1763670 - 34.65 - 2.97% twitch loadtime / netflix loadtime + 12 more (Linux, OSX, Windows) regression on Thu March 24 2022

Status: RESOLVED WONTFIX

(Core :: Layout, defect)

Description

[Acasandrei Beatrice (needinfo me)]

Perfherder has detected a browsertime performance regression from push 8535cc3be6904ee6659ea549fba019740a9988ae. 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)
35%	twitch loadtime	linux1804-64-shippable-qr	cold fission webrender	1,051.60 -> 1,416.00
30%	twitch loadtime	linux1804-64-shippable-qr	cold fission webrender	1,038.77 -> 1,354.08
28%	linkedin dcf	windows10-64-shippable-qr	cold fission webrender	1,382.08 -> 1,770.83
15%	tumblr dcf	macosx1015-64-shippable-qr	fission warm webrender	349.04 -> 402.46
13%	amazon loadtime	macosx1015-64-shippable-qr	fission warm webrender	323.12 -> 363.54
12%	twitch dcf	linux1804-64-shippable-qr	fission warm webrender	644.17 -> 722.17
10%	microsoft loadtime	linux1804-64-shippable-qr	cold fission webrender	309.64 -> 341.96
10%	twitter dcf	linux1804-64-shippable-qr	fission warm webrender	400.71 -> 440.29
8%	google-slides LastVisualChange	windows10-64-shippable-qr	cold fission webrender	3,698.88 -> 3,989.17
7%	twitch SpeedIndex	windows10-64-shippable-qr	cold fission webrender	786.86 -> 840.67
6%	google-slides loadtime	windows10-64-shippable-qr	cold fission webrender	4,364.58 -> 4,625.79
6%	twitch PerceptualSpeedIndex	windows10-64-shippable-qr	cold fission webrender	587.54 -> 622.00
6%	twitch PerceptualSpeedIndex	windows10-64-shippable-qr	cold fission webrender	590.63 -> 623.25
3%	netflix loadtime	linux1804-64-shippable-qr	fission warm webrender	929.31 -> 956.96

Improvements:

Ratio	Test	Platform	Options	Absolute values (old vs new)
5%	reddit loadtime	linux1804-64-shippable-qr	fission warm webrender	1,792.75 -> 1,709.17

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) will be backed out in accordance with our regression policy.

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 1760007

Comment 2

[Olli Pettay [:smaug][[e-mail]]]

This is a tricky chain of changes to scheduling, starting from bug 1763670, but I don't think anything will be done here.

Comment 3

[Daniel Holbert [:dholbert]]

smaug, should we WONTFIX this, then? (Or are we anticipating this will get better with further still-in-progress changes?)

Comment 4

[Olli Pettay [:smaug][[e-mail]]]

I was keeping this open to ensure no other major regressions show up.