Schedulability analysis of dynamic priority real-time systems with contention

Abstract

In multicore scheduling of hard real-time systems, there is a significant source of unpredictability due to the interference caused by the sharing of hardware resources. This paper deals with the schedulability analysis of multicore systems where the interference caused by the sharing of hardware resources is taken into account. We rely on a task model where this interference is integrated in a general way, without depending on a specific type of hardware resource. There are similar approaches but they consider fixed priorities. The schedulability analysis is provided for dynamic priorities assuming constrained deadlines and based on the demand bound function. We propose two techniques, one more pessimistic than the other but with a lower computational cost. We evaluate the two proposals for different task allocators in terms of the increased estimated utilization. The results show that both bounds are valid for ensuring schedulability although, as expected, one is tighter than the other. The evaluation also serves to compare allocators to see which one produces less interference.