From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754597Ab0EXBOD (ORCPT ); Sun, 23 May 2010 21:14:03 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:56920 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751835Ab0EXBOA (ORCPT ); Sun, 23 May 2010 21:14:00 -0400 Message-ID: <4BF9D265.70008@cn.fujitsu.com> Date: Mon, 24 May 2010 09:12:05 +0800 From: Gui Jianfeng User-Agent: Thunderbird 2.0.0.24 (Windows/20100228) MIME-Version: 1.0 To: Vivek Goyal CC: Jens Axboe , linux kernel mailing list Subject: Re: [PATCH 0/4] io-controller: Add new interfaces to trace backlogged group status References: <4BF64712.1070500@cn.fujitsu.com> <20100521131751.GA15302@redhat.com> In-Reply-To: <20100521131751.GA15302@redhat.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Vivek Goyal wrote: > On Fri, May 21, 2010 at 04:40:50PM +0800, Gui Jianfeng wrote: >> Hi, >> >> This series implements three new interfaces to keep track of tranferred bytes, >> elapsing time and io rate since group getting backlogged. If the group dequeues >> from service tree, these three interfaces will reset and shows zero. > > Hi Gui, > > Can you give some details regarding how this functionality is useful? Why > would somebody be interested in only in stats of till group was > backlogged and not in total stats? > > Groups can come and go so fast and these stats will reset so many times > that I am not able to visualize how these stats will be useful. Hi Vivek, Currently, we assign weight to a group, but user still doesn't know how fast the group runs. With io rate interface, users can check the rate of a group at any moment, or to determine whether the weight assigned to a group is enough. bytes and time interface is just for debug purpose. Thanks, Gui > > Thanks > Vivek > >> Thanks >> Gui > >