1651700 - 100% Utilization of all Cores

Status: RESOLVED WORKSFORME

(Core :: General, defect)

Description

[mkg]

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:77.0) Gecko/20100101 Firefox/77.0

Steps to reproduce:

Platform: NixOS Linux
Firefox: 77.0.1 (64-bit)
Addons:

• Firefox Multi-Account Containers
• HTTPS Everywhere
• Privacy Badger
• uBlock Origin
• ClearURLs
• Cookie AutoDelete
• Disable Autoplay for YouTube
• Google search link fix
• Auto Tab Discard
• URLs List

I'm having trouble reproducing it but several times a day FF utilization shoots up to 396% (according to top) which is effectively 100% utilization of all four cores on the machine. It seems to happen around the time I interacted with Google web apps (Gmail, Google Groups, Chat) and Zoom. The only recourse is to restart FF.

I've tried some things to see what the problem might be. I installed Auto Tab Discard to reduce memory usage (because top showed FF & WebContent using a huge amount of VIRT and RES). It may have helped a little. I also turned down the Content Process Limit from 8 to 4. Problem seems to be somewhat reduced. Recently turned it down to 1 but haven't had enough time to comment. All the tasks shown in about:performance are medium or low so it isn't clear that the code in a tab is acting up.
Anything else I should be checking?

Actual results:

All four cores are fully utilized and remain so until FF is restarted.

Expected results:

While I expect occasional spikes in core utilization periodically, FF should not peg all the cores and remain that way until restarted.

Comment 1

[Marcela (Please NI request to Brindusa Tot)]

Thanks for your collaboration. I'll set a component to have a starting point of this. Graphics team, if this is not the right component please feel free to route this ticket to the corresponding team, thanks!

Comment 2

[Jessie [:jbonisteel] pls NI]

Can you share the contents of your about:support as a text file?

Comment 3

[mkg]

Attachment: Copied from about:support

Comment 4

[Jessie [:jbonisteel] pls NI]

Not sure there is anything here that makes this stand out as a Graphics issue.

Comment 5

[Sean Voisen (:svoisen)]

plawless: Anything someone on your team might be aware of or has seen recently?

Comment 6

[Alex Thayer [:alexical] (she/her)]

mkg, would you be able to try to capture a profile while this is happening with the Gecko profiler? I realize that it may end up being infeasible given the situation. (Alternatively you can use perf to capture a profile, which you can load and share with the Gecko profiler UI.)

Comment 7

[mkg]

Because this is a show stopper for my work, I switched to Brave for my day to day use. But I have Firefox open with all the tabs and windows I usually use. If it acts up I will see if I can get a profile.

Comment 8

[mkg]

I haven't seen the problem recur since I switched to using another browser (in order to get work done). Even though I still have Firefox up with all the state from before, the problem hasn't happened yet. It appears the issue is triggered by my heavy usage style and not using it actively fails to cause the issue to happen. You may close the issue.

Comment 9

[Alex Thayer [:alexical] (she/her)]

(In reply to mkg from comment #8)

I haven't seen the problem recur since I switched to using another browser (in order to get work done). Even though I still have Firefox up with all the state from before, the problem hasn't happened yet. It appears the issue is triggered by my heavy usage style and not using it actively fails to cause the issue to happen. You may close the issue.

:( All right, well if you do ever come back to FF for your heavy workloads and the issue shows up again please feel free to reopen this. Thank you for filing a bug on it!