From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756009Ab0CVTTE (ORCPT ); Mon, 22 Mar 2010 15:19:04 -0400 Received: from mail-pv0-f174.google.com ([74.125.83.174]:41991 "EHLO mail-pv0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755932Ab0CVTS5 (ORCPT ); Mon, 22 Mar 2010 15:18:57 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:date:message-id:subject:from:to:content-type; b=d73iH5k5hQcCj/itdfFBXSCE+uvcZ4eVXuesbPi+iqmhFVEQVMwE4PvaaIzq7d9FRw BCPv/JQNldo2htbYekSMd2t2TO0T46mUKuaO2eQRsfwGSUjMeu1wjCeygJBNDb71o1bK JKbbMqrO0mTYNQS83ZFnKA87+Khsgn1eOF3/U= MIME-Version: 1.0 Date: Mon, 22 Mar 2010 20:18:49 +0100 Message-ID: Subject: Memory-mapped I/O barriers, state of affairs? From: Leon Woestenberg To: linux-kernel@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, searching for good info on device IO racing against host memory writes I came upon this 2006 article: http://lwn.net/Articles/198988/ "there is no guaranteed ordering between writes to regular memory and writes to a memory-mapped I/O range. " What is the current solution for that particular problem, i.e. how should I make sure host memory writes are committed before I have an external DMA device act on it? Thanks, -- Leon Woestenberg.