[LAU] Ubuntu: changing realtime priority of irqs

[james]

On Saturday 21 July 2007 10:03:24 David Causse wrote:
> Atte André Jensen a écrit :
> > Hi
> >
> > I trying out ubuntu with ubuntustudio kernel. In debian I always set the
> > priority of the IRQ's using
> >
> > chrt -f -p 85 `pidof "IRQ 8"`
> >
> > However that doesn't work in ubuntu. The reason is that there seems to
> > be no process named "IRQ 8":
> >
> > atte at ajstrup:~$ ps aux | grep -i IRQ
> > root         3  0.0  0.0      0     0 ?        SN   13:43   0:00
> > [ksoftirqd/0]
> > atte      6274  0.0  0.0   2884   772 pts/0    R+   13:51   0:00 grep -i
> > irq
>
> Hi,
>
> Your ubuntu kernel doesn't support this feature, to be sure try to look
> at /proc/config.gz
> zcat /proc/config.gz | grep PREEMPT
>
> You must have something like this :
> CONFIG_PREEMPT_HARDIRQS=y
>
> It appears that the default kernel used by Ubuntu studio
> (linux-image-lowlatency) is not patched against the Ingo's RT patch
> (required to do what you want)
> http://www.mail-archive.com/debian-multimedia@lists.debian.org/msg01756.htm
>l The RT kernel package seems to be linux-image-2.6.21-1-multimedia-486
> <http://apt.64studio.com/64studio/testing/pool/main/l/linux-2.6/linux-image
>-2.6.21-1-multimedia-486_2.6.21-2_i386.deb>
>
> David C.
>
>
>
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> Linux-audio-user at lists.linuxaudio.org
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it's probably, actually, because there's a dash in the proc name. IRQ-8, 
etc...

james