[PlanetCCRMA] qjackctl/jackd acting differently?

bernie@vcn.bc.ca bernie@vcn.bc.ca
Fri Sep 16 10:46:01 2005

hi everybody,

after months of lurking on this list and happily pecking away at learning
my planet ccrma setup, i've worked up the courage to try and ask for help.
i'm noticing funny behavior trying to get jack to operate in realtime.

first specs:

fujitsu s2020 laptop
athlon xp-m 2100+ (1.4GHz)
768MB ram

running FC3 w/CCRMA
trying both kernels 2.6.10-2.1.ll.rhfc3.ccrma and 2.6.11-0.3.rdt.rhfc3.ccrma
(same trouble with either kernel)

next the (current) problem:

when starting jack from qjackctl, i get:

10:28:46.977 /usr/bin/jackd -R -dalsa -dhw:0 -r48000 -p256 -n3 -S
10:28:46.985 JACK was started with PID=5827 (0x16c3).
cannot write to jackstart sync pipe 4 (Bad file descriptor)
jackd: wait for startup process exit failed
jackd 0.99.36
Copyright 2001-2003 Paul Davis and others.

(etc. etc.)

it starts after that but no "RT" light in the qjackctl window.  however,
when starting it from command line (same command), i get no "cannot write
to jackstart..." message, but from command line i don't know how to check
if jack is running realitme.  either way i get a few xruns a minute
without any real activity, and if i run, say alsaplayer through jack i get
thousands of xruns constantly (and very often distorted sound, but i think
that may have to do with 48k/44.1kHz discrepancy and maybe the period

i've checked to see that the rtload init.d ran:

[root@localhost audio]# /etc/rc.d/init.d/rtload status
Realtime kernel module is loaded, current parameters are:
 any=1; gid=-1; mlock=1
[root@localhost audio]# /sbin/lsmod | grep realtime
realtime                5128  0
commoncap               8064  1 realtime
[root@localhost audio]# /sbin/chkconfig --list rtload
rtload          0:off   1:off   2:on    3:on    4:on    5:on    6:off

(this is me as root, but the jack calls were done as normal user)

is that what it should look like?

i spent the better part of last night googling the problem, and found bits
and pieces, but no clear idea of what to do next.  thanks in advance for
any help, please tell me if i should post any other info...

bernie arai