1685703 - 31.19 - 36.6% tp5n main_startup_fileio (windows10-64-shippable, windows10-64-shippable-qr) regression on push 7dc6ee63d69a011e7fafd515c26184b9b1f390c0 (Tue January 5 2021)

Status: RESOLVED FIXED

(Toolkit :: Startup and Profile System, defect)

Description

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

Perfherder has detected a talos performance regression from push 7dc6ee63d69a011e7fafd515c26184b9b1f390c0. 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)
37%	tp5n	main_startup_fileio	windows10-64-shippable	e10s stylo	725,048.67 -> 990,451.58
36%	tp5n	main_startup_fileio	windows10-64-shippable	e10s stylo	729,673.46 -> 993,965.92
33%	tp5n	main_startup_fileio	windows10-64-shippable-qr	e10s stylo webrender	809,462.00 -> 1,076,229.83
31%	tp5n	main_startup_fileio	windows10-64-shippable-qr	e10s stylo webrender-sw	819,106.58 -> 1,074,612.17

Improvements:

Ratio	Suite	Test	Platform	Options	Absolute values (old vs new)
45%	tp5n	nonmain_normal_fileio	windows10-64-shippable-qr	e10s stylo webrender	666,042,314.33 -> 365,054,889.58
45%	tp5n	nonmain_normal_fileio	windows10-64-shippable	e10s stylo	664,070,492.58 -> 366,136,497.17
45%	tp5n	nonmain_normal_fileio	windows10-64-shippable-qr	e10s stylo webrender-sw	663,187,019.00 -> 365,823,330.67
32%	tp5n	nonmain_startup_fileio	windows10-64-shippable-qr	e10s stylo webrender	2,058,763.83 -> 1,400,079.42
31%	tp5n	nonmain_startup_fileio	windows10-64-shippable-qr	e10s stylo webrender-sw	2,039,068.88 -> 1,413,435.75
5%	startup_about_home_paint_realworld_webextensions	startup_about_home_paint_realworld_webextensions	windows10-64-shippable	e10s stylo	704.33 -> 669.33
3%	startup_about_home_paint_realworld_webextensions	startup_about_home_paint_realworld_webextensions	windows10-64-shippable-qr	e10s stylo webrender	717.42 -> 694.50
3%	startup_about_home_paint	startup_about_home_paint	windows10-64-shippable-qr	e10s stylo webrender-sw	665.21 -> 645.92

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

[Markus Stange [:mstange]]

Do we call dllServices->DisableFull() sooner than before because dllServicesDisable goes out of scope sooner?

Comment 2

[(No longer employed by Mozilla) Aaron Klotz]

These four lines should not have been moved to an inner scope. DllServices is not startup-only code; they must remain active through the event loop.

Comment 3

[Markus Stange [:mstange]]

I'll write the patch.

Comment 4

[Markus Stange [:mstange]]

Attachment: Bug 1685703 - Make the dllServicesDisable RAII object cover all of XRE_mainRun, including the call to nsAppStartup::Run. r=aklotz

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/9ec199693b08
Make the dllServicesDisable RAII object cover all of XRE_mainRun, including the call to nsAppStartup::Run. r=aklotz

Comment 6

[Brad Werth [:bradwerth]]

Thank you, Markus. Sorry for the mishap in the original patch.

Comment 7

[Alexandru Michis [:malexandru]]

https://hg.mozilla.org/mozilla-central/rev/9ec199693b08

Comment 8

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

(In reply to Pulsebot from comment #5)

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/9ec199693b08
Make the dllServicesDisable RAII object cover all of XRE_mainRun, including
the call to nsAppStartup::Run. r=aklotz

== Change summary for alert #28377 (as of Mon, 11 Jan 2021 10:28:35 GMT) ==

Regressions:

Ratio	Suite	Test	Platform	Options	Absolute values (old vs new)
82%	tp5n	nonmain_normal_fileio	windows10-64-shippable-qr	e10s stylo webrender	365,372,149.75 -> 666,391,444.58
81%	tp5n	nonmain_normal_fileio	windows10-64-shippable	e10s stylo	367,221,734.08 -> 664,995,819.67
81%	tp5n	nonmain_normal_fileio	windows10-64-shippable-qr	e10s stylo webrender-sw	367,248,621.00 -> 664,803,201.25
41%	tp5n	nonmain_startup_fileio	windows10-64-shippable	e10s stylo	1,415,039.83 -> 1,988,810.83

Improvements:

Ratio	Suite	Test	Platform	Options	Absolute values (old vs new)
27%	tp5n	main_startup_fileio	windows10-64-shippable	e10s stylo	991,458.67 -> 728,378.58
24%	tp5n	main_startup_fileio	windows10-64-shippable-qr	e10s stylo webrender	1,077,920.08 -> 814,499.08
23%	tp5n	main_startup_fileio	windows10-64-shippable-qr	e10s stylo webrender-sw	1,072,887.92 -> 823,120.17

For up to date results, see: https://treeherder.mozilla.org/perfherder/alerts?id=28377