From mboxrd@z Thu Jan 1 00:00:00 1970 From: Segher Boessenkool Subject: Re: [PATCH 0/24] make atomic_read() behave consistently across all architectures Date: Sat, 18 Aug 2007 00:14:30 +0200 Message-ID: <1f265c14b28f2c5922059a130b1d8aa5@kernel.crashing.org> References: <18115.52863.638655.658466@cargo.ozlabs.ibm.com> <20070816053945.GB32442@gondor.apana.org.au> <18115.62741.807704.969977@cargo.ozlabs.ibm.com> <20070816070907.GA964@gondor.apana.org.au> <46C40587.7050708@s5r6.in-berlin.de> <20070816081049.GA1431@gondor.apana.org.au> <46C41EE4.9090806@s5r6.in-berlin.de> <46C42767.4070104@s5r6.in-berlin.de> <20070816104250.GB2927@gondor.apana.org.au> <20070816163441.GB16957@linux.vnet.ibm.com> <46C512EB.7020603@yahoo.com.au> Mime-Version: 1.0 (Apple Message framework v623) Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Cc: paulmck@linux.vnet.ibm.com, Christoph Lameter , Paul Mackerras , heiko.carstens@de.ibm.com, Stefan Richter , horms@verge.net.au, Satyam Sharma , Linux Kernel Mailing List , rpjday@mindspring.com, netdev@vger.kernel.org, ak@suse.de, cfriesen@nortel.com, jesper.juhl@gmail.com, linux-arch@vger.kernel.org, Andrew Morton , zlynx@acm.org, schwidefsky@de.ibm.com, Chris Snook , Herbert Xu , davem@davemloft.net, Linus Torvalds , wensong@linux-vs.org, wjiang@resilience.com To: Nick Piggin Return-path: Received: from gate.crashing.org ([63.228.1.57]:45347 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754374AbXHQWR1 (ORCPT ); Fri, 17 Aug 2007 18:17:27 -0400 In-Reply-To: <46C512EB.7020603@yahoo.com.au> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org > (and yes, it is perfectly legitimate to > want a non-volatile read for a data type that you also want to do > atomic RMW operations on) ...which is undefined behaviour in C (and GCC) when that data is declared volatile, which is a good argument against implementing atomics that way in itself. Segher