Hi Gernot,
Gernot Heiser wrote:
NHW> I recollect from a talk that Jorrit Herder gave about that Minix3 does NHW> not support paged memory: it uses segments for enforcing protection, NHW> which explains a large part of the difference you observe.
... which, among others, means that it cannot set up shared memory regions for high-bandwidth cross address-space communication. ...
It is possible to setup shared memory with the x86 segments by letting them overlap. The x86 segments just add an offset (and check the limit) to the segment local address. The result of this translation maps to a flat and untranslated (if only segments are used) address space.
Marcus