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Journal of Inforamtion Science and Engineering, Vol.13 No.3, pp.447-460 (September 1997)
Criticality-Based Load Adjustment in
Adaptive Real-Time Systems*

Shie-Kai Ni, Tei-Wei Kuo and Giun-Haur Huang
Department of Computer Science and Information Engineering
National Chung Cheng University
Chiayi, Taiwan 621, R.O.C.

This paper generalizes the load scaling techniques proposed in [7, 8] by relating the criticality and flexibility of a process to the resource allocation problem. We propose a framework for adjusting the system workload when the timing parameters of processes may change in reaction to the environment. When the list of allowable configurations is implicitly given by scalable periodic processes, the corresponding weighted period assignment problem is shown to be NP-complete. We present an approximation algorithm for the period assignment problem and show some very encouraging results.

Keywords: adaptive scheduling, configuration selection, load adjustment, load scaling, period assignment, process criticality, application semantics, real-time systems

Received April 15, 1996; revised May 12, 1997.
Communicated by Jan-Ming Ho.
* Supported in part by a research grant from the national Science Council under Grant NSC84-2213-E-194-037.