[Musix-usuarios] Re: [LAU] Musix Kernels

Mie Mayo 9 03:08:01 CEST 2007

El Dom 06 May 2007 19:53, Ken Restivo escribió:
 | On Sun, May 06, 2007 at 12:58:16PM +0300, David Baron wrote:
 | > Along with (a currently uninstallable rosegarden), the musix reporistory
 | > was 2.61-rt kernels. Are these with the rt patch applied or are they
 | > simply with 1000hz timer as some "rt" kernels are?
 | >
 | > Anyone used these yet?
 |
 | I thought it was RT-patched, downloaded, and found out that it wasn't.
 |
 | I ended up building a 2.6.21 with Ingo's RT patch -1, from source.  Took
 | only a short time to build, and worked great. Yay make-kpkg.
 |
 | -ken
 | _______________________________________________

by David Baron  May 08, 2007; 02:31pm 

"
These are more relevant:
# 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
CONFIG_RCU_TRACE=y

The PREEMPT_RT is the main thing of the "rt" patch.
The security realtime module is realtime-lsm. Setting this here has no effect
since it is not included in the sources but must be compiled seperately. I
think the put that here just to tell you it is (in their estimation)
obsolete. It still works and I do not have rlimits available. "

Thanks, see:

64studio's kernel:

cat config-2.6.17-2-multimedia-486 | grep -i preem
# 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_PREEMPT_RCU=y
# CONFIG_CRITICAL_PREEMPT_TIMING is not set

Ok, this is the Musix's kernel:

marcos en 4[boot]$ cat config-2.6.21-rt1 | grep -i preem
# 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_PREEMPT_RCU=y
# CONFIG_DEBUG_PREEMPT is not set
# CONFIG_CRITICAL_PREEMPT_TIMING is not set

The only thing I dont see is: CONFIG_RCU_TRACE=y, but it's there:

cat config-2.6.21-rt1 | grep -i rcu
# CONFIG_CLASSIC_RCU is not set
CONFIG_PREEMPT_RCU=y
CONFIG_RCU_TRACE=y

So, I dont know why did you told the world they are not realtime patched ¿why?

Am I missing something here?

Just install it and see. But, thanks for your report.

On the other hand, we could not build 2.6.21 with aufs and all the RT patches, 
see:

cat config-2.6.21 | grep -i preem
# CONFIG_PREEMPT_NONE is not set
# CONFIG_PREEMPT_VOLUNTARY is not set
CONFIG_PREEMPT=y
CONFIG_PREEMPT_BKL=y
# CONFIG_DEBUG_PREEMPT is not set

Because of an error related to aufs and realtime patches, the live CD runs 
this 2.6.21 kernel and you can install 2.6.21-rt from our repositories.

But, the performance is not too bad for a Live CD, see:

Performance Tests:

PC: AMD Duron 1800 (64kb cache: too low!), 384mb RAM, HD 30GB IDE 7200 RPM, 
Soundcard: SB Live! So: cheap hardware! Not good for this things, but, see:

Distro: Live-CD Musix GNU/Linux 1.0-r0b3

Linux Musix 2.6.21 #1 SMP PREEMPT Fri Apr 27 18:08:33 EEST 2007 i686 GNU/Linux

Desktop: Icewm + Rox-Filer (Musix's default)

Ardour 0.99.3

Recording to HD (IDE, 7200 RMP)

I am not using plugins (LADSPA)

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

JACK: 5.3 ms latency, 48khz

20 mono tracks: I can play or record 20 mono tracks without problems at all, 
no xruns, no stop.

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

JACK: 2.7 ms latency, 48khz

20 mono tracks: I can play or record 20 mono tracks without problems at all, 
no xruns, no stop.

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

Less latency: my SB Live! does not allow me to lower the latency less than 
2.7ms when JACK is in Duplex mode, but I can lower it if I choose only 
playback from the qjackctl setup.

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

JACK: 42,7 ms latency, 48khz

39 mono tracks into Ardour: OK, no xruns... sometimes Ardour stop and 
says "your machine is not fast enought...etc", but it happends when I move 
some slider into Ardour or something like this. If I just record or play, 
there are no problems.

I have to do more tests, but it woud be useful to use better hardware for them

-- 
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/

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