1789877 - 9.16 - 8.6% tabswitch / tabswitch + 1 more (Linux) regression on Tue September 6 2022

Status: VERIFIED FIXED

(Firefox :: Theme, defect)

Description

[Andrej (:aglavic)]

Perfherder has detected a talos performance regression from push de5bd66dff7834e7eab425b7091f38140cc26ea9. 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)
9%	tabswitch	linux1804-64-shippable-qr	e10s fission stylo webrender-sw	6.93 -> 7.56
9%	tabswitch	linux1804-64-shippable-qr	e10s fission stylo webrender	6.95 -> 7.57
9%	tabswitch	linux1804-64-shippable-qr	e10s fission stylo webrender	6.98 -> 7.58

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) 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 1789125

Comment 2

[Emilio Cobos Álvarez (:emilio)]

Attachment: Bug 1789877 - Simplify statuspanel a bit. r=dao

I'm a bit baffled about bug 1789877. My best theory so far is that we're
inserting the element a bit deeper in the DOM and that causes us to
reflow slightly more stuff when tab-switching, but...

In any case while going through the code the status panel can be
simplified a bit now, so do that.

Comment 3

[Phabricator Automation]

Comment on attachment 9293772 [details]
Bug 1789877 - Simplify statuspanel a bit. r=dao

Revision D156876 was moved to bug 1789892. Setting attachment 9293772 [details] to obsolete.

Comment 4

[Emilio Cobos Álvarez (:emilio)]

https://treeherder.mozilla.org/perfherder/compare?originalProject=try&originalRevision=6d248aad5c2343fa71b16783ed02ab55322a306d&newProject=try&newRevision=8a41dd9b4b42e02a4fec03e86ee79d40ff3e02f4&framework=1&page=1

shows improvements from just making the invisible status panel display: none, so yeah, it's probably reflow slowness when moving the status panel around.

Comment 5

[Emilio Cobos Álvarez (:emilio)]

Attachment: Bug 1789877 - Hide inactive statuspanel. r=dao

Mostly for reference, since this does fix the regression and avoids
having frames for the panel in ~all cases.

I guess it'd be nice to keep the fade-in transitions (tho tbh I had
never noticed them).

Dao, do you know if we have an existing pattern for such thing? I know
panels do that with transitionend listeners and so, I can do that but if
we have existing code to do that it'd be great.

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/bbeb7b3a1cf6
Hide inactive statuspanel. r=dao

Comment 7

[Cristina Cozmuta (:CrissCozmuta)]

https://hg.mozilla.org/mozilla-central/rev/bbeb7b3a1cf6

Comment 8

[Acasandrei Beatrice (needinfo me)]

== Change summary for alert #35407 (as of Fri, 16 Sep 2022 12:08:44 GMT) ==

Improvements:

Ratio	Test	Platform	Options	Absolute values (old vs new)
8%	tabswitch	linux1804-64-shippable-qr	e10s fission stylo webrender	7.53 -> 6.89
8%	tabswitch	linux1804-64-shippable-qr	e10s fission stylo webrender-sw	7.48 -> 6.90
7%	tabswitch	linux1804-64-shippable-qr	e10s fission stylo webrender	7.53 -> 6.97

For up to date results, see: https://treeherder.mozilla.org/perfherder/alerts?id=35407