Partitioning and global scheduling are two approaches for scheduling real-time tasks on multiprocessors. Though partitioning is sub-optimal, it has traditionally been preferred; this is mainly due to the fact that well-understood uniprocessor scheduling algorithms can be used on each processor. In recent years, global-scheduling algorithms based on the concept of “proportionate fairness” (Pfairness) have received considerable attention. Pfair algorithms are of interest because they are currently the only known method for optimally scheduling periodic, sporadic, and “rate-based” task systems on multiprocessors. In addition, there has been growing practical interest in scheduling with fairness guarantees. However, the frequency of context switching and migration in Pfair-scheduled systems has led to some questions concerning the practicality of Pfair scheduling. In this paper, we investigate this issue by comparing the PD2 Pfair algorithm to the EDF-FF partitioning scheme, which...
Anand Srinivasan, Philip Holman, James H. Anderson