• base: support cgroup2 #40174

• metrics (docker stats): cgroup2: implement docker stats #40657

• disable cgroupns for privileged containers? (add KEP for cgroups v2 support kubernetes/enhancements#1370) (Probably not needed for Moby : cgroup2: privileged and cgroupns containers/podman#5341)

• systemd cgroup driver for rootless mode: rootless: support --exec-opt native.cgroupdriver=systemd #40486

• use "systemd" cgroup driver by default when available : cgroup2: use "systemd" cgroup driver by default when available #40846

• CI (rootful+systemd) : Jenkinsfile: add cgroup2 #41925

• CI (rootless+systemd)

• docs: v20.10 docs for cgroup v2 and rootless docker/docs#11042

Low hanging fruits:

• Put cgroup version to docker info: cgroup2: implement docker info #40662
• dockerd --cpu-rt-{period,runtime} (Can't be supported)

related: containerd/containerd#3726 opencontainers/runc#2209