Do I run a low-latency and realtime kernel?
Hi all, I'm experiencing tons of xruns and sound saturation when I use zynAddSubFx in combination with freewheeling (live looper). I went through the linux-audio-users-request mailing list and I saw that a low-latency kernel is not the same with a realtime kernel. When I do : uname - a, I have : ... 2.6.16-beyond4.1 #1 PREEMPT Sun May 28 ... So my kernel is low-latency? But, it doesn't seem it is realtime as I have installed no patch (Ingo Molnar patch). It doesn't seem to be PREEMPT_RT. Or is it included in Musix by default? This might be the problem. Another thing I see is that when I run QJackCtl, it doesn't seem to run realtime! Although it does not complain and I have activated the R (realtime) switch. I can see it is not realtime because there is a RT indicator that is not yellow. I tried running as root, and it is the same. I have libpam-modules installed (0.79-4) and I added : /etc/security/limits.conf @audio - rtprio 99 @audio - nice -10 @audio - memlock 250000 (I belong to the audio group of course) (I also tried some optimizations with fluxbox, no 3D accel, disable unnecessary services, increase pci latency for soundcard..) So, I is the problem the lack of realtime patch, or a bad version of QJackCtl? Thank you very much, and sorry for this long post ! Julien
El Lun 09 Abr 2007 12:54, julien bodd escribió: | Hi all, | | I'm experiencing tons of xruns and sound saturation when I use | zynAddSubFx in combination with freewheeling (live looper). | | I went through the linux-audio-users-request mailing list and I saw | that a low-latency kernel is not the same with a realtime kernel. | | When I do : uname - a, I have : | ... 2.6.16-beyond4.1 #1 PREEMPT Sun May 28 ... | | So my kernel is low-latency? But, it doesn't seem it is realtime as I | have installed no patch (Ingo Molnar patch). It doesn't seem to be | PREEMPT_RT. Or is it included in Musix by default? | | This might be the problem. I dont think it could be, but, in that case, you can start Musix using the 64studio kernel that comes with it... cat /boot/config-2.6.17-2-multimedia-486 | grep -i realtime CONFIG_SECURITY_REALTIME=m marcos@musix099b16:~$ cat /boot/config-2.6.16-beyond4.1 | grep -i realtime CONFIG_SECURITY_REALTIME=m Also, I suggest to try the new kernel: linux-image-2.6.21-rc4 apt-get update apt-get install linux-image-2.6.21-rc4 | Another thing I see is that when I run QJackCtl, it doesn't seem to | run realtime! Why it does not seems? To try it, start jack and type into a konsole: ps -C jackd -cmL You must see something like this: ps -C jackd -cmL PID LWP CLS PRI TTY TIME CMD 11213 - - - ? 00:00:00 jackd - 11213 TS 19 - 00:00:00 - - 11218 TS 20 - 00:00:00 - - 11219 TS 24 - 00:00:00 - - 11222 FF 90 - 00:00:00 - - 11223 FF 80 - 00:00:00 - If there are no FF, it's not in realtime, also, Musix 0.99 tells you if you are not using a realtime kernel or JACK was not started in realtime... cat ~/.jackdrc jackd -R -P40 -p128 -t2000 -m -dalsa -dhw:0 -r48000 -p128 -n2 -s -S That "-R" is from realtime | Although it does not complain and I have activated the R (realtime) | switch. I can see it is not realtime because there is a RT indicator | that is not yellow. | I tried running as root, and it is the same. Well, that's weird, mmm Is realtime-lsm installed and loaded? lsmod | grep realtime | I have libpam-modules installed (0.79-4) and I added : | /etc/security/limits.conf | @audio - rtprio 99 | @audio - nice -10 | @audio - memlock 250000 | | (I belong to the audio group of course) | | (I also tried some optimizations with fluxbox, no 3D accel, disable | unnecessary services, increase pci latency for soundcard..) | | So, I is the problem the lack of realtime patch, or a bad version of | QJackCtl? Mmmm... the realtime patch is into Musix, in both kernels. If you have no luck with 2.6.16-x, try to install any of these: linux-image-2.6.21-rc3 - Linux kernel binary image for version 2.6.21-rc3 linux-image-2.6.21-rc4 - Linux kernel binary image for version 2.6.21-rc4 They dont need realtime-lsm to work fine Those kernels just needs this lines into: /etc/security/limits.conf # there is no way to say "allow locking all memory", 4G should be enough # * - rt_priority 0 * - nice 0 # @audio - rtprio 99 @audio - memlock 250000 @audio - nice -10 | | Thank you very much, and sorry for this long post ! It is a pleasure if I could help you, man! | Julien | | _______________________________________________ | Musix GNU+Linux - www.musix.org.ar | Musix-users mailing list | [email protected] | https://lists.ourproject.org/cgi-bin/mailman/listinfo/musix-users -- Marcos Guglielmetti * Director del desarrollo de Musix GNU+Linux, 100% Software Libre * Colabora: http://www.musix.org.ar/wiki/index.php/Musix1.0tasks * CD Download: (http://www.musix.org.ar/en/) * Videos, programas, etc.: ftp://musix.ourproject.org/pub/musix/ * Reporte de errores: https://www.musix.org.ar/wiki/index.php?title=Problemas-Bugs *IRC: #musix channel on freenode * http://autosus.wordpress.com/ «No te tomes en serio nada que no te haga reír» [un amigo de E. Galeano] ... tampoco sigas al pie de la letra ninguna de estas frases...
Hi, I was thinking for a while, and... there is possible that the problem with freewheeling could be related to a bad video configuration (slow), it should not be, JACK must run OK and realtime in any case, but... lets see Did you tried another video configurations? is your videocard accelerated? Did you tried using xorgmusix.sh? ctrl+alt+f1 login as root killall kdm killall Xorg xorgmusix.sh kdm And see if it works better... Also you can try with videoconfig.sh as root. El Lun 09 Abr 2007 12:54, julien bodd escribió: | Hi all, | | I'm experiencing tons of xruns and sound saturation when I use | zynAddSubFx in combination with freewheeling (live looper). | | I went through the linux-audio-users-request mailing list and I saw | that a low-latency kernel is not the same with a realtime kernel. | | When I do : uname - a, I have : | ... 2.6.16-beyond4.1 #1 PREEMPT Sun May 28 ... | | So my kernel is low-latency? But, it doesn't seem it is realtime as I | have installed no patch (Ingo Molnar patch). It doesn't seem to be | PREEMPT_RT. Or is it included in Musix by default? | | This might be the problem. | | Another thing I see is that when I run QJackCtl, it doesn't seem to | run realtime! | Although it does not complain and I have activated the R (realtime) | switch. I can see it is not realtime because there is a RT indicator | that is not yellow. | I tried running as root, and it is the same. | | I have libpam-modules installed (0.79-4) and I added : | /etc/security/limits.conf | @audio - rtprio 99 | @audio - nice -10 | @audio - memlock 250000 | | (I belong to the audio group of course) | | (I also tried some optimizations with fluxbox, no 3D accel, disable | unnecessary services, increase pci latency for soundcard..) | | So, I is the problem the lack of realtime patch, or a bad version of | QJackCtl? | | | Thank you very much, and sorry for this long post ! | | Julien | | _______________________________________________ | Musix GNU+Linux - www.musix.org.ar | Musix-users mailing list | [email protected] | https://lists.ourproject.org/cgi-bin/mailman/listinfo/musix-users -- Marcos Guglielmetti * Director del desarrollo de Musix GNU+Linux, 100% Software Libre * Colabora: http://www.musix.org.ar/wiki/index.php/Musix1.0tasks * CD Download: (http://www.musix.org.ar/en/) * Videos, programas, etc.: ftp://musix.ourproject.org/pub/musix/ * Reporte de errores: https://www.musix.org.ar/wiki/index.php?title=Problemas-Bugs *IRC: #musix channel on freenode * http://autosus.wordpress.com/ «No te tomes en serio nada que no te haga reír» [un amigo de E. Galeano] ... tampoco sigas al pie de la letra ninguna de estas frases...
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Marcos Guglielmetti