No abstract

SymTA/S is a system-level performance and timing analysis approach based on formal scheduling analysis techniques and symbolic simulation. The tool supports heterogeneous architectures, complex task dependencies and context aware analysis. It determines system-level performance data such as end-to-end latencies, bus and processor utilization, and worst-case scheduling scenarios. SymTA/S furthermore combines optimization algorithms with system sensitivity analysis for rapid design space exploration. This paper gives an overview of the current research interests in the SymTA/S project.

System level performance analysis plays a fundamental role in the design process of real-time embedded systems. Several different approaches have been presented so far to address the problem of accurate performance analysis of distributed embedded systems in early design stages. The existing formal analysis methods are based on essentially different concepts of abstraction. However, the influence of these different models on the accuracy of the system analysis is widely unknown, as a direct comparison of performance analysis methods has not been considered so far. We define a set of benchmarks aimed at the evaluation of performance analysis techniques for distributed systems. We apply different analysis methods to the benchmarks and compare the results obtained in terms of accuracy and analysis times, highlighting the specific effects of the various abstractions. We also point out several pitfalls for the analysis accuracy of single approaches and investigate the reasons for pessimistic performance predictions.

System level performance analysis plays a fundamental role in the design process of hard real-time embedded systems. Several different approaches have been presented so far to address the problem of accurate performance analysis of distributed embedded systems in early design stages. The existing formal analysis methods are based on essentially different concepts of abstraction. However, the influence of these different models on the accuracy of the system analysis is widely unknown, as a direct comparison of performance analysis methods has not been considered so far. We define a set of benchmarks aimed at the 28 S. Perathoner et al. evaluation of performance analysis techniques for distributed systems. We apply different analysis methods to the benchmarks and compare the results obtained in terms of accuracy and analysis times, highlighting the specific effects of the various abstractions. We also point out several pitfalls for the analysis accuracy of single approaches and investigate the reasons for pessimistic performance predictions.

Round-Robin scheduling is the most popular time triggered scheduling policy, and has been widely used in communication networks for the last decades. It is an efficient scheduling technique for integration of unrelated system parts, but the worst-case timing depends on the system properties in a very complex way. The existing works on response time analysis of task scheduled under RoundRobin determine very pessimistic response time bounds, without considering in detail the interactions between tasks. This may lead to a degradation of the efficiency of Round-Robin scheduling algorithm, and becomes a practical obstacle to its application in realtime systems. In this paper we present an approach to compute much tighter best-case and worst-case response time bounds of tasks scheduled under preemptive Round-Robin, including also the effects of the scheduling algorithm.