([#44744](https://github.com/kubernetes/kubernetes/pull/44744), [@yguo0905](https://github.com/yguo0905))

  * Kubernetes now shares a single PID namespace among all containers in a pod when running with docker >= 1.13.1. This means processes can now signal processes in other containers in a pod, but it also means that the `kubectl exec {pod} kill 1` pattern will cause the Pod to be restarted rather than a single container. ([#45236](https://github.com/kubernetes/kubernetes/pull/45236), [@verb](...

for COS images on GCE has changed to `/home/kubernetes/flexvolume`, rather than `/etc/srv/kubernetes/kubelet-plugins/volume/exec`. Existing Flexvolume installations in clusters using COS images must be moved to the new directory, and installation processes must be updated with the new path. ([#58171](https://github.com/kubernetes/kubernetes/pull/58171), [@verult](https://github.com/verult))

* Default values differ between the Kubelet's componentconfig (config file) API and the Kubelet's...

- Enabled kube-controller-manager '--concurrent-job-syncs' flag works on orphan Pod processors ([#126567](https://github.com/kubernetes/kubernetes/pull/126567), [@fusida](https://github.com/fusida)) [SIG Apps]

a pod only applied to CPU resources (such as `cpu_shares`). The Kubernetes cgroup manager uses `memory.limit_in_bytes` in v1 cgroups to limit the memory capacity for a container, and uses `oom_scores` to recommend an order for killing container processes if an out-of-memory event occurs. This implementation has shortcomings: for `Guaranteed` pods, memory can not be fully reserved, and the page cache is at risk of being recycled. For `Burstable` pods, overcommitting memory (setting `request` less...

          ([#275](https://github.com/containerd/containerd/issues/275))

        - Additional memory overhead per container.
          ([#21737](https://github.com/kubernetes/kubernetes/pull/21737))

        - Processes may be leaked when Docker is repeatedly terminated in a short
          time frame.
          ([#41450](https://github.com/kubernetes/kubernetes/issues/41450))

- GCE/Windows: When the service cannot be stopped Stackdriver logging processes are now force killed ([#77378](https://github.com/kubernetes/kubernetes/pull/77378), [@yujuhong](https://github.com/yujuhong))

- Fixed issue on Windows when calculating cpu limits on nodes with more than 64 logical processors ([#114231](https://github.com/kubernetes/kubernetes/pull/114231), [@mweibel](https://github.com/mweibel))

- Kubelet: Fixed the bug of getting the number of cpu when the number of cpu logical processors is more than 64 in windows ([#97378](https://github.com/kubernetes/kubernetes/pull/97378), [@hwdef](https://github.com/hwdef)) [SIG Node and Windows]

### SIG-cloud-provider

This is the first Kubernetes release for this SIG! In v1.12, SIG Cloud Provider focused on building the processes and infrastructure to better support existing and new cloud providers. Some of these initiatives (many of which are still in progress) are:

- 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...