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Date: Fri, 12 Oct 2001 19:04:46 -0700 (PDT)
From: Linus Torvalds <torvalds@transmeta.com>
To: Davide Libenzi <davidel@xmailserver.org>
cc: Paul Mackerras <paulus@samba.org>, <linux-kernel@vger.kernel.org>
Subject: Re: [Lse-tech] Re: RFC: patch to allow lock-free traversal of lists
 with insertion
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On Fri, 12 Oct 2001, Davide Libenzi wrote:
>
> The problem is that even if cpu1 schedule the load of  p  before the
> load of  *p  and cpu2 does  a = 1; wmb(); p = &a; , it could happen that
> even if from cpu2 the invalidation stream exit in order, cpu1 could see
> the value of  p  before the value of  *p  due a reordering done by the
> cache controller delivering the stream to cpu1.

Umm - if that happens, your cache controller isn't honouring the wmb(),
and you have problems quite regardless of any load ordering on _any_ CPU.

Ehh?

		Linus

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