Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S937590AbWLFUAa (ORCPT ); Wed, 6 Dec 2006 15:00:30 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S937589AbWLFUA3 (ORCPT ); Wed, 6 Dec 2006 15:00:29 -0500 Received: from caramon.arm.linux.org.uk ([217.147.92.249]:4630 "EHLO caramon.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S937590AbWLFUA3 (ORCPT ); Wed, 6 Dec 2006 15:00:29 -0500 Date: Wed, 6 Dec 2006 20:00:19 +0000 From: Russell King To: Linus Torvalds Cc: Christoph Lameter , David Howells , Andrew Morton , linux-arm-kernel@lists.arm.linux.org.uk, Linux Kernel Mailing List , linux-arch@vger.kernel.org Subject: Re: [PATCH] WorkStruct: Implement generic UP cmpxchg() where an arch doesn't support it Message-ID: <20061206200019.GB15281@flint.arm.linux.org.uk> Mail-Followup-To: Linus Torvalds , Christoph Lameter , David Howells , Andrew Morton , linux-arm-kernel@lists.arm.linux.org.uk, Linux Kernel Mailing List , linux-arch@vger.kernel.org References: <20061206164314.19870.33519.stgit@warthog.cambridge.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1149 Lines: 31 On Wed, Dec 06, 2006 at 11:05:22AM -0800, Linus Torvalds wrote: > > > On Wed, 6 Dec 2006, Christoph Lameter wrote: > > > > I'd really appreciate a cmpxchg that is generically available for > > all arches. It will allow lockless implementation for various performance > > criticial portions of the kernel. > > I suspect ARM may have been the last one without one, no? > > That said, cmpxchg won't necessarily be "high-performance" unless the hw > supports it naturally in hardware, so.. > > Russell, are you ok with the code DavidH posted (the "try 2" one)? I'd > like to get an ack from the ARM maintainer before applying it, but it > looked ok. I've only recently got in today, so it'll be a while (== tomorrow) before I can get around to doing any tests. (It's evening this side of the pond.) -- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: - 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/