This is needed because for nested containers cgroups. Without this patch
they creating unnecessary intermediate cgroup like:
/sys/fs/cgroup/memory/system.slice/docker-9409d9f0b68fb9e9d7d532d5b3f35e7c7f9cca1312af392ae3b28436f1f2998f.scope/system.slice/docker-9409d9f0b68fb9e9d7d532d5b3f35e7c7f9cca1312af392ae3b28436f1f2998f.scope/docker/908ebcc9c13584a14322ec070bd971e0de62f126c0cd95c079acdb99990ad3a3
It is because in /proc/self/cgroup we see paths from host, and they don't
exist in container.
Signed-off-by: Alexander Morozov <lk4d4@docker.com>
Before name=systemd cgroup was mounted inside container to
/sys/fs/cgroup/name=systemd, which is wrong, it should be
/sys/fs/cgroup/systemd
Signed-off-by: Alexander Morozov <lk4d4@docker.com>