> Seeing these results touted as being pretty good makes me wonder why we haven't fully adopted microkernels yet. Their singular disadvantage, which is the need

> Seeing these results touted as being pretty good makes me wonder why we haven't fully adopted microkernels yet. Their singular disadvantage, which is the need for two IPC calls vs one for a monolithic kernel, is completely irrelevant in comparison to these numbers. And that's even the worst case of synchronous/blocking calls. With different API design - e.g. asynchronous interactions as done with io_uring or IOCP - the latency becomes less important as long as the overall efficiency and thereby throughput is high.