From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751678Ab1IKFRy (ORCPT ); Sun, 11 Sep 2011 01:17:54 -0400 Received: from out4.smtp.messagingengine.com ([66.111.4.28]:41234 "EHLO out4.smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751050Ab1IKFRx (ORCPT ); Sun, 11 Sep 2011 01:17:53 -0400 X-Sasl-enc: 7Iam+RqTXKnXoRRS679uQdZaNtERBk7QdbYP/mlv7XmG 1315718272 Date: Sun, 11 Sep 2011 07:08:29 +0200 From: Greg KH To: Anthony DeRobertis Cc: Linux-kernel mailing list Subject: Re: RFC: [PATCH] Add a sysfs entry queue/ignore_flushes. Message-ID: <20110911050829.GA15269@kroah.com> References: <4E6A783D.9040708@metrics.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4E6A783D.9040708@metrics.net> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Sep 09, 2011 at 04:34:05PM -0400, Anthony DeRobertis wrote: > I have an Oracle workload that ran quite fast under 2.6.32 due to mdraid > not supporting barriers. 2.6.33 slowed it down very substantially, and > its remains slow in 3.1. (Oracle is running on raw LVM logical volumes, > not filesystems, so ext4 barrier=0 doesn't help). > > This patch adds a sysfs attribute to allow flush/fua to to turned off > (ignored) on a per-block-device basis. I have tested it on both a VM and > real hardware. > > I'm not sure that queue_flags is the best place to put the bit, seems > like it may more logically go in flush_flags, but everything else is in > queue_flags. > > I'm not subscribed, but will be looking for replies via list archives. > Feel free to CC me. If you add/remove/change sysfs attributes, you also need to do the same to Documentation/ABI. thanks, greg k-h