TL;DR Linux Kernel 6.11.10+/6.12/6.13 has AMDGPU regressions.
Add
Option "SWCursor" "True"to/usr/share/X11/xorg.conf.d/10-amdgpu.confto resolve.Other's note
amdgpu.dcdebugmask=0x10as a kernel parameter helps, didn't work for me.
Updating to Kernel 6.12, (after waiting for zfs-dkms to take a proverbial forever) I'd noticed that after opening an application in AwesomeWM moving the mouse would bring my system to a halt.
I'd run into a regression on the kernel side of things with 6.11.10 which I'd not upgraded to. At the time, I just migrated back to kernel 6.6.67 and moved on for a while.
ZFS (and zfs-dkms) now support 6.13, so I was forced to revisit this after updating. A few folks recommended setting
amdgpu.dcdebugmask=0x10 as a kernel parameter, this didn't work.
https://www.reddit.com/r/archlinux/comments/1gzy0xd/amdgpu_regression_on_kernel_612_choppy/
Digging around, I'd noticed a post on the arch forums that suggested this may be an issue with the compositor. However, I am presently not using any with AwesomeWM.
https://bbs.archlinux.org/viewtopic.php?id=290868
About this time, I checked Plasma, and, interestingly enough, the issue was not present there. Maybe this can be due to my lack of a compositor?
Regardless, I'd also observed I had a little bit of time until this issue cropped up, namely opening in Firefox. At this time, I was able to observe in htop that xorg was pegging a core at 100% for a while. Thankfully, this let me find this obscure comment on the Manjaro forum.
https://forum.manjaro.org/t/high-cpu-use-by-xorg-with-kernel-6-12/174418/12
So I modified my /etc/X11/xorg.conf.d/20-amdgpu.conf to the following:
❯ cat /etc/X11/xorg.conf.d/20-amdgpu.conf
───────┬─────────────────────────────────────────────
│ File: /etc/X11/xorg.conf.d/20-amdgpu.con
│ f
───────┼─────────────────────────────────────────────
1 │ Section "OutputClass"
2 │ Identifier "AMD"
3 │ MatchDriver "amdgpu"
4 │ Driver "amdgpu"
5 │ Option "VariableRefresh" "true"
6 │ Option "SWCursor" "true"
7 │ EndSection
───────┴─────────────────────────────────────────────
Trying it out, and, success!
❯ neofetch | lolcat
-` disconsented@cadia
.o+` ------------------
`ooo/ OS: Arch Linux x86_64
`+oooo: Host: B650 Pro RS
`+oooooo: Kernel: 6.13.7-arch1-1
-+oooooo+: Uptime: 1 hour, 15 mins
`/:-:++oooo+: Packages: 1556 (pacman)
`/++++/+++++++: Shell: fish 4.0.1
`/++++++++++++++: Resolution: 3440x1440
`/+++ooooooooooooo/` WM: awesome
./ooosssso++osssssso+` Theme: Breeze-Dark [GTK2/3]
.oossssso-````/ossssss+` Icons: breeze [GTK2/3]
-osssssso. :ssssssso. Terminal: alacritty
:osssssss/ osssso+++. CPU: AMD Ryzen 9 7950X3D (32)
/ossssssss/ +ssssooo/- GPU: AMD ATI Radeon RX 7900 XT
`/ossssso+/:- -:/+osssso+- GPU: AMD ATI 11:00.0 Raphael
`+sso+:-` `.-/+oso: Memory: 18258MiB / 63402MiB
`++:. `-/+/
.` `/
At this point, I am not entirely sure what's gone on. And, frankly I lack the skills and interest to dig further. I hope my process and discovery is helpful to someone else!