On a realtime kernel you can set the maximum RTPRIO higher than the lower halves (higher than 50) with the `-P` flag. Check `man 1 jackd` for more info. To extend this: The systemd user unit needs to allow for it to happen (see LimitRTPRIO, LimitRTTIME and LimitMEMLOCK in `man systemd.exec`) and your user must be allowed to actually do this as well (e.g. by using
I realized, that I wrote some inconsistent stuff in regards to IRQ tuning last night, which I'd like to clarify. On 2019-08-06 00:12:18 (+0200), David Runge wrote: the realtime-privileges package - which is Arch specific! - and adding your user to the 'realtime' group).
No worries. Usually, there's really not much needed, besides a realtime kernel and starting jackd with a reasonably high RTPRIO. I currently use this systemd user unit [2] and these environment configs [3] (depending on hardware). Note: If your audio hardware IRQs have a lower RTPRIO, than jackd (e.g. your audio card runs at 50, but you start jackd at 80), this *will* lead to problems! Ordering is important when tuning IRQs!
Again: The Arch Wiki really lacks info on all of this. Best, David -- https://sleepmap.de