You are assuming copying around buffers won't consume any cpu? Maybe it's perfectly fine, maybe it's not. But it needs some experiment before we can handwave it.
This publication (http://www.minix3.org/docs/jorrit-herder/asci06.pdf) claims that MINIX3 could saturate a 1 Gb/s Ethernet link with an user-space network stack, with separate processes for the stack and the driver, on a rusty 32-bit micro-kernel that can't do SMP. In 2006.
This publication (http://www.minix3.org/docs/jorrit-herder/asci06.pdf) claims that MINIX3 could saturate a 1 Gb/s Ethernet link with an user-space network stack, with separate processes for the stack and the driver, on a rusty 32-bit micro-kernel that can't do SMP. In 2006.