1871085 - 4.36 - 3.01% instagram ContentfulSpeedIndex / instagram ContentfulSpeedIndex (Linux) regression on Wed December 13 2023

Status: RESOLVED WONTFIX

(Core :: Widget: Gtk, defect)

Description

[Andra Esanu (needinfo me)]

Perfherder has detected a browsertime performance regression from push 89da90df398f5aee595e14748b0241ede2a9fd4d. 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%	instagram ContentfulSpeedIndex	linux1804-64-shippable-qr	fission warm webrender	413.17 -> 431.21	Before/After
3%	instagram ContentfulSpeedIndex	linux1804-64-shippable-qr	fission warm webrender	413.68 -> 426.14	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.

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Comment 1

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

Set release status flags based on info from the regressing bug 1869299

:emilio, since you are the author of the regressor, bug 1869299, could you take a look? Also, could you set the severity field?

For more information, please visit BugBot documentation.

Comment 2

[Emilio Cobos Álvarez (:emilio)]

Is it possible that the different toolbar colors changed the Speedindex heuristics? I don't see how this can be a real regression.

Comment 3

[Greg Mierzwinski [:sparky]]

Attachment: warm-side-by-side.mp4

I don't think so given that we use the orange frame to find the area that should be used in the calculation. I was looking at some of the side-by-side videos, and I see that that the "notifications" popup is changing sizes later: https://firefoxci.taskcluster-artifacts.net/Hq42PHU1S0myimYcccSFOg/0/public/build/side-by-side/browsertime-tp6-essential-firefox-instagram/warm-side-by-side.mp4

Locally, I reran the side-by-side and I'm seeing the warm pageload is taking a bit longer in the after video. I've attached that video. It's possible the regression has something to do with the scrollbar though because that does get captured in the orange frame, and makes it into the calculation.

Comment 4

[Donal Meehan [:dmeehan]]

:emilio could you take a look at Comment 3

Comment 5

[Emilio Cobos Álvarez (:emilio)]

I think it's likely to be due to the scrollbar track color, and thus not real. My patch only changed some colors in the front-end and scrollbars.