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.

In this paper 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.