Re: low priority soft RT?

Rik van Riel (riel@nl.linux.org)
Thu, 22 Jul 1999 21:39:48 +0200 (CEST)


On Thu, 22 Jul 1999, Bryn Paul Arnold Jones wrote:
> On Wed, 21 Jul 1999 cd_smith@ou.edu wrote:
>
> > Anyone thought about allowing soft RT (SCHED_FIFO or SCHED_RR) tasks with
> > negative priorities? These would only be executed if no other tasks of
> > any type are there. Giving a normal Linux task a niceness value won't do
> > this, as the task will still get some CPU time.
>
> So SCHED_IDLE then (only execute this if we would otherwise be
> executing the idle task)? It's been talked about before, IIRC
> even implemented, it just never got into the mainstream kernel.

I have made a fairly substantial SCHED_IDLE patch, but due to
the (never resolved) deadlock issues I haven't submitted it.

OTOH, if we make SCHED_IDLE a sysctl tunable thing, we should
be able to just ship it with the standard kernel and provide
a Big Fat Warning(tm) along with it...

If there's demand, I'll create a patch RSN.

regards,

Rik -- Open Source: you deserve to be in control of your data.
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