Problems running Mixbus with Jack on Slackware Linux

[rutsch]

I want to run Mixbus with JACK on Slackware. I have no problems to run Mixbus on Debian or any other Distro with PAM installed. Slackware does not use PAM, Slackware uses capabilities to grant special rights to an application (http://man7.org/linux/man-pages/man7/cap...ies.7.html) so there is no limits.conf or something else to manage user or group rights regarding audio realtime threads and memory locks. With capabilities I'm able to run Renoise or Tracktion with JACK realtime threads as a user but there is a problem with Mixbus doing the same. Mixbus creates a realtime thread (I can see it in the terminal) when starting but when I want to open or create a project there is always a Mixbus dialog that the project cannot be opened or created. This is not a file permission problem! Running Mixbus with ALSA backend works without problems, but Jack would be the better option. Running Mixbus as root with JACK works too.

I know I can use another Distro and I'm doing so but it would be great (for me) if Mixbus works on Slackware too. Maybe x42 or any other Mixbus Developer can have a look what the problem is. For me it looks like a Mixbus only problem. Thanks!

[x42]

Check Realtime permissions of jack to be > 5.
Mixbus asks jack to create threads for it. And jack uses "audio-rt-priority - 5" for those threads. It's a bug in jack, really it should not allow to start with -P 5 or less.

other than that, try Mixbus' ALSA backend.

Edit: or configure Mixbus to only use one CPU core, in which case no additional process-threads are created, but that assumes you can visit the preference dialog, which needs a running Mixbus,...
in the ~/.config/mixbus4/config set <Option name="processor-usage" value="1"/>

[rutsch]

Thanks x42.