- The scheduling queue didn't notice any extenders' failures, it could miss some cluster events,
  and it could end up Pods rejected by Extenders stuck in unschedulable pod pool in 5min in the worst-case scenario.
  Now, the scheduling queue notices extenders' failures and requeue Pods rejected by Extenders appropriately. ([#122044](https://github.com/kubernetes/kubernetes/pull/122044), [@sanposhiho](https://github.com/sanposhiho)) [SIG Scheduling]

 - For all kinds in the API group version, a spec.selector default value is no longer
 available, because it's incompatible with `kubectl
 apply` and strategic merge patch. You must explicitly set the spec.selector value
 in your manifest. An object with a spec.selector value that does not match the labels in
 its spec.template is invalid.

 - Selector mutation is disabled for all kinds in the

- The scheduling queue didn't notice any extenders' failures, it could miss some cluster events,
  and it could end up Pods rejected by Extenders stuck in unschedulable pod pool in 5min in the worst-case scenario.
  Now, the scheduling queue notices extenders' failures and requeue Pods rejected by Extenders appropriately. ([#122045](https://github.com/kubernetes/kubernetes/pull/122045), [@sanposhiho](https://github.com/sanposhiho)) [SIG Scheduling]

  - PreemptionByKubeScheduler (Pod preempted by kube-scheduler)
  - DeletionByTaintManager (Pod deleted by taint manager due to NoExecute taint)
  - EvictionByEvictionAPI (Pod evicted by Eviction API)
  - DeletionByPodGC (an orphaned Pod deleted by PodGC) ([#110959](https://github.com/kubernetes/kubernetes/pull/110959), [@mimowo](https://github.com/mimowo))

  don't match the node affinity/selector. This may lead to unschedulable pods if you previously had pods
  matching the spreading selector on those excluded nodes (not matching the node affinity/selector),
  especially when the `topologyKey` is not node-level. Revisit the node affinity and/or pod selector in the

- Kube-scheduler implemented scheduling hints for the `NodeResourceFit` plugin. The scheduling hints allowed the scheduler to only retry scheduling a Pod that had been previously rejected by the `NodeResourceFit` plugin if a new Node or a...

- `kube-proxy` will...

### Bug or Regression

- Fix: statle smb mount issue when smb file share is deleted and then unmount ([#121851](https://github.com/kubernetes/kubernetes/pull/121851), [@andyzhangx](https://github.com/andyzhangx)) [SIG Storage]
- The scheduling queue didn't notice any extenders' failures, it could miss some cluster events,
  and it could end up Pods rejected by Extenders stuck in unschedulable pod pool in 5min in the worst-case scenario.