1752602 - over 200% CPU usage except if in safe mode v91.5.0esr (64-bit) on Debian GNU/Linux

Status: RESOLVED INACTIVE

(Core :: Performance: General, defect)

Description

[Z]

User Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.212 Safari/537.36

Steps to reproduce:

deleted and created new profile.
deleted all extensions.
removed firefox-esr and purged as well, reinstalled
ff task bar doesn't show anything unusual
chromium browser or ff in safe mode are capable of playing two yt 4K videos simultaneously, so hardware is not a problem here.

Actual results:

over 200% CPU usage all the time. very slow performance, despite having no extensions after purge and reinstall. despite that fact running it in safe mode sorts it.

Expected results:

30% of cpu usage, maybe spiking to 50 sometimes

Comment 1

[Negritas Sergiu, Desktop QA]

Hello!

I have tried to reproduce the issue with firefox 98.0a1(2022-01-31) unfortunately I haven't managed to reproduce the issue with Ubuntu 20.
Could you please answer the following questions in order for us to investigate it further:

1. Does this issue happen with a new profile? Here is a link on how to create one: https://support.mozilla.org/en-US/kb/profile-manager-create-remove-switch-firefox-profiles
2. Does this issue happen in the latest nightly? Here is a link from where you can download it: https://www.mozilla.org/en-US/firefox/channel/desktop/

Comment 2

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

The Bugbug bot thinks this bug should belong to the 'Core::Performance' component, and is moving the bug to that component. Please revert this change in case you think the bot is wrong.

Comment 3

[Florian Quèze [:florian]]

It would be useful to know what is using the CPU. You can use about:processes to see which process is using the CPU. If you set toolkit.aboutProcesses.showThreads to true in about:config, and reload about:processes, you will also be able to see which thread is using the CPU.

It would also be very useful to capture a performance profile by following the instructions at https://profiler.firefox.com/. Then upload the profile and insert the link here.

Comment 4

[Benjamin De Kosnik [:bdekoz]]

Am hitting some high CPU warnings when reproducing on linux-FF 97 (fedora 35) with the following two windows open and playing in 2160/4k mode:

1. https://www.youtube.com/watch?v=v--WI9Vyflo
2. https://www.youtube.com/watch?v=LXb3EKWsInQ

This is not in safe mode. The video hardware is old intel. Florian, I see this for processes:
firefox 25%, renderer 20%, 3x WRRender 20%, socket thread 20%

Comment 5

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

Redirect a needinfo that is pending on an inactive user to the triage owner.
:fdoty, since the bug has recent activity, could you have a look please?

For more information, please visit auto_nag documentation.

Comment 6

[Frank Doty [:fdoty]]

Closing this bug as inactive since we cannot get a profile from the reporter. If this issue continues, please note here to reopen or create a new bug.