1891923 - 153% amazon largestContentfulPaint (OSX) regression on Tue April 9 2024

Status: RESOLVED WONTFIX

(Testing :: Raptor, defect)

Description

[Alex Finder]

Perfherder has detected a browsertime performance regression from push 0952e6765442e7b623010cc9b7b52ebee241bd40. 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
153%	amazon largestContentfulPaint	macosx1015-64-shippable-qr	bytecode-cached fission warm webrender	103.73 -> 262.77	Before/After
144%	amazon largestContentfulPaint	windows10-64-shippable-qr	bytecode-cached fission warm webrender	147.18 -> 359.38	Before/After
143%	amazon largestContentfulPaint	macosx1015-64-shippable-qr	fission warm webrender	105.16 -> 255.28	Before/After
133%	instagram SpeedIndex	macosx1015-64-shippable-qr	bytecode-cached fission warm webrender	294.99 -> 687.51	Before/After
131%	amazon largestContentfulPaint	windows10-64-shippable-qr	fission warm webrender	150.53 -> 347.80	Before/After
114%	amazon largestContentfulPaint	linux1804-64-shippable-qr	bytecode-cached fission warm webrender	162.29 -> 347.46	Before/After
111%	instagram ContentfulSpeedIndex	macosx1015-64-shippable-qr	bytecode-cached fission warm webrender	177.03 -> 372.65	Before/After
109%	instagram SpeedIndex	linux1804-64-shippable-qr	bytecode-cached fission warm webrender	411.43 -> 859.82	Before/After
106%	instagram SpeedIndex	windows10-64-shippable-qr	bytecode-cached fission warm webrender	362.41 -> 747.57	Before/After
102%	instagram FirstVisualChange	linux1804-64-shippable-qr	fission warm webrender	59.30 -> 119.82	Before/After
...	...	...	...	...	...
7%	instagram fcp	macosx1015-64-shippable-qr	cold fission webrender	204.95 -> 219.57	Before/After
5%	imgur fcp	linux1804-64-shippable-qr	fission warm webrender	463.33 -> 487.81	Before/After
5%	amazon loadtime	windows10-64-shippable-qr	bytecode-cached fission warm webrender	378.40 -> 397.96	Before/After
3%	imgur LastVisualChange	linux1804-64-shippable-qr	fission warm webrender	3,394.63 -> 3,486.28	Before/After
3%	imgur LastVisualChange	windows10-64-shippable-qr	fission warm webrender	3,360.30 -> 3,449.84	Before/After

Improvements:

Ratio	Test	Platform	Options	Absolute values (old vs new)	Performance Profiles
44%	instagram loadtime	windows10-64-shippable-qr	cold fission webrender	1,558.81 -> 877.00	Before/After
44%	instagram loadtime	linux1804-64-shippable-qr	cold fission webrender	1,929.39 -> 1,087.02	Before/After
43%	instagram loadtime	windows10-64-shippable-qr	bytecode-cached cold fission webrender	1,566.28 -> 885.25	Before/After
42%	instagram loadtime	linux1804-64-shippable-qr	bytecode-cached cold fission webrender	1,937.86 -> 1,129.60	Before/After
41%	instagram loadtime	macosx1015-64-shippable-qr	bytecode-cached cold fission webrender	1,294.82 -> 761.58	Before/After
...	...	...	...	...	...
4%	imgur SpeedIndex	linux1804-64-shippable-qr	cold fission webrender	1,238.00 -> 1,183.98	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 these tests on try with ./mach try perf --alert 42219

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 1889241

Comment 2

[Kash Shampur [:kshampur] ⌚EST]

This is expected changes as I've updated the recordings

Comment 3

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

The bug is marked as tracked for firefox126 (beta). However, the bug still isn't assigned.

:davehunt, could you please find an assignee for this tracked bug? Given that it is a regression and we know the cause, we could also simply backout the regressor. If you disagree with the tracking decision, please talk with the release managers.

For more information, please visit BugBot documentation.