[linux-audio-user] jackd and realtime priority

[Hector Centeno-Garcia]

Hi,

I've been playing around a little with the priority thing. I would like 
to understand better the way it works. Looking at the priority of jackd 
(running realtime, as user, and with a RT kernel, full-preemption) I 
can't figure out why if I start jackd with -P 60 (or any other number > 
0) the output of chrt is always:

$ chrt -p (jackd's pid)
pid 8115's current scheduling policy: SCHED_OTHER
pid 8115's current scheduling priority: 0

I checked this in two different distros (FC4+CCRMA and Ubuntu with 
custom RT kernel) and the result is the same. Is it not supposed to read:

$ chrt -p 8115
pid 8115's current scheduling policy: SCHED_FIFO (maybe?)
pid 8115's current scheduling priority: 60

I know that I can set this manually, but I'm just wondering what is the 
real effect of the -P flag.

Any help will be appreciated,

Cheers!

Hector