1685315 - cpu 100% from rogue FirefoxCP process

Status: RESOLVED INCOMPLETE

(Core :: Performance: General, defect)

Description

[Nick Parlante]

Attachment: screenshot shows 100% cpu FirefoxCP while all tabs are low-cpu

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:84.0) Gecko/20100101 Firefox/84.0

Steps to reproduce:

This is not an easily reproducible bug, so it should be closed ultimately. I am submitting just to submit the attached screenshot which shows what may be a useful clue about managing FirefoxCP processes. My hope is that screenshot can get in front of the right person.

Actual results:

I was using Firefox 84 normally, on Mac OS, noticed cpu use was high and the machine was sluggish, closed a few tabs and waited a while. I opened the Firefox Task Manager, and all my actual tabs were low cpu, as expected. However in the OS process manager, there was a FirefoxCP Web Content process pegged at 100%. This combination is what's shown in the screenshot. Restarting Firefox killed off the 100% cpu process, returning things to normal.

Expected results:

Closing tabs should kill any underlying Firefox processes very reliably.

Comment 1

[Virginia (please send need info request to Brindusa Tot)]

Hi Nick,

Thanks for reporting this bug and adding a screenshot.

I'll add this to the Core: Memory Allocator component in the hope someone from their team can take a look and advice.

Regards,