From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752706Ab2AOWdP (ORCPT ); Sun, 15 Jan 2012 17:33:15 -0500 Received: from mx1.redhat.com ([209.132.183.28]:40885 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752541Ab2AOWdO (ORCPT ); Sun, 15 Jan 2012 17:33:14 -0500 Date: Sun, 15 Jan 2012 17:32:46 -0500 From: Vivek Goyal To: Shaohua Li Cc: Jan Kara , Dave Chinner , linux-kernel@vger.kernel.org, axboe@kernel.dk, jmoyer@redhat.com Subject: Re: [RFC 0/3]block: An IOPS based ioscheduler Message-ID: <20120115223246.GC3174@redhat.com> References: <20120104065337.230911609@sli10-conroe.sh.intel.com> <20120104071931.GB17026@dastard> <1325746241.22361.503.camel@sli10-conroe> <1325826750.22361.533.camel@sli10-conroe> <20120106143759.GE20291@quack.suse.cz> <1326072405.22361.553.camel@sli10-conroe> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1326072405.22361.553.camel@sli10-conroe> 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 09, 2012 at 09:26:45AM +0800, Shaohua Li wrote: [..] > > Could you for example compare a latency of reads while running heavy > > background writing between CFQ and your scheduler? Loads like this where > > original motivation for CFQ I believe. > CFQ supports preemption, FIOPS doesn't, so I suppose read latency of CFQ > is still better in such workload. > In this initial post, I just want to demonstrate the basic idea of the > ioscheduler. I'll post more data for both latency and throughput in next > round. I think before numbers what will be more helpful to know is that what are you trying to achieve and why existing CFQ code can not do that with little modification. Thanks Vivek