After update, Firefox uses copious amounts of CPU while being idle
(Core :: Performance, defect)
(Reporter: herth, Unassigned, NeedInfo)
User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:105.0) Gecko/20100101 Firefox/105.0
Steps to reproduce:
Starting with 104 but also on 105, after performing an update of Firefox, the restarted Firefox uses a lot of CPU (60%-200%) without any activity or obviously busy tabs. This lasts for many and only very gradually goes down. Even after several days, the browser creates a "base" cpu load of 30%. This has been observed using several different machines, x86 and ARM, OS versions ranging from Mojave to Monterrey.
After restart, the CPU load should be very small.
6 months ago
The Bugbug bot thinks this bug should belong to the 'Core::Performance' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.
5 months ago
Sorry to hear you are having problems after the update, this slowness is unexpected and undesirable and we would like to fix it. We are trying to track down this issue, but need more info from you about your machine and configuration.
Could you make sure the following information is on this bug?
- For slowness or high CPU usage, capture a profile with http://profiler.firefox.com/ , upload it and share the link here.
- For processes and activity usage issues, Got to about:processes and screen shot what you see, upload it to this bug report.
- Troubleshooting information: Go to about:support, click "Copy raw data to clipboard", paste it into a file, save it, and attach the file here.