Comment # 65 on bug 1159882 from Michal Hocko

(In reply to Robert Delahunt from comment #64)
[...] 
> By the way this is the stock kernel with cgroup_disable=memory boot
> parameter and no swap.

Sorry, I should have been more explicit. We are interested in who is using
memory cgroup controller. But the cgroup_disable kernel command line makes it
disabled.

>From the systemctl it seems no service is really trying to use it so I suspect
it will be cgroup v1 created automatically and the hierarchy will mirror the
systemd organization structure (slices, scopes etc.). Please boot again with
the kernel command line parameter dropped.