From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chuck Ebbert Subject: Re: [PATCH] make atomic_t volatile on all architectures Date: Thu, 09 Aug 2007 13:36:11 -0400 Message-ID: <46BB508B.7050601@redhat.com> References: <20070808230733.GA17270@shell.boston.redhat.com> <46BAC2BE.1090106@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Linus Torvalds , akpm@linux-foundation.org, ak@suse.de, heiko.carstens@de.ibm.com, davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, schwidefsky@de.ibm.com, wensong@linux-vs.org, horms@verge.net.au, wjiang@resilience.com, cfriesen@nortel.com, zlynx@acm.org To: Chris Snook Return-path: Received: from mx1.redhat.com ([66.187.233.31]:58688 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965112AbXHIRmV (ORCPT ); Thu, 9 Aug 2007 13:42:21 -0400 In-Reply-To: <46BAC2BE.1090106@redhat.com> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On 08/09/2007 03:31 AM, Chris Snook wrote: > > Fair enough. Casting to (volatile int *) will give us the behavior > people expect when using atomic_t without needing to use inefficient > barriers. > You can use this forget() macro to make the compiler reread a variable: #define forget(var) asm volatile ("" : "=m"(var))