From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id o4OJWVHw198141 for ; Mon, 24 May 2010 14:32:32 -0500 Received: from out1.smtp.messagingengine.com (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id 29AF91DF9768 for ; Mon, 24 May 2010 12:34:52 -0700 (PDT) Received: from out1.smtp.messagingengine.com (out1.smtp.messagingengine.com [66.111.4.25]) by cuda.sgi.com with ESMTP id 99CVr3pPA1EV3J1v for ; Mon, 24 May 2010 12:34:52 -0700 (PDT) Date: Mon, 24 May 2010 14:34:28 -0500 From: Roman Kononov Subject: Re: WARNING in xfs_lwr.c, xfs_write() Message-ID: <20100524143428.6f3a117c@abend.internal.xtremedata.com> In-Reply-To: <4BF9FCA8.8090906@hardwarefreak.com> References: <20100523002023.41f5a5c8@aaa.pulp.binarylife.net> <20100523101856.GL2150@dastard> <20100523092344.0fcaab42@aaa.pulp.binarylife.net> <4BF9FCA8.8090906@hardwarefreak.com> Mime-Version: 1.0 List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: xfs@oss.sgi.com On Sun, 23 May 2010 23:12:24 -0500 Stan Hoeppner wrote: > "The whole notion of "direct IO" is totally braindamaged. Just say no. ... > From: http://lkml.org/lkml/2007/1/10/235 I definitely measure dramatic overall performance benefit using O_DIRECT carefully. In that thread, it is doubtful that madvise+mmap+msync allow asynchronous zero-copy reads and writes to/from already pinned by a device driver memory of data produced/consumed by that device, without cache pollution and with intelligent handling of disk errors. Am I wrong? Thanks, Roman _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs