Shuttleworth: Losing graciously

Posted Feb 20, 2014 18:15 UTC (Thu) by MrWim (subscriber, #47432)
In reply to: Shuttleworth: Losing graciously by HelloWorld
Parent article: Shuttleworth: Losing graciously

That's what I meant by "all pids have to appear in the cgroup tree so to put a pid in a cgroup you have to remove it from another". My assumption is that there cannot be a process which isn't a member of any cgroup. If init starts in a cgroup and it's children end up in the same cgroup and there's no way of unlink()ing pids from the cgroup tree then you're guaranteed that every process is in the tree.

In that setup you can't steal other users processes and put them in your subtree, you can only move pids around in the trees you own. You can then use whichever cgroup manager that you desire in your subtree. Containers work while still only co-operating with the kernel, rather than having to communicate with other user-space programs running outside.