Hello, Eric.

On Mon, Nov 16, 2015 at 04:24:27PM -0600, Eric W. Biederman wrote:

Does this allow mixing of cgroupfs and cgroupfs2?  That is can I: "mount
-t cgroupfs" inside a container and "mount -t cgroupfs2" outside a
container? and still have reasonable things happen?  I suspect the
semantics of cgroups prevent this but I am interested to know what happens.

cgroup v1 and v2 are just separate hierarchies.  They can't nest each
other but co-existing and namespacing on their own is completely fine.
The caveat is that a given controller can be on only one hierarchy but
that's the same among v1 hierarchies too.

Thanks.

-- 
tejun