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Date: Mon, 21 Jan 2002 14:26:12 -0500 (EST)
From: Mark Hahn <hahn@physics.mcmaster.ca>
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To: <linux-kernel@vger.kernel.org>
Subject: Re: [2.4.17/18pre] VM and swap - it's really unusable
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> > > To me the benefit is clear enough: ASAP scheduling of IO threads, a 
> > > simple heuristic that improves both throughput and latency.
> > 
> > I think of "benefit", perhaps naiively, in terms of something that can
> > be measured or demonstrated rather than just announced.
> 
> But you see why asap scheduling improves latency/throughput *in theory*, 
> don't you?  

NO, IT DOES NOT. why can't you preempt-ophiles get that through your heads? 

	eager scheduling is NOT optimal in general.  

for instance, suppose my disk can only read a sector at a time.
scheduling my sequentially-reading process to wake eagerly
is most definitly PESSIMAL.  laziness is a cardinal virtue!
this doesn't preclude heuristics to sometimes short-cut the laziness.

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