Utilization based schedulability bounds for age constraint process sets in real-time systems
| Document type: | Journal Articles |
|---|---|
| Article type: | Original article |
| Peer reviewed: | Yes |
| Author(s): | Lars Lundberg |
| Title: | Utilization based schedulability bounds for age constraint process sets in real-time systems |
| Journal: | REAL-TIME SYSTEMS |
| Year: | 2002 |
| Pagination: | 273-295 |
| ISSN: | 0922-6443 |
| Publisher: | KLUWER ACADEMIC PUBL |
| City: | DORDRECHT |
| ISI number: | 000177986900004 |
| Organization: | Blekinge Institute of Technology |
| Department: | Department of Software Engineering and Computer Science (Institutionen för programvaruteknik och datavetenskap) Dept. of Software Engineering and Computer Science S-372 25 Ronneby +46 455 38 50 00 http://www.bth.se/eng/ipd/ |
| Language: | English |
| Abstract: | Some real-time systems consist of a number of processes that operate under age constraints. In such systems, the maximum time from the start of process L-i in cycle k to the end in cycle k+1 must not exceed the age constraint A(i) for that process. The age constraint can be met by using fixed priority scheduling and periods equal to A(i)/2. However, this approach restricts the number of process sets which are schedulable. In this paper, we define a method for obtaining process periods other than A(i)/2. The periods are calculated in such a way that the age constraints are met. Our approach is better in the sense that a larger number of process sets can be scheduled compared to using periods equal to A(i)/2. The main results in this paper are a number of performance bounds on age constraint processes. These bounds show that there is a significant gain in worst case as well as in best case behavior by using periods other than A(i)/2, particularly when there are a large number of processes in the system. |
| Subject: | Software Engineering\General |
| Keywords: | age constraint, scheduling, performance bounds, harmonic periods, real-time |
