1749926 - 100% cpu while running in troubleshooting mode

Status: VERIFIED DUPLICATE of bug 1749910

(Core :: Networking, defect)

Description

[0zeroth]

Attachment: Screenshot 2022-01-13 101151.jpg

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/97.0.4692.71 Safari/537.36

Steps to reproduce:

Windows, 64 bit Firefox build. Run using Windows+R (or cmd.exe):

firefox.exe -safe-mode

(Exactly the same behaviour is seen running normally, but safe mode should rule out plugins being the problem).

Actual results:

Firefox launches, the main process uses 100% of one CPU (ie task manager reports 13%) and does not change (I stopped watching after 30 minutes).

Three -contentproc processes are started and sit at 0% CPU.

No website loads. You cannot update firefox from the browser (hangs checking for updates) or restart using the Help menu (old process does not exit so new process is stuck waiting).

Exiting the UI does not exit the process - process can only be killed from Task Manager.

Expected results:

Firefox should work the same as it did yesterday!

AFAIK nothing has changed between running perfectly for months and today :)

Comment 2

[0zeroth]

A 'clean install' of 95.0.2 fixed this - so might not be a true duplicate. In any case it is now fixed.