Using Platform-Specific Optimizations in Stub-Code Generation

The use of a stub code generator can greatly reduce the effort required to implement a multi-server system on top of a microkernel. However, stub code has traditionally been highly generic and therefore rather slow, which has prevented it from being used in performance-critical applications. In this work, we show that this restriction can be eliminated by specialization for the underlying platform, i.e. by exploiting specific properties of the kernel, compiler, or hardware platform that are being used. We demonstrate our approach for an example platform, the L4 microkernel, and present a variety of optimization techniques that can be used to improve stub code performance on this platform. Our techniques are implemented and validated in IDL , our optimizing stub code generator. A comparison with traditional stub code generators shows that IDL stubs can perform up to an order of magnitude better, and that they can increase application performance by more than 10 percent.