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Date: Thu, 6 Dec 2001 15:52:16 -0200 (BRST)
From: Rik van Riel <riel@conectiva.com.br>
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To: Davide Libenzi <davidel@xmailserver.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>,
        "David S. Miller" <davem@redhat.com>, <lm@bitmover.com>,
        "Martin J. Bligh" <Martin.Bligh@us.ibm.com>, <lars.spam@nocrew.org>,
        Alan Cox <alan@lxorguk.ukuu.org.uk>, <hps@intermeta.de>,
        lkml <linux-kernel@vger.kernel.org>
Subject: Re: SMP/cc Cluster description
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On Thu, 6 Dec 2001, Davide Libenzi wrote:

> > Machines get dragged down by _uncontended_ locks, simply
> > due to cache line ping-pong effects.
>
> Rik, i think you're confused about lockless algos.
> It's not an rwlock where the reader has to dirty a cacheline in any case,
> the reader simply does _not_ write any cache line accessing the
> list/hash/tree or whatever you use.

Hmmm indeed, so the cache lines can be shared as long
as the data is mostly read-only. I think I see it now.

However, this would only work for data which is mostly
read-only, not for anything else...

Rik
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