Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754888AbZI3Rla (ORCPT ); Wed, 30 Sep 2009 13:41:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754862AbZI3Rl3 (ORCPT ); Wed, 30 Sep 2009 13:41:29 -0400 Received: from einhorn.in-berlin.de ([192.109.42.8]:59071 "EHLO einhorn.in-berlin.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754518AbZI3Rl3 (ORCPT ); Wed, 30 Sep 2009 13:41:29 -0400 X-Envelope-From: stefanr@s5r6.in-berlin.de Message-ID: <4AC397FE.8060001@s5r6.in-berlin.de> Date: Wed, 30 Sep 2009 19:40:14 +0200 From: Stefan Richter User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.8.1.22) Gecko/20090926 SeaMonkey/1.1.17 MIME-Version: 1.0 To: Linus Torvalds 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 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> In-Reply-To: X-Enigmail-Version: 0.95.7 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 945 Lines: 23 Linus Torvalds wrote: > 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. Ah, right, I could have taken a hint from /* disable interrupts */ in Arjan's cmpxchg8b_emu. -- Stefan Richter -=====-==--= =--= ====- http://arcgraph.de/sr/ -- 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/