Pfair scheduling of fixed and migrating periodic tasks on multiple resources

This paper concerns the problem of scheduling sets of preemptable, periodic tasks on multiple resources. We consider a task model that allows arbitrary mixes of fixed and migratable tasks, and prove the existence of an optimal pfair scheduler in this model. Fixed tasks must always be scheduled on a given resource, while migratable tasks can be scheduled on different resources at different times. A pfair scheduler produces a periodic schedule in which the times each task is allocated a processor are approximately evenly spread throughout its period. This paper extends work of Baruah et al., who proved a similar result for systems in which all tasks are migratable.