System impacted is a AMD workstation with NVIDIA graphics, running Gnome desktop on X11. The operating system is Ubuntu Desktop 22.04.4 LTS.
The latest mutter update causes stutter and lagging in Gnome terminal sessions. Switching to xterm relieves the problem, but not a real solution.
The problem was finally identified as a bug in the code to Canonical's latest update for Gnome's mutter window manager and compositor (Bug #2059847). A preliminary workaround PPA from mutter maintainer Daniel Van Vugt (vanvugt) stopped working after a new official update that retained the original bug. In a 15 May 2024 comment to the bug report (#135), Daniel posted links to corrected packages that fix the issue:
You don't really need to enable jammy-proposed. Just download the 3 proposed packages:
* https://launchpad.net/ubuntu/+source/mutter/42.9-0ubuntu8/+build/28435945/+files/gir1.2-mutter-10_42.9-0ubuntu8_amd64.deb
* https://launchpad.net/ubuntu/+source/mutter/42.9-0ubuntu8/+build/28435945/+files/libmutter-10-0_42.9-0ubuntu8_amd64.deb
* https://launchpad.net/ubuntu/+source/mutter/42.9-0ubuntu8/+build/28435945/+files/mutter-common_42.9-0ubuntu8_all.deb
and if you already had the 'mutter' package (which you don't need) then also:
* https://launchpad.net/ubuntu/+source/mutter/42.9-0ubuntu8/+build/28435945/+files/mutter_42.9-0ubuntu8_amd64.deb
And install them as one:
sudo dpkg -i *.deb
I installed these packages and they fixed the issue for me. Because they bear a higher version number than the official Ubuntu packages, apt hasn't overwritten them.
Marek. "Input lag or freezes on Nvidia desktops with X11 after logging 'MetaSyncRing: Sync object is not ready -- were events handled properly?'". Bug #2059847. Ubuntu Launchpad, https://bugs.launchpad.net/ubuntu/+source/mutter/+bug/2059847.
Problem fixed, many thanks.