Interprocessor-blocking independent static task allocation for shared-bus real-time multiprocessors

Abstract

In real-time systems, guaranteeing the schedulability of high priority tasks is more important than being able to schedule more tasks under resource constraints. The system bus in bus-based multiprocessors is a shared resource that is usually arbitrated by priority and fairness. This paper presents a new static task allocation strategy that takes into consideration the impact of bus arbitration policy on schedulability. By allocating task sets, partitioned by descending order of priorities, to the processors in the order of physical priorities, we can minimize the loss of schedulability caused by interference among processors. It is shown via simulation that the proposed strategy keeps high priority tasks schedulable and reduces the schedulability loss up to 26% compared with the conventional allocation scheme.<>