A Toolkit for Specializing Production Operating System Code

Specialization has been recognized as a powerful technique for optimizing operating systems. However, specialization has not been broadly applied beyond the research community because the current techniques, based on manual specialization, are time-consuming and error-prone. This paper describes a specialization toolkit that should help broaden the applicability of specializing operating systems by assisting in the automatic generation of specialized code, and {\em guarding} the specialized code to ensure the specialized system continues to be correct. We demonstrate the effectiveness of the toolkit by describing experiences we have had applying it in real, production environments. We report on our experiences with applying the tools to three disparate portions of operating systems: signal delivery, memory allocation and RPC. We describe how we used the toolkit to specialize these components, and present the resulting performance improvements. We conclude that a toolkit-based approach to specialization can work, and is an effective operating system optimization technique.