Mach is fine. The IPC primitives it exposes are a lot more straightforward than Unix sockets. The performance issues everyone talked about in the '80s are not r

Mach is fine. The IPC primitives it exposes are a lot more straightforward than Unix sockets. The performance issues everyone talked about in the '80s are not really problems anymore in 2017. L4's send/recv context switch trick is great until you get to SMP, at which point its performance necessarily moves closer to that of traditional microkernels like Mach.