 While these results demonstrate that the poor performance of systems based on first-generation microkernels is not representative for second-generation kernels such as L4, this constitutes no proof that microkernel-based systems can be built with good performance.It has been shown that a monolithic Linux server ported to L4 exhibits only a few percent overhead over native Linux.However, such a single-server system exhibits few, if any, of the advantages microkernels are supposed to provide by structuring operating system functionality into separate servers.