1947124 - 66.06 - 2.17% tumblr loadtime / microsoft ContentfulSpeedIndex + 41 more (Linux) regression on Mon February 3 2025

Status: RESOLVED WONTFIX

(Core :: Widget: Gtk, defect)

Description

[Treeherder Bug Filer]

Perfherder has detected a browsertime performance regression from push 9efb94e533503b0cd1309c16d01d488a69941059. 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
66%	tumblr loadtime	linux1804-64-shippable-qr	fission warm webrender	378.12 -> 627.88	Before/After
52%	pinterest FirstVisualChange	linux1804-64-shippable-qr	fission warm webrender	185.88 -> 282.10	Before/After
46%	tumblr largestContentfulPaint	linux1804-64-shippable-qr	fission warm webrender	460.68 -> 672.92	Before/After
34%	pinterest ContentfulSpeedIndex	linux1804-64-shippable-qr	fission warm webrender	378.81 -> 508.37	Before/After
33%	tumblr LastVisualChange	linux1804-64-shippable-qr	fission warm webrender	568.90 -> 754.05	Before/After
24%	pinterest SpeedIndex	linux1804-64-shippable-qr	fission warm webrender	392.07 -> 487.23	Before/After
21%	tumblr ContentfulSpeedIndex	linux1804-64-shippable-qr	fission warm webrender	217.38 -> 264.04	Before/After
21%	instagram ContentfulSpeedIndex	linux1804-64-shippable-qr	fission warm webrender	341.67 -> 411.90	Before/After
14%	instagram ContentfulSpeedIndex	linux1804-64-shippable-qr	bytecode-cached cold fission webrender	823.61 -> 936.81	Before/After
14%	tumblr SpeedIndex	linux1804-64-shippable-qr	fission warm webrender	148.82 -> 169.17	Before/After
...	...	...	...	...	...
3%	linkedin PerceptualSpeedIndex	linux1804-64-shippable-qr	fission warm webrender	594.94 -> 611.98	Before/After
3%	paypal SpeedIndex	linux1804-64-shippable-qr	cold fission webrender	661.16 -> 679.02	Before/After
2%	facebook LastVisualChange	linux1804-64-shippable-qr	cold fission webrender	1,923.94 -> 1,969.58
2%	facebook LastVisualChange	linux1804-64-shippable-qr	fission warm webrender	796.42 -> 814.50
2%	microsoft ContentfulSpeedIndex	linux1804-64-shippable-qr	fission warm webrender	1,512.42 -> 1,545.20	Before/After

Improvements:

Ratio	Test	Platform	Options	Absolute values (old vs new)	Performance Profiles
77%	imdb PerceptualSpeedIndex	linux1804-64-shippable-qr	fission warm webrender	1,110.40 -> 258.48	Before/After
76%	imdb SpeedIndex	linux1804-64-shippable-qr	fission warm webrender	1,077.62 -> 264.03	Before/After
75%	imdb LastVisualChange	linux1804-64-shippable-qr	fission warm webrender	7,230.39 -> 1,810.26	Before/After
74%	imdb ContentfulSpeedIndex	linux1804-64-shippable-qr	fission warm webrender	1,023.57 -> 264.67	Before/After
71%	imdb ContentfulSpeedIndex	linux1804-64-shippable-qr	cold fission webrender	3,869.51 -> 1,135.18	Before/After
...	...	...	...	...	...
3%	pinterest SpeedIndex	linux1804-64-shippable-qr	cold fission webrender	1,151.91 -> 1,113.48	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 43712

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 581863

Comment 2

[Emilio Cobos Álvarez (:emilio)]

Given:

• This is more improvements that regressions.
• The regressing patch changed window sizing.
• The regressions and improvements are mostly about Speedindex-like things, which scan video output.

I suspect I just changed the effective viewport size, and that triggered changes in the output of the video scanning... Sparky, do you think it's worth digging into this given that?

Comment 3

[Greg Mierzwinski [:sparky]]

I agree, these are very likely to be related to the window change and can be closed as a WONTFIX.

That said, I took a look at the IMDB recordings because of the large improvements, and for some reason the carousel images are no longer showing up. Not sure if that's because of a problem in this patch, or if it's because we need to update our pageload recordings now (maybe we don't have the right image size for the carousel now) but I thought I would mention it in case it points to something breaking.

Triggered a side-by-side here for it: https://treeherder.mozilla.org/jobs?repo=autoland&group_state=expanded&tochange=9efb94e533503b0cd1309c16d01d488a69941059&fromchange=ff5432cc7e7c0d223330a7c8f09a89d797793f83&searchStr=imdb&selectedTaskRun=FPA6bvQCS5Gi29tzz7wzAQ.0

Comment 5

[Greg Mierzwinski [:sparky]]

I took a look at the side-by-side videos and the carousel problem seems to have existed before this patch (see the cold pageload). Closing this as WONTFIX.