Pfair scheduling: Beyond periodic task systems

In this paper, we consider variants of Pfair and ERfair scheduling in which subtasks may be released late, i.e., there may be separation between consecutive windows of the same task. We call such tasks intra-sporadic tasks. There are two main contributions of this paper. First, we show the existence of a Pfair land hence ERfair) schedule for any intra-sporadic task system whose utilization is at most the number of available processors. Second, we give a polynomial-time algorithm that is optimal for scheduling intra-sporadic tasks in a Pfair or ERfair manner on systems of one or two processors.