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From: "Sherif F. Fahmy" <fahmy@vt.edu>
To: "'Casey Dahlin'" <cdahlin@redhat.com>
Cc: <linux-kernel@vger.kernel.org>
Subject: RE: scheduling co-processors
Date: Tue, 4 Aug 2009 13:28:00 +0300	[thread overview]
Message-ID: <000301ca14ee$401f8560$c05e9020$@edu> (raw)
In-Reply-To: <4A774858.6080106@redhat.com>

> -----Original Message-----
> From: linux-kernel-owner@vger.kernel.org [mailto:linux-kernel-
> owner@vger.kernel.org] On Behalf Of Casey Dahlin
> Sent: Monday, August 03, 2009 11:28 PM
> To: Sherif Fadel
> Cc: linux-kernel@vger.kernel.org
> Subject: Re: scheduling co-processors
> 
> On 08/03/2009 11:08 AM, Sherif Fadel wrote:
> > Hi,
> >
> > I have a dual-core system on which I would like to treat one
> processor
> > as a scheduling co-processor. I have already implemented some custom
> > scheduling policies and tested them with SMP disabled, I would not
> like
> > to see if it is possible to have the scheduling algorithm running on
> one
> > core and the scheduled tasks running on another.
> >
> > I do not know if I can somehow use cpus_allowed to restrict the
> kernel
> > to one core and the running tasks to another. Is this possible? If
> so,
> > could you please inform me how one would go about this?
> >
> > In case you are wondering why I would need this, I am writing a bunch
> of
> > high-overhead distributed scheduling algorithms and I want to
> mitigate
> > their overhead in this way.
> >
> > Thanks.
> >
> 
> The design I would have for this would be to have a kthread that does
> whatever busy work your scheduler has as a separate process. You could
> then replace the existing scheduler with a sort of "schedulerlet" that
> would simply schedule according to directions queued up for it by the
> kthread task. From there cpu affinity should get you the "dedicated
> scheduler processor" you want.
> 
> I can't even begin to envision the scheduling algorithm that would be
> able to operate this way, but I have to assume that if it makes sense
> for your scheduler to run on another CPU then it must be able to fit
> into this pattern.

Thanks for the info. I think that this will do perfectly.

> 
> --CJD
> --
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      reply	other threads:[~2009-08-04 10:28 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-08-03 15:08 scheduling co-processors Sherif Fadel
2009-08-03 15:59 ` Peter Zijlstra
2009-08-03 19:52 ` Bill Davidsen
2009-08-03 20:28 ` Casey Dahlin
2009-08-04 10:28   ` Sherif F. Fahmy [this message]

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