From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from outpipe-village-512-1.bc.nu ([81.2.110.250]:5605 "EHLO lxorguk.ukuu.org.uk") by vger.kernel.org with ESMTP id S964839AbWCHAeF (ORCPT ); Tue, 7 Mar 2006 19:34:05 -0500 Subject: Re: [PATCH] Document Linux's memory barriers From: Alan Cox In-Reply-To: <200603071257.24234.ak@suse.de> References: <200603071134.52962.ak@suse.de> <7621.1141756240@warthog.cambridge.redhat.com> <1141759408.2617.9.camel@serpentine.pathscale.com> <200603071257.24234.ak@suse.de> Content-Type: text/plain Content-Transfer-Encoding: 7bit Date: Wed, 08 Mar 2006 00:35:16 +0000 Message-Id: <1141778116.2455.23.camel@localhost.localdomain> Mime-Version: 1.0 Sender: linux-arch-owner@vger.kernel.org To: Andi Kleen Cc: Bryan O'Sullivan , David Howells , torvalds@osdl.org, akpm@osdl.org, mingo@redhat.com, linux-arch@vger.kernel.org, linuxppc64-dev@ozlabs.org, linux-kernel@vger.kernel.org List-ID: On Maw, 2006-03-07 at 12:57 +0100, Andi Kleen wrote: > > They don't, but according to Documentation/DocBook/deviceiobook.tmpl > > they are performed by the compiler in the order specified. > > I don't think that's correct. Probably the documentation should > be fixed. It would be wiser to ensure they are performed in the order specified. As far as I can see this is currently true due to the volatile cast and most drivers rely on this property so the brown and sticky will impact the rotating air impeller pretty fast if it isnt.