Dual-Priority versus Background Scheduling: A Path-Wise Comparison
Résumé
In this paper two well-known scheduling policies for Real Time Systems, namely Background Scheduling and Dual-Priority are compared in terms of response times for Soft Real Time traffic (SRT). It is proved that, when the SRT traffic is FIFO, the Dual-Priority policy always behaves better, in the preemptive case as well as in the non-preemptive case. The proof is based on a trajectorial method. As a complementary result, some non-FIFO examples where the Background Scheduling outperforms the Dual-Priority, are given.