Budget allocations for hierarchical fixed-priority scheduling of sporadic tasks with deferred preemptions upon EDP resources

In this paper we revisit the admission of applications upon a processor share modeled by the explicit-deadline periodic (EDP) resource-supply model. In particular, we consider applications that represent a fixed-priority sporadic task system. Existing works heavily build on the analysis of a hierarchy of preemptive task schedulers. We instead consider the feasibility of such tasks and applications for a hierarchy of deferredpreemptive schedulers, so that we can efficiently deal with the scenario where tasks and applications execute their work in nonpreemptive chunks. Our model therefore gives better control over preemptions of tasks of different applications. We present exact analysis for deferred-preemptive scheduling of tasks on EDP resources. In addition, we propose algorithms for dimensioning an application’s budget tightly.