We introduce a new fixed priority scheduling algorithm. This algorithm assign two distinct priority to a periodic task in a mixed task system. The mixed task system has two kinds of real-time task stream; periodic hard real-time task and aperiodic soft real-time task, and these tasks are scheduled under fixed priority scheme. In the mixed task system, periodic task is required to meet its deadline, and to minimize the response time of aperiodic tasks. Our algorithm aims to produce the periodic task schedule that guarantees maximum slack times for aperiodic tasks.
In this paper, we proved that our algorithm can schedule the RM-feasible periodic task set. And we proved that the response time of aperiodic tasks can be minimized when our algorithm is used for assigning the priority of periodic tasks in mixed task system that using the slack stealing for aperiodic task processing.
