Processor tradeoffs in distributed real-time systems
IEEE Transactions on Computers
Distributed Scheduling of Tasks with Deadlines and Resource Requirements
IEEE Transactions on Computers
Load Sharing in Distributed Real-Time Systems with State-Change Broadcasts
IEEE Transactions on Computers
A Performance Analysis of Minimum Laxity and Earliest Deadline Scheduling in a Real-Time System
IEEE Transactions on Computers
Scheduling Algorithms for Multiprogramming in a Hard-Real-Time Environment
Journal of the ACM (JACM)
Scheduling Hard Real-Time Constrained Tasks on One Processor
Scheduling Hard Real-Time Constrained Tasks on One Processor
Parametric Design Synthesis of Distributed Embedded Systems
IEEE Transactions on Computers
Semaphore Queue Priority Assignment for Real-Time Multiprocessor Synchronization
IEEE Transactions on Software Engineering
A Utilization Bound for Aperiodic Tasks and Priority Driven Scheduling
IEEE Transactions on Computers
Supporting Demanding Hard-Real-Time Systems with STI
IEEE Transactions on Computers
Flexible design of complex high-integrity systems using trade offs
HASE'04 Proceedings of the Eighth IEEE international conference on High assurance systems engineering
A fault-tolerant reservation-based strategy for scheduling aperiodic tasks in multiprocessor systems
EUROMICRO-PDP'02 Proceedings of the 10th Euromicro conference on Parallel, distributed and network-based processing
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This paper considers the problem of scheduling both periodic and aperiodic tasks in real-time systems. A new, called reservation-based (RB), algorithm is proposed for ordering the execution of real-time tasks. This algorithm can guarantee all periodic-task deadlines while minimizing the probability of missing aperiodic-task deadlines. Periodic tasks are scheduled according to the rate monotonic priority algorithm (RMPA), and aperiodic tasks are scheduled by utilizing the processor time left unused by periodic tasks in each unit cycle. The length, u, of a unit cycle is defined as the greatest common divisor of all task periods, and a task is assumed to be invoked at the beginning of a unit cycle. For a set S of periodic tasks, the RB algorithm reserves a fraction RS of processor time in each unit cycle for executing aperiodic tasks without missing any periodic-task deadline. The probability of meeting aperiodic-task deadlines is proved to be a monotonic increasing function of RS. We derive the value of RS that maximizes the processor time reservable for the execution of aperiodic tasks without missing any periodic-task deadline. We also show that if the ratio of the computation time to the deadline of each aperiodic task is bounded by RS, the RB algorithm can meet the deadlines of all periodic and aperiodic tasks. Our analysis and simulation results show that the RB algorithm outperforms all other scheduling algorithms in meeting aperiodic-task deadlines.