In most practical systems, periodic tasks commonly contribute to the
major parts of application tasks in the systems. Under preemptive
scheduling, priorities are assigned to the periodic tasks. Task
priorities can be static, which remains constant, or dynamic, which
will change, during the life of the system. A preemptive static
priority scheduling algorithm possesses predictable behavior for
which, given a set of periodic tasks, the schedulability can be well
analyzed. In this paper, an exact schedulability analysis, called an
exact execution time test, for a set of periodic tasks scheduled by a
static priority scheduling algorithm will be introduced and
investigated.
