I've often wanted to find out which job is holding up a single-threaded job queue. The Work with Active Jobs (WRKACTJOB) command shows which jobs are running in a subsystem, but it doesn't identify the job queue name. If you have more than one single-threaded job queue assigned to the subsystem, you can't determine which job queue originated a job.
After a little research, I was surprised to find a command that does list all job queues and their associated active jobs. It is the Work with User Jobs (WRKUSRJOB) command executed in the following form:
WRKUSRJOB USER(*ALL) + STATUS(*ACTIVE) + JOBTYPE(*BATCH) + ASTLVL(*BASIC)
The trick to making this work is to use the basic assistance level. In this case, the Work with Jobs panel lists each job queue; and below the job queue name, a list of the jobs running from the queue.