Re: [patch 1/4] io controller: documentation

[Li Zefan <lizf@cn.fujitsu.com>]

Hi, Vivek

Thanks for your work. :)

A question below.

> +For example, assume there are two cgroups A and B with weights 1024 and 2048
> +in the system. Tasks in two cgroups A and B are doing IO to two disks sda and
> +sdb in the system. A user has enabled IO control on both sda and sdb. Now on
> +both sda and sdb, tasks in cgroup B will get to use 2/3 of disk BW and
> +tasks in cgroup A will get to use 1/3 of disk bandwidth, only in case of
> +contention. If tasks in any of the groups stop doing IO to a particular disk,
> +task in other group will get to use full disk BW for that duration.
> +

So in this example, I can't assign 1/3 of sda's disk BW while 2/3 of sdb's
disk BW to A. Am I right?