Real-time scheduling of non-preemptive periodic tasks for continuous media retrieval

Author

Baek, Yun-Cheol ; Koh, Kern

Author_Institution

Dept. of Comput. Sci., Seoul Nat. Univ., South Korea

fYear

1994

fDate

22-26 Aug 1994

Firstpage

481

Abstract

A real-time system should guarantee that each hard real-time task completes execution before its deadline. When non-preemptive earliest deadline first (EDF) scheduling is used for a set of periodic tasks, one can achieve full processor utilization, but its schedulability test is known to be an NP-hard problem. Continuous media (CM) retrieval is becoming an important application of real-time systems. In such an application, the CM server should provide CM data requested by clients within the specified deadline. We examine the O(1) time online schedulability tests for a set of equal computation time tasks and for a set of equal period tasks using non-preemptive EDF algorithm. We also demonstrate that these results can be used for scheduling a set of client requests in CM retrieval system

Keywords

computational complexity; processor scheduling; real-time systems; CM retrieval system; NP-hard problem; client requests; continuous media retrieval; earliest deadline first scheduling; equal computation time tasks; equal period tasks; full processor utilization; hard real-time task; non-preemptive periodic tasks; online schedulability tests; real-time scheduling; schedulability test; Computer science; Dynamic scheduling; NP-hard problem; Network servers; Processor scheduling; Real time systems; Runtime; Scheduling algorithm; Testing; Timing;

fLanguage

English

Publisher

ieee

Conference_Titel

TENCON '94. IEEE Region 10's Ninth Annual International Conference. Theme: Frontiers of Computer Technology. Proceedings of 1994

Print_ISBN

0-7803-1862-5

Type

conf

DOI

10.1109/TENCON.1994.369254

Filename

369254