Expected behavior when workloads in different queues compete for borrowable resources?

[qti-haeyoon]

Hi everyone, I have one question related to the expected behavior when different queues compete for borrowable resources.

Suppose the below setup (fair sharing disabled):

• CQ A has zero quota.
• CQ B has zero quota.
• CQ C has 4 CPU quota and it lends them to A and B.

Now suppose the below scenario:

1. CQ C is using all of its quota by running 4-CPU job.
2. Two 2-CPU workloads with high priority submitted to A. Pending because C has no available quota.
3. Two 2-CPU workloads with low priority submitted to B. Pending because C has no available quota.

The question is, what is the expectation when CQ C's 4-CPU job completes?

I thought all of A's high priority jobs should be admitted respecting the sorting criteria, but when I tested, both A and B gets only one of their workloads admitted. I suppose this is because in one scheduling cycle, we only look at the head of a cluster queue, not considering all the pending workloads.

I want some clarification from the community if this is expected or is considered a bug. And if there is any documentation for this, would appreciate any links to it. Thank you very much as always!