17 Aug
2020
17 Aug
'20
9:44 p.m.
On 8/17/20 3:30 PM, Larry McVoy wrote:
On Mon, Aug 17, 2020 at 03:27:15PM -0400, Noel Chiappa
wrote:
Bill Joy
imagined it, the prototype is in one the 4.x BSD releases.
Sun (Joe Moran) actually implemented it first in any Unix variant.
It's possible the concept existed in some other OS but I'm not aware
of it.
I have a clear memory of having a discussion with Bill Joy about the
idea of vread(2) and vwrite(2) when we were both grad students at
Berkeley. I remember we were eating sausages from Top Dog and sitting
outside Etcheverry Hall on or near the grassy plaza. I think vfork may
have already existed, and we were talking about adding some kind of
memory-mapped file I/O. I think I suggested the actual names, as a
parallel to vfork. Some of my thinking might have come from my
experience with TENEX while working summers at BBN. I was just a
sounding board; I wasn't implementing any of this. vread and vwrite were
in BSD4.1, but dropped in 4.2 (so my Googling says). I think it became
clear later that mmap was an easier concept than the initial vread and
vwrite ideas.
Dan H.
From: Jim
Geist
When did mmap(2) come about?
Pretty sure it's a Berserkleyism. I think it came in with the VM stuff that
DARPA mandated for VAX Unix (for the research project they funded).