From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gui Jianfeng Subject: Re: [PATCH 1/9] io-throttle documentation Date: Fri, 17 Apr 2009 17:29:25 +0800 Message-ID: <49E84BF5.4070604__41331.835758365$1239960860$gmane$org@cn.fujitsu.com> 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> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20090417164351.ea85012d.kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: KAMEZAWA Hiroyuki Cc: randy.dunlap-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org, Paul Menage , Carl Henrik Lunde , eric.rannaud-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, Balbir Singh , fernando-gVGce1chcLdL9jVzuh4AOg@public.gmane.org, Andrea Righi , dradford-cT2on/YLNlBWk0Htik3J/w@public.gmane.org, agk-9JcytcrH/bA+uJoB2kUjGw@public.gmane.org, subrata-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org, axboe-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org, akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, dave-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org, matt-cT2on/YLNlBWk0Htik3J/w@public.gmane.org, roberto-5KDOxZqKugI@public.gmane.org, ngupta-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org List-Id: containers.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