pkg syscall (netbsd-arm64-cgo), func Kevent(int, []Kevent_t, []Kevent_t, *Timespec) (int, error)
pkg syscall (netbsd-arm64-cgo), func Kill(int, Signal) error
pkg syscall (netbsd-arm64-cgo), func Kqueue() (int, error)
pkg syscall (netbsd-arm64-cgo), func Listen(int, int) error
pkg syscall (netbsd-arm64-cgo), func Lstat(string, *Stat_t) error
pkg syscall (netbsd-arm64-cgo), func Mkfifo(string, uint32) error

pkg syscall (darwin-arm64), func Kevent(int, []Kevent_t, []Kevent_t, *Timespec) (int, error)
pkg syscall (darwin-arm64), func Kill(int, Signal) error
pkg syscall (darwin-arm64), func Kqueue() (int, error)
pkg syscall (darwin-arm64), func Listen(int, int) error
pkg syscall (darwin-arm64), func Lstat(string, *Stat_t) error
pkg syscall (darwin-arm64), func Mkfifo(string, uint32) error

  When the scheduling queue receives a cluster event, before moving each Pod from unschedulable pod pool to activeQ/backoffQ, it will call QueueingHintFn of plugins that rejected each Pod in the previous scheduling cycle.
  Depending on the value returned from QueueingHintFn, the scheduling queue changes how it queues each Pod:
  - if more than one QueueingHintFn returns QueueImmediately, it queues Pod to activeQ.

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` queue. ([#120334](https://github.com/kubernetes/kubernetes/pull/120334), [@pohly](https://github.com/pohly))...

- 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" queue. ([#120334](https://github.com/kubernetes/kubernetes/pull/120334), [@pohly](https://github.com/pohly))...

  Now, when unschedulable Pods are updated, the scheduling queue checks with QueueingHint(s) whether the update may make the pods schedulable, and requeues them to activeQ/backoffQ **only when** at least one QueueingHint(s) return Queue. 
  
  Action required for custom scheduler plugin developers:

- Fixes the bug in PodTopologySpread that only happens with QHint enabled, 

- 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.

- 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" queue. ([#120334](https://github.com/kubernetes/kubernetes/pull/120334), [@pohly](https://github.com/pohly))...

- Implement the scheduling framework with `Reserve`, `Prebind`, `Permit`, `Post-bind`, `Queue sort` and `Unreserve` extension points.
([#77567](https://github.com/kubernetes/kubernetes/pull/77567), [@wgliang](https://github.com/wgliang))