The idea here is to allow someone that runs a “timesharing=*,*” job, to run a new job on the resource but with the more restrictive specification: “timesharing=user,*”, if no “timesharing=*,*” jobs are running from other users.

With the semantic of the Digitalis platform where:

• -t shared ⇔ -t timesharing=*,*
• -t exclusive ⇔ -t timesharing=user,*

This would allow a user to place a exclusive slot on top of a larger shared slot if he is alone on the machine.

Currently, the 4 timesharing specifications are handle at a same level:

• timesharing=*,*
• timesharing=user,*
• timesharing=*,name
• timesharing=user,name

No hierarchy like timesharing=*,* < timesharing=user,*.

Implementing such a “hierarchical management” in the gantt data-structure mechanisms could allow that feature.