1546882 - 9.24 - 60.5% build times (linux64) regression on push 17040bb20e256476df548a6be770e7d8f78387ef

Status: RESOLVED WONTFIX

(Testing :: General, defect, P3)

Description

[Ionuț Goldan [:igoldan]]

We have detected a build metrics regression from push:

https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=ac23ad5ef0c18d7bf5b55fd9d07cfd1c0da33033&tochange=17040bb20e256476df548a6be770e7d8f78387ef

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

Regressions:

61% build times linux64 debug base-toolchains taskcluster-c4.4xlarge 1,158.78 -> 1,859.88
9% build times linux64 debug base-toolchains taskcluster-m4.4xlarge 1,088.63 -> 1,189.23

You can find links to graphs and comparison views for each of the above tests at: https://treeherder.mozilla.org/perf.html#/alerts?id=20588

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

[Ionuț Goldan [:igoldan]]

I'm not 100% sure bug 524410 really caused this build time increase, as there are multiple bugs in its time range that tweak the build configs.

Still, by inspecting the metrics from all instance types, I've managed to narrow down to it.

Comment 2

[Ionuț Goldan [:igoldan]]

Also, there's so much noise in these metrics, that what I can say for sure is there's a regression, but can't precisely say of what magnitude. Note the difference between 9% and 61%...

Comment 3

[Nathan Froyd [:froydnj]]

I can believe that dump_syms is doing more work...I wouldn't think it slowed down by that much, though! I think this is a change that we're willing to accept...especially if it's only with base toolchains, which we don't impact shipping builds, or many developers.

Comment 4

[Ionuț Goldan [:igoldan]]

I'm inclined to close this as WONTFIX. Geoff, do you have other opinions?

Comment 5

[Geoff Brown [:gbrown]]

That sounds right to me.