16 Jul
2021
16 Jul
'21
4:40 p.m.
On Fri, Jul 16, 2021 at 9:57 AM Larry McVoy <lm(a)mcvoy.com> wrote:
I'm pretty sure SGI used a similar approach for
networking packets.
Yeah, it was pretty standard for networking interfaces. I think I first
saw it I'm the MIT Chaos driver maybe? In many ways, Gurwitz's whole mbuf
memory scheme for the ethernet controllers and the whole IP stack that
lives on in BSD is based on the idea. Rob used a number of different size
buffers, not just the two, but the idea is the same, never copy anything if
we can avoid it. Play pointer games in the top, bottom, and middle parts
of the driver/stack.
A huge difference, as Ted I'm sure knows, is that you tended to have many
more serial lines than network interfaces. I suspect Rob's scheme
would have sucked trying to support traditional single-byte serial
interfaces or really just use too much memory to be practical.
ᐧ