1936489 - 22.36 - 2.35% wikipedia largestContentfulPaint / wikipedia LastVisualChange + 27 more (Linux, OSX, Windows) regression on Thu December 5 2024

Status: RESOLVED FIXED

(Core :: Layout: Text and Fonts, defect)

Description

[Treeherder Bug Filer]

Perfherder has detected a browsertime performance regression from push 89dc35ac064b58e1bf783f4c4750f119e572e8b3. 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
22%	wikipedia largestContentfulPaint	macosx1015-64-shippable-qr	cold fission webrender	551.74 -> 675.09	Before/After
18%	wikipedia fcp	linux1804-64-shippable-qr	cold fission webrender	929.22 -> 1,092.93	Before/After
18%	wikipedia fcp	linux1804-64-shippable-qr	bytecode-cached cold fission webrender	944.15 -> 1,110.18	Before/After
17%	wikipedia largestContentfulPaint	macosx1015-64-shippable-qr	bytecode-cached cold fission webrender	561.78 -> 658.88	Before/After
15%	wikipedia FirstVisualChange	linux1804-64-shippable-qr	bytecode-cached cold fission webrender	1,037.13 -> 1,194.29	Before/After
15%	wikipedia ContentfulSpeedIndex	linux1804-64-shippable-qr	bytecode-cached cold fission webrender	1,038.40 -> 1,194.60	Before/After
15%	wikipedia FirstVisualChange	linux1804-64-shippable-qr	cold fission webrender	1,040.59 -> 1,196.13	Before/After
15%	wikipedia PerceptualSpeedIndex	linux1804-64-shippable-qr	bytecode-cached cold fission webrender	1,043.34 -> 1,198.75	Before/After
15%	wikipedia ContentfulSpeedIndex	linux1804-64-shippable-qr	cold fission webrender	1,041.79 -> 1,196.32	Before/After
15%	wikipedia largestContentfulPaint	linux1804-64-shippable-qr	cold fission webrender	1,083.39 -> 1,243.58	Before/After
...	...	...	...	...	...
7%	wikipedia fcp	macosx1015-64-shippable-qr	cold fission webrender	465.02 -> 496.74	Before/After
6%	yahoo-mail fcp	windows11-64-shippable-qr	bytecode-cached cold fission webrender	99.51 -> 105.47	Before/After
3%	wikipedia loadtime	linux1804-64-shippable-qr	bytecode-cached cold fission webrender	1,456.54 -> 1,495.17	Before/After
2%	wikipedia loadtime	linux1804-64-shippable-qr	cold fission webrender	1,457.49 -> 1,493.82	Before/After
2%	wikipedia LastVisualChange	linux1804-64-shippable-qr	cold fission webrender	2,166.78 -> 2,217.71	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 all of these tests on try with ./mach try perf --alert 43021

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 1935337

Comment 2

[Emilio Cobos Álvarez (:emilio)]

Attachment: Bug 1936489 - Effectively back out bug 1935337. r=jfkthame,smaug

This is quite a surprising regression and I don't have time to
investigate it right now. Let's effectively back out the behavior
change.

Comment 3

[Emilio Cobos Álvarez (:emilio)]

https://perf.compare/compare-results?baseRev=2fd134b66db4d02e3b6c875efea4e8674fe8a46a&newRev=fcba503f5682a9b311fb05742e6712baeaced4a7&baseRepo=try&newRepo=try&framework=13

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/91a3e96912fb
Effectively back out bug 1935337. r=smaug

Comment 5

[agoloman]

https://hg.mozilla.org/mozilla-central/rev/91a3e96912fb

Comment 6

[Alex Finder]

(In reply to Pulsebot from comment #4)

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/91a3e96912fb
Effectively back out bug 1935337. r=smaug

Perfherder has detected a browsertime performance change from push 91a3e96912fbe32a7b29c5686fb96f8c67369db9.

Improvements:

Ratio	Test	Platform	Options	Absolute values (old vs new)	Performance Profiles
18%	wikipedia largestContentfulPaint	macosx1015-64-shippable-qr	bytecode-cached cold fission webrender	666.70 -> 544.48	Before/After
16%	wikipedia fcp	linux1804-64-shippable-qr	bytecode-cached cold fission webrender	1,123.52 -> 947.24	Before/After
15%	wikipedia largestContentfulPaint	macosx1015-64-shippable-qr	cold fission webrender	656.28 -> 556.24	Before/After
14%	wikipedia largestContentfulPaint	linux1804-64-shippable-qr	bytecode-cached cold fission webrender	1,258.57 -> 1,082.04	Before/After
14%	wikipedia fcp	linux1804-64-shippable-qr	cold fission webrender	1,108.95 -> 956.92	Before/After
...	...	...	...	...	...
2%	wikipedia loadtime	linux1804-64-shippable-qr	bytecode-cached cold fission webrender	1,496.46 -> 1,461.66	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 a sheriff to do that for you.

You can run these tests on try with ./mach try perf --alert 43100

For more information on performance sheriffing please see our FAQ.