- Sometimes, the scheduler incorrectly placed a pod in the "unschedulable" queue instead of the "backoff" queue. This happened when some plugin previously declared the pod as "unschedulable" and then in a later attempt encounters some other error. Scheduling of that pod then got delayed by up to five minutes, after which periodic flushing moved the pod back into the "active"...

## Changes by Kind

### Bug or Regression

- Fix race condition in scheduler where a new unschedulable Pod might never be retried. ([#105015](https://github.com/kubernetes/kubernetes/pull/105015), [@alculquicondor](https://github.com/alculquicondor)) [SIG Apps, Scheduling and Testing]

- Sometimes, the scheduler incorrectly placed a pod in the "unschedulable" queue instead of the "backoff" queue. This happened when some plugin previously declared the pod as "unschedulable" and then in a later attempt encounters some other error. Scheduling of that pod then got delayed by up to five minutes, after which periodic flushing moved the pod back into the "active"...

- The calculations for Pod topology spread skew now exclude nodes that
  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),

- Sometimes, the scheduler incorrectly placed a pod in the "unschedulable" queue instead of the "backoff" queue. This happened when some plugin previously declared the pod as "unschedulable" and then in a later attempt encounters some other error. Scheduling of that pod then got delayed by up to five minutes, after which periodic flushing moved the pod back into the "active"...

- DRA: the explanation for why a pod which wasn't using ResourceClaims was unscheduleable included a useless "no new claims to deallocate" when it was unscheduleable for some other reasons. ([#129823](https://github.com/kubernetes/kubernetes/pull/129823), [@googs1025](https://github.com/googs1025)) [SIG Node and Scheduling]

* Fix data race during addition of new CRD ([#50098](https://github.com/kubernetes/kubernetes/pull/50098), [@nikhita](https://github.com/nikhita))
* Fix bug in scheduler that caused initially unschedulable pods to stuck in Pending state forever. ([#50028](https://github.com/kubernetes/kubernetes/pull/50028), [@julia-stripe](https://github.com/julia-stripe))

* CRI: respect container's stopping timeout. ([#44998](https://github.com/kubernetes/kubernetes/pull/44998), [@feiskyer](https://github.com/feiskyer))
* Fix problems with scaling up the cluster when unschedulable pods have some persistent volume claims. ([#44860](https://github.com/kubernetes/kubernetes/pull/44860), [@mwielgus](https://github.com/mwielgus))

- Fixed a scheduler racing issue to ensure low priority pods are unschedulable on the node(s) where high priority pods have `NominatedNodeName` set to the node(s).  ([#77990](https://github.com/kubernetes/kubernetes/pull/77990), [@Huang-Wei](https://github.com/Huang-Wei))

### Storage

 - Scheduling failures due to no nodes available are now reported as unschedulable under ```schedule_attempts_total``` metric. ([#90989](https://github.com/kubernetes/kubernetes/pull/90989), [@ahg-g](https://github.com/ahg-g)) [SIG Scheduling]

### Other (Cleanup or Flake)