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

From: Gui Jianfeng
Date: Fri Apr 17 2009 - 03:35:29 EST


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

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/