Re: [PATCH] cgroup: deprecate remount option changes and "name=" mount option

[Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>]

Hello,

On Thu, Mar 15, 2012 at 12:29:25AM +0100, Lennart Poettering wrote:
> Hmm, this is not clear to me. Are you intending to remove the name=
> mount option entirely, or just intend to remove that you can change it
> in remounts?
> 
> systemd uses name=systemd to get its own private cgroup tree, that has
> no controller bound, hence we kinda need this option. Or are you
> suggesting there was an other way to get a private cgroup tree that
> systemd can use for grouping and labelling things?

Eh, you're right.  I want to remove support for duplicate mounting by
name or subsys as it just isn't necessary, so what I want is,

* "mount -t cgroupfs -o SUBSYS" will fail if SUBSYS is already mounted
  somewhere else.

* "mount -t cgroupfs -o none" will always create a new cgroup
  hierarchy w/o any controller attached.

I didn't realize that the mount code didn't allow none w/o name and
now I don't see a non-intrusive way to remove the name option. :( Eh
well, I'll drop that part.

Thanks.

-- 
tejun