DRA: preemption

[pohly]

Enhancement Description

• One-line enhancement description (can be used as a release note): Support for preemption in the DRA scheduler plugin

Preemption in the scheduler works by simulating whether evicting a lower-priority pod will make a higher-priority pod scheduleable. For DRA that means that the scheduler plugin must simulate whether evicting a pod will make it possible to deallocate ResourceClaims, which in turn then will free resources requested by the higher-priority pod.

At the moment, the plugin does not support this at all, thus disabling preemption of pods using DRA devices. This enhancement is about designing and implementing the necessary support.

• Kubernetes Enhancement Proposal:
• Discussion Link: face-to-face discussions
• PRs by stage and milestone:
  • Alpha - v1.xx
    • KEP (k/enhancements) update PR(s):
    • Code (k/k) update PR(s):
    • Docs (k/website) update PR(s):

Please keep this description up to date. This will help the Enhancement Team to track the evolution of the enhancement efficiently.

/wg device-management
/cc @johnbelamaric @dom4ha @macsko

Priority to be determined. It comes up occasionally, but not with any urgency.