From mboxrd@z Thu Jan 1 00:00:00 1970 From: KAMEZAWA Hiroyuki Subject: Re: [PATCH 1/9] io-throttle documentation Date: Fri, 17 Apr 2009 16:43:51 +0900 Message-ID: <20090417164351.ea85012d.kamezawa.hiroyu__46183.2884386697$1239954582$gmane$org@jp.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> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <49E8311D.5030901-BthXqXjhjHXQFUHtdCDX3A@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: Gui Jianfeng Cc: randy.dunlap-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org, Paul Menage , Henrik Lunde , eric.rannaud-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, Balbir Singh , fernando-gVGce1chcLdL9jVzuh4AOg@public.gmane.org, Carl-FOgKQjlUJ6BQetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@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 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. Thanks, -Kame