From: Warner Losh <firstname.lastname@example.org>
To: Ronald Natalie <email@example.com>
Cc: The Eunuchs Hysterical Society <firstname.lastname@example.org>
Subject: [TUHS] Re: Split addressing (I/D) space (inspired by the death of the python... thread)
Date: Thu, 3 Aug 2023 15:16:25 -0600 [thread overview]
Message-ID: <CANCZdfqreERYboMZH+UzJFUyzriNxQu6L1vxSdHgSf=FUE_Zug@mail.gmail.com> (raw)
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2BSD also did split I&D in the kernel (as well as run TCP in supervisor
mode to get another I/D space). A lot of the overlays was done in the
linker, but it wasn't completely automated.
I had to tweak the overlay tables a little as I did the 2.11pl0 work since
the early stuff wasn't exactly careful about distributing the hacks to the
makefile to make it happen...
On Thu, Aug 3, 2023 at 3:10 PM Ronald Natalie <email@example.com> wrote:
> Having cut my UNIX teeth on the JHU 11/45, I can tell you very much that
> it did have split I/D. V6 supported split I/D for user mode programs.
> The kernel originally wasn’t split I/D. Version 7, if I’m recalling
> properly, did run the kernel split I/D on the 45 and 70.
> ------ Original Message ------
> From "Kenneth Goodwin" <firstname.lastname@example.org>
> To "Will Senn" <email@example.com>
> Cc "The Eunuchs Hysterical Society" <firstname.lastname@example.org>
> Date 8/3/23, 5:05:31 PM
> Subject [TUHS] Re: Split addressing (I/D) space (inspired by the death of
> the python... thread)
> At the risk of exposing my ignorance and thus being events long long ago
> in history....
> And my mind now old and feeble...
> 😆 🤣
> 1. I don't think the 11/45 had split I & d.
> But I could be wrong.
> That did not appear until the 11/70
> And was in the later generation 11/44 several years later.
> 2. The kernel determined it by MMU type and managed it solely. The
> assembler and loader always built the binary object file as the three
> sections - instructions, data and bss spaces so loading an object file
> could be done on any platform.
> Programmers generally did not worry about the underlying hardware
> 3. I don't recall if a systype style system call was available in v7 to
> give you a machine type to switch off of.
> With something like that you could determine memory availability hard
> limits on the DATA/bss side if you needed to.
> But that was also easily determined by a allocation failure in malloc/sbrk
> with an out of memory error.
> If you really needed to know availability, you could have a start up
> subroutine that would loop trying to malloc ever decreasing memory sizes
> until success and until out of available memory error.
> Then release it all back via free(). Or manage it internally.
> As I recall however vaguely, there was an attempt to split the kernel
> into two pieces. One running in kernel mode and one running in supervisor
> mode in order to double the amount of available instruction and data
> spaces for the operating system. I recall playing around with what was
> there trying to get it to work right.
> I was trying to support over 200 users on a pdp 11/70 at the time running
> a massive insurance database system.
> On Thu, Aug 3, 2023, 4:35 PM Will Senn <email@example.com> wrote:
>> Does unix (v7) know about the PDP-11 45's split I/D space through
>> configuration or is it convention and programmer's responsibility to
>> know and manage what's actually available?
>> On 8/3/23 12:00, Rich Salz wrote:
>> > What, we all need something to kick now that we've beaten sendmail?
>> > How about something unix, ideally a decade old?
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next prev parent reply other threads:[~2023-08-03 21:16 UTC|newest]
Thread overview: 83+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-30 18:22 [TUHS] Re: Cool talk on Unix and Sendmail history, by Eric Allman Norman Wilson
2023-07-30 21:43 ` Rob Pike
2023-07-30 23:34 ` George Michaelson
2023-07-30 23:59 ` Erik E. Fair
2023-07-31 0:26 ` Warner Losh
2023-07-31 22:57 ` Grant Taylor via TUHS
2023-07-31 23:05 ` Warner Losh
2023-08-01 2:45 ` Grant Taylor via TUHS
2023-08-01 1:51 ` Niklas Karlsson
2023-08-01 2:47 ` Grant Taylor via TUHS
2023-08-01 3:20 ` Theodore Ts'o
2023-07-31 0:41 ` segaloco via TUHS
2023-08-01 9:22 ` Marc Donner
2023-08-01 10:58 ` Erik E. Fair
2023-08-02 0:37 ` Dave Horsfall
2023-08-02 14:52 ` Ron Natalie
2023-08-02 21:14 ` Grant Taylor via TUHS
2023-08-02 22:20 ` segaloco via TUHS
2023-08-02 22:37 ` Warner Losh
2023-08-02 23:49 ` Rich Salz
2023-08-03 0:51 ` [TUHS] Re: python Larry McVoy
2023-08-03 1:20 ` George Michaelson
2023-08-03 2:53 ` Bakul Shah
2023-08-03 2:55 ` segaloco via TUHS
2023-08-03 3:24 ` George Michaelson
2023-08-03 3:32 ` Warner Losh
2023-08-03 3:55 ` Bakul Shah
2023-08-03 8:32 ` Rob Pike
2023-08-03 14:19 ` Bakul Shah
2023-08-03 14:56 ` Dan Halbert
2023-08-03 15:20 ` will.senn
2023-08-03 22:05 ` Dan Cross
2023-08-04 0:24 ` John Cowan
2023-08-04 15:17 ` Dan Cross
2023-08-05 4:44 ` Bakul Shah
2023-08-03 15:41 ` John Cowan
2023-08-03 2:07 ` Clem Cole
2023-08-03 2:21 ` Pete Wright via TUHS
2023-08-03 2:56 ` Warner Losh
2023-08-03 12:36 ` Mike Markowski
2023-08-03 13:29 ` Rob Pike
2023-08-03 15:24 ` emanuel stiebler
2023-08-03 15:39 ` Steffen Nurpmeso
2023-08-04 1:01 ` Larry McVoy
2023-08-04 1:28 ` segaloco via TUHS
2023-08-04 1:58 ` Adam Thornton
2023-08-04 15:04 ` Dan Cross
2023-08-04 15:10 ` Larry McVoy
2023-08-03 16:57 ` [TUHS] Re: [TULSA] " Phil Budne
2023-08-03 17:00 ` Rich Salz
2023-08-03 20:35 ` [TUHS] Split addressing (I/D) space (inspired by the death of the python... thread) Will Senn
2023-08-03 21:05 ` [TUHS] " Kenneth Goodwin
2023-08-03 21:10 ` Ronald Natalie
2023-08-03 21:16 ` Warner Losh [this message]
2023-08-03 21:24 ` Ronald Natalie
2023-08-03 22:34 ` Kenneth Goodwin
2023-08-03 21:05 ` Ronald Natalie
2023-08-03 21:44 ` Clem Cole
2023-08-03 22:08 ` Will Senn
2023-08-03 22:54 ` Clem Cole
2023-08-03 23:08 ` Dave Horsfall
2023-08-03 23:15 ` Clem Cole
2023-08-04 0:38 ` John Cowan
2023-08-03 17:29 ` [TUHS] Re: [TULSA] Re: python Alejandro Colomar
2023-08-03 17:51 ` John Cowan
2023-08-03 18:05 ` Alejandro Colomar
2023-08-03 21:29 ` Dan Cross
2023-08-03 23:55 ` [TUHS] printf (was: python) Alejandro Colomar
2023-08-04 16:06 ` [TUHS] " Dan Cross
2023-08-04 16:57 ` Alejandro Colomar
2023-08-04 21:16 ` Dan Cross
2023-08-03 21:02 ` [TUHS] Re: [TULSA] Re: python Steffen Nurpmeso
2023-08-03 23:47 ` Larry McVoy
2023-08-03 23:54 ` Will Senn
2023-08-04 19:20 ` [TUHS] " Ed Bradford
2023-08-04 19:47 ` Larry McVoy
2023-08-05 5:40 ` Ed Bradford
2023-08-02 23:33 ` [TUHS] Re: Cool talk on Unix and Sendmail history, by Eric Allman Dave Horsfall
2023-08-03 21:48 [TUHS] Re: Split addressing (I/D) space (inspired by the death of the python... thread) Noel Chiappa
2023-08-03 23:10 Noel Chiappa
2023-08-03 23:42 ` Warner Losh
2023-08-03 23:14 Steve Simon
2023-08-04 21:40 Noel Chiappa
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