From mboxrd@z Thu Jan  1 00:00:00 1970
From: Ingo Molnar <mingo@elte.hu>
Subject: Re: RFC: THE OFFLINE SCHEDULER
Date: Wed, 26 Aug 2009 20:04:07 +0200
Message-ID: <20090826180407.GA13632@elte.hu>
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Cc: Peter Zijlstra <peterz@infradead.org>,
	raz ben yehuda <raziebe@gmail.com>,
	Maxim Levitsky <maximlevitsky@gmail.com>,
	Chris Friesen <cfriesen@nortel.com>,
	Mike Galbraith <efault@gmx.de>, riel@redhat.com,
	andrew motron <akpm@linux-foundation.org>,
	wiseman@macs.biu.ac.il, lkml <linux-kernel@vger.kernel.org>,
	linux-rt-users@vger.kernel.org
To: Christoph Lameter <cl@linux-foundation.org>
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* Christoph Lameter <cl@linux-foundation.org> wrote:

> On Wed, 26 Aug 2009, Peter Zijlstra wrote:
> 
> > On Wed, 2009-08-26 at 11:41 -0400, Christoph Lameter wrote:
> > > On Wed, 26 Aug 2009, Peter Zijlstra wrote:
> > >
> > > > Why waste a whole cpu for something that could be done by part of one?
> > >
> > > Because of latency and performance requirements
> >
> > Latency is the only one, and yes people have been using hacks 
> > like this, I've also earlier mentioned RTAI, RTLinux and 
> > L4-Linux which basically do the same thing.
> >
> > The problem is, that its not linux, you cannot run something on 
> > a these off-cores and use the same functionality as linux, if 
> > you could it'd not be offline.
> 
> Right. We discussed this. Why are you repeating the same old 
> arguments?

The thing is, you have cut out (and have not replied to) this 
crutial bit of what Peter wrote:

> > The past year or so you've been whining about the tick latency, 
> > and I've seen exactly _0_ patches from you slimming down the 
> > work done in there, even though I pointed out some obvious 
> > things that could be done.

... which pretty much settles the issue as far as i'm concerned. If 
you were truly interested in a constructive solution to lower 
latencies in Linux you should have sent patches already for the low 
hanging fruits Peter pointed out.

	Ingo