From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764026AbXGWGsr (ORCPT ); Mon, 23 Jul 2007 02:48:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759007AbXGWGsi (ORCPT ); Mon, 23 Jul 2007 02:48:38 -0400 Received: from smtp109.mail.mud.yahoo.com ([209.191.85.219]:40570 "HELO smtp109.mail.mud.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1758985AbXGWGsh (ORCPT ); Mon, 23 Jul 2007 02:48:37 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com.au; h=Received:X-YMail-OSG:Message-ID:Date:From:User-Agent:X-Accept-Language:MIME-Version:To:CC:Subject:References:In-Reply-To:Content-Type:Content-Transfer-Encoding; b=03iUO3uHH5CTWpJryaIxnvg1YYens10/zQo0v/KilNKIa/kFZyxvbQGuGxwmarS3v6VE6aMQwqpfswzSkdRIQ0gZBwDvXjMs7H9HIuEK8teMtER+wSOXeH9RTau6jDdGBirPIEhs08+TQyciMZj8obih6MiQe5bd4i1J7lvsYig= ; X-YMail-OSG: frkylg4VM1kYKRM6mtWOIH0ZASoarbsxGg3vCqYJ11eFlBXVAoEJV9hb8BoXQCPrvN.MhNBAEA-- Message-ID: <46A44F3C.5080301@yahoo.com.au> Date: Mon, 23 Jul 2007 16:48:28 +1000 From: Nick Piggin User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.12) Gecko/20051007 Debian/1.7.12-1 X-Accept-Language: en MIME-Version: 1.0 To: Dave Airlie CC: Andrew Morton , David Miller , airlied@linux.ie, linux-kernel@vger.kernel.org Subject: Re: cmpxchg is not available to generic code References: <20070719000549.1e57b5b2.akpm@linux-foundation.org> <20070719.002716.30181989.davem@davemloft.net> <21d7e9970707190115r15e691d5s123c9889a8ebd8a5@mail.gmail.com> <20070719012141.47911bd7.akpm@linux-foundation.org> <21d7e9970707190123n328300a6m8debe274b959ab30@mail.gmail.com> In-Reply-To: <21d7e9970707190123n328300a6m8debe274b959ab30@mail.gmail.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Dave Airlie wrote: > On 7/19/07, Andrew Morton wrote: > >> On Thu, 19 Jul 2007 18:15:03 +1000 "Dave Airlie" >> wrote: >> >> > Maybe we could add CONFIG_HAVE_CMPXCHG and let DRM depend on it.. >> >> That would certainly be better than adding a sprinkle of architectures >> in DRM Kconfig dependencies. >> >> I don't know how important DRM is on ARM. Zero? >> > > I'd guess zero I suppose if you wanted you could hook up a PCI > graphics card on ARM, but if you do that I think you could implement > cmpxchg :-) ARM does the locked load / store conditional thing which is at least as strong as cmpxchg, so I imagine it could implement this API in kernel and userspace quite easily if needed. -- SUSE Labs, Novell Inc.