From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752719AbYFBVyq (ORCPT ); Mon, 2 Jun 2008 17:54:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751859AbYFBVyd (ORCPT ); Mon, 2 Jun 2008 17:54:33 -0400 Received: from gate.crashing.org ([63.228.1.57]:46423 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751292AbYFBVyc (ORCPT ); Mon, 2 Jun 2008 17:54:32 -0400 Subject: Re: MMIO and gcc re-ordering issue From: Benjamin Herrenschmidt Reply-To: benh@kernel.crashing.org To: Ingo Molnar Cc: Linus Torvalds , David Miller , linux-arch@vger.kernel.org, scottwood@freescale.com, linuxppc-dev@ozlabs.org, alan@lxorguk.ukuu.org.uk, linux-kernel@vger.kernel.org, tpiepho@freescale.com In-Reply-To: <20080602103643.GA21285@elte.hu> References: <1211852026.3286.36.camel@pasglop> <20080526.184047.88207142.davem@davemloft.net> <1211854540.3286.42.camel@pasglop> <20080526.192812.184590464.davem@davemloft.net> <1211859542.3286.46.camel@pasglop> <20080602103643.GA21285@elte.hu> Content-Type: text/plain Date: Tue, 03 Jun 2008 07:53:24 +1000 Message-Id: <1212443604.26672.7.camel@pasglop> Mime-Version: 1.0 X-Mailer: Evolution 2.22.1.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2008-06-02 at 12:36 +0200, Ingo Molnar wrote: > The patch passed initial light testing in -tip (~30 successful random > self-builds and bootups on various mixed 32-bit/64-bit boxes) but > it's > still v2.6.27 material IMO. I think adding the "memory" clobber should be .26 and even -stable. We know for sure newer gcc will re-order things, we know it for sure some drivers will break in subtle ways because of that, ad we know as well that sticking "memory" clobber in there will fix that breakage we know about ... So I don't see the point of waiting. Ben.