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From: dot at dotat.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: <alpine.DEB.2.20.2008190041300.21522@grey.csi.cam.ac.uk> (raw)
In-Reply-To: <CABH=_VS=Wyvnb_SoiCfRd3GaYwA47TJhMSRwpryBoEo38T6fyw@mail.gmail.com>

--> COFF

Paul Winalski <paul.winalski at gmail.com> 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.

https://en.wikipedia.org/wiki/Single-level_store

Tony.
-- 
f.anthony.n.finch  <dot at dotat.at>  http://dotat.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] <20200817192715.22D9518C09E@mercury.lcs.mit.edu>
     [not found] ` <20200817193050.GC11413@mcvoy.com>
     [not found]   ` <CABH=_VS=Wyvnb_SoiCfRd3GaYwA47TJhMSRwpryBoEo38T6fyw@mail.gmail.com>
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] <20200817195108.75FED18C09E@mercury.lcs.mit.edu>
2020-08-21  9:08 ` lars

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