[LAU] debian realtime kernel config 2.6.25.8.rt7

[David Baron]

On Sunday 13 July 2008 23:58:19 Emanuel Rumpf wrote:
> things to do additionally
> ---------------------------------------------------------------------------
>---
>
>
> enable realtime clock
> ----------------------
>
> for the realtime clock to work, you've got to load these modules:
>   modprobe rtc_core
>   modprobe rtc_cmos
>
> you should then have a device
>   /dev/rtc0

I have /dev/rtc from previous

>
> then change the max-user-frequency of rtc (default is only 64):
>   echo 2048 > /sys/class/rtc/rtc0/max_user_freq

I have this set to 1024 (kernel hz?) in /etc/sysctl.conf.

> test:
>   cat /sys/class/rtc/rtc0/max_user_freq
>
>
> and maybe of hpet as well (?)
>   echo 2048 > /proc/sys/dev/hpet/max-user-freq
> (Is hpet emulated by rtc ?)
There are hpet source files in the kernel sources and among them an 
hpet/emulate.rtc.h. No particular hpet.ko was built, however.

There is a /usr/src/linux-2.6.25.8/Documentation/hpet.txt which says that this 
is a REPLACEMENT for the rtc stuff and the first two of its 32  timers will 
stand in for the rtc. So it would seem one or the other.
> ---------------------------------------------------------------------------
>---
>
>
>
> set realtime priorities
> -----------------------
>
> install scheduling tools (/usr/bin/chrt)
>   apt-get install schedutils
This one threatened to remove some stuff
> or
>   apt-get install schedtool
This one was clean.
>
>
> install,setup and run the rtirq script by Rui Nuno Capela
> download:
>   wget http://www.rncbc.org/jack/rtirq-20071012.tar.gz
Got it, copied the files to places and my startup stuff to run it.

So will give everything a try out. The kernel runs fine. Debian's nvidia built 
and works OK. One caveat is that hal kicks out all the dma and 32-bit disk 
accesses but they can be immediately set back so I put that in my startup 
stuff as well.