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From: dot at (Tony Finch)
Subject: [COFF] [TUHS] Memory management in Dennis Ritchie's C Compiler
Date: Wed, 19 Aug 2020 00:48:16 +0100
Message-ID: <> (raw)
In-Reply-To: <>

--> COFF

Paul Winalski <paul.winalski at> wrote:

mmap() / $CRETVA

> The VMS image activator (runtime loader in Unix-speak) used these
> primitives to load program images into virtual memory.  More than one
> process can map the same region of a file.  This is how sharing of
> read-only program segments such as .text is implemented.
> I think Burroughs OSes had this concept even before VMS.

Did MULTICS work the same way?

The Manchester / Ferranti Atlas had virtual memory in 1962 but I don't
know how much they used it for multiprogramming (and by implication shared
text segments) - it didn't do timesharing until later, but AIUI virtual
memory helped it to have an exceptionally good job throughput for the
time. Perhaps their motivation was more to do with having a good shared
implementation of overlays and paged IO.

f.anthony.n.finch  <dot at>
reject all prejudice and discrimination based upon race, colour,
religion, age, disability, gender, or sexual orientation

       reply	other threads:[~2020-08-18 23:48 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <>
     [not found] ` <>
     [not found]   ` <>
2020-08-18 23:48     ` dot [this message]
2020-08-19 17:39       ` paul.winalski
2020-08-19 20:36         ` clemc
2020-08-19 22:09           ` paul.winalski
     [not found] <>
2020-08-21  9:08 ` lars

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