Comment 20 for bug 1749779

Yes, sorry. I can confirm the bug exists in 18.04. It is trivial to reproduce, which is unusual :(

When the screen freezes multiple process start spinning:

  PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
13113 dan 20 0 12.947g 7.897g 7.788g R 91.0 51.5 1:00.90 gnome-shell
13773 dan 20 0 2169752 277244 142700 S 46.2 1.7 0:17.66 firefox
13832 dan 20 0 2039840 165760 109716 S 28.6 1.0 0:10.49 Web Content
13132 dan 20 0 1241100 241772 220172 S 13.3 1.5 0:09.01 Xwayland

To un-freeze the system I just have to:
killall -9 firefox

This is a scary bug because it's also spinning consuming memory (see the above list).

I will get the upstream Gnome guys to look at this ASAP.