[LAU] unable to set scheduling priority with rt kernel

Hallo.
I posted to the jackit-devel list too, so apologies if you're seeing this
again. No luck there...

jackd version 0.103.0 tmpdir /dev/shm protocol 16
2.6.22.1-rt9
Debian testing

I've just noticed that I am unable to set jackd priority on the command
line. I have a script set up to use "sudo chrt" to change it, but when I
comment out that line in the script, jackd runs at 0 with schedule "other".

My script:
sudo chrt -fp 82 `pidof "IRQ-16"`
jackd --realtime -P 70 -dalsa -P -p256 -n2 -r44100 &
sudo chrt -fp 70 `pidof "jackd"`
chrt -p `pidof "IRQ-16"`
chrt -p `pidof "jackd"`
exit

If I comment out the second sudo chrt line, the last line returns:
pid 5032's current scheduling policy: SCHED_OTHER
pid 5032's current scheduling priority: 0
otherwise it is SCHED_FF and 70.

My kernel has:
# CONFIG_PREEMPT_NONE is not set
# CONFIG_PREEMPT_VOLUNTARY is not set
# CONFIG_PREEMPT_DESKTOP is not set
CONFIG_PREEMPT_RT=y
CONFIG_PREEMPT=y
CONFIG_PREEMPT_SOFTIRQS=y
CONFIG_PREEMPT_HARDIRQS=y
CONFIG_PREEMPT_BKL=y
# CONFIG_CLASSIC_RCU is not set
CONFIG_PREEMPT_RCU=y

/etc/security/limits.conf has:
@audio - nice -10
@audio - rtprio 99
@audio - memlock 4000000 (someone on the jack list suggested
that my previous value "unlimited" was not recognized, so I stuck this in
but no change)

and user "chuckk" is in group "audio".

Lastly, the output from my script when the second sudo chrt line is
commented out:
------------------------------
pid 684's current scheduling policy: SCHED_FIFO
pid 684's current scheduling priority: 82
jackd 0.103.0
Copyright 2001-2005 Paul Davis and others.
jackd comes with ABSOLUTELY NO WARRANTY
This is free software, and you are welcome to redistribute it
under certain conditions; see the file COPYING for details

JACK compiled with System V SHM support.
pid 5132's current scheduling policy: SCHED_OTHER
pid 5132's current scheduling priority: 0
loading driver ..
Enhanced3DNow! detected
SSE2 detected
apparent rate = 44100
creating alsa driver ... hw:0|-|256|2|44100|0|0|nomon|swmeter|-|32bit
control device hw:0
configuring for 44100Hz, period = 256 frames, buffer = 2 periods
ALSA: final selected sample format for playback: 32bit little-endian
ALSA: use 2 periods for playback

--------------------------------------

Any ideas what I may have missed or misconfigured?

Thanks!
-Chuckk

-- 
http://www.badmuthahubbard.com

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Received on Wed Oct 24 16:15:04 2007