Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754698Ab1EDPVQ (ORCPT ); Wed, 4 May 2011 11:21:16 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:51791 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754310Ab1EDPVP (ORCPT ); Wed, 4 May 2011 11:21:15 -0400 Date: Wed, 4 May 2011 17:20:54 +0200 From: Ingo Molnar To: Christoph Lameter Cc: Tejun Heo , Thomas Gleixner , Pekka Enberg , Linus Torvalds , Jens Axboe , Andrew Morton , werner , "H. Peter Anvin" , Linux Kernel Mailing List Subject: Re: [block IO crash] Re: 2.6.39-rc5-git2 boot crashs Message-ID: <20110504152054.GA23210@elte.hu> References: <20110504101932.GA3392@elte.hu> <20110504112746.GE8007@htj.dyndns.org> <20110504132022.GA17294@htj.dyndns.org> <20110504142532.GC17294@htj.dyndns.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-08-17) X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.3.1 -2.0 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1126 Lines: 31 * Christoph Lameter wrote: > On Wed, 4 May 2011, Tejun Heo wrote: > > > The cmpxchg_double optimization made the fast path go quite faster > > when CPU supports it but it may as well slow things down considerably > > if CPU doesn't, due to extra irq on/off's. Anyways, here's hoping > > that the slow down is acceptable compared to the base code without > > cmpxchg_double and the ugliness can be removed. > > I think we are all in agreement. First path to fix the percpu macros: > > > Subject: percpu: Fix irqsafe_cpu_cmpxchg_double > > The function in the macro was not updated when the function was given a bool return value. > > Signed-off-by: Christoph Lameter Note, the final commit needs to have a proper Reported-by and explanation about how this was triggered, to fairly credit all the hard work done by Werner ... Thanks, Ingo -- 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/