Range-Based Run-time Requirement Enforcement of Non-Functional Properties on MPSoCs

Embedded system applications normally come with a set of non-functional requirements defined over properties (e.g., latency), expressed as a corridor of correct values via a lower and an upper bound per requirement. These requirements should be guaranteed during each execution of an application program on a given MPSoC platform. This can be achieved using a reactive control loop, where an enforcer controls a set of properties to be enforced, e.g., by adapting the number of cores allocated to a program or by scaling the voltage/frequency mode of active processors. An enforcement strategy may react on a requirement response differently, depending on (a) satisfying a requirement, or violating (b) a lower bound or (c) an upper bound. A better strategy might be to differentiate the reaction taken according to the amount of violation of a lower or upper bound, thus to react in a finer granular way. In this paper, we propose a design space exploration (DSE) method called Co-explore that automatically partitions the requirement corridors into so-called response ranges (i.e., sub-corridors) such that formulated verification goals of simultaneously generated enforcer FSMs, e.g., the number of consecutive violations of a requirement, are optimized. The evaluation shows that the explored enforcement FSMs can achieve higher probabilities of meeting a given set of requirements compared to reacting solely based on the ternary information (a), (b), or (c).