From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752016AbXHTFI3 (ORCPT ); Mon, 20 Aug 2007 01:08:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751144AbXHTFIU (ORCPT ); Mon, 20 Aug 2007 01:08:20 -0400 Received: from pentafluge.infradead.org ([213.146.154.40]:55632 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751080AbXHTFIU (ORCPT ); Mon, 20 Aug 2007 01:08:20 -0400 Subject: Re: Non atomic unaligned writes From: Arjan van de Ven To: Mathieu Desnoyers Cc: Andi Kleen , patches@x86-64.org, Jeremy Fitzhardinge , Zachary Amsden , Rusty Russell , linux-kernel@vger.kernel.org, "S. P. Prasanna" , Chris Wright In-Reply-To: <20070820005522.GA5069@Krystal> References: <200707191105.44056.ak@suse.de> <469FC9D4.5070604@goop.org> <200707192246.58047.ak@suse.de> <20070820005522.GA5069@Krystal> Content-Type: text/plain Organization: Intel International BV Date: Sun, 19 Aug 2007 22:03:13 -0700 Message-Id: <1187586193.5408.1.camel@laptopd505.fenrus.org> Mime-Version: 1.0 X-Mailer: Evolution 2.11.90 (2.11.90-1.fc8) Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > > > Are misaligned/cross-cache-line updates atomic? > > > > In theory yes, in practice there can be errata of course. Afaik the theory is "Platform specific; most x86 will be in practice"; it's up to the system vendor and chipset vendor. The practice is "mixed ball, slow as h*ck anyway, just never ever do it"