Real-Time Job Scheduling in Hypercube Systemsy

O-Hoon Kwon*, Jong Kim*, SungJe Hong*, and Sunggu Lee** *Dept. of Computer Science and Engineering **Dept. of Electronic and Electrical Engineering Pohang University of Science and Technology San 31 Hyoja Dong, Pohang 790-784, KOREA Phone : +(82)-562-279-2257, Fax : +(82)-562-279-2299 E-mail : [email protected] Abstract As application areas that have real-time requirements become diverse and parallel processing becomes practical, advanced real-time systems are faced with the need for utilizing high-performance parallel processing systems. Moreover, hard real-time systems need sophisticated scheduling algorithms to decide the sequence of job execution, so that each job can be executed without violating its timing restriction. In this paper, we present the problem of scheduling real-time jobs in a hypercube system and propose a scheduling algorithm. The goals of the proposed scheduling algorithm are to determine whether all jobs can complete their processing before their xed deadlines in a hypercube system and to nd such a schedule. All jobs are considered to be aperiodic, independent, nonpreemptable, and ready to start execution at the time of invocation of the scheduling algorithm. Also, each job requests a subcube for the execution of its job and the processors requested by the job are used throughout the job's execution time. Hence, associated with each job is a computation time, a deadline, and a dimensional requirement. We show that determining a schedule such that all jobs meet before their respective xed deadlines in a hypercube system when preemption is not allowed is an NP-complete problem. We thus present a heuristic scheduling algorithm for scheduling non-preemptable real-time jobs in a hypercube system. Finally, we evaluate the proposed algorithm using simulation.