3 Oct
2007
3 Oct
'07
6:49 p.m.
On Wednesday 03 October 2007 21:57, Roman Muñoz wrote:
May be you have some shared IRQ's? Just
guessing...
Hi Roman. Thanks for your reply. Normally sound cards don't have any problems
sharing IRQ's, and as realtime is working with Fedora 7 on the same machine
as Etch with my audigy2 soundblaster card, I think that there is something
else going on here on Etch, that I havn't quite figured out.
I wonder what could be the problem here, since I'm using realtime on
Debian Etch with no xruns... and the card is an infamous intel-hda on an
nvidia ck804 motherboard.
The fact that you've got the intel-hda card to even work deserves 10 out of 10
full marks. I've seen so many problems with the infinite variations of it.
I'm not really doing serious audio work (I'm not a musician) but worked
for a music school willing to change from Microsotf. They use Audigy
(and some usb m-audio) cards, and they look like being quite happy. They
used to be Windows-only people until June. Yes, they are using Etch now.
So I would say that Etch works fine with realtime.
We made a live-cd for that music school. We are not advertising nor
promoting it as a multimedia distro, it is simply what we made in order
to get a system installed and configured quickly, then the music school
came to us and we added the realtime stuff, etc. It worked for them
rigth after installing and setting qjackctl for their card (frames,
sample rate & period, no more). Anyway, you can download it as a Debian
Etch-based livecd, with some (quite few) packages added from testing,
musix, kiberpipa and debian-multimedia:
http://gisa-elkartea.org/gisalivecd-012.iso
kernel is 2.6.21.6-rt21, also available to download separatedly:
http://gisa-elkartea.org/linux-image-2.6.21.6-rt21-gisa-686_03_i386.deb
I don't think the kernel version is the problem. There's some other problem,
but your kernel is later than Marcos's, so I'll install that as well. I'm on
dialup so downloading iso's takes some time, but I'll look at your distro.
I think first I'll download the latest version of Musix. This way I can see if
realtime is working ok on it, and may get some clues as to why realtime is
not working on Etch.
To install it, you should log in as root with password gisanagusia. On
root's desktop you will find icons for install instructions, gparted and
install script.
However, install instructions and script are spanish-only at this
moment, sorry. It asks for devices where /, swap, /home and /multimedia
partitions are (you can leave /home and /multimedia blank if not used),
username, user password (twice), root password (twice). grub
destination, and finally, it asks if /home and multimedia contents (if
any) should be preserved.
Hope this helps,
Roman
Many thanks for your reply.
Nigel.
PS: no rtirq on this livecd, but a script /usr/sbin/rtprio_snd is
called at qjackctl's start. Still, rtirq is probably much better...
PS2: Many thanks to all the people that worked/wrote on/about linux
audio. They made it easy for us to go now to the music school and see so
many smiles. Thank you all very much.
Nigel Henry escribió:
On Wednesday 03 October 2007 15:05, Florian
Schmidt wrote:
_______________________________________________
Linux-audio-user mailing list
Linux-audio-user(a)lists.linuxaudio.org
http://lists.linuxaudio.org/mailman/listinfo.cgi/linux-audio-user On Wednesday 03 October 2007, Wolfgang Woehl
wrote:
I started this thread, but at the moment I'm not having much success at
getting realtime to work on Debian Etch, and that's before I start on
Lenny.
Realtime works fine on Fedora 7, using the realtime low latency kernel
from planetccrma, plus rtirq, and a pam update from planetccrma that gave
me a limits.conf.rpmnew file, as below.
# limit realtime and memory locking access to users in the group audio
# there is no way to say "allow locking all memory", 4G should be enough
#
#* - rtprio 0
#* - nice 0
#
#@audio - rtprio 99
#@audio - nice -10
#@audio - memlock 4000000
# or (default) allow everyone access
* - rtprio 99
* - nice -10
* - memlock 4000000
Editing the existing limits.conf, adding the above, and commenting out
the default entries for jack, works fine. When starting jackd in
qjackctl, I'm getting one xrun every 6m 25secs on average, and the
largest xrun over the time I tested was about 0.325 msecs. I tested over
about 2 1/2 hours, and the only other apps open on the desktop were
Xawtv, and Gkrellm.
On Debian Etch, after adding Marcos's repo to /atc/apt.sources.list, I
installed the 2.6.21-rt4, and 2.5.21.5-rt18 kernel, along with rtirq
version 20070101. I edited limits.conf, and added the part above that I
received from planetccrma. That didn't work, with xruns every 2-3secs. I
commented out the default uncommented lines, and uncommented the audio
lines, which are at the top of this post. Still I get xruns every 2-3
secs, and if I reboot and try a non rt kernel, xruns every 2-3 secs
again. It appears that there is still something missing to get realtime
working on Etch.
I may have to download Musix again, and see how realtime runs on it. I
DL'd before, but that was when there was a problem with it booting with
some hardware. As I'm on dialup, I'd put off DL'ing it again, since the
booting problem has been resolved.
Marcos. If your reading this. Could you provide the link to download
Musix again please.
Thanks for all the replies to this thread.
Nigel.
_______________________________________________
Linux-audio-user mailing list
Linux-audio-user(a)lists.linuxaudio.org
http://lists.linuxaudio.org/mailman/listinfo.cgi/linux-audio-user Montag, 1. Oktober 2007 Marcos Guglielmetti:
> @audio - rtprio 99
> @audio - nice -10
> @audio - memlock 4000000
Marcos, looking at these numbers (and variations of these on various
netpages) I always wonder whether they are such a good idea: Wouldn't
rtprio 99 allow for banzai processes to almost lock down the machine?
Wouldn't memlock 4000000 (4GB) be like begging for a swapfest on
standard 1GB/2GB machines? Isn't the whole point about limits.conf to
effectively prevent processes from sucking in all resources? So that
when realtime processes go havoc you'll be left with cycles and memory
to survive the situation?
Yes,
one always assumes with settings like this, that the programs which are
run are nicely behaved (e.g. jackd has a watchdog to kill its clients
when they run havok)..
But whether you give one process RT prio 1 or 99 doesn't matter. It can
always keep all SCHED_OTHER threads [the rest of your system, X, xterms,
whatnot] from running at all effectively freezing the box (though in
reality this is expected behaviout).
A typical method to counter this scenario would be to limit user
processes to prio 98 and have another watchdog process runnning at prio
99. That watchdog would have another thread running at SCHED_OTHER and
checks at regular intervals whether this thread got to run at all. If
not -> take action and make e.g. all SCHED_FIFO threads in the system
SCHED_OTHER so the user is able to recover from the situation.. There
are several watchdogs available (including one from yours truly which
needs an overhaul though)..
And yes, of course, you wouldn't want to give all system memory away to
mlocking. You need some reserve..
Nice -10 otoh is pretty uncritical i guess.
Regards,
FLo