On the Schedulability Analysis for Dynamic QoS Management in Distributed Embedded Systems

Dynamic Quality-of-Service (QoS) management has been shown to be an effective way to make an efficient use of systems resources, such as computing, communication or energy. This is particularly important in resource-contrained embedded systems, such as vehicles, multimedia devices, etc.. Deploying dynamic QoS management requires using an appropriate schedulability test that is fast enough and ensures continued schedulability while the system adapts its configuration. In this paper we consider four utilization-based tests with release jitter, a particularly relevant feature in distributed systems, three of which were recently proposed and one is added in this work. We carry out an extensive comparison using random task sets to characterize their relative merits and we show a case study where multiple video streams are dynamically managed in a fictitious automotive application using such schedulability bounds.