Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932153AbWCaRsw (ORCPT ); Fri, 31 Mar 2006 12:48:52 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932152AbWCaRsw (ORCPT ); Fri, 31 Mar 2006 12:48:52 -0500 Received: from cantor2.suse.de ([195.135.220.15]:15026 "EHLO mx2.suse.de") by vger.kernel.org with ESMTP id S932153AbWCaRsv (ORCPT ); Fri, 31 Mar 2006 12:48:51 -0500 From: Andi Kleen To: Christoph Lameter Subject: Re: Synchronizing Bit operations V2 Date: Fri, 31 Mar 2006 19:48:37 +0200 User-Agent: KMail/1.9.1 Cc: Zoltan Menyhart , "Boehm, Hans" , "Grundler, Grant G" , "Chen, Kenneth W" , akpm@osdl.org, linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200603311948.38218.ak@suse.de> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1267 Lines: 28 On Friday 31 March 2006 19:45, Christoph Lameter wrote: > On Fri, 31 Mar 2006, Andi Kleen wrote: > > > Christoph Lameter writes: > > > MODE_BARRIER > > > An atomic operation that is guaranteed to occur between > > > previous and later memory operations. > > I think it's a bad idea to create such an complicated interface. > > The chances that an average kernel coder will get these right are > > quite small. And it will be 100% untested outside IA64 I guess > > and thus likely be always slightly buggy as kernel code continues > > to change. > > Powerpc can do similar things AFAIK. Not sure what other arches have > finer grained control over barriers but it could cover a lot of special > cases for other processors as well. Yes, but I don't think the goal of a portable atomic operations API in Linux is it to cover everybody's special case in every possible combination. The goal is to have an abstraction that will lead to portable code. I don't think your proposal will do this. -Andi - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/