* kubeadm now detects the Docker cgroup driver and starts the kubelet with the matching driver. This eliminates a common error experienced by new users in when the Docker cgroup driver is not the same as the one set for the kubelet due to different Linux distributions setting different cgroup drivers for Docker, making it hard to start the kubelet properly.

### Quality of Service for memory resources

* The `PodSecurityPolicy` API has been moved to the `policy/v1beta1` API group. The `PodSecurityPolicy` API in the `extensions/v1beta1` API group is deprecated and will be removed in a future release. Authorizations for using pod security policy resources should change to reference the `policy` API group after upgrading to 1.11. ([#54933](https://github.com/kubernetes/kubernetes/pull/54933), [@php-coder](https://github.com/php-coder))

Kubelet flag `--enforce-node-allocatable` with a default value of `pods` is added which will make kubelet create a top level cgroup for all pods to enforce Node Allocatable. Optionally, `system-reserved` & `kube-reserved` values can also be specified separated by comma to enforce node allocatable on cgroups specified via `--system-reserved-cgroup` & `--kube-reserved-cgroup` respectively. Note the default value of the latter flags are "". ([#41234](https://github.com/kubernetes/kubernetes/pull/41234),...

- If using cgroups v2, then the cgroup aware OOM killer will be enabled for container cgroups via  `memory.oom.group` .  This causes processes within the cgroup to be treated as a unit and killed simultaneously in the event of an OOM kill on any process in the cgroup. ([#117793](https://github.com/kubernetes/kubernetes/pull/117793), [@tzneal](https://github.com/tzneal)) [SIG Apps, Node and...

* kube-apiserver: `--runtime-config` can once again be used to enable/disable serving specific resources in the `extensions/v1beta1` API group. Note that specific resource enablement/disablement is only allowed for the `extensions/v1beta1` API group for legacy reasons. Attempts to enable/disable individual resources in other API groups will print a warning, and will return an error in future releases. ([#72249](https://github.com/kubernetes/kubernetes/pull/72249), [@liggitt](https:/...

- Fixed AWS Cloud Provider attempting to delete LoadBalancer security group it didn’t provision, and fixed AWS Cloud Provider creating a default LoadBalancer security group even if annotation `service.beta.kubernetes.io/aws-load-balancer-security-groups` is present because the intended behavior of aws-load-balancer-security-groups is to replace all security groups assigned to the load balancer. ([#84265](https://github.com/kubernetes/kubernetes/pull/84265), [@bhag...

- Fix pod launch by kubelet when --cgroups-per-qos=false and --cgroup-driver="systemd" ([#66617](https://github.com/kubernetes/kubernetes/pull/66617), [@pravisankar](https://github.com/pravisankar))

- Fix handling of aws-load-balancer-security-groups annotation. Security-Groups assigned with this annotation are no longer modified by kubernetes which is the expected behaviour of most users. Also no unnecessary Security-Groups are created anymore if this annotation is used. ([#88689](https://github.com/kubernetes/kubernetes/pull/88689), [@Elias481](https://github.com/Elias481)) [SIG...

- Fixed a bug where the kubelet ephemerally failed with `failed to initialize top level QOS containers: root container [kubepods] doesn't exist`, due to the cpuset cgroup being deleted on cgroup v2 with systemd cgroup manager.
   ([#125923](https://github.com/kubernetes/kubernetes/pull/125923), [@haircommander](https://github.com/haircommander)) [SIG Node and Testing]