Date: Tue, 7 Mar 2006 17:23:37 -0800
From: Andrew Morton <akpm@osdl.org>
To: Con Kolivas <kernel@kolivas.org>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, ck@vds.kolivas.org
Subject: Re: [PATCH] mm: yield during swap prefetching
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Con Kolivas <kernel@kolivas.org> wrote:
>
> > but, but.  If prefetching is prefetching stuff which that game will soon
> > use then it'll be an aggregate improvement.  If prefetch is prefetching
> > stuff which that game _won't_ use then prefetch is busted.  Using yield()
> > to artificially cripple kprefetchd is a rather sad workaround isn't it?
> 
> It's not the stuff that it prefetches that's the problem; it's the disk 
> access.

But the prefetch code tries to avoid prefetching when the disk is otherwise
busy (or it should - we discussed that a bit a while ago).

Sorry, I'm not trying to be awkward here - I think that nobbling prefetch
when there's a lot of CPU activity is just the wrong thing to do and it'll
harm other workloads.
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