From: Arthur Krewat <krewat@kilonet.net>
To: tuhs@minnie.tuhs.org
Subject: Re: [TUHS] Memory management in Dennis Ritchie's C Compiler
Date: Tue, 25 Aug 2020 19:06:04 -0400 [thread overview]
Message-ID: <950cbd43-9ddb-e723-943d-9fb7ce3f746e@kilonet.net> (raw)
In-Reply-To: <CAEoi9W6iyOJH93ODeZC6LmRK6Yu4PbCmpkncFJtHZv1c0JZjEw@mail.gmail.com>
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On 8/24/2020 1:20 PM, Dan Cross wrote:
> On Mon, Aug 24, 2020 at 1:08 PM John Cowan <cowan@ccil.org
> <mailto:cowan@ccil.org>> wrote:
>
> On Mon, Aug 24, 2020 at 12:00 PM Dan Cross <crossd@gmail.com
> <mailto:crossd@gmail.com>> wrote:
>
> Stacks may be at the top of the user portion of the address
> space; but I'd have to double check the details.
>
>
> That's always true on the PDP-11 and Vax, no matter what the OS,
> because the processor architecture (which has pre-increment and
> post-decrement instructions, but not their counterparts) makes
> anything but a downward-growing stack unmanageable.
>
>
> Ah, but if one has a fixed-size stack that cannot be extended, one can
> put it anywhere one wants in the virtual address space. E.g., right
> after the program text segment or whatever (effectively using the text
> as a guard to detect stack overflow). I don't know why one would want
> to do that, except that it makes freeing the virtual address space
> slightly simpler when the process exits, but the point is that the
> Unix choice isn't the only way. That said, stacks and data growing
> toward each gives the maximum amount of flexibility.
>
> In OSes without virtual memory like RSX-11[ABC], RT-11, and
> mini-Unix/LSX-11, what counts as the top naturally varies.
>
>
On TOPS-10, I got into the habit of putting the PDL at the end of the
lowseg. If it ran over, it would die.
ak
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next prev parent reply other threads:[~2020-08-25 23:07 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-15 21:50 Dibyendu Majumdar
2020-08-16 15:20 ` arnold
2020-08-16 15:27 ` Jim Geist
2020-08-17 16:13 ` Dan Cross
2020-08-17 20:16 ` Dibyendu Majumdar
2020-08-17 20:34 ` Paul Winalski
2020-08-17 20:43 ` Dibyendu Majumdar
2020-08-17 21:05 ` Warner Losh
2020-08-17 22:47 ` Dave Horsfall
2020-08-17 23:06 ` Nemo Nusquam
2020-08-17 21:29 ` Dibyendu Majumdar
2020-08-24 15:58 ` Dan Cross
2020-08-24 17:08 ` John Cowan
2020-08-24 17:15 ` Clem Cole
2020-08-24 17:24 ` Clem Cole
2020-08-24 17:20 ` Dan Cross
2020-08-25 23:06 ` Arthur Krewat [this message]
2020-08-17 2:02 Noel Chiappa
2020-08-17 18:02 ` Paul Winalski
2020-08-17 18:13 ` Jim Geist
2020-08-17 18:48 ` Paul Winalski
2020-08-17 19:08 ` Jim Geist
2020-08-17 19:28 ` Paul Winalski
2020-08-17 19:35 ` Jim Geist
2020-08-17 19:41 ` Richard Salz
2020-08-17 23:40 ` Steffen Nurpmeso
2020-08-17 19:27 Noel Chiappa
2020-08-17 19:30 ` Larry McVoy
2020-08-17 19:44 ` Dan Halbert
2020-08-17 19:50 ` Paul Winalski
2020-08-17 22:05 ` Arthur Krewat
2020-08-18 0:52 ` Rob Gingell
2020-08-17 19:51 Noel Chiappa
2020-08-17 22:32 Norman Wilson
2020-08-17 22:55 ` Bakul Shah
2020-08-17 23:12 ` Chet Ramey
2020-08-18 6:33 ` arnold
2020-08-25 9:36 Steve Simon
2020-08-26 13:24 Doug McIlroy
2020-08-26 15:41 ` John Cowan
2020-08-26 15:59 Noel Chiappa
2020-08-26 16:09 ` Warner Losh
2020-08-26 19:13 ` Clem Cole
2020-08-26 16:14 ` Jim Geist
2020-08-26 17:31 ` John Cowan
2020-08-27 8:37 Paul Ruizendaal
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