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From: David Howells <dhowells@redhat.com>
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Subject: Re: [PATCH] Document Linux's memory barriers [try #2] 
Date: Wed, 08 Mar 2006 19:31:42 +0000
Message-ID: <19984.1141846302@warthog.cambridge.redhat.com>
Sender: linux-arch-owner@vger.kernel.org
To: Linus Torvalds <torvalds@osdl.org>
Cc: David Howells <dhowells@redhat.com>, Alan Cox <alan@redhat.com>, akpm@osdl.org, mingo@redhat.com, linux-arch@vger.kernel.org, linuxppc64-dev@ozlabs.org, linux-kernel@vger.kernel.org
List-ID: <linux-arch.vger.kernel.org>

Linus Torvalds <torvalds@osdl.org> wrote:

> Actually, since the different NUMA things may have different paths to the 
> PCI thing, I don't think even the mmiowb() will really help. It has 
> nothing to serialize _with_.

On NUMA PowerPC, should mmiowb() be a SYNC or an EIEIO instruction then? Those
do inter-component synchronisation.

David