Microkernels are slow and Elvis didn't do no drugs
The main issue I have with microkernels is that they don't solve any problem that I have.<p>A robust system is designed such that any machine in it can randomly crash. Crashing machines then only represent a risk that needs to be mitigated by having enough spare capacity to handle however many machines are expected to be down at once. Linux is already stable enough that this amount is too small to care about; making it more stable doesn't help me.<p>Would I expect meaningful performance improvements from microkernels? I'm doubtful that you'd get as much as 10%, but I'd be interested in seeing evidence if anybody has any.<p>Do microkernels offer any application-visible features that I don't have today with Linux? To the best of my knowledge they do not.