1 Jan
2023
1 Jan
'23
8:50 p.m.
Paging was what they were referring to. The Bell releases at the time
only swapped like they did on the PDP-11.
BSD allowed only fragments of the program to need be resident.
The joke as “It ain’t virtual unless it isn’t all there."
------ Original Message ------
From "Dan Cross" <crossd(a)gmail.com>
To "Warner Losh" <imp(a)bsdimp.com>
Cc "Jonathan Gray" <jsg(a)jsg.id.au>; "Paul Ruizendaal"
<pnr(a)planet.nl>;
"The Eunuchs Hysterical Society" <tuhs(a)tuhs.org>; "segaloco"
<segaloco(a)protonmail.com>
Date 1/1/2023 12:35:12 AM
Subject [TUHS] Re: A few comments on porting the Bourne shell
On Sun, Jan 1, 2023 at 12:27 AM Warner Losh
<imp(a)bsdimp.com> wrote:
On Sat, Dec 31, 2022, 9:38 PM Jonathan Gray
<jsg(a)jsg.id.au> wrote:
One wonders what is meant by "virtual memory" in this context. I
contend that Unix has had "virtual memory" since moving off of the
PDP-11/20, in the sense of having a virtual address space that was
mapped onto a (possibly contiguous) physical address space. I think
all of these references mean demand paging, possibly with page
reclamation or whole-process swapping under memory pressure.
- Dan C. [snip]
Bourne's AsiaBSDCon 2016 talk also lists 1976
and goes on to discuss sbrk() use causing problems with ports
https://youtu.be/7tQ2ftt3LO8?t=715
And at 5:18 he says he had a vax lab with three vaxen and the Lab's vax port
didn't have virtual memory. Bill Joy with 3BSD which had virtual memory. They
installed it on the vaxen because they were hitting physical memory limits for some of
their programs....