[Musix-users] Re: Do I run a low-latency and realtime kernel?

Mon Apr 9 21:15:12 CEST 2007

El Lun 09 Abr 2007 23:07, julien bodd escribió:
 | Hi again,
 | Thanks for the replies !
 |
 | > I suggest to Try the 2.6.16-multimedia kernel that it's into Musix,
 | > Also, the 2.6-16-beyond4.1 it's a realtime kernel...
 |
 | Ok, I'll try the multimedia one.
 |
 | > To try it, start jack and type into a konsole:
 | > ps -C jackd -cmL
 |
 | my output is :
 |  PID   LWP CLS PRI TTY          TIME CMD
 | 14745     - -     - ?        00:00:00 jackd
 |     - 14745 TS    7 -        00:00:00 -
 |     - 14746 TS   34 -        00:00:00 -
 |     - 14747 TS   22 -        00:00:00 -
 |     - 14748 #4   40 -        00:00:00 -
 |     - 14749 #4   40 -        00:00:00 -
 |
 | So, no FF.. Does this mean no realtime kernel or no jackd realtime
 | support?

Some of both

 | > Julien: is realtime-lsm loaded?
 | > Type into a konsole:
 | > lsmod | grep realtime
 |
 | The output from this comand is :
 | realtime                5384  0
 | commoncap         6912  1 realtime

Well, that confuses me!!

Here this kernel works in realtime, maybe there is an unknown bug somewhere!

 | Is this realtime-lsm?
 | (When I do apt-get install realtime-lsm it says it is already
 | installed. But do I have to turn it on? Or it is the above and is ok?)

It's ok, it's loaded... maybe it's not loaded fine, try this

modprobe -r realtime

modprobe realtime any=1

 | > If you want more evidences:
 | > marcos at musix099b16:~$ cat /boot/config-2.6.17-2-multimedia-486 | grep -i
 | > realtime CONFIG_SECURITY_REALTIME=m
 |
 | Mine is :
 | cat /boot/config-2.6.16-beyond4.1 |grep -i realtime
 | CONFIG_SECURITY_REALTIME=m

 | So it seems ok.

Yes :)

 | > Julien, what could be wrong with zynaddsubfx? or does it happends with
 | > any other apps?
 |
 | Well, the tons of xruns and sound saturation comes only with
 | zynaddsubfx with that SPECIFIC configuration. That is :
 | midi keyboard -->midi input to freewheeling -->midi output to
 | zynaddsubfx -->audio output back to freewheeling -->audio output to
 | alsa_pcm.
 |
 | I don't know what is bad with that configuration. May be it is the
 | fact that it makes a kind of loop, and so has to take too much time..

Maybe... I dont really know... but try another kernel as you said

 | But in general, all soundfonts I use sound crap too. No saturation,
 | but bad sound quality (for that, I don't know, may be I only have bad
 | soundfonts)

Yes, I believe... but, if you want to record the output and upload it to some 
place, we could listen to them

 |
 | So..let's summarize. With the commands you made me run, It seems I
 | have realtime kernel and realtime-lsm..but on the other hand, it seems
 | jackd is not realtime..??

Maybe, I dont know, JACK is not running in realtime, I think, you must try new 
kernels

 | Is your advice still to try the 2.16-multimedia?

yes, or 2.6.17-multimedia or 2.6.21-rc4 from Musix

 | Thanks !

To you

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-- 
Marcos Guglielmetti  
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