Closed Bug 1540960 Opened 3 years ago Closed 3 years ago

4.35% compiler_metrics num_static_constructors (linux64) regression on push 3a81fd4a729b5a850b9ba3ece1ad7625b5f13205 (Wed Mar 27 2019)

Categories

(Firefox Build System :: General, defect)

x86_64
Linux
defect
Not set
normal

Tracking

(Not tracked)

RESOLVED WONTFIX

People

(Reporter: igoldan, Unassigned)

References

Details

(Keywords: regression)

We have detected a build metrics regression from push:

https://hg.mozilla.org/releases/mozilla-beta/pushloghtml?changeset=3a81fd4a729b5a850b9ba3ece1ad7625b5f13205

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

Regressions:

4% compiler_metrics num_static_constructors linux64 opt base-toolchains-clang 92.00 -> 96.00

Improvements:

10% compiler_metrics num_static_constructors linux64 opt base-toolchains 126.00 -> 113.00

You can find links to graphs and comparison views for each of the above tests at: https://treeherder.mozilla.org/perf.html#/alerts?id=20218

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! ***

Product: Testing → Firefox Build System
Flags: needinfo?(mh+mozilla)

Before bug 1538134, those builds were wrongfully PGOed, which has an effect on the number of static constructors. It's funny that with GCC PGO added static constructors (thus the improvement). But the opposite effect on clang is not unexpected: PGOed clang builds are also LTO'ed, which is known to remove static constructors.

Flags: needinfo?(mh+mozilla)

triaging. Glandium can this bug be closed given your comments in comment 1?

Flags: needinfo?(mh+mozilla)
Status: NEW → RESOLVED
Closed: 3 years ago
Flags: needinfo?(mh+mozilla)
Resolution: --- → WONTFIX
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