From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Wed, 20 May 2009 08:58:59 +0100 (BST) Received: from [222.92.8.141] ([222.92.8.141]:35108 "EHLO lemote.com" rhost-flags-FAIL-FAIL-OK-OK) by ftp.linux-mips.org with ESMTP id S20024866AbZETH6x (ORCPT ); Wed, 20 May 2009 08:58:53 +0100 Received: from localhost (localhost [127.0.0.1]) by lemote.com (Postfix) with ESMTP id 0E64531C8F3; Wed, 20 May 2009 15:53:59 +0800 (CST) X-Virus-Scanned: Debian amavisd-new at lemote.com Received: from lemote.com ([127.0.0.1]) by localhost (www.lemote.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id jS135HUT++vX; Wed, 20 May 2009 15:53:44 +0800 (CST) Received: from [172.16.2.16] (unknown [222.92.8.142]) by lemote.com (Postfix) with ESMTP id 6391231C92D; Wed, 20 May 2009 15:53:40 +0800 (CST) Subject: Re: [PATCH 26/30] loongson: flush irq write operation From: yanh Reply-To: yanh@lemote.com To: Ralf Baechle Cc: Wu Zhangjin , linux-mips@linux-mips.org, Arnaud Patard , loongson-dev@googlegroups.com, zhangfx@lemote.com, Philippe Vachon , Zhang Le , Erwan Lerale In-Reply-To: <20090520070719.GA24231@linux-mips.org> References: <1242426527.10164.174.camel@falcon> <20090518163603.GA22779@linux-mips.org> <1242700637.4382.21.camel@localhost.localdomain> <20090519160117.GA19672@linux-mips.org> <1242786494.4382.58.camel@localhost.localdomain> <20090520070719.GA24231@linux-mips.org> Content-Type: text/plain; charset="UTF-8" Date: Wed, 20 May 2009 15:58:04 +0800 Message-Id: <1242806284.4382.72.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.24.1 (2.24.1-2.fc10) Content-Transfer-Encoding: 8bit Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 22838 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: yanh@lemote.com Precedence: bulk X-list: linux-mips 在 2009-05-20三的 08:07 +0100，Ralf Baechle写道： > On Wed, May 20, 2009 at 10:28:14AM +0800, yanh wrote: > > > I have test this patch just now. It works well on yeeloong. > > Thanks for testing. > > > I have one question what's the difference between the two patch? > > Uncached writes can't be re-ordered. By adding a read after the last > write my patch forces not only completion of the preceding write but due > to this ordering constraint also completion of all preceding writes is > enforced. > > I/O space writes are slow. I mean slower than slugs in space. So my > patch is an optimization but that was not the point; I really only meant > to verify that we understood what's going on and we seem to. Now let's > fix the real issue and make outX() non-posted. Thanks for your explanation. > > Ralf >