Re: [patch 3/3] Enable setting of IRQ-thread priorities from kernel cmdline. (repost:CC to LKML)

From: Juergen Beisert
Date: Thu Dec 20 2007 - 08:19:52 EST


On Thursday 20 December 2007 13:45, Jaswinder Singh wrote:
> On 12/20/07, Remy Bohmer <linux@xxxxxxxxxx> wrote:
> > So, Is this a serious requirement? Should this be possible?
>
> I have noticed this problem:
> root@xxxxxxxxxxxxx:~# cat /proc/loadavgrt
> 1.00 1.00 1.00 0/52 1158
> root@xxxxxxxxxxxxx:~# cat /proc/loadavg
> 0.00 0.00 0.02 1/52 1159
> root@xxxxxxxxxxxxx:~#
>
> So I am curious, if possible, user can switch softirq-threads or IRQs
> RT tasks to non-RT tasks for slow hardware or least important hardware
> for NON-RT tasks. So this will improve RT behaviour.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Why?

IMHO: Simply decrease the RT priority of less important IRQs or increase all
other more important IRQs. IRQs are always more important than other
processes in a system, also in non RT systems.

Juergen
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