Resource sharing in EDF-scheduled systems: a closer look

Resource sharing in priority-based systems can give rise to priority-inversion and blocking, wherein a job's execution is delayed because a lower-priority job holds some resource that is needed for execution. The Stack Resource Policy (SRP) can be used to reduce such blocking in EDF-scheduled systems. An efficient implementation of an algorithm is presented for determining whether systems scheduled in this manner are feasible. Some interesting properties of such systems are derived. The technique of reducing the duration of blocking by the replication of selected resources is explored: an algorithm is presented which determines the minimum amount of resource replication necessary to achieve specified blocking times.