Abstract
Cluster scheduling, where processors are grouped into clusters and the tasks that are allocated to one cluster are scheduled by a global scheduler, has attracted attention in multiprocessor real-time systems research recently. In this paper, assuming that an optimal global scheduler is adopted within each cluster, we investigate the worst-case utilization bounds for cluster scheduling with different task allocation/partitioning heuristics. First, we develop a lower limit on the utilization bounds for cluster scheduling with any reasonable task allocation scheme. Then, the lower limit is shown to be the exact utilization bound for cluster scheduling with the worst-fit task allocation scheme. For other task allocation heuristics (such as first-fit, best-fit, first-fit decreasing, best-fit decreasing and worst-fit decreasing), higher utilization bounds are derived for systems with both homogeneous clusters (where each cluster has the same number of processors) and heterogeneous clusters (where clusters have different number of processors). In addition, focusing on an efficient optimal global scheduler, namely the boundary-fair (Bfair) algorithm, we propose a period-aware task allocation heuristic with the goal of reducing the scheduling overhead (e.g., the number of scheduling points, context switches and task migrations). Simulation results indicate that the percentage of task sets that can be scheduled is significantly improved under cluster scheduling even for small-size clusters, compared to that of the partitioned scheduling. Moreover, when comparing to the simple generic task allocation scheme (e.g., first-fit), the proposed period-aware task allocation heuristic markedly reduces the scheduling overhead of cluster scheduling with the Bfair scheduler.
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References
Andersson B, Jonsson J (2003) The utilization bounds of partitioned and pfair static-priority scheduling on multiprocessors are 50%. In: Proc of the 15th Euromicro conference on real-time systems, pp 33–40
Anderson J, Srinivasan A (2000a) Early-release fair scheduling. In: Proc of the 12th Euromicro conference on real-time systems, pp 35–43
Anderson J, Srinivasan A (2000b) Pfair scheduling: Beyond periodic task systems. In: Proc of the 7th int’l workshop on real-time computing systems and applications, pp 297–306
Anderson J, Srinivasan A (2001) Mixed pfair/erfair scheduling of asynchronous periodic tasks. In: Proc of the 13th Euromicro conference on real-time systems, pp 76–85
Andersson B, Tovar E (2006) Multiprocessor scheduling with few preemptions. In: Proc of the IEEE int’l conference on embedded and real-time computing systems and applications, pp 322–334
Andersson B, Baruah S, Jonsson J (2001) Static-priority scheduling on multiprocessors. In: Proc of the 22th IEEE real-time systems symposium, pp 193–202
Andersson B, Bletsas K, Baruah S (2008) Scheduling arbitrary-deadline sporadic task systems on multiprocessors. In: Proc of the IEEE real-time systems symposium, pp 385–394
Baker T (2003) Multiprocessor edf and deadline monotonic schedulability analysis. In: Proc. of the 24th IEEE real-time systems symposium, pp 120–129
Baruah S (2007) Techniques for multiprocessor global schedulability analysis. In: Proc of the IEEE real-time systems symposium, pp 119–128
Baruah S, Baker T (2008) Schedulability analysis of global edf. Real-Time Syst 38(3):223–235
Baruah SK, Gehrke J, Plaxton CG (1995) Fast scheduling of periodic tasks on multiple resources. In: Proc of the international parallel processing symposium, pp 280–288
Baruah SK, Cohen NK, Plaxton CG, Varel DA (1996) Proportionate progress: a notion of fairness in resource allocation. Algorithmica 15(6):600–625
Bletsas K, Andersson B (2009) Preemption-light multiprocessor scheduling of sporadic tasks with high utilisation bound. In: Proc of the IEEE real-time systems symposium, pp 447–456
Burchard A, Liebeherr J, Oh Y, Son SH (1996) New strategies for assigning real-time tasks to multiprocessor systems. IEEE Trans Comput 44(12):1429–1442
Calandrino JM, Anderson JH, Baumberger DP (2007) A hybrid real-time scheduling approach for large-scale multicore platforms. In: Proc of the Euromicro conference on real-time systems, pp 247–258
Cho H, Ravindran B, Jensen E (2006) An optimal real-time scheduling algorithm for multiprocessors. In: Proc of the IEEE real-time systems symposium, pp 101–110
Cho H, Ravindran B, Jensen ED (2010) T-l plane-based real-time scheduling for homogeneous multiprocessors. J Parallel Distrib Comput 70(3):225–236
Darera VN (2006) Bounds for scheduling in non-identical uniform multiprocessor systems. Master’s thesis, Indian Institute of Science, India
Davis R, Burns A (2009a) Priority assignment for global fixed priority pre-emptive scheduling in multiprocessor real-time systems. In: Proc of the IEEE real-time systems symposium, pp 398–409
Davis R, Burns A (2009b) A survey of hard real-time scheduling algorithms and schedulability analysis techniques for multiprocessor systems. Tech Rep YCS-2009-443, University of York, Department of Computer Science
Dertouzos ML, Mok AK (1989) Multiprocessor on-line scheduling of hard-real-time tasks. IEEE Trans Softw Eng 15(12):1497–1505
Devi U, Anderson J (2005) Tardiness bounds under global edf scheduling on a multiprocessor. In: Proc of the 26th IEEE real-time systems symposium, pp 330–341
Dhall SK, Liu CL (1978) On a real-time scheduling problem. Oper Res 26(1):127–140
Funaoka K, Kato S, Yamasaki N (2008) Work-conserving optimal real-time scheduling on multiprocessors. In: Proc of the Euromicro conference on real-time systems, pp 13–22
Goossens J, Funk S, Baruah S (2003) Priority-driven scheduling of periodic task systems on multiprocessors. Real-Time Syst 25(2-3):187–205
Guan N, Stigge M, Yi W, Yu G (2009) New response time bounds for fixed priority multiprocessor scheduling. In: Proc of the IEEE real-time systems symposium, pp 387–397
Guan N, Stigge M, Yi W, Yu G (2010) Fixed-priority multiprocessor scheduling with Liu & Layland’s utilization bound. In: Proc of the 16th IEEE real-time and embedded technology and applications symposium, pp 165–174
Herbert S, Marculescu D (2007) Analysis of dynamic voltage/frequency scaling in chip-multiprocessors. In: Proc of Int’l symposium on low power electronics and design, pp 38–43
Holman P, Anderson J (2001) Guaranteeing pfair supertasks by reweighting. In: Proc of the 22nd IEEE real-time systems symposium, pp 203–212
Kato S, Yamasaki N (2007) Real-time scheduling with task splitting on multiprocessors. In: Proc of the IEEE int’l conference on embedded and real-time computing systems and applications, pp 441–450
Kato S, Yamasaki N (2008) Portioned edf-based scheduling on multiprocessors. In: Proc of the 8th ACM int’l conference on embedded software, pp 139–148
Kato S, Funaoka K, Yamasaki N (2009) Semi-partitioned scheduling of sporadic task systems on multiprocessors. In: Proc of the 21th Euromicro conference on real-time systems, pp 249–258
Lauzac S, Melhem R, Mossé D (2003) An improved rate-monotonic admission control and its applications. IEEE Trans Comput 52:337–350
Levin G, Funk S, Sadowski C, Pye I, Brandt S (2010) Dp-fair: a simple model for understanding optimal multiprocessor scheduling. In: Proc of the Euromicro conference on real-time systems, pp 3–13
Liu JW (2000) Real-time systems. Prentice Hall/PTR, New York
Liu CL, Layland JW (1973) Scheduling algorithms for multiprogramming in a hard real-time environment. J ACM 20(1):46–61
Liu D, Lee YH (2004) Pfair scheduling of periodic tasks with allocation constraints on multiple processors. In: Proc of the 18th int’l parallel and distributed processing symposium, pp 119–126
Lopez J, Garcia M, Diaz J, Garcia D (2000) Worst-case utilization bound for edf scheduling on real-time multiprocessor systems. In: Prof of the 12th Euromicro conference on real-time systems, pp 25–33
Lopez J, Diaz J, Garcia D (2001) Minimum and maximum utilization bounds for multiprocessor rm scheduling. In: Proc. of the 13th Euromicro conference on real-time systems, pp 67–75
Lopez J, Diaz J, Garcia D (2004) Utilization bound for edf scheduling on real-time multiprocessor systems. Real-Time Syst 28(1):39–68
Moir M, Ramamurthy S (1999) Pfair scheduling of fixed and migrating tasks on multiple resources. In: Proc. of the 20th IEEE real-time systems symposium, pp 294–303
Oh D, Baker T (1998) Utilization bound for n-processor rate monotone scheduling with stable processor assignment. Real-Time Syst 15(2):183–193
Qi X, Zhu D (2008) Power management for real-time embedded systems on block-partitioned multicore platforms. In: Proc of the int’l conference on embedded software and systems, pp 110–117
Shin I, Easwaran A, Lee I (2008) Hierarchical scheduling framework for virtual clustering of multiprocessors. In: Proc of the 20th Euromicro conference on real-time systems, pp 181–190
Zhu D, Mossé D, Melhem R (2003) Periodic multiple resource scheduling problem: how much fairness is necessary. In: Proc of the 24th IEEE real-time systems symposium, pp 142–151
Zhu D, Qi X, Mossé D, Melhem R (2009) An optimal boundary-fair scheduling algorithm for multiprocessor real-time systems. Tech Rep CS-TR-2009-005, Dept of CS, Univ of Texas at San Antonio
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Qi, X., Zhu, D. & Aydin, H. Cluster scheduling for real-time systems: utilization bounds and run-time overhead. Real-Time Syst 47, 253–284 (2011). https://doi.org/10.1007/s11241-011-9121-1
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DOI: https://doi.org/10.1007/s11241-011-9121-1