[RFD] cgroup: about multiple hierarchies

[Peter Zijlstra]

On Tue, 2012-03-13 at 10:10 -0400, Vivek Goyal wrote:
> Implementing hierarchy is a pain and is expensive at run time. 

Yeah, suck it up :-)

I would really rather we mandate one implementation standard for
controllers for the sake of consistency and uniformity. A direct result
of doing away with the multiple hierarchy crap is that all controllers
are co-mounted. Allowing differences like this just doesn't make any
sense.

So either we drop full hierarchy support from all controllers or we
deprecate and remove all non-hierarchical controllers.

I'm fine with either, but I'm not fine with with the half-arsed
solutions proposed here.