1733957 - 11.32% perf_reftest_singletons inline-style-cache-1.html (Linux) regression on Wed September 29 2021

Status: RESOLVED FIXED

(Core :: DOM: Content Processes, defect, P3)

Description

[Andra Esanu (needinfo me)]

Perfherder has detected a talos performance regression from push 8f2f2cfb962094db37c4a08ca10c181000699930. 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)
11%	perf_reftest_singletons inline-style-cache-1.html	linux1804-64-shippable-qr	e10s fission stylo webrender	1,034.14 -> 1,151.25

Improvements:

Ratio	Test	Platform	Options	Absolute values (old vs new)
7%	tsvgr_opacity	macosx1014-64-shippable-qr	e10s fission stylo webrender	152.22 -> 141.51
4%	tp5o_scroll	macosx1015-64-shippable-qr	e10s fission stylo webrender	1.63 -> 1.57
3%	tp5o	linux1804-64-shippable-qr	e10s fission stylo webrender	260.42 -> 251.46
3%	tp5o	windows10-64-shippable-qr	e10s fission stylo webrender	273.18 -> 264.81
3%	tsvg_static	macosx1014-64-shippable-qr	e10s fission stylo webrender	67.67 -> 65.62

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

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

I think the performance change is coming from bug 1731132. Bug 1731792 just made that change effective on Fission.

But inline-style-cache-1.html seems to be a bit bogus. It depends on whether or not paint happens before load event.

Comment 2

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

emilio, would it make sense to wait for the page load in the test and only then create all the elements?

Comment 3

[Emilio Cobos Álvarez (:emilio)]

Yeah, that'd make sense to me.

Comment 4

[Chris Peterson [:cpeterson]]

Setting status-firefox94=wontfix because we don't need to uplift a fix to Beta 94. This bug is a problem with the inline-style-cache-1.html Talos test.

Comment 5

[Chris Peterson [:cpeterson]]

Olli says fixing this test doesn't need to block Fission MVP.

Comment 6

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

Attachment: Bug 1733957, tweak inline-style-cache-1.html to depend less on how the page is loaded (perf numbers are expected to change a bit), r=emilio

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/e2cae4b15039
tweak inline-style-cache-1.html to depend less on how the page is loaded (perf numbers are expected to change a bit), r=emilio,perftest-reviewers,sparky

Comment 8

[Norisz Fay [:noriszfay]]

https://hg.mozilla.org/mozilla-central/rev/e2cae4b15039