Re: [mm] [PATCH 4/4] Memory cgroup hierarchy feature selector

[Balbir Singh <balbir@linux.vnet.ibm.com>]

KAMEZAWA Hiroyuki wrote:
> On Sun, 02 Nov 2008 11:33:51 +0530
> Balbir Singh <balbir@linux.vnet.ibm.com> wrote:
> 
>> KAMEZAWA Hiroyuki wrote:
>>> On Sun, 02 Nov 2008 00:19:02 +0530
>>> Balbir Singh <balbir@linux.vnet.ibm.com> wrote:
>>>
>>>> Don't enable multiple hierarchy support by default. This patch introduces
>>>> a features element that can be set to enable the nested depth hierarchy
>>>> feature. This feature can only be enabled when there is just one cgroup
>>>> (the root cgroup).
>>>>
>>> Why the flag is for the whole system ?
>>> flag-per-subtree is of no use ?
>> Flag per subtree might not be useful, since we charge all the way up to root,
> Ah, what I said is "How about enabling/disabling hierarhcy support per subtree ?"
> Sorry for bad text.
> 
> like this.
>   - you can set hierarchy mode of a cgroup turned on/off when...
>     * you don't have any tasks under it && it doesn't have any child cgroup.

I see.. the presence of tasks don't matter, since the root cgroup will always
have tasks. Presence of child groups does matter.

-- 
	Balbir