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Subject: Re: [PATCH 0/6] [RFC] Proposal for optimistic suspend idea.
From: Peter Zijlstra <peterz@infradead.org>
To: Richard Cochran <richardcochran@gmail.com>
Cc: John Stultz <john.stultz@linaro.org>, lkml <linux-kernel@vger.kernel.org>,
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        Thomas Gleixner <tglx@linutronix.de>
Date: Wed, 28 Sep 2011 10:02:55 +0200
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On Wed, 2011-09-28 at 09:57 +0200, Richard Cochran wrote:
> On Wed, Sep 28, 2011 at 09:51:45AM +0200, Peter Zijlstra wrote:
> > SCHED_FIFO is an utter trainwreck, you're talking to the guy who gave a
> > conference talk on why SCHED_FIFO sucks.
> 
> That sounds interesting. Do you have a link to the paper and/or
> presentation?

Not really, I'm also the guy who doesn't write papers and has minimal
slides (and has lost those he had).

But the gist is that SCHED_FIFO doesn't provide proper resource control:
its possible to overload the system, nor does it provide proper resource
isolation: (like already stated) its impossible to fold two properly
working RT systems onto one machine and still have them work correctly
(even when the combined utilization < 1).