Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934706AbXEHWUF (ORCPT ); Tue, 8 May 2007 18:20:05 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S934695AbXEHWT6 (ORCPT ); Tue, 8 May 2007 18:19:58 -0400 Received: from smtp-out.google.com ([216.239.45.13]:10938 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934644AbXEHWT5 (ORCPT ); Tue, 8 May 2007 18:19:57 -0400 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=received:date:from:x-x-sender:to:cc:subject:in-reply-to: message-id:references:mime-version:content-type; b=YZvcXjv4STD3gmv6G7Il/B/D5WoemdphCLJ0UszaOyMMvCp+KPwwiY2OzYfc4kitY 9gpzioJ16n5fNQOJoSB4A== Date: Tue, 8 May 2007 15:19:29 -0700 (PDT) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: Jeremy Fitzhardinge cc: Randy Dunlap , Andrew Morton , Paul Sokolovsky , linux-kernel@vger.kernel.org, Andi Kleen Subject: Re: [RFC/PATCH] doc: volatile considered evil In-Reply-To: <4640F3FD.80001@goop.org> Message-ID: References: <516386418.20070501080839@gmail.com> <20070430235642.e576e917.akpm@linux-foundation.org> <20070508121404.17bd97a6.randy.dunlap@oracle.com> <4640E98B.4030107@goop.org> <4640ED7D.708@goop.org> <4640F3FD.80001@goop.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1087 Lines: 24 On Tue, 8 May 2007, Jeremy Fitzhardinge wrote: > > You're point about reordering "asm volatile" constructs differs depending > > on -mvolatile-asm-stop or -mno-volatile-asm-stop, however. > > > > Erm, that seems to be ia64 specific, and I have no idea what adding a > "stop bit" implies. Can you set even or odd parity too? > It is analogous with a sequence point for ia64. But, as you mentioned, it is ia64 specific so your comment about "asm volatile" constructs not being reordered is always appropriate outside of ia64 specific code but may not apply to ia64 if we ever compiled with -mvolatile-asm-stop. If we do not compile with that option, the behavior is unspecified. I don't think we'll be adding -mvolatile-asm-stop support any time soon so your warning certainly is appropriate for all code at this time. David - 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/