1985327 - Firefox doesn't seem use 'above normal' priority for GPU process on Windows like some other browsers

Status: RESOLVED FIXED

(Core :: Graphics, defect, P3)

Description

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

I was testing a new Intel 268v based Windows 11 laptop and scrolling feels a bit jank-y when using it on battery. Based on Task Manager Edge uses 'above normal' priority for couple of processes, I assume one of those is their GPU process. FF doesn't.
When tweaking FF's GPU process priority manually using Task Manager, scrolling/panning becomes very smooth.

Bug 1671490 was supposed to fix this, but at least I don't see it working.

Comment 1

[Florian Quèze [:florian]]

A profile would help, we have markers showing the priorities (both requested, and actual priorities).

Comment 2

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

https://share.firefox.dev/45D5WXO

And with high prio gpu process https://share.firefox.dev/3Vq4bal

Comment 3

[Bas Schouten (:bas.schouten)]

The Performance Impact Calculator has determined this bug's performance impact to be medium. If you'd like to request re-triage, you can reset the Performance Impact flag to "?" or needinfo the triage sheriff.

Platforms: Windows
Impact on browser: Causes noticeable jank
[x] Able to reproduce locally

Comment 4

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

The severity field is not set for this bug.
:bhood, could you have a look please?

For more information, please visit BugBot documentation.

Comment 5

[Florian Quèze [:florian]]

(In reply to Olli Pettay [:smaug][[e-mail]] from comment #2)

https://share.firefox.dev/45D5WXO

Thanks for the profiles. The patch from bug 1671490 seems to behave as expected in this profile. The parent process main thread and the GPU process main thread have the same priorities (before the patch the GPU process had a lower priority because it didn't have any visible window). The GPU process Rendered thread priority is slightly higher, and the content process priorities are slightly lower.

And with high prio gpu process https://share.firefox.dev/3Vq4bal

In this profile the priority of the entire GPU process is very high, close to the maximum.

Comment 6

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

Based on the Windows profile manager GPU process had normal priority.
And anyhow, FF behavior is pretty bad with the current setup.

Comment 7

[Bob Hood [:bhood]]

Dropping into triage for the team to evaluate this week.

Comment 8

[Glenn Watson [:gw]]

Discussed this with Bob briefly - we should definitely make sure we do what's needed to ensure the main GPU process threads don't get scheduled on e-cores. I don't know exactly what the win apis are to do this, but I imagine it's fairly straightforward.

Comment 9

[Brad Werth [:bradwerth]]

I think I'll be able to improve behavior here.

Comment 10

[Brad Werth [:bradwerth]]

Attachment: Bug 1985327 Part 1: Elevate the priority of gpu process at process launch.

This one-time sets the priority of the gpu process, which should have a
lasting effect, because it's not set anywhere else.

Comment 11

[Brad Werth [:bradwerth]]

Attachment: Bug 1985327 Part 2: Make Windows handle PROCESS_PRIORITY_FOREGROUND_HIGH.

Comment 12

[Brad Werth [:bradwerth]]

Attachment: Bug 1985327 Part 3: Make Linux process kill heuristic handle PROCESS_PRIORITY_FOREGROUND_HIGH.

Comment 13

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/d251e90a0e53
https://hg.mozilla.org/integration/autoland/rev/69c03f267834
Part 1: Elevate the priority of gpu process at process launch. r=gfx-reviewers,lsalzman
https://github.com/mozilla-firefox/firefox/commit/0c524cd10984
https://hg.mozilla.org/integration/autoland/rev/2a38ef12ba09
Part 2: Make Windows handle PROCESS_PRIORITY_FOREGROUND_HIGH. r=gfx-reviewers,lsalzman
https://github.com/mozilla-firefox/firefox/commit/58ac339f24a1
https://hg.mozilla.org/integration/autoland/rev/dd18a149c9af
Part 3: Make Linux process kill heuristic handle PROCESS_PRIORITY_FOREGROUND_HIGH. r=aosmond

Comment 14

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/98c65944dc28
https://hg.mozilla.org/integration/autoland/rev/91931310a2ae
Revert "Bug 1985327 Part 3: Make Linux process kill heuristic handle PROCESS_PRIORITY_FOREGROUND_HIGH. r=aosmond" for causing build bustages @LinuxProcessPriority.cpp.

Comment 15

[agoloman]

Backed out for causing build bustages @LinuxProcessPriority.cpp.

• Backout link
• Push with failures
• Failure Log

Comment 16

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/2e834c389bb2
https://hg.mozilla.org/integration/autoland/rev/e0147286c6fd
Part 1: Elevate the priority of gpu process at process launch. r=gfx-reviewers,lsalzman
https://github.com/mozilla-firefox/firefox/commit/d18227084c2c
https://hg.mozilla.org/integration/autoland/rev/d49a066f2459
Part 2: Make Windows handle PROCESS_PRIORITY_FOREGROUND_HIGH. r=gfx-reviewers,lsalzman
https://github.com/mozilla-firefox/firefox/commit/6a788c4a95df
https://hg.mozilla.org/integration/autoland/rev/33bfa51fd872
Part 3: Make Linux process kill heuristic handle PROCESS_PRIORITY_FOREGROUND_HIGH. r=aosmond

Comment 17

[Sandor Molnar[:smolnar]]

https://hg.mozilla.org/mozilla-central/rev/e0147286c6fd
https://hg.mozilla.org/mozilla-central/rev/d49a066f2459
https://hg.mozilla.org/mozilla-central/rev/33bfa51fd872