Implementation of a Speedup-Optimal Global EDF Schedulability Test

Recent results have demonstrated the existence of a sufficient global EDF schedulability test for sporadic task systems that makes the following guarantee: any task system that is not determined to be schedulable on an m-processor platform by this test is guaranteed to actually not be so on a platform in which each processor is m/(2m - 1) times as fast. A new global EDF schedulability test is proposed here that builds on this result. This new test is shown to be less pessimistic and more widely applicable than the earlier result was, while retaining the strong theoretical properties - in particular, the speedup bound - of the earlier result.