1683885 - 8.42 - 48.61% about_newtab_with_snippets responsiveness / startup_about_home (linux64, windows10-64) regression on push 453811f08638fd0aca96e53331adeda1b10de81b (Fri December 18 2020)

Status: RESOLVED FIXED

(Toolkit Graveyard :: OS.File, defect)

Description

[Alexandru Ionescu (needinfo me) [:alexandrui]]

Perfherder has detected a talos performance regression from push 453811f08638fd0aca96e53331adeda1b10de81b. As author of one of the patches included in that push, we need your help to address this regression.

Regressions:

Ratio	Suite	Test	Platform	Options	Absolute values (old vs new)
49%	about_newtab_with_snippets	responsiveness	linux64-shippable-qr	e10s stylo webrender	0.17 -> 0.25
48%	about_newtab_with_snippets	responsiveness	linux64-shippable-qr	e10s stylo webrender	0.17 -> 0.25
14%	startup_about_home_paint_realworld_webextensions	startup_about_home_paint_realworld_webextensions	linux64-shippable-qr	e10s stylo webrender	834.29 -> 954.83
13%	startup_about_home_paint	startup_about_home_paint	windows10-64-shippable-qr	e10s stylo webrender-sw	648.92 -> 731.42
13%	startup_about_home_paint	startup_about_home_paint	linux64-shippable	e10s stylo	654.58 -> 737.00
11%	startup_about_home_paint	startup_about_home_paint	windows10-64-shippable-qr	e10s stylo webrender	678.67 -> 750.83
8%	startup_about_home_paint	startup_about_home_paint	linux64-shippable-qr	e10s stylo webrender	861.33 -> 933.83

Improvements:

Ratio	Suite	Test	Platform	Options	Absolute values (old vs new)
63%	tp5n	nonmain_startup_fileio	windows10-64-shippable-qr	e10s stylo webrender-sw	2,018,907.00 -> 738,650.92
63%	tp5n	nonmain_startup_fileio	windows10-64-shippable-qr	e10s stylo webrender	2,018,176.08 -> 750,141.00
63%	tp5n	nonmain_startup_fileio	windows10-64-shippable	e10s stylo	1,967,205.08 -> 736,222.67
40%	tp5n	main_startup_fileio	windows10-64-shippable	e10s stylo	735,970.33 -> 444,272.08
37%	tp5n	main_startup_fileio	windows10-64-shippable-qr	e10s stylo webrender-sw	815,017.92 -> 515,802.67
36%	tp5n	main_startup_fileio	windows10-64-shippable-qr	e10s stylo webrender	809,127.33 -> 516,056.17
20%	sessionrestore_no_auto_restore	sessionrestore_no_auto_restore	linux64-shippable-qr	e10s stylo webrender-sw	607.17 -> 484.25
13%	sessionrestore_no_auto_restore	sessionrestore_no_auto_restore	linux64-shippable	e10s stylo	567.08 -> 492.17
13%	sessionrestore_no_auto_restore	sessionrestore_no_auto_restore	windows10-64-shippable	e10s stylo	586.71 -> 510.92
11%	sessionrestore_no_auto_restore	sessionrestore_no_auto_restore	windows10-64-shippable-qr	e10s stylo webrender-sw	584.33 -> 517.25
11%	sessionrestore	sessionrestore	windows10-64-shippable	e10s stylo	534.38 -> 475.67
11%	sessionrestore	sessionrestore	windows10-64-shippable-qr	e10s stylo webrender	543.25 -> 486.00
10%	sessionrestore	sessionrestore	linux64-shippable-qr	e10s stylo webrender-sw	524.00 -> 470.83
9%	sessionrestore	sessionrestore	linux64-shippable	e10s stylo	531.83 -> 481.83
8%	sessionrestore	sessionrestore	windows10-64-shippable-qr	e10s stylo webrender-sw	539.88 -> 498.75

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

[Michelle Goossens [:masterwayz]]

This will need perf people to look at it, which will be after the holidays.
I've requested a backout.

Comment 2

[Pascal Chevrel:pascalc]

Fixed by the backout of bug 1649599