Bandwidth allocation for fixed-priority-scheduled compositional real-time systems

Recent research in compositional real-time systems has focused on determination of a component's real-time interface parameters. An important objective in interface-parameter determination is minimizing the bandwidth allocated to each component of the system while simultaneously guaranteeing component schedulability. With this goal in mind, in this article, we explore fixed-priority schedulability in compositional setting. First we derive an efficient exact test based on iterative convergence for sporadic task systems scheduled by fixed-priority (e.g., deadline monotonic, rate monotonic) upon an explicit-deadline periodic (EDP) resource. Then we address the time complexity of the exact test by developing a fully-polynomial-time approximation scheme (FPTAS) for allocating bandwidth to components. Our parametric algorithm takes the task system and an accuracy parameter ε > 0 as input and returns a bandwidth which is guaranteed to be at most a factor (1 + ε) times the optimal minimum bandwidth required to successfully schedule the task system. We perform thorough simulation over synthetically generated task systems to compare the performance of our proposed efficient-exact and the approximate algorithm and observe a significant decrease in runtime and a very small relative error when comparing the approximate algorithm with the exact algorithm and the sufficient algorithm.

[1]  Insup Lee,et al.  Compositional Analysis Framework Using EDP Resource Models , 2007, 28th IEEE International Real-Time Systems Symposium (RTSS 2007).

[2]  Aloysius K. Mok,et al.  A model of hierarchical real-time virtual resources , 2002, 23rd IEEE Real-Time Systems Symposium, 2002. RTSS 2002..

[3]  Insup Lee,et al.  Compositional real-time scheduling framework with periodic model , 2008, TECS.

[4]  Frank Slomka,et al.  An event stream driven approximation for the analysis of real-time systems , 2004, Proceedings. 16th Euromicro Conference on Real-Time Systems, 2004. ECRTS 2004..

[5]  Luís Almeida,et al.  Scheduling within temporal partitions: response-time analysis and server design , 2004, EMSOFT '04.

[6]  Lui Sha,et al.  Aperiodic task scheduling for Hard-Real-Time systems , 2006, Real-Time Systems.

[7]  Pjl Pieter Cuijpers,et al.  Revised budget allocations for fixed-priority-scheduled periodic resources , 2012 .

[8]  Sanjoy K. Baruah,et al.  Feasibility Problems for Recurring Tasks on one Processor , 1993, Theor. Comput. Sci..

[9]  Insup Lee,et al.  Hierarchical Scheduling Framework for Virtual Clustering of Multiprocessors , 2008, 2008 Euromicro Conference on Real-Time Systems.

[10]  Nathan Fisher,et al.  Fixed-Priority Schedulability of Arbitrary-Deadline Sporadic Tasks upon Periodic Resources , 2012, 2012 IEEE International Conference on Embedded and Real-Time Computing Systems and Applications.

[11]  Joseph Y.-T. Leung,et al.  On the complexity of fixed-priority scheduling of periodic, real-time tasks , 1982, Perform. Evaluation.

[12]  Giorgio C. Buttazzo,et al.  Biasing effects in schedulability measures , 2004, Proceedings. 16th Euromicro Conference on Real-Time Systems, 2004. ECRTS 2004..

[13]  Jay K. Strosnider,et al.  The Deferrable Server Algorithm for Enhanced Aperiodic Responsiveness in Hard Real-Time Environments , 1987, IEEE Trans. Computers.

[14]  Nathan Fisher,et al.  Minimizing peak temperature in embedded real-time systems via thermal-aware periodic resources , 2011, Sustain. Comput. Informatics Syst..

[15]  Insup Lee,et al.  Periodic resource model for compositional real-time guarantees , 2003, RTSS 2003. 24th IEEE Real-Time Systems Symposium, 2003.

[16]  Nathan Fisher,et al.  Approximate Bandwidth Allocation for Fixed-Priority-Scheduled Periodic Resources , 2010, 2010 16th IEEE Real-Time and Embedded Technology and Applications Symposium.

[17]  Mikael Sjödin,et al.  Improved response-time analysis calculations , 1998, Proceedings 19th IEEE Real-Time Systems Symposium (Cat. No.98CB36279).

[18]  John P. Lehoczky,et al.  The rate monotonic scheduling algorithm: exact characterization and average case behavior , 1989, [1989] Proceedings. Real-Time Systems Symposium.

[19]  Sanjoy K. Baruah,et al.  A fully polynomial-time approximation scheme for feasibility analysis in static-priority systems with arbitrary relative deadlines , 2005, 17th Euromicro Conference on Real-Time Systems (ECRTS'05).

[20]  Sanjoy K. Baruah,et al.  A fully polynomial-time approximation scheme for feasibility analysis in static-priority systems with bounded relative deadlines , 2006, J. Embed. Comput..

[21]  Shuichi Oikawa,et al.  Resource kernels: a resource-centric approach to real-time and multimedia systems , 2001, Electronic Imaging.

[22]  Giuseppe Lipari,et al.  Resource partitioning among real-time applications , 2003, 15th Euromicro Conference on Real-Time Systems, 2003. Proceedings..

[23]  Alan Burns,et al.  Hard Real-Time Scheduling: The Deadline-Monotonic Approach , 1991 .

[24]  Jay K. Strosnider,et al.  ENHANCED APERIODIC RESPONSIVENESS IN HARD REAL-TIME ENVIRONMENTS. , 1987, RTSS 1987.

[25]  Aloysius K. Mok.  Task Management Techniques for Enforcing ED Scheduling on Periodic Task Set , 1988 .

[26]  Lui Sha,et al.  Exploiting unused periodic time for aperiodic service using the extended priority exchange algorithm , 1988, Proceedings. Real-Time Systems Symposium.

[27]  Nathan Fisher,et al.  A bandwidth allocation scheme for compositional real-time systems with periodic resources , 2011, Real-Time Systems.

[28]  Alan Burns,et al.  Applying new scheduling theory to static priority pre-emptive scheduling , 1993, Softw. Eng. J..

[29]  Enrico Bini,et al.  Efficient computation of response time bounds under fixed-priority scheduling , 2007 .

[30]  Jane W.-S. Liu,et al.  Scheduling real-time applications in an open environment , 1997, Proceedings Real-Time Systems Symposium.

[31]  Insup Lee,et al.  Compositional real-time scheduling framework , 2004, 25th IEEE International Real-Time Systems Symposium.

[32]  Alan Burns,et al.  Efficient Exact Schedulability Tests for Fixed Priority Real-Time Systems , 2008, IEEE Transactions on Computers.

[33]  Frank Slomka,et al.  Advanced Hierachical Event-Stream Model , 2008, 2008 Euromicro Conference on Real-Time Systems.

[34]  Insup Lee,et al.  A Compositional Scheduling Framework for Digital Avionics Systems , 2009, 2009 15th IEEE International Conference on Embedded and Real-Time Computing Systems and Applications.

[35]  Le Yi Wang,et al.  The Design and Analysis of Thermal-Resilient Hard-Real-Time Systems , 2012, 2012 IEEE 18th Real Time and Embedded Technology and Applications Symposium.

[36]  Benjamin Sach.  Fully Polynomial Time Approximation Schemes , 2007 .

[37]  Alan Burns,et al.  New results on fixed priority aperiodic servers , 1999, Proceedings 20th IEEE Real-Time Systems Symposium (Cat. No.99CB37054).

[38]  Aloysius Ka-Lau Mok,et al.  Fundamental design problems of distributed systems for the hard-real-time environment , 1983 .

[39]  N. Fisher.  An FPTAS for Interface Selection in the Periodic Resource Model , 2009 .

[40]  Johan J. Lukkien,et al.  Exploiting harmonic periods to improve linearly approximated response-time upper bounds , 2010, 2010 IEEE 15th Conference on Emerging Technologies & Factory Automation (ETFA 2010).

[41]  Insup Lee,et al.  Compositional Analysis Framework Using EDP Resource Models , 2007, RTSS 2007.