I have an LSF queue, say it's queue A. I only want higher priority jobs in queue A to preempt lower priority jobs in queue A, but not jobs in any other queues. If I set queue A to be preemptable, could I set it to be preemptable only by itself (queue A)? Or if this is not allowed, what could achieve my goal?
If your two jobs are part of different license scheduler projects, and the running job is borrowing a license from the project of the pending job, then preemption can happen. But from your description I'm guessing that this isn't the case.
Unfortunately preemption based on (for example) job priority or fairshare weight is not supported.