Abstract

Abstract General-purpose operating systems such as Linux are in-creasingly replacing custom embedded counterparts on a wide variety of devices. Despite their convenience and flex-ibility, however, such operating systems may be overly general and thus incur unnecessary performance overheads inthese contexts. This paper describes a new approach to mitigating these overheads by automatically specializing the OSkernel for particular execution environments. We use value profiling to identify targets for specialization such as fre-quent system call parameters. A novel profiling technique is used to identify frequently invoked procedure call sequenceswithin the kernel. This information is used to sidestep the problems arising from indirect function calls when carryingout interprocedural compiler optimization. It drives a variety of compiler optimizations such as function inlining and codespecialization that reduce the execution overheads along frequent paths. A prototype implementation that uses the PLTObinary rewriting system to specialize the Linux kernel is described. While overall performance data are mixed, the im-provements we see argue for the potential of this approach.

Citations