Linköping University: Students Alumni Trade and Industry/Society Internal Search
date04_luico

Quasi-Static Scheduling for Real-Time Systems with Hard and Soft Tasks

Luis Alejandro Cortes
 
Petru Eles Author homepage
Zebo Peng Author homepage

Design, Automation and Test in Europe (DATE 2004), Paris, France, February 16-20, 2004, pp. 1176-1181

ABSTRACT
This paper addresses the problem of scheduling for real-time systems that include both hard and soft tasks. The relative importance of soft tasks and how the quality of results is affected when missing a soft deadline are captured by utility functions associated to soft tasks. Thus the aim is to find the execution order of tasks that makes the total utility maximum and guarantees hard deadlines. We consider time intervals rather than fixed execution times for tasks. Since a purely off-line solution is too pessimistic and a purely on-line approach incurs an unacceptable overhead due to the high complexity of the problem, we propose a quasi-static approach where a number of schedules are prepared at design-time and the decision of which of them to follow is taken at run-time based on the actual execution times. We propose an exact algorithm as well as different heuristics for the problem addressed in this paper.


Related files:
date04_luico.pdfAdobe Acrobat portable document
date04_luico.ps.gzpostscript document, compressed (with gzip)


[AEP04] Luis Alejandro Cortes, Petru Eles, Zebo Peng, "Quasi-Static Scheduling for Real-Time Systems with Hard and Soft Tasks", Design, Automation and Test in Europe (DATE 2004), Paris, France, February 16-20, 2004, pp. 1176-1181
( ! ) perl script by Giovanni Squillero with modifications from Gert Jervan   (v3.1, p5.2, September-2002-)