Re: [RFC PATCH 2/3] sched: add yield_to function

[Rik van Riel]

On 12/03/2010 10:09 AM, Mike Galbraith wrote:
> On Fri, 2010-12-03 at 09:48 -0500, Rik van Riel wrote:
> > On 12/03/2010 09:45 AM, Mike Galbraith wrote:
> >
> > > I'll have to go back and re-read that.  Off the top of my head, I see no
> > > way it could matter which container the numbers live in as long as they
> > > keep advancing, and stay in the same runqueue.  (hm, task weights would
> > > have to be the same too or scaled. dangerous business, tinkering with
> > > vruntimes)
> >
> > They're not necessarily in the same runqueue, the
> > VCPU that is given time might be on another CPU
> > than the one that was spinning on a lock.
>
> I don't think pumping vruntime cross cfs_rq would be safe, for the
> reason noted (et al).  No competition means vruntime is meaningless.
> Donating just advances a clock that nobody's looking at.

Do you have suggestions on what I should do to make
this yield_to functionality work?

I'm willing to implement pretty much anything the
scheduler people will be happy with :)

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