Traditional methods rely on Static Timing Analysis techniques to compute the Worst Case Response Time for tasks in real-time systems. Multi-Core real-time systems are faced up with concurrent task executions, semaphore accesses, and task migrations where it may be difficult to obtain the worst case upper bound. A new three staged probabilistic estimation concept is presented. Worst Case Response Times are estimated for tasksets which consist of tasks with multiple time bases. The concept involves data generation with sample classification and sample size equalization, model fit and Worst Case Response Time estimation on the basis of extreme value distribution models. A Generalized Pareto Distribution model fit method which includes threshold detection and parameter estimation is also presented. Sample classification in combination with the new Generalized Pareto Distribution model fit method allows to estimate Worst Case Response Times with low pessimism ranges compared to estimation methods that uses the Generalized Pareto or the Gumbel max distribution without sample classification.
[1]
Alan Burns,et al.
Statistical analysis of WCET for scheduling
,
2001,
Proceedings 22nd IEEE Real-Time Systems Symposium (RTSS 2001) (Cat. No.01PR1420).
[2]
R. Shanmugam.
Introduction to Time Series and Forecasting
,
1997
.
[3]
Richard A. Davis,et al.
Introduction to time series and forecasting
,
1998
.
[4]
Alan Burns,et al.
Realism in Statistical Analysis of Worst Case Execution Times
,
2010,
WCET.
[5]
Michael Deubzer,et al.
Robust scheduling of real-time applications on efficient embedded multicore systems
,
2011
.
[6]
J. Hartigan,et al.
The Dip Test of Unimodality
,
1985
.
[7]
Meng Liu,et al.
Applying the peak over thresholds method on worst-case response time analysis of complex real-time systems
,
2013,
2013 IEEE 19th International Conference on Embedded and Real-Time Computing Systems and Applications.