From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760411AbZDQJaA (ORCPT ); Fri, 17 Apr 2009 05:30:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759782AbZDQJ3u (ORCPT ); Fri, 17 Apr 2009 05:29:50 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:56343 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1759632AbZDQJ3t (ORCPT ); Fri, 17 Apr 2009 05:29:49 -0400 Message-ID: <49E84BF5.4070604@cn.fujitsu.com> Date: Fri, 17 Apr 2009 17:29:25 +0800 From: Gui Jianfeng User-Agent: Thunderbird 2.0.0.5 (Windows/20070716) MIME-Version: 1.0 To: KAMEZAWA Hiroyuki CC: Andrea Righi , Paul Menage , Balbir Singh , agk@sourceware.org, akpm@linux-foundation.org, axboe@kernel.dk, baramsori72@gmail.com, Carl Henrik Lunde , dave@linux.vnet.ibm.com, Divyesh Shah , eric.rannaud@gmail.com, fernando@oss.ntt.co.jp, Hirokazu Takahashi , Li Zefan , matt@bluehost.com, dradford@bluehost.com, ngupta@google.com, randy.dunlap@oracle.com, roberto@unbit.it, Ryo Tsuruta , Satoshi UCHIDA , subrata@linux.vnet.ibm.com, yoshikawa.takuya@oss.ntt.co.jp, containers@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/9] io-throttle documentation References: <1239740480-28125-1-git-send-email-righi.andrea@gmail.com> <1239740480-28125-2-git-send-email-righi.andrea@gmail.com> <20090417102417.88a0ef93.kamezawa.hiroyu@jp.fujitsu.com> <49E8311D.5030901@cn.fujitsu.com> <20090417164351.ea85012d.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20090417164351.ea85012d.kamezawa.hiroyu@jp.fujitsu.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 KAMEZAWA Hiroyuki wrote: > On Fri, 17 Apr 2009 15:34:53 +0800 > Gui Jianfeng wrote: > >> KAMEZAWA Hiroyuki wrote: >>> On Tue, 14 Apr 2009 22:21:12 +0200 >>> Andrea Righi wrote: >>> >>>> +Example: >>>> +* Create an association between an io-throttle group and a bio-cgroup group >>>> + with "bio" and "blockio" subsystems mounted in different mount points: >>>> + # mount -t cgroup -o bio bio-cgroup /mnt/bio-cgroup/ >>>> + # cd /mnt/bio-cgroup/ >>>> + # mkdir bio-grp >>>> + # cat bio-grp/bio.id >>>> + 1 >>>> + # mount -t cgroup -o blockio blockio /mnt/io-throttle >>>> + # cd /mnt/io-throttle >>>> + # mkdir foo >>>> + # echo 1 > foo/blockio.bio_id >>> Why do we need multiple cgroups at once to track I/O ? >>> Seems complicated to me. >> Hi Kamezawa-san, >> >> The original thought to implement this function is for sharing a bio-cgroup >> with other subsystems, such as dm-ioband. If the bio-cgroup is already mounted, >> and used by dm-ioband or others, we just need to create a association between >> io-throttle and bio-cgroup by echo a bio-cgroup id, just like what dm-ioband does. >> > > - Why we need multiple I/O controller ? > - Why bio-cgroup cannot be a _pure_ infrastructe as page_cgroup ? > - Why we need extra mount ? > > I have no answer but, IMHO, > - only one I/O controller should be enabled at once. > - bio cgroup should be tightly coupled with I/O controller and should work as > infrastructure i.e. naming/tagging I/O should be automatically done by > I/O controller. not by the user's hand. It seems dm-ioband has to make use of bio-cgroup by the user's hand. Because dm-ioband is not cgroup based. :( Is that possible that another subsystem(not cgroup based, and not an IO Controller) also would like to use bio-cgroup in the future? There's no such case at least now, so i don't object to get rid of this part. :) > > Thanks, > -Kame > > > > > -- Regards Gui Jianfeng