1958825 - 45.05 - 4.09% damp inspector.mutations / damp custom.styleeditor.open.DAMP + 5 more (Linux, OSX, Windows) regression on Mon March 31 2025

Status: RESOLVED WONTFIX

(DevTools :: General, defect)

Description

[Treeherder Bug Filer]

Perfherder has detected a devtools performance regression from push f8a44e5555771302d8a4fe479a07b00fff154159. As author of one of the patches included in that push, we need your help to address this regression.

Please acknowledge, and begin investigating this alert within 3 business days, or the patch(es) may be backed out in accordance with our regression policy. Our guide to handling regression bugs has information about how you can proceed with this investigation.

If you have any questions or need any help with the investigation, please reach out to [e-mail]. Alternatively, you can find help on Slack by joining #perf-help, and on Matrix you can find help by joining #perftest.

Regressions:

Ratio	Test	Platform	Options	Absolute values (old vs new)
45%	damp inspector.mutations	windows11-64-24h2-shippable	e10s fission stylo webrender	736.29 -> 1,067.96
31%	damp custom.styleeditor.reload.DAMP	linux1804-64-shippable-qr	e10s fission stylo webrender	578.09 -> 759.70
29%	damp custom.styleeditor.reload.DAMP	macosx1470-64-shippable	e10s fission stylo webrender	535.82 -> 689.30
26%	damp custom.styleeditor.reload.DAMP	windows11-64-24h2-shippable	e10s fission stylo webrender	371.05 -> 468.26
13%	damp custom.styleeditor.open.DAMP	linux1804-64-shippable-qr	e10s fission stylo webrender	570.79 -> 644.90
11%	damp custom.styleeditor.close.DAMP	linux1804-64-shippable-qr	e10s fission stylo webrender	7.82 -> 8.65
4%	damp custom.styleeditor.open.DAMP	windows11-64-24h2-shippable	e10s fission stylo webrender	300.84 -> 313.15

Improvements:

Ratio	Test	Platform	Options	Absolute values (old vs new)
11%	damp custom.inspector.expandall.balanced	linux1804-64-shippable-qr	e10s fission stylo webrender	618.54 -> 549.64

Details of the alert can be found in the alert summary, including links to graphs and comparisons for each of the affected tests.

If you need the profiling jobs you can trigger them yourself from treeherder job view or ask [e-mail] to do that for you.

You can run all of these tests on try with ./mach try perf --alert 44579

The following documentation link provides more information about this command.

Comment 1

[Julian Descottes [:jdescottes]]

This is consistent with what I mentioned at https://bugzilla.mozilla.org/show_bug.cgi?id=1788133#c2 so I think we can close as WONTFIX, but let's discuss in today's meeting first.

(note, I didn't spot the improvement, but it sounds like an unrelated sideeffect)

Comment 2

[BugBot [:suhaib / :marco/ :calixte]]

Set release status flags based on info from the regressing bug 1788133