quoted

quoted

Some degree of flexibility is provided so that you may disable some controllers
in a subtree. For example:

root                  ---> child1
(cpuset,memory,cpu)        (cpuset,memory)
                      \
                       \-> child2
                           (cpu)

Whew, that's a relief.  Thanks.

But somehow I'm not feeling a whole lot better.

"May" means if you don't explicitly take some action to disable group
scheduling, you get it (I don't care if I have an off button), but that
would also seemingly mean that we would then have rt tasks in taskgroups
with no bandwidth allocated, ie you have to make group scheduling for rt
tasks meaningless until a bandwidth appeared, and to make bandwidth
appear, you'd have to stop the world, distribute, continue, no?

The current "just say no" seems a lot more sensible.

I just realized we allow removing/adding controllers from/to cgroups
while there are tasks in them, which isn't safe unless we eliminate all
can_attach callbacks. We've done so for some cgroup subsystems, but
there are still a few of them...