Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965061AbWH2QUe (ORCPT ); Tue, 29 Aug 2006 12:20:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965060AbWH2QUe (ORCPT ); Tue, 29 Aug 2006 12:20:34 -0400 Received: from ftp.linux-mips.org ([194.74.144.162]:60545 "EHLO ftp.linux-mips.org") by vger.kernel.org with ESMTP id S965056AbWH2QUd (ORCPT ); Tue, 29 Aug 2006 12:20:33 -0400 Date: Tue, 29 Aug 2006 17:20:55 +0100 From: Ralf Baechle To: Christoph Lameter Cc: David Howells , Nick Piggin , Arjan van de Ven , Dong Feng , ak@suse.de, Paul Mackerras , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org Subject: Re: Why Semaphore Hardware-Dependent? Message-ID: <20060829162055.GA31159@linux-mips.org> References: <44F395DE.10804@yahoo.com.au> <1156750249.3034.155.camel@laptopd505.fenrus.org> <11861.1156845927@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: 661 Lines: 19 On Tue, Aug 29, 2006 at 08:56:36AM -0700, Christoph Lameter wrote: > > Because i386 (and x86_64) can do better by using XADDL/XADDQ. > > And Ia64 would like to use fetchadd.... > > > CMPXCHG is not available on all archs, and may not be implemented on all archs > > through other atomic instructions. > > Which arches do not support cmpxchg? MIPS, Alpha - probably any pure RISC load/store architecture. Ralf - 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/