From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754071AbcAVOni (ORCPT ); Fri, 22 Jan 2016 09:43:38 -0500 Received: from mx1.redhat.com ([209.132.183.28]:55145 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753756AbcAVOnf (ORCPT ); Fri, 22 Jan 2016 09:43:35 -0500 Date: Fri, 22 Jan 2016 09:43:34 -0500 From: Vivek Goyal To: Tejun Heo Cc: Shaohua Li , linux-kernel@vger.kernel.org, axboe@kernel.dk, jmoyer@redhat.com, Kernel-team@fb.com Subject: Re: [RFC 0/3] block: proportional based blk-throttling Message-ID: <20160122144334.GC9499@redhat.com> References: <20160121211002.GH5157@mtj.duckdns.org> <20160121222449.GA3770911@devbig084.prn1.facebook.com> <20160121224157.GL5157@mtj.duckdns.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160121224157.GL5157@mtj.duckdns.org> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 21, 2016 at 05:41:57PM -0500, Tejun Heo wrote: [..] > A simple approximation of IO cost such as fixed cost > per IO + cost proportional to IO size would do a far better job than > just depending on bandwidth or iops and that requires approximating > two variables over time. I'm not sure how easy / feasible that > actually would be tho. Hi Tejun, "A fixed cost per IO sounds" like iops and "cost proportional to IO size" sounds like bandwidth. I am wondering can we dynamically control both bps and iops rate of cgroup based on cgroup weight and average bw/iops of device queue. That way a cgroup can not get unfair share of disk neither by throwing lots of small IOs, nor by sending down a small number of large IOs. Will that be good enough. Thanks Vivek