Re: Scheduler priorities

Wessel Dankers (
Thu, 28 Mar 2002 08:08:55 +0100

On 2002-03-27 16:14:55-0500, Robert Love wrote:
> On Wed, 2002-03-27 at 15:23, Wessel Dankers wrote:
> > Any plans for a SCHED_IDLE?
> I think Ingo Molnar has mentioned lately doing one.
> The problem is, it is not easy to implement right - there are priority
> inversion issues to deal with ...

Well evidently it should be root-only, just like SCHED_RR and SCHED_FIFO.
If the priority inversion issues are worked out this restriction could be
removed. I remember discussing this problem with Rik van Riel.
The kernel-preempt patch seems to be able to detect when a process holds a
lock; perhaps the process scheduler can temporarily revert to SCHED_NORMAL
when this is the case? Preferably with a large nice value.

Wessel Dankers <>

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