Hardware Microkernels for Heterogeneous Manycore Systems

The migration away from single power-hungry, speculative execution processors towards manycore architectures is good news for the embedded and real-time systems community. Commodity platforms with large numbers of heterogeneous processors can be leveraged to meet the stringent real-time requirements of next-generation embedded systems. Although promising, the large numbers of heterogeneous cores that can bring about new levels of performance also bring with them new challenges for designers of real-time operating systems. Researchers are already conjecturing that the scalability and heterogeneity of manycores will result in the retirement of our existing monolithic operating system structure. In this paper we first discuss some of the challenges that these manycore chips will present. We then discuss how hardware-based microkernels can provide the low latency, low jitter performance envelopes that are needed within real-time systems. We show how our hthreads hardware microkernel provides these characteristics for scalable numbers of threads and processors. A hardware-based microkernel approach also provides ISA-neutral OS services, such as basic atomic operations, upon which higher-level programming models can be built.