Reconfiguration of Synchronous Real-Time Operating System

Real-time scheduling is the theoretical basis of real-time systems engineering. Earliest Deadline first EDF is an optimal scheduling algorithm for uniprocessor real-time systems. The paper deals with Reconfigurable Uniprocessor embedded Real-Time Systems classically implemented by different OS tasks that the authors suppose independent, synchronous and periodic to meet functional and temporal properties described in user requirements. They define two forms of automatic reconfigurations which are applied at run-time: Addition-Remove of tasks or just modifications of their temporal parameters: WCET and/or Periods. The authors define a new semantic of the reconfiguration where a crucial criterion to consider is the automatic improvement of the system's feasibility at run-time by using an Intelligent Agent that automatically checks the system's feasibility after any reconfiguration scenario to verify if all tasks meet the required deadlines. To handle all possible reconfiguration solutions, the authors propose an agent-based architecture that applies automatic reconfigurations to re-obtain the system's feasibility and satisfy user requirements. Therefore, they developed the tool RT-Reconfiguration to support these contributions that they apply on the running example system and the authors apply the Real-Time Simulator, Cheddar to check the whole system behavior and evaluate the performance of the algorithm. They present simulations of this architecture where the agent that implemented is evaluated.

[1]  Christo Angelov,et al.  Design Models for Reusable and Reconfigurable State Machines , 2005, EUC.

[2]  Thomas I. Strasser,et al.  Zero Downtime Reconfiguration of Distributed Automation Systems: The epsilonCEDAC Approach , 2007, HoloMAS.

[3]  Giuseppe Lipari,et al.  Elastic task model for adaptive rate control , 1998, Proceedings 19th IEEE Real-Time Systems Symposium (Cat. No.98CB36279).

[4]  Laurent Nana,et al.  Cheddar: a flexible real time scheduling framework , 2004 .

[5]  Mohamed Khalgui.  NCES-based modelling and CTL-based verification of reconfigurable embedded control systems , 2010, Comput. Ind..

[6]  Parameswaran Ramanathan,et al.  A Dynamic Priority Assignement Technique for Streams with (m, k)-Firm Deadlines , 1995, IEEE Trans. Computers.

[7]  Giuseppe Lipari,et al.  Elastic Scheduling for Flexible Workload Management , 2002, IEEE Trans. Computers.

[8]  Alan Burns,et al.  Weakly Hard Real-Time Systems , 2001, IEEE Trans. Computers.

[9]  James H. Anderson,et al.  Improving the Schedulability of Sporadic Self-Suspending Soft Real-Time Multiprocessor Task Systems , 2010, 2010 IEEE 16th International Conference on Embedded and Real-Time Computing Systems and Applications.

[10]  Ragunathan Rajkumar,et al.  Scheduling Self-Suspending Real-Time Tasks with Rate-Monotonic Priorities , 2010, 2010 16th IEEE Real-Time and Embedded Technology and Applications Symposium.

[11]  Marcel Staroswiecki,et al.  Reconfiguration Analysis Using Generic Component Models , 2008, IEEE Transactions on Systems, Man, and Cybernetics - Part A: Systems and Humans.

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

[13]  Enrico Bini,et al.  Optimal task rate selection in fixed priority systems , 2005, 26th IEEE International Real-Time Systems Symposium (RTSS'05).

[14]  Dennis Shasha,et al.  D/sup over/; an optimal on-line scheduling algorithm for overloaded real-time systems , 1992, [1992] Proceedings Real-Time Systems Symposium.

[15]  Karl-Erik Årzén,et al.  The Jitter Margin and Its Application in the Design of Real-Time Control Systems , 2004 .

[16]  Robert W. Brennan,et al.  A Holonic Approach to Reconfiguring Real-Time Distributed Control Systems , 2001, Multi-Agent-Systems and Applications.

[17]  Chenyang Lu,et al.  Multi-core real-time scheduling for generalized parallel task models , 2011, 2011 IEEE 32nd Real-Time Systems Symposium.

[18]  Joseph Y.-T. Leung,et al.  Scheduling real-time tasks: algorithms and complexity , 2004 .

[19]  Valeriy Vyatkin,et al.  A deployment of an ontology-based reconfiguration agent for intelligent mechatronic systems , 2007, 2008 IEEE International Symposium on Industrial Electronics.

[20]  Geoffrey Nelissen,et al.  Techniques Optimizing the Number of Processors to Schedule Multi-threaded Tasks , 2012, 2012 24th Euromicro Conference on Real-Time Systems.

[21]  Chenyang Lu,et al.  Multi-core Real-Time Scheduling for Generalized Parallel Task Models , 2011, RTSS.

[22]  Sanjoy K. Baruah,et al.  Scheduling periodic task systems to minimize output jitter , 1999, Proceedings Sixth International Conference on Real-Time Computing Systems and Applications. RTCSA'99 (Cat. No.PR00306).

[23]  Friedrich Eisenbrand,et al.  EDF-schedulability of synchronous periodic task systems is coNP-hard , 2010, SODA '10.

[24]  Laurent George,et al.  Analysis of deadline assignment methods in distributed real-time systems , 2004, Comput. Commun..

[25]  Patricia Balbastre Betoret,et al.  Optimal deadline assignment for periodic real-time tasks in dynamic priority systems , 2006, 18th Euromicro Conference on Real-Time Systems (ECRTS'06).

[26]  Chung Laung Liu,et al.  Scheduling Algorithms for Multiprogramming in a Hard-Real-Time Environment , 1989, JACM.