Evaluation of resource arbitration methods for multi-core real-time systems

Multi-core systems have become prevalent in the last years, because of their favorable properties in terms of energy consumption, computing power and design complexity. First attempts have been made to devise WCET analyses for multi-core processors, which have to deal with the problem that the cores may experience interferences during accesses to shared resources. To limit these interferences, the vast amount of previous work is proposing a strict TDMA (time division multiple access) schedule for arbitrating shared resources. Though this type of arbitration yields a high predictability, this advantage is paid for with a poor resource utilization. In this work, we compare different arbitration methods with respect to their predictability and average case performance. We show how known WCET analysis techniques can be extended to work with the presented arbitration strategies and perform an evaluation of the resulting ACETs and WCETs on an extensive set of realworld benchmarks. Results show that there are cases when TDMA is not the best strategy, especially when predictability and performance are equally important.