Re: [PATCH 1/9] io-throttle documentation

[Gui Jianfeng <guijianfeng@cn.fujitsu.com>]

KAMEZAWA Hiroyuki wrote:
> On Tue, 14 Apr 2009 22:21:12 +0200
> Andrea Righi <righi.andrea@gmail.com> 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.

> 
> Thanks,
> -Kame
> 
> 
> 
> 

-- 
Regards
Gui Jianfeng