Issue No. 08 - Aug. (2012 vol. 61)
DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/TC.2011.142
Sanjoy Baruah , University of North Carolina, Chapel Hill
Vincenzo Bonifaci , Universita Telematica Internazionale Uninettuno
Gianlorenzo D'Angelo , Universita degli Studi dell' Aquila, Monteluco di Roio
Haohan Li , University of North Carolina, Chapel Hill
Alberto Marchetti-Spaccamela , Sapienza University, Rome
Nicole Megow , Max-Planck-Institut fur Informatik, Saarbrucken
Leen Stougie , VU University and CWI, Amsterdam
Many safety-critical embedded systems are subject to certification requirements; some systems may be required to meet multiple sets of certification requirements, from different certification authorities. Certification requirements in such "mixed-criticality” systems give rise to interesting scheduling problems, that cannot be satisfactorily addressed using techniques from conventional scheduling theory. In this paper, we study a formal model for representing such mixed-criticality workloads. We demonstrate first the intractability of determining whether a system specified in this model can be scheduled to meet all its certification requirements, even for systems subject to merely two sets of certification requirements. Then we quantify, via the metric of processor speedup factor, the effectiveness of two techniques, reservation-based scheduling and priority-based scheduling, that are widely used in scheduling such mixed-criticality systems, showing that the latter of the two is superior to the former. We also show that the speedup factors we obtain are tight for these two techniques.
Preemptive scheduling, safety-critical systems, mixed criticality, certification.
A. Marchetti-Spaccamela et al., "Scheduling Real-Time Mixed-Criticality Jobs," in IEEE Transactions on Computers, vol. 61, no. , pp. 1140-1152, 2011.