[PATCH 1/1] cr: define CHECKPOINT_SUBTREE flag and sysctl

[Alexey Dobriyan]

On Mon, Apr 27, 2009 at 01:07:17PM -0500, Serge E. Hallyn wrote:
> Heh, because there is no such thing as a 'container'.

Oh, yes, there is.

Set of tasks shares set of uts_ns, ipc_ns, mnt_ns, pid_ns and net_ns.
No other task shares this set.
Pid_ns set has tree hierarchy.
All user_ns which come from credentials of set of tasks aren't shared
with other tasks.

Such set of tasks logically forms a container.

> There is a set of tasks in the same freezer control group, and it's
> possible that there is a task not in that cgroup which is in the same
> utsname as the rest of the tasks in that freezer cgroup.