Arnoldo Díaz-Ramírez1*, Pedro Mejía-Alvarez2, Luis E. Leyva-del-Foyo3
1 Departamento de Sistemas y Computación Instituto Tecnológico de Mexicali Mexicali, Baja California, México. *adiaz@itmexicali.edu.mx.
2 Departamento de Computación CINVESTAV-IPN México, D. F., México.
3 Departamento de Tecnologías de la Información Universidad Autónoma Metropolitana México, D. F., México.
ABSTRACT
]]> Schedulability conditions are used in real-time systems to verify the fulfillment of the temporal constraints of task sets. In this paper, a performance analysis is conducted for the best-known real-time schedulability conditions that can be used in online admission control on uni-processor systems executing under the Rate-Monotonic scheduling policy. Since Liu and Layland introduced the Rate-Monotonic scheduling algorithm, many research studies have been conducted on the schedulability analysis of real-time periodic task sets. However, in most cases, the performance of the proposed schedulability conditions were compared only against the Liu and Layland test and not against the remaining schedulability tests. The goal of this paper is to provide guidelines for system designers in order to decide which schedulability condition provides better performance under different task characteristics. Extensive simulation experiments were conducted to evaluate the inexact schedulability conditions and compare their performance and computational complexity.Keywords: real-time systems, real-time scheduling, rate-monotonic scheduling.
RESUMEN
Las condiciones de planificabilidad son utilizadas en los sistemas de tiempo real para verificar el cumplimiento de las restricciones temporales de los conjuntos de tareas. En este artículo se presenta un análisis del desempeño de las condiciones de planificabilidad mas conocidas y que pueden ser usadas como control de admisión en línea en sistemas monoprocesador que se ejecutan con la política de planificación rate-monotonic. Desde que Liu y Layland propusieron el algoritmo de planificación R-M, se han llevado a cabo muchos proyectos de investigación acerca del análisis de planificabilidad de conjuntos de tareas periódicas de tiempo real. Sin embargo, en la mayoría de los casos, el desempeño de las condiciones de planificabilidad ha sido comparado tan solo con la prueba de Liu y Layland y no consideran al resto de las condiciones de planificabilidad. El objetivo de este artículo es el de proporcionar una guía a los diseñadores de sistemas para que puedan decidir qué condición de planificabilidad presenta un mejor desempeño con diferentes características de las tareas. Se llevaron a cabo extensos experimentos de simulación para evaluar a las condiciones inexactas de planificabilidad, así como para comparar su desempeño y complejidad computacional.
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References
[1] C-G. Lee, L. Sha, A. Peddi. "Enhanced Utilization Bounds for QoS Management". IEEE Transactions on Computers, 53(2):187-200, 2004. [ Links ]
[2] H. Vin, P. Goyal, A. Goyal. "A Statistical Admission Control Algorithm for Multimedia Servers". In Proceedings of the 2nd ACM International Conference on Multimedia, 33-40, New York, USA, 1994. ACM. [ Links ]
[3] A. Banerjea, D. Ferrari, B.A. Moran Mah. "The Tenet Real-Time Protocol Suite: Design, Implementation, and Experiences". IEEE/ACM Transactions on Networking, 4(8):1-10, 1994. [ Links ]
[4] H. Chen, B.C. Tjaden, L.R. Welch, C. Bruggeman, L. Tong, B. Pfarr. "Monitoring Network QoS in a Dynamic Real-Time System". Proceedings of the 16th IEEE International Parallel and Distributed Processing Symposium: 93-99, 2002. [ Links ]
[5] T.F. Atdelzater, E.M. Atkins, K.G. Shin. "QoS Negotiation in Real-Time Systems and Its Application to Automated flight Control". IEEE Transactions on Computers, 49(11):1170-1183, 2000. [ Links ]
[6] L.K. Miller, A.M.K. Cheng. "Admission of high priority real-time calls in an ATM network via bandwidth reallocation and dynamic rerouting of active channels". Proceedings of the 21st Real-Time Systems Symposium: 249-258, 2000. [ Links ]
[7] A.M. K. Cheng, S.M. Rao. "Real-Time Traffic Scheduling and Routing in Packet-Switched Networks Using a Least-Laxity-First Strategy". Journal of VLSI Signal Processing Systems, 34(1/2):139-148, 2003. [ Links ]
[8] T-W. Kuo, C-H. Li. "A fixed-priority-driven open environment for real-time applications". Proceedings of the 20th IEEE Real-Time Systems Symposium: 256-267, 1999. [ Links ]
[9] T-W. Kuo, C-H. Li, Y-C. Wang. "An Open Real-Time Environment for Parallel and Distributed Systems". Proceedings of the 20th International Conference on Distributed Computing Systems: 206-213, 2000. [ Links ]
[10] C.L. Liu, W. Layland. "Scheduling Algorithms for Multiprogramming in a Hard Real-Time Environment". Journal of the ACM, 20(1):46-61, 1973. [ Links ]
[11] J.W.S. Liu. "Real-Time Systems". Prentice Hall, 2000. [ Links ]
[12] S.K. Dhall, C.L. Liu. "On a Real-Time Scheduling Problem". Operations Research, 26(1):127-140, 1978. [ Links ]
[13] Y. Oh, S.H. Son. "Fixed-Priority Scheduling of Periodic Tasks on Multiprocessor Systems". Technical Report CS-95-16. Univ. of Virginia. Dept. of Computer Science. 1995. [ Links ]
[14] A. Burchard, J. Liebeherr, Y. Oh, S.H. Son. "New Strategies for Assigning Real-Time Tasks to Multiprocessor Systems". IEEE Transactions on Computers, 44(12):1429-1442, 1995. [ Links ]
[15] T. Kuo, A. Mok. "Load Adjustment in Adaptive Real-Time Systems". Proceedings of the 12th IEEE Real-Time Systems Symposium: 160-170, 1991. [ Links ]
[16] T. Kuo, K. Lin. "Efficient On-Line Schedulability Tests for Priority Driven Real-Time Systems". Proceedings of 6th IEEE Real-Time Technology and Applications Symposium: 4-14, 2000. [ Links ]
[17] C.C. Han, H.Y. Tyan. "A better polynomial-time schedulability test for real-time fixed-priority scheduling algorithms". Proceedings of 19th IEEE Real-Time Systems Symposium:36-45, 1997. [ Links ]
[18] W.-C. Lu, K.J. Lin, H.-W. Wei, W.-K. Shih. "Rate monotonic schedulability tests using period-dependent conditions". Real-Time Systems, 37(2):123-138, 2007. [ Links ]
[19] S. Lauzac, R. Melhem, D. Mosse. "An Improved Rate-Monotonic Admission Control and Its Applications". IEEE Transactions on Computers, 52(2):337-350, 2003. [ Links ]
[20] D. Chen, R. Mok, T. Kuo. "Utilization Bound Revisited". IEEE Transactions on Computers, 53(3):351-361, 2003. [ Links ]
[21] D.W. Park, S. Natarajan, A. Kanevsky. "Fixedpriority scheduling of real-time systems using utilization bounds". Journal of Systems and Software, 33(1): 57-63, 1996. [ Links ]
[22] J.P. Lehoczky, L. Sha, Y. Ding. "The Rate-Monotonic Scheduling Algorithm: Exact Characterization and Average Case Behavior". Proceedings of the IEEE Real-Time Systems Symposium: 166-171, 1989. [ Links ]
[23] M. Joseph, P. Pandya. "Finding Response Times in a Real-Time System". British Computer Society Computer Journal, 29(5):390-395, 1986. [ Links ]
[24] N. Audsley, A. Burns, M. Richardson, K. Tindell, A.J. Wellings. "Applying New Scheduling Theory to Static Priority Pre-emptive Scheduling". Software Engineering Journal, 8:284-292, 1993. [ Links ]
[25] E. Bini, G.C. Buttazzo. "Schedulability Analysis of Periodic Fixed Priority Systems". IEEE Transactions on Computers, 53(11):1462-1473, Nov 2004. [ Links ]
[26] W.C. Lu, K.J. Lin, H.W. Wei, W.K. Shih. "Period-Dependent Initial Values for Exact Schedulability Test of Rate Monotonic Systems". Proceedings of the IEEE International Parallel and Distributed Processing Symposium: 1-8, 2007. [ Links ]
[27] R.I. Davis, A. Zabos, A. Burns. "Efficient Exact Schedulability Tests for Fixed Priority Real-Time Systems". IEEE Transactions on Computers, 57(9):1261-1276, 2008. [ Links ]
[28] J.Y. Leung, J. Whitehead. "On the Complexity of Fixed-Priority Scheduling of Periodic Real-Time Tasks". Performance Evaluation (Netherlands), 4(2): 237-250, 1982. [ Links ]
[29] E. Bini, G.C. Buttazzo, G.M. Buttazzo. "Rate Monotonic Analysis: The Hyperbolic Bound". IEEE Transactions on Computers, 52(7):933-942, 2003. [ Links ]
[30] S. Lauzac, R. Melhem, D. Mosse. "n Efficient RMS Admission Control and its Application to Multiprocessor Scheduling". Proceedings of the IEEE 1st Merged International Symposium on Parallel and Distributed Processing:511-518, 1998. [ Links ]
[31] C.-C.J. Han. "A better polynomial-time schedulability test for real-time multiframe tasks". Proceedings of the 19th IEEE Real-Time Systems Symposium: 104-113, 1998. [ Links ]
[32] V. Klee, G.J. Minty. "How Good is the Simplex Algorithm?", In Inequalities III. O. Shisha (ed), Academic Press Inc, New York, April 1997. [ Links ]
[33] Michael Berkelaar, Kjell Eikland, Peter Notebaert. lp_solve 5.5. 2004. [ Links ]
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