Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753537AbZIOP7E (ORCPT ); Tue, 15 Sep 2009 11:59:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754844AbZIOP67 (ORCPT ); Tue, 15 Sep 2009 11:58:59 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35277 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753765AbZIOP66 (ORCPT ); Tue, 15 Sep 2009 11:58:58 -0400 Message-ID: <4AAFB98F.80201@redhat.com> Date: Tue, 15 Sep 2009 11:58:07 -0400 From: Rik van Riel Organization: Red Hat, Inc User-Agent: Thunderbird 2.0.0.17 (X11/20080915) MIME-Version: 1.0 To: balbir@linux.vnet.ibm.com CC: Ryo Tsuruta , dhaval@linux.vnet.ibm.com, vgoyal@redhat.com, linux-kernel@vger.kernel.org, dm-devel@redhat.com, jens.axboe@oracle.com, agk@redhat.com, akpm@linux-foundation.org, nauman@google.com, guijianfeng@cn.fujitsu.com, jmoyer@redhat.com Subject: Re: Regarding dm-ioband tests References: <20090909105122.GF8828@linux.vnet.ibm.com> <20090910.165849.104059407.ryov@valinux.co.jp> <20090911095347.GD4474@linux.vnet.ibm.com> <20090916.001237.226784704.ryov@valinux.co.jp> <20090915151952.GH4846@balbir.in.ibm.com> In-Reply-To: <20090915151952.GH4846@balbir.in.ibm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1191 Lines: 34 Balbir Singh wrote: > * Ryo Tsuruta [2009-09-16 00:12:37]: >> Why it is so bad to have multiple ways to configure? I think that it >> rather gains in flexibility of configurations. >> > > The main issue I see is user confusion and distro issues. If a distro > compiles cgroups and dmsetup provides both methods, what method > do we recommend to end users? Also should system management tool > support two configuration mechanisms for the same functionality? It gets worse. If the distro sets up things via cgroups and the admin tries to use dmsetup - how does the configuration propagate between the two mechanisms? The sysadmin would expect that any changes made via dmsetup will become visible via the config tools (that use cgroups), too. This will quickly increase the code requirements to ridiculous proportions - or leave sysadmins confused and annoyed. Neither is a good option, IMHO. -- All rights reversed. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/