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Date: Mon, 10 Mar 2003 23:47:12 -0800
From: William Lee Irwin III <wli@holomorphy.com>
To: "Martin J. Bligh" <mbligh@aracnet.com>
Cc: Andi Kleen <ak@muc.de>, linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: Dcache hash distrubition patches
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On Mon, Mar 10, 2003 at 11:41:07PM -0800, Martin J. Bligh wrote:
> It's not perfect, but not bad either. Some mathematician can go calculate
> just how imperfect it is over random distribution, but it looks OK to me ;-)

Okay, the standards are a bit more stringent for hash functions. You
basically want the total number of collisions to be minimized.

That said, standard statistical things are useful for first-pass
discrimination.

This looks basically okay, but if it's really just even with respect
to cache pressure the need for a different data structure in the
eventual future is clear. I'd need a baseline (pre-hlist) dcache
snapshot to compare against to get a better idea.


-- wli
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