we already have the code to account page fractions shared between containers.OpenVZ assumes that tasks can't move between task-groups for a single reason:
user shouldn't be able to escape from the container.
But this have no implication on the design/implementation.
It does, for the memory controller at least. Things like shared
anon_vma's between tasks across containers make it somewhat harder.
It's much worse if you allow threads to split across containers.
BTW, do you see any practical use cases for tasks jumping between resource-containers?