1901222 - 3.51 - 2.87% stylebench Descendant and child combinators/Removing classes - 0/Async / stylebench Nth pseudo classes/Adding leaf elements - 4 + 2 more (Linux, Windows) regression on Thu May 30 2024

Status: RESOLVED FIXED

(Core :: CSS Parsing and Computation, defect, P2)

Description

[Alex Finder]

Perfherder has detected a browsertime performance regression from push e07b07b08958af7d59d7fbc50699d24cd6755c25. 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)	Performance Profiles
4%	stylebench Descendant and child combinators/Removing classes - 0/Async	linux1804-64-shippable-qr	fission webrender	3.79 -> 3.93	Before/After
3%	stylebench Nth pseudo classes/Adding leaf elements - 4/Async	windows10-64-shippable-qr	fission webrender	81.22 -> 83.66	Before/After
3%	stylebench Nth pseudo classes/Adding leaf elements - 4	windows10-64-shippable-qr	fission webrender	82.90 -> 85.29	Before/After
3%	stylebench Nth pseudo classes/Adding leaf elements - 4	windows10-64-shippable-qr	fission webrender	82.64 -> 85.01	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. 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 these tests on try with ./mach try perf --alert 636

For more information on performance sheriffing please see our FAQ.

Comment 1

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

Set release status flags based on info from the regressing bug 1886441

Comment 2

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

Set release status flags based on info from the regressing bug 1886441

Comment 3

[Emilio Cobos Álvarez (:emilio)]

My understanding is that David is actively looking at this.

Comment 4

[Donal Meehan [:dmeehan]]

:dshin, the Fx129 soft code freeze starts on Thursday 2024-07-04, ahead of Fx129 merging to beta on Monday 2024-07-08.
Do you plan on landing a fix for Fx129, before the merge or something that could be uplifted to beta?

Comment 5

[David Shin[:dshin]]

:dmeehan, don't think so, need a bit more digging & testing on my side.

Comment 6

[David Shin[:dshin]]

Attachment: Bug 1901222: Optimize get_matching_rules. r=emilio

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/8b478a5040ac
Optimize get_matching_rules. r=emilio

Comment 8

[Cristina Horotan [:chorotan]]

https://hg.mozilla.org/mozilla-central/rev/8b478a5040ac

Comment 9

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

The patch landed in nightly and beta is affected.
:dshin, is this bug important enough to require an uplift?

• If yes, please nominate the patch for beta approval.
• If no, please set status-firefox129 to wontfix.

For more information, please visit BugBot documentation.

Comment 10

[David Shin[:dshin]]

The change itself is small, but there could be another perf side-effect, and I'd like to give it time to ensure that isn't the case.

Comment 11

[Andrej (:aglavic)]

(In reply to Pulsebot from comment #7)

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/8b478a5040ac
Optimize get_matching_rules. r=emilio

We're seeing the perf improvements from your patch, TY!

Perfherder has detected a talos performance change from push 8b478a5040ac29dfd88f309b528800486df8a0a6.

Improvements:

Ratio	Test	Platform	Options	Absolute values (old vs new)
71%	perf_reftest style-sharing.html	windows11-64-qr	e10s fission stylo webrender	1.67 -> 0.48
64%	perf_reftest style-sharing-style-attr.html	windows11-64-qr	e10s fission stylo webrender	1.84 -> 0.66
62%	perf_reftest_singletons bloom-basic-2.html	windows11-64-qr	e10s fission stylo webrender	63.25 -> 24.17
62%	perf_reftest_singletons bloom-basic.html	windows11-64-qr	e10s fission stylo webrender	62.77 -> 24.13
23%	perf_reftest_singletons style-sharing-style-attr.html	windows11-64-qr	e10s fission stylo webrender	5.24 -> 4.04
...	...	...	...	...
10%	perf_reftest	windows11-64-qr	e10s fission stylo webrender	1.20 -> 1.08

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 a sheriff to do that for you.

You can run these tests on try with ./mach try perf --alert 1299

For more information on performance sheriffing please see our FAQ.