Supernova "cannot raise thread priority" (kubuntu studio)

1

Hi all, I’m still relatively new to linux and especially linux audio so my hope is that there is maybe some simple thing that I don’t yet know about that would fix this. Also mine isn’t some super personal arch setup but pretty much a straightforward ubu studio install.

system specs

Operating System: Ubuntu Studio 24.04
KDE Plasma Version: 5.27.12
KDE Frameworks Version: 5.115.0
Kernel Version: 6.17.0-22-generic (64-bit)
Graphics Platform: Wayland
Processors: 6 × Unknown Type, 6 × AMD Ryzen 5 7530U with Radeon Graphics
Memory: 14.5 Gio of RAM

SC 3.15, Built from branch ‘develop’ [21347a84c]

Supernova runs ok-ish for lighter loads but when it boots I get warnings:

Warning: cannot raise thread priority
Warning: cannot raise thread priority
Warning: cannot set thread affinity of audio helper thread
(3x)

Is this to be expected and ignored, and if not, what can I do about it?
I already ran rtcqs and did all the changes recommended there except the spectre/meltdown related one; the user running sclang and scsynth is in the audio group, and am going over the list here System configuration [Linux-Sound]…

2

If you don’t see a file that looks like that in /etc/security/limits.d, you can add it yourself. It will have exacly the same effect. For example, something like /etc/security/limits.d/95-audio.conf with:

@audio - rtprio 95 
@audio - memlock unlimited 
@audio - nice -19

Then make sure the user is a member of that group: sudo usermod -aG audio "$USER"

1 Like
3

Thanks! I did that again, and I noticed that in my audio.conf the nice-related line was commented out; so I uncommented that. Also the file contained a hint saying “If you want to enable/disable realtime permissions, rundpkg-reconfigure -p high jackd2”… so I did that too. Restarted, and now indeed the Warning: cannot set thread affinity of audio helper thread has disappeared (either because of the nice change or the other command). So that’s good!
But the cannot raise thread priority warning still happens…

EDIT: upon further investigation (looking in the supernova source), I think the warning happens when the user is running pipewire, because supernova won’t distinguish between jack not being able to get rt priorities and jack not running at all. So I guess I have to figure out jack if I want supernova…