Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763054AbXHPIMq (ORCPT ); Thu, 16 Aug 2007 04:12:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758323AbXHPIMY (ORCPT ); Thu, 16 Aug 2007 04:12:24 -0400 Received: from rhun.apana.org.au ([64.62.148.172]:1278 "EHLO arnor.apana.org.au" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755603AbXHPIMV (ORCPT ); Thu, 16 Aug 2007 04:12:21 -0400 Date: Thu, 16 Aug 2007 16:10:49 +0800 From: Herbert Xu To: Stefan Richter Cc: Paul Mackerras , Satyam Sharma , Christoph Lameter , "Paul E. McKenney" , Chris Snook , Linux Kernel Mailing List , linux-arch@vger.kernel.org, Linus Torvalds , netdev@vger.kernel.org, Andrew Morton , 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: <20070816081049.GA1431@gondor.apana.org.au> References: <18115.44462.622801.683446@cargo.ozlabs.ibm.com> <20070816020042.GA30650@gondor.apana.org.au> <18115.45316.702491.681906@cargo.ozlabs.ibm.com> <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> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <46C40587.7050708@s5r6.in-berlin.de> User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1098 Lines: 25 On Thu, Aug 16, 2007 at 10:06:31AM +0200, Stefan Richter wrote: > > > > Do you (or anyone else for that matter) have an example of this? > > The only code I somewhat know, the ieee1394 subsystem, was perhaps > authored and is currently maintained with the expectation that each > occurrence of atomic_read actually results in a load operation, i.e. is > not optimized away. This means all atomic_t (bus generation, packet and > buffer refcounts, and some other state variables)* and likewise all > atomic bitops in that subsystem. Can you find an actual atomic_read code snippet there that is broken without the volatile modifier? Thanks, -- Visit Openswan at http://www.openswan.org/ Email: Herbert Xu ~{PmV>HI~} Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt - 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/