[LAU] small/cheap devices that can run jackd?

[Jeremy Jongepier]

On 10/25/2011 10:44 AM, Renato wrote:
> On Tue, 25 Oct 2011 10:20:18 +0200
> Jeremy Jongepier <jeremy at autostatic.com> wrote:
> 
>> True. I've set up the netbook to disable all services and unload all
>> drivers I don't need when booting with a realtime kernel. 
> 
> for doing this you simply run a script which figures out the running
> kernel with "uname"?
> 

Hi Renato,

Yes:

if [ $(uname -r | cut -d "-" -f 3) = "realtime" ]
then /path/to/startstudio
fi

And the 'startstudio' script looks like this:

#!/bin/sh

modprobe -r ppdev
modprobe -r lp
modprobe -r uvcvideo
modprobe -r videodev
modprobe -r ath9k
modprobe -r r8169
modprobe -r btusb

/etc/init.d/bluetooth stop &
/etc/init.d/cups stop &
/etc/init.d/networking stop &
/etc/init.d/network-manager stop &
/etc/init.d/ondemand stop

killall modem-manager
killall wpa_supplicant

modprobe snd-hrtimer

echo -n performance > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor

TASKLETPR=76

ps -eLo pid,cmd | grep tasklet | grep -v grep | awk '{ system("chrt -f
-p '$TASKLETPR' " $1)}'

echo -n "0000:00:13.0" > /sys/bus/pci/drivers/ohci_hcd/unbind

>> And it runs
>> a light DE, rtirq and CPU scaling is set to performance. Also make
>> sure your audio device isn't sharing an interrupt with something
>> else. In my case the onboard soundcard shares an interrupt with a USB
>> controller. I need to unbind the controller otherwise CPU load on the
>> tasklets will quickly rise.
> 
> what do you mean exactly by unbinding the controller? physically
> removing it?
> 

No, writing the ID of the controller to an unbind file, it's the last
line in the startstudio script.

> cheers,
> renato

Best,

Jeremy