Hello,

On Thu, Feb 01, 2018 at 05:49:42PM +0100, Peter Zijlstra wrote:

quoted

Well, they're upper limits, not strict allocations.  The current
behavior implemented by cpu isn't either a strict allocation or upper
limits.  It disallows a child from having a value higher than the
parent (allocation-ish) but the sum of the children is allowed to
exceed the parent's (limit-ish).

True; but its still weird to have the parent 'promise' something and
then retract that 'promise' later.

Yeah, depending on how you look at it, it can feel weird.  It's just
that viewing these absolute resource limits (cpu.max,
memory.{high,max}, io.max, pids.max) as upper bounds seems to be the
best abstraction in terms of capturing what they do and making uses of
them in a robust way.

quoted

We had this sort of input validations in different controllers all in
their own ways.  In most cases, these aren't well thought out and we
can't support things like delegation without aligning controller
behaviors.

I suppose.. 

Acked-by: Peter Zijlstra (Intel) <redacted>

Will route it through cgroup fixes branch in a week or so.

Thanks a lot.

-- 
tejun