A novel method for adding multiprocessor support to a large and complex uniprocessor kernel

Summary form only given. The current trend of using multiprocessor computers for server applications requires operating system adoptions for high performance. However, modifying large bodies of software is very costly and time-consuming, and the cost of porting an operating system to a multiprocessor might not be motivated by the potential performance benefits. We present a novel method, the application kernel approach, for adaption of an existing uniprocessor kernel to SMP hardware. Our approach considers the existing kernel as a "black box", to which no or small changes are made. Instead, the original kernel runs OS-services unmodified on one processor whereas the other processors execute applications on top of a small custom kernel. A prototype implementation illustrates that the approach can be realized with fairly small resources. We also present an initial performance evaluation where we show that the performance is good for user-bound applications.