Re: If QNX is successful, why NOT GNU Microkernels

[Niels Möller]

Olivier Galibert <galibert@pobox.com> writes:

> Fixing it must be fun though, I'll have to look up the proposed
> solutions.  Comparing with the linux syscall speeds will be _tough_.

I think the cost of an L4 ipc between address spaces is on the order
of a few hundred cycles. Then there are the effects on caches etc, I
don't know any numbers but at least the L4 footprint is reaonably
small.

> You'll notice btw that what I cite is not incompatible with a
> microkernel approach (well, the cache unification may be hard).  It's
> Mach itself I consider badly designed by today standards, not the
> microkernel concept per se.

We can all agree Mach is big and slow. That's no news.

Regards,
/Niels