On utilization bounds for a periodic resource under rate monotonic scheduling

This paper revisits utilization bounds for a periodic resource under the rate monotonic (RM) scheduling algorithm. We show that the existing utilization bound, as presented in [8, 9], is optimistic. We subsequently show that by viewing the unavailability of the periodic resource as a deferrable server at highest priority, existing utilization bounds for systems with a deferrable server [3, 11] can be reused. Moreover, using this view, the utilization bound presented in [7] for hierarchical fixed-priority scheduling turns out to be similar to the bound in [3].