[ardour-users] some questions

[Jack O'Quin]

Dave Phillips <dlphilp at bright.net> writes:

> > I do, but it's not normally advised.  A kernel with "capabilities
> > patch" is supposed to alleviate the requirement to run as root in
> > order to gain real-time scheduling priority or whatever it is you
> > gain by running as root.  I am going to begin trying to run Ardour
> > as non-root and see how it goes...
> 
> I've been running Ardour as normal user but recently I thought I'd try
> doing so as root. My system isn't very powerful (800 MHz Duron CPU),
> and JACK kicks Ardour out when things get too active. Running as root
> appears to alleviate (but not totally eradicate) that problem. Btw, I
> always shut down my network connection when I use Ardour as root. It
> seems the safe thing to do...

I've heard people claim to get better realtime response by running as
root.  But, I suspect the real problem is usually a system or
configuration issue preventing the user from obtaining realtime
privileges at all.  Subtle problems like the SCHED_FIFO bug in NPTL
0.60 can cause that.

I can't think of any reason why running as root should save any
noticeable amount of system overhead.  There's a little extra work at
startup time running jackstart which then exec()'s jackd, plus maybe
an extra message exchange when each client connects, but AFAICT the
main line code paths in JACK and in the kernel are about the same.
-- 
  joq