[arch-proaudio] Introducing: dedicated realtime group (not only for jack/jack2)

[Joakim Hernberg]

A few observations, there might be more use cases for rtprio/memlock
privileges than so called "pro audio", so it seems more correct to use a
realtime group (as some other distros already do).  The realtime
privileges are really orthogonal to access to audio hardware..

Also giving audio group users direct access to audio hardware, breaks
how the "kits" grant access to audio hardware.

I'd agree that letting JACK1/2 "optionally" depend on the new package
seems like the right way to do it.  Note that nothing here makes it
depend on the linux-rt kernel.

If you look at the package, it gives the realtime group rtprio up to
98 & unlimited memlock.  It also gives the group access to /dev/rtc0,
hpet and cpu-dma-latency.

Nothing of this is really specific to "pro" audio, but rather could be
viewed as realtime related, so I'm fully aboard with this change.

I think it would be bad for a package like this to depend on jack,
linux-rt, etc.  I might want to install and run some realtime app, or
just run reaper with alsa, why should I then be forced to install jack,
linux-rt, etc..?

On the other hand if you need low latency audio, install whatever
combination you want/need, of realtime-privileges, jack1/2(-dbus),
linux-rt, (udev-)rtirq, apps, etc.

-- 

   Joakim