YASMIN: a real-time middleware for COTS heterogeneous platforms

Commercial-off-the-shelf (COTS) heterogeneous platforms provide immense computational power, but are difficult to program and to correctly use when real-time requirements come into play: A sound configuration of the operating system scheduler is needed, and a suitable mapping of tasks to computing units must be determined. Flawed designs lead to sub-optimal system configurations and, thus, to wasted resources or even to deadline misses and system failures. We propose YASMIN, a middleware to schedule end-user applications with real-time requirements in user space and on behalf of the operating system. YASMIN combines an easy-to-use programming interface with portability across a wide range of architectures. It treats heterogeneity on COTS embedded platforms as a first-class citizen: YASMIN supports multiple functionally equivalent task implementations with distinct extra-functional behaviour. This enables the system designer to quickly explore different scheduling policies and task-to-core mappings, and thus, to improve overall system performance. In this paper, we present the design and implementation of YASMIN and provide an analysis of the scheduling overhead on an Odroid-XU4 platform. We demonstrate the merits of YASMIN on an industrial use-case involving a search-and-rescue drone.