Quoting Tejun Heo (tj@xxxxxxxxxx): > On Wed, Feb 11, 2015 at 05:00:23PM +0100, Serge E. Hallyn wrote: > > We absolutely would love to use cgroup namespaces to run older > > userspace in containers. I don't know that it's actually possible > > to do both that and use unified hierarchy at the same time though, > > which is unfortunate. So an Ubuntu 12.04 container will never, afaics, > > be able to run inside an ubuntu 16.04 host that is using unified > > hierarchy, without using backported newer versions of lxc (etc) in > > the container. > > So, the constraint there are the controllers. A controller can't be > attached to two hierarchies at the same time for obvious reasons, so > regardless of NS, you can't use the same controller on a unified > hierarchy *and* a traditional hierarchy. NS doesn't adds or > substracts from the situation. If you decide to attach a controller > to a traditional hierarchy, that's where it's gonna be available. If > you attach it to the unified hierarchy, the same story. Right, exactly. thanks, -serge -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html