[LAU] Ubuntu: changing realtime priority of irqs

[Atte André Jensen]

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

Whereas on debian I would get:

atte at ajstrup:~$ ps aux | grep IRQ
root        18  0.2  0.0      0     0 ?        S<   13:34   0:00 [IRQ 9]
root       261  0.0  0.0      0     0 ?        S<   13:34   0:00 [IRQ 4]
root       286  0.0  0.0      0     0 ?        S<   13:34   0:00 [IRQ
12]
root       300  0.0  0.0      0     0 ?        S<   13:34   0:00 [IRQ 1]
root       608  0.0  0.0      0     0 ?        S<   13:34   0:00 [IRQ
11]
root       761  0.0  0.0      0     0 ?        S<   13:34   0:00 [IRQ
14]
root       787  0.0  0.0      0     0 ?        S<   13:34   0:00 [IRQ
15]
root      1592  0.0  0.0      0     0 ?        S<   13:34   0:00 [IRQ 8]
root      1593  0.0  0.0      0     0 ?        S<   13:34   0:00 [IRQ 7]
root      1683  0.0  0.0      0     0 ?        S<   13:34   0:00 [IRQ
10]
atte      4672  0.0  0.0   2848   704 pts/1    R+   13:41   0:00 grep
IRQ

I suspect it has something to do with "ksoftirqd" which according to the
man page seems to be a daemon handling irqs.

http://tapas.affenbande.org/wordpress/?page_id=40 also doesn't seem to
take ksoftirqd into account.

So my question is: How do I set the priorities in ubuntu? Is it
possible/clever/stupid to get rid og ksoftirqd and get things working
the way I'm used to under debian, and if so how?

-- 
peace, love & harmony
Atte

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