ionescu (needinfo me) [:alexandrui]]

The build times jobs are running on different machines from commit to commit. I was lucky that I even found the bug causing the regression. So I have to believe you :)

Comment 3

[Andi [:andi]]

:glandium, like always is right, is right, clearing the needinfo.