From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263522AbTKWWyf (ORCPT ); Sun, 23 Nov 2003 17:54:35 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263517AbTKWWyf (ORCPT ); Sun, 23 Nov 2003 17:54:35 -0500 Received: from dbl.q-ag.de ([80.146.160.66]:24965 "EHLO dbl.q-ag.de") by vger.kernel.org with ESMTP id S263522AbTKWWye (ORCPT ); Sun, 23 Nov 2003 17:54:34 -0500 Message-ID: <3FC13AA0.9030204@colorfullife.com> Date: Sun, 23 Nov 2003 23:54:24 +0100 From: Manfred Spraul User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4.1) Gecko/20031030 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Russell King CC: Paul Mackerras , Pavel Machek , linux-kernel@vger.kernel.org Subject: Re: Fix locking in input References: <3FC13382.3060701@colorfullife.com> <20031123223443.A560@flint.arm.linux.org.uk> In-Reply-To: <20031123223443.A560@flint.arm.linux.org.uk> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Russell King wrote: >On Sun, Nov 23, 2003 at 11:24:02PM +0100, Manfred Spraul wrote: > > >>I think one platform (early ARM?) cannot access bytes directly, and >>implement the access with read 16-bit, change 8-bit, write back 16 bit. >> >> > >Nope. > It seems it's Alpha: On Thu, 28 Dec 2000, Linus wrote: >FreeBSD doesn't try to be portable any more, but Linux does, and there are >architectures where 8- and 16-bit accesses aren't *atomic* but have to be >done with read-modify-write cycles. > >And even for fields like "age", where we don't care whether the age itself >is 100% accurate, we _do_ care that the fields close-by don't get strange >effects from updating "age". We used to have exactly this problem on alpha >back in the 2.1.x timeframe. > -- Manfred