2006332 - 5.71% bing-search SpeedIndex (Linux) regression on Wed December 10 2025

Status: RESOLVED DUPLICATE of bug 2001630

(Firefox :: Address Bar, defect)

Description

[Treeherder Bug Filer]

Perfherder has detected a browsertime performance regression from push 31298ba1737e850dcf67963349d8168198c5b458. 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)	Performance Profiles
6%	bing-search SpeedIndex	linux1804-64-shippable-qr	bytecode-cached fission warm webrender	296.03 -> 312.92	Before/After

Improvements:

Ratio	Test	Platform	Options	Absolute values (old vs new)	Performance Profiles
22%	google-search LastVisualChange	linux1804-64-shippable-qr	cold fission webrender	855.42 -> 666.95	Before/After
10%	bing-search ContentfulSpeedIndex	linux1804-64-shippable-qr	bytecode-cached fission warm webrender	309.28 -> 278.93	Before/After
10%	bing-search ContentfulSpeedIndex	linux1804-64-shippable-qr	bytecode-cached fission warm webrender	309.13 -> 279.53	Before/After
6%	bing-search ContentfulSpeedIndex	linux1804-64-shippable-qr	fission warm webrender	285.15 -> 267.03	Before/After

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 47930

The following documentation link provides more information about this command.

Comment 1

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

Set release status flags based on info from the regressing bug 1988726

Comment 2

[Moritz Beier [:mbeier]]

We think this is a duplicate of 2001630 because this happened around the same time that the fix of the other bug landed and on the performance graph, it looks like it actually improved after a lot of noise on the day this was filed.