Re: [REPORT] cfs-v4 vs sd-0.44

Ray Lee
2007-04-24T15:09:40Z

On 4/23/07, Linus Torvalds <torvalds@linux-foundation.org> wrote:
> On Mon, 23 Apr 2007, Ingo Molnar wrote:
> >
> > The "give scheduler money" transaction can be both an "implicit
> > transaction" (for example when writing to UNIX domain sockets or
> > blocking on a pipe, etc.), or it could be an "explicit transaction":
> > sched_yield_to(). This latter i've already implemented for CFS, but it's
> > much less useful than the really significant implicit ones, the ones
> > which will help X.
>
> Yes. It would be wonderful to get it working automatically, so please say
> something about the implementation..
>
> The "perfect" situation would be that when somebody goes to sleep, any
> extra points it had could be given to whoever it woke up last. Note that
> for something like X, it means that the points are 100% ephemeral: it gets
> points when a client sends it a request, but it would *lose* the points
> again when it sends the reply!

It would seem like there should be a penalty associated with sending
those points as well, so that two processes communicating quickly with
each other won't get into a mutual love-fest that'll capture the
scheduler's attention.

Ray