Re: Interesting scheduling times

Rik van Riel (H.H.vanRiel@phys.uu.nl)
Fri, 18 Sep 1998 08:15:40 +0200 (CEST)


On Thu, 17 Sep 1998, Linus Torvalds wrote:
> On Fri, 18 Sep 1998, Richard Gooch wrote:
> >
> > Linus: what do you think of this idea? A valid project for 2.3?
>
> A single run-queue is almost always better than multiple run-queues, and
> I'm very unlikely to change that.

Not necessarily. In a QNX-sched style scheduler, we may
have to scan multiple queues, but we don't have to calculate
process priority, as we need to do now.

It's just a different way of spending your cycles, but
it doesn't mean you have to do more. I am currently
rewriting the specs for the QNX-style scheduler (on
request, for the Alliance OS) and the docs will be
ready in about a week. After that, pseudo-code (for
alliance) and maybe some real code (when school doesn't
take up too much time) for Linux will emerge.

> Even under heavy load, the runqueue is seldom more than a few entries
> deep. More than 10 entries on the run-queue is already very rare, and

This is a good point. Maybe the code should be semantically
QNX-like but with a different implementation? I'll think it
over...

Rik.
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