Towards a scalable microkernel personality for multicore processors

Abstract

With a steady trend from singe-core to multicore processors, scalability has become a significant design issue for the Operating Systems (OS), as many critical OS functions must be re-designed in order to achieve scalable performance. While numerous efforts have been made to improve scalability of monolithic OS kernels, comparatively little work has been done for microkernels. In this paper, we begin by studying the scalability of Fiasco.OC, a state-of-the-art microkernel implementation. We then present OmniRE, a new personality for the Fiasco.OC microkernel that is aimed at being multicore scalable. Compared to L4Re (the vanilla "off-the-shelf" Fiasco.OC personality), OmniRE aims to eliminate contention by decentralizing resource management, scheduling, and kernel access. The design also aims to minimize inter-process communication (IPC) across CPUs by localizing resource functionality such as page-fault handling. We conduct experiments to compare OmniRE against L4Re as well as Linux on a 48-core AMD server and a 6-core Intel workstation. Our results indicate that OmniRE provides better scalability than L4Re and can in fact exceed absolute performance of Linux in memory page management at higher core counts. © 2013 Springer-Verlag.