1743004 - 103.15 - 19.13% tp5o responsiveness / tp5o_webext responsiveness + 9 more (Linux, Windows) regression on Tue November 23 2021

Status: RESOLVED FIXED

(Firefox :: Downloads Panel, defect, P1)

Description

[Andra Esanu (needinfo me)]

Perfherder has detected a talos performance regression from push 1d2d2a48cec9606a22bc5589c932baf6672d6de4. 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)
103%	tp5o responsiveness	windows10-64-shippable-qr	e10s stylo webrender-sw	0.44 -> 0.90
87%	tp5o responsiveness	windows10-64-shippable-qr	e10s stylo webrender	0.46 -> 0.85
68%	tp5o responsiveness	windows10-64-shippable-qr	e10s stylo webrender	0.56 -> 0.93
64%	tp5o_webext responsiveness	windows10-64-shippable-qr	e10s stylo webrender	1.05 -> 1.71
61%	tp5o_webext responsiveness	windows10-64-shippable-qr	e10s stylo webrender-sw	1.04 -> 1.67
37%	tp5o_webext responsiveness	windows10-64-shippable-qr	e10s fission stylo webrender	1.97 -> 2.71
29%	tp5o responsiveness	linux1804-64-shippable-qr	e10s stylo webrender	2.15 -> 2.78
28%	tp5o_webext responsiveness	linux1804-64-shippable-qr	e10s stylo webrender-sw	4.14 -> 5.32
27%	tp5o_webext responsiveness	linux1804-64-shippable-qr	e10s stylo webrender	3.93 -> 5.01
26%	tp5o responsiveness	linux1804-64-shippable-qr	e10s stylo webrender-sw	2.32 -> 2.93
19%	tp5o_webext responsiveness	linux1804-64-shippable-qr	e10s fission stylo webrender	6.53 -> 7.78

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

[Micah [:mtigley] (she/her)]

I believe this is related to us creating the download spam protection module even when it's not used. I'm currently looking into this in Bug 1739145.

Comment 2

[Micah [:mtigley] (she/her)]

Comparison on PerfHerder: https://treeherder.mozilla.org/perfherder/compare?originalProject=try&originalRevision=195790cad577b1632ec56562ea064ccc7d8ee404&newProject=try&newRevision=d3a84e73558641794f1d087193ed35a725a5fe71&framework=1&page=1

Comment 3

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

Set release status flags based on info from the regressing bug 1725354

Comment 4

[Micah [:mtigley] (she/her)]

The patch in bug 1725354 just recently landed and I did another perf comparision here: https://treeherder.mozilla.org/perfherder/compare?originalProject=try&originalRevision=1749e71ea697ab61eb489bed4ad0b0042b997d55&newProject=try&newRevision=7823ff4bd7d7f65359ca941edfd95e3cf175da50&framework=1&page=1&showOnlyImportant=1&filter=tp5o.

After discussing the issue with :mconley and :gijs, it looks like the download spam protection module may been unncessarily loaded during each page load, which could have caused the spike in lag. With bug 1725354, it looks like loading this module lazily took this out of the page load test.

Andra, is there anything else I can do for this ticket? Could we close this?

Comment 5

[Micah [:mtigley] (she/her)]

I'm going to mark this as fixed. Feel free to re-open if that's not the case!