From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753859Ab2A3Pav (ORCPT ); Mon, 30 Jan 2012 10:30:51 -0500 Received: from mx1.redhat.com ([209.132.183.28]:20989 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753753Ab2A3Par (ORCPT ); Mon, 30 Jan 2012 10:30:47 -0500 Date: Mon, 30 Jan 2012 10:30:09 -0500 From: Vivek Goyal To: Shaohua Li Cc: axboe@kernel.dk, linux-kernel@vger.kernel.org, david@fromorbit.com, jack@suse.cz, zhu.yanhai@gmail.com, namhyung.kim@lge.com Subject: Re: [patch v2 0/8]block: An IOPS based ioscheduler Message-ID: <20120130153009.GB30245@redhat.com> References: <20120130070213.793690895@sli10-conroe.sh.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120130070213.793690895@sli10-conroe.sh.intel.com> 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 Mon, Jan 30, 2012 at 03:02:13PM +0800, Shaohua Li wrote: > An IOPS based I/O scheduler > > Flash based storage has some different characteristics against rotate disk. > 1. no I/O seek. > 2. read and write I/O cost usually is much different. > 3. Time which a request takes depends on request size. > 4. High throughput and IOPS, low latency. Hi Shaohua, Last time we agreed that you will try to extend CFQ iops mode to take care of this case. I was wondering that if that idea is out of the window? Also what's the real workload where this is going to benefit us. I had struggled to run something which drove constantly deep queue depths to get the fairness without idling. Thanks Vivek