Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754700AbZI3RKY (ORCPT ); Wed, 30 Sep 2009 13:10:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752987AbZI3RKX (ORCPT ); Wed, 30 Sep 2009 13:10:23 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:35699 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752475AbZI3RKW (ORCPT ); Wed, 30 Sep 2009 13:10:22 -0400 Date: Wed, 30 Sep 2009 10:08:53 -0700 (PDT) From: Linus Torvalds X-X-Sender: torvalds@localhost.localdomain To: Stefan Richter cc: Arjan van de Ven , Eric Dumazet , Martin Schwidefsky , Thomas Gleixner , John Stultz , Linux Kernel Mailing List , Peter Zijlstra , Ingo Molnar Subject: Re: Linux 2.6.32-rc1 In-Reply-To: <4AC38D7A.7030407@s5r6.in-berlin.de> Message-ID: References: <4AC060AE.1090401@gmail.com> <20090928191506.40b61793@mschwide.boeblingen.de.ibm.com> <4AC10365.7090802@gmail.com> <4AC2712C.4080901@gmail.com> <20090929232248.735bf4df@infradead.org> <20090930170754.0886ff2e@infradead.org> <4AC38D7A.7030407@s5r6.in-berlin.de> User-Agent: Alpine 2.01 (LFD 1184 2008-12-16) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 760 Lines: 20 On Wed, 30 Sep 2009, Stefan Richter wrote: > > As long as it can't be turned into an atomic access, shouldn't cmpxchg64 > be hidden from the common kernel coder? Almost everybody will assume > that it is an atomic operation and happily use it in unsafe places. But it _is_ atomic. We don't support SMP on the platforms that we have to do it with emulation on. There's a theoretical problem with NMI, but it's not one we can solve or that is really all that interesting, so might as well ignore it. Linus -- 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/