- Fixed a situation when, 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`...

rejected via `UnschedulableAndUnresolvable`. Consequently, these nodes are excluded from the candidates for the preemption process. Additionally, this update corrects how the scheduling framework handles the Unschedulable status from PreFilter. Previously, if PreFilter returned `Unschedulable`, it could lead to an unexpected abortion in the preemption process, which shouldn't occur in the default scheduler but might occur in schedulers with custom plugins. ([#119779](https://github.com/kubernetes...

- Improve Node QueueHint in the NodeAffinty plugin by ignoring unrelated changes that keep pods unschedulable. ([#127444](https://github.com/kubernetes/kubernetes/pull/127444), [@dom4ha](https://github.com/dom4ha)) [SIG Scheduling and Testing]

  Previously, when unschedulable Pods are updated, the scheduler always put Pods back to activeQ/backoffQ. But, actually not all updates to Pods make Pods schedulable, especially considering many scheduling constraints nowadays are immutable.

* scheduler: use incremental scheduling cycle in PriorityQueue to put all in-flight unschedulable pods back to active queue if we received move request ([#73309](https://github.com/kubernetes/kubernetes/pull/73309), [@cofyc](https://github.com/cofyc))

- 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"...

- 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]

  // +optional
  optional string providerID = 3;

  // Unschedulable controls node schedulability of new pods. By default, node is schedulable.
  // More info: https://kubernetes.io/docs/concepts/nodes/node/#manual-node-administration
  // +optional
  optional bool unschedulable = 4;

  // If specified, the node's taints.
  // +optional
  repeated Taint taints = 5;

- 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"...