Precise Response Time Analysis for Ravenscar Kernels

The Ravenscar Profile defines a subset of the Ada95 task-ing constructs which can be implemented using a small, reliable kernel. One of the benefits of this approach is to improve the timing analysis because non-deterministic and non-analyzable features are excluded. But to perform a pre-cise schedulability analysis of a Ravenscar compliant ap-plication, the kernel overheads must be taken into account. Therefore, a set of metrics and documentation requirements has to be defined in order to model the kernel influence in response time analysis. In this paper the main components of the response time of periodic and sporadic tasks running on a Ravenscar kernel are identified, and the set of kernel metrics which are required to perform a precise timing ana-lysis is identified