Issue No. 01 - January (2008 vol. 57)
DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/TC.2007.70787
Real-time systems are often designed using a set of periodic tasks. Task periods are usually set by the system requirements, but deadlines and computation times can be modified in order to improve system performance. Sensitivity analysis in real-time systems has focused on changes in task computation times, using fixed priority analysis. Only a few studies deal with the modification of deadlines in dynamic-priority scheduling. The aim of this work is to provide a sensitivity analysis for task deadlines in the context of dynamic-priority, pre-emptive, uniprocessor scheduling. In this paper, we present a deadline minimisation method that computes the shortest deadline of a periodic task. As undertaken in other studies concerning computation times, we also define and calculate the critical scaling factor for task deadlines. Our proposal is evaluated and compared with other works. The deadline minimisation proposed strongly reduces jitter and response time of control tasks, which can lead to a significant improvement of the system performance.
Real-time systems and embedded systems, Scheduling
I. Ripoll, A. Crespo and P. Balbastre, "Minimum Deadline Calculation for Periodic Real-Time Tasks in Dynamic Priority Systems," in IEEE Transactions on Computers, vol. 57, no. , pp. 96-109, 2007.