2007660 - 44.41% instagram loadtime (Android) regression on Thu December 18 2025

Status: NEW

(Core :: JavaScript Engine: JIT, defect)

Description

[Treeherder Bug Filer]

Perfherder has detected a browsertime performance regression from push 025f924ef21e4d94d22befb0e72f8036b6ba7235. 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
44%	instagram loadtime	android-hw-a55-14-0-aarch64-shippable	warm webrender	464.68 -> 671.04

Improvements:

Ratio	Test	Platform	Options	Absolute values (old vs new)	Performance Profiles
41%	jetstream3 splay-Geometric	linux1804-64-shippable-qr	fission webrender	88.82 -> 124.90	Before/After
37%	jetstream3 splay-Average	linux1804-64-shippable-qr	fission webrender	43.15 -> 26.98	Before/After
25%	jetstream3 splay-First	linux1804-64-shippable-qr	fission webrender	63.31 -> 47.31	Before/After
23%	jetstream3 splay-Worst	linux1804-64-shippable-qr	fission webrender	65.88 -> 50.54	Before/After
12%	jetstream3 splay-First	macosx1500-aarch64-shippable	fission webrender	9.50 -> 8.34
...	...	...	...	...	...
2%	speedometer EmberJS-Debug-TodoMVC/Adding100Items/Sync	macosx1500-aarch64-shippable	fission webrender	53.82 -> 52.74	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 48014

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 1999828