Multikernel operating systems (OSs) were introduced to match the architectural characteristics of lightweight manycores. While several multikernel OS designs are possible, in this work we argue on one that is structured in asymmetric microkernel instances. We deliver an open-source implementation of an OS kernel with these characteristics, and we provide a comprehensive assessment using a representative benchmark suite. Our results show that an asymmetric microkernel design is scalable and introduces at most 0.9% of performance interference in an application execution. Also, our results unveil co-design aspects between an OS kernel and the architecture of lightweight manycore, concerning the memory system and core grouping.

Multikernel Operating Systems (OSs) were introduced to cope with challenges in software development and deployment in lightweight manycores. Among the possible structures for a multikernel OS, we focus on designs based on asymmetric kernels. This design delivers better performance isolation, but it suffers from an overhead in energy efficiency. In this work, we overcome this issue with a co-design solution between the cluster of a lightweight manycore and an asymmetric kernel. We designed a 4-core heterogeneous cluster with one core tuned for the OS kernel and we patched the OS kernel to better match the characteristics of this core. Our experiments unveiled that our solution consumes 14.1% less power than the baseline and also improves the OS kernel performance by up to 6.5%.