Optimizing the Resource Requirements of Hierarchical Scheduling Systems

International audienceCompositional reasoning on hierarchical scheduling systems is a well-founded formal method that canconstruct schedulable and optimal system configurations in a compositional way. However, a compositionalframework formulates the resource requirement of a component, called an interface, by assuming that aresource is always supplied by the parent components in the most pessimistic way. For this reason, thecomponent interface demands more resources than the amount of resources that are really sufficient to satisfysub-components. We provide two new supply bound functions which provides tighter bounds on the resourcerequirements of individual components. The tighter bounds are calculated by using more information aboutthe scheduling system.We evaluate our new tighter bounds by using a model-based schedulability framework for hierarchicalscheduling systems realized as Uppaal models. The timed models are checked using model checking toolsUppaal and Uppaal SMC, and we compare our results with the state of the art tool CARTS