1853969 - 11.27 - 5.39% perf_reftest_singletons bloom-basic.html / perf_reftest_singletons link-style-cache-1.html + 3 more (OSX, Windows) regression on Fri September 15 2023

Status: VERIFIED FIXED

(Core :: CSS Parsing and Computation, defect)

Description

[Andrej (:aglavic)]

Perfherder has detected a talos performance regression from push 68b06857f48d8ebfcb58df8817595e0b1c505ea2. 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)
11%	perf_reftest_singletons bloom-basic.html	macosx1015-64-shippable-qr	e10s fission stylo webrender	51.91 -> 57.76
9%	perf_reftest_singletons link-style-cache-1.html	macosx1015-64-shippable-qr	e10s fission stylo webrender	235.76 -> 257.66
9%	perf_reftest_singletons bloom-basic-2.html	macosx1015-64-shippable-qr	e10s fission stylo webrender	52.76 -> 57.46
6%	perf_reftest_singletons link-style-cache-1.html	windows10-64-shippable-qr	e10s fission stylo webrender	274.61 -> 291.50
5%	perf_reftest_singletons link-style-cache-1.html	windows10-64-shippable-qr	e10s fission stylo webrender	275.69 -> 290.54

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 offending 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.

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 1853206

Comment 2

[Emilio Cobos Álvarez [:emilio]]

https://treeherder.mozilla.org/perfherder/compare?originalProject=try&originalRevision=6f0164143af00325c9f15e7c6387d8f9c7993daf&newProject=try&newRevision=78b672e152c65fbacd3f0bccc4bd069b177addd6

Comment 3

[Emilio Cobos Álvarez [:emilio]]

https://github.com/servo/rust-smallvec/pull/315 seems to address the regression at least on macos, and is neutral on Windows.

Comment 4

[Emilio Cobos Álvarez [:emilio]]

Attachment: GitHub Pull Request

Comment 5

[Emilio Cobos Álvarez [:emilio]]

Attachment: Bug 1853969 - Update smallvec. r=#layout,glandium

This contains a micro-optimization that fixes the performance
regression.

Also miri fixes and such, and a drain_filter implementation.

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/73a6d130439c
Update smallvec. r=glandium,supply-chain-reviewers

Comment 7

[Sandor Molnar[:smolnar]]

https://hg.mozilla.org/mozilla-central/rev/73a6d130439c

Comment 8

[Andrej (:aglavic)]

(In reply to Emilio Cobos Álvarez (:emilio) from comment #5)

Created attachment 9354194 [details]
Bug 1853969 - Update smallvec. r=#layout,glandium

This contains a micro-optimization that fixes the performance
regression.

Also miri fixes and such, and a drain_filter implementation.

I am confirming that we are also seeing the improvements!

== Change summary for alert #39651 (as of Tue, 26 Sep 2023 16:54:55 GMT) ==

Improvements:

Ratio	Test	Platform	Options	Absolute values (old vs new)
10%	perf_reftest_singletons bloom-basic.html	macosx1015-64-shippable-qr	e10s fission stylo webrender	57.47 -> 51.71
9%	perf_reftest_singletons bloom-basic.html	macosx1015-64-shippable-qr	e10s fission stylo webrender	57.00 -> 51.70
9%	tresize	linux1804-64-shippable-qr	e10s fission stylo webrender	34.05 -> 30.96
9%	perf_reftest_singletons bloom-basic-2.html	macosx1015-64-shippable-qr	e10s fission stylo webrender	56.85 -> 51.71
9%	tresize	linux1804-64-shippable-qr	e10s fission stylo webrender-sw	33.33 -> 30.48

For up to date results, see: https://treeherder.mozilla.org/perfherder/alerts?id=39651