Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S937003AbXHOXvr (ORCPT ); Wed, 15 Aug 2007 19:51:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1762959AbXHOXvb (ORCPT ); Wed, 15 Aug 2007 19:51:31 -0400 Received: from e6.ny.us.ibm.com ([32.97.182.146]:45932 "EHLO e6.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757973AbXHOXv3 (ORCPT ); Wed, 15 Aug 2007 19:51:29 -0400 Date: Wed, 15 Aug 2007 16:51:25 -0700 From: "Paul E. McKenney" To: Herbert Xu Cc: Chris Snook , satyam@infradead.org, clameter@sgi.com, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, torvalds@linux-foundation.org, netdev@vger.kernel.org, akpm@linux-foundation.org, ak@suse.de, heiko.carstens@de.ibm.com, davem@davemloft.net, schwidefsky@de.ibm.com, wensong@linux-vs.org, horms@verge.net.au, wjiang@resilience.com, cfriesen@nortel.com, zlynx@acm.org, rpjday@mindspring.com, jesper.juhl@gmail.com, segher@kernel.crashing.org Subject: Re: [PATCH 0/24] make atomic_read() behave consistently across all architectures Message-ID: <20070815235125.GT9645@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <46C32618.2080108@redhat.com> <20070815234021.GA28775@gondor.apana.org.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070815234021.GA28775@gondor.apana.org.au> User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 819 Lines: 19 On Thu, Aug 16, 2007 at 07:40:21AM +0800, Herbert Xu wrote: > On Wed, Aug 15, 2007 at 12:13:12PM -0400, Chris Snook wrote: > > > > Part of the motivation here is to fix heisenbugs. If I knew where they > > By the same token we should probably disable optimisations > altogether since that too can create heisenbugs. Precisely the point -- use of volatile (whether in casts or on asms) in these cases are intended to disable those optimizations likely to result in heisenbugs. But they are also intended to leave other valuable optimizations in force. Thanx, Paul - 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/