Experience Report: Combining Mixed-Criticality Support with Resource Reservation and Spare Capacity Allocation

This paper reports upon our on-going research in supporting mixed criticality by means of an OSEK-compliant real-time operating system (RTOS). In our earlier work, we presented support for an (extended) adaptive mixed-criticality (AMC*) scheme using the OSEK-compliant RTOS μC/OS-II. Based on experiments with that set-up, we identified AMC-inherited undesirable behavior, and sketched improvements of that scheme to resolve or mitigate those issues. In this paper, we revisit the identified undesirable behavior, and specify and illustrate improvements based on resource reservation and space-capacity allocation. Our proposed improvements have also been implemented in μC/OS- II in combination with RELTEQ (Relative Timed Event Queues).