DRA: List Types for Attributes

[johnbelamaric]

Enhancement Description

The ResourceSlice API allows users to attach scalar attributes to devices. These can be used to allocate devices that share common topology within the node. For certain types of topological relationships, scalar values are insufficient. For example, a CPU may have adjacency to multiple PCIe roots. This enhancement proposes allowing attributes to be lists. The semantics of the MatchAttribute and DistinctAttribute constraints and of the CEL expressions must adapt to the possibility of lists. For example, rather than defining an attribute "match" as equality, it would be defined as a non-empty intersection, treating scalars as single-element lists. Conversely, "distinct" attributes for lists would be defined as an empty intersection.

/wg device-management
/sig scheduling
cc @everpeace @pohly @pravk03 @klueska @liggitt

• One-line enhancement description (can be used as a release note): Device attributes in a ResourceSlice may now be lists, rather than just scalars.
• Kubernetes Enhancement Proposal: TBD
• Discussion Link:
  • Broader problem description
  • DRA: Introduce a helper function producing standardized 'resource.kubernetes.io/pcieRoot' device attributes for DRA drivers kubernetes#132296 (comment)
  • KEP-4381: Define standard device attributes #5316 (comment)
• PRs by stage and milestone:
  • Alpha - v1.35
    • 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.

[kad]

/cc

[dom4ha]

/label lead-opted-in
/milestone v1.35

[johnbelamaric]

/assign @bg-chun

[johnbelamaric]

/assign @everpeace