I have a total of 8 GB of RAM and 2 GB of swap. Reproducing the issue with a memory monitor opened, however, showed that the issue was not related to memory exhaustion: I had at least 2 GB of unused RAM at all times, and although the swap was enabled, it was not used (the swap usage remained at 0 throughout the entire period).
Also observed during this test: eight Firefox processes (seven Web Content and one WebExtensions) were running at 50% CPU usage each throughout the time of nonresponsiveness (my computer has 4 cores, so between them they were using up the entire CPU usage of the computer). ** Changed in: firefox (Ubuntu) Status: Incomplete => New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1856624 Title: Firefox freezes temporarily at 100% CPU when Chromium is opened To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/firefox/+bug/1856624/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs