[PlanetCCRMA] Problems startig jackd

[Don Levey]

Fernando Pablo Lopez-Lezcano wrote:

>
> Which distro are you running? Why 2.6.x?
>
I'm running Fedora Core 1.  I'm on 2.6 because...  Well, in addition to the
"it's one more" than the 2.4 stream (well, two more), it's got some things
built in that I like (such as ALSA).  Also, Fedora Core 2 is coming out
soon, and will be including 2.6 as their standard core (2.6.3, I think).

> 2.6.x is not yet (AFAIK) at the same level of low latency performance
> as a patched 2.4.x kernel. There are a couple of critical patches
> that I don't think have made it to the mainline kernel yet (by
> Takashi Iwai). Also, the kernel should be built with the preemptible
> kernel option turned on, that optimizes latency a bit more but
> supposedly at the cost of stability (not all drivers are well tested
> with preempt on).
>
OK, I think that's the way I built it, with few stability complaints
(Evolution doesn't like to start up, but other than that I'm OK).  I will
look forward to the critical patches making their way into the mainline
kernel.

> Regarding the "capabilities" complain, that is jackstart trying to get
> realtime capabilities from the kernel so that jack apps can run with
> SCHED_FIFO even as a non-root user.
>
> You could patch the kernel to enable capabilities, but under 2.6.x a
> better option is to use the LSM module. See:
>     http://www.joq.us/realtime/
>
Ah, OK - thanks!  I'm recompiling my kernel now, with the additional
security options enabled (required for the patch).

> See above...
> If you don't have a real need to be running 2.6.x you may be better
> off (for the time being) running the patched Planet CCRMA 2.4.26
> kernel...
>
> -- Fernando

I may set that up as yet another kernel on this box; I'll see how the LSM
module helps later tonight.  Thanks!
 -Don