Re: [PATCH 1/3] cgroup : add clone_children control file

[Daniel Lezcano <daniel.lezcano-GANU6spQydw@public.gmane.org>]

On 09/07/2010 10:26 PM, Paul Menage wrote:
> On Tue, Sep 7, 2010 at 1:23 PM, Daniel Lezcano<daniel.lezcano-GANU6spQydw@public.gmane.org>  wrote:
>    
>>> This bit is awkward - you're storing the original value of the
>>> clone_children flag to report in the mount options, but this isn't
>>> necessarily the current state. Might it be better to not store this
>>> and just report the current value of the root cgroup's
>>> CGRP_CLONE_CHILDREN flag?
>>>
>>>        
>> Sure. Shall I do the same as the release agent mount option ?
>>      
> I think so - the slight problem with this new flag is that it's
> possible for the root cgroup to have one setting for clone_children
> and all its children to have a different setting. But I guess we can
> live with that. (Or maybe simply not make the default clone_children
> value a mount option, but require it to be set on the root cgroup
> after mounting?)
>    

The clone_children option behaves like the release-agent mount option no 
? We can mount with a specific release agent and change it at runtime. 
IMHO it would be better to give a chance to the administrator to set its 
system with the mount option instead of force him to write post mount 
scripts. An alternative would be to set this cgroup option *only* via 
the mount option, but I am not sure it is good as it may be an 
unresolvable constraint for a system wanting to use the cgroups with and 
without this option (same kind of constraint we have with the ns_cgroup).

I am favorable to keep the mount option and the ability to change it for 
another cgroup.

   -- Daniel