1954740 - 3.87% cpstartup content-process-startup (Windows) regression on Wed March 12 2025

Status: RESOLVED WONTFIX

(Core :: IPC, defect)

Description

[Treeherder Bug Filer]

Perfherder has detected a talos performance regression from push 017c9f9793ecaed3435ad4fd2674fb1d6a9e6358. As author of one of the patches included in that push, we need your help to address this regression.

Regressions:

Ratio	Test	Platform	Options	Absolute values (old vs new)
5%	perf_reftest_singletons thai-reflow.html	linux1804-64-shippable-qr	e10s fission stylo webrender	72.37 -> 76.25

Improvements:

Ratio	Test	Platform	Options	Absolute values (old vs new)
5%	cpstartup content-process-startup	windows11-64-shippable-qr	e10s fission stylo webrender	42.25 -> 40.17
4%	cpstartup content-process-startup	windows11-64-shippable-qr	e10s fission stylo webrender-sw	42.46 -> 40.67
4%	cpstartup content-process-startup	windows11-64-24h2-shippable	e10s fission stylo webrender-sw	44.50 -> 42.67
4%	cpstartup content-process-startup	windows11-64-24h2-shippable	e10s fission stylo webrender	44.12 -> 42.42

Details of the alert can be found in the alert summary, including links to graphs and comparisons for each of the affected tests. Please follow our guide to handling regression bugs and let us know your plans within 3 business days, or the patch(es) may be backed out in accordance with our regression policy.

If you need the profiling jobs you can trigger them yourself from treeherder job view or ask a sheriff to do that for you.

You can run all of these tests on try with ./mach try perf --alert 44342

The following documentation link provides more information about this command.

For more information on performance sheriffing please see our FAQ.

If you have any questions, please do not hesitate to reach out to [e-mail].

Comment 1

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

Set release status flags based on info from the regressing bug 1951925

Comment 2

[Alex Franchuk [:afranchuk]]

If I'm not mistaken, it appears as if the broken bug 1942129 improved perf_reftest_singletons a bit and the fix in bug 1951925 has removed that improvement and may have caused a small regression over the pre-bug 1942129 numbers (just eyeballing it). Notably perf.compare shows no significant improvement/regressions when comparing with a commit pre-bug 1942129: https://perf.compare/compare-results?baseRev=1e008cadd9d03b21e2e658ac253941d3cdef39d2&baseRepo=autoland&newRev=017c9f9793ecaed3435ad4fd2674fb1d6a9e6358&newRepo=autoland&framework=1&filter_status=improvement%2Cregression

Comment 3

[Alex Franchuk [:afranchuk]]

Based on perf.compare, I'm closing this as there's no overall regression since pre-bug 1942129 numbers.