On Saturday 10 May 2008 08:13:15 Andres Cabrera wrote:
> Hi Felipe,
>
> I mean using the preemptive option in the kernel (I think for kernels
> before around 2.23 you needed to apply the rt patches to get the preemptive
> option). I think a part of the rt patches was merged recently into the
> mainline kernel, but there's probably still some improvements from the rt
> patches (I haven't built my own kernel in a while, so I'm not sure about
> the current state).

Ok, I'll try building a preemtive kernel and see how it goes.

> But anyway for jack to work wihtout xruns you definetely need a preemptive
> kernel and the realitme-lsm module (to allow apps to get realtime
> privileges without being root). This information may also be out of date as
> well =) If you have this jack will probably work excellent.

The realtime-lsm module is no longer necessary. To get realtime privilege 
without that module you just need to have the pam_limits PAM module (which I 
suspect most linux distros will have), and then 
edit /etc/security/limits.conf to contain lines like this

user	hard	rtprio	30
user	soft	rtprio	30
@group	hard	rtprio	30

Then you can tell jack and/or csound to get a 30 realtime priority.



-- 
Felipe Sateler