Path: utzoo!attcan!uunet!lll-winken!ncis.tis.llnl.gov!helios.ee.lbl.gov!pasteur!ucbvax!POSTGRES.BERKELEY.EDU!dillon
From: dillon@POSTGRES.BERKELEY.EDU (Matt Dillon)
Newsgroups: comp.sys.amiga.tech
Subject: Re: Virtual Memory / doable 1.4 request
Message-ID: <8905181714.AA08425@postgres.Berkeley.EDU>
Date: 18 May 89 17:14:27 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Lines: 25

:In article <8905132040.AA27524@postgres.Berkeley.EDU> dillon@POSTGRES.BERKELEY.EDU (Matt Dillon) writes:
:>	    (C) Reserve a partition to be used for VM.  I do not like this idea
:>		at all.  In fact, I hate it.  [ ... ]
:
:	Doesn't UNIX do it this way?
:

	Yup. As I said, learn from UNIX's mistakes.  Remember that UNIX is
essentially something that people normally build up and up and up and up....
until it becomes a bloated mess.  

	In this case, the fact that there are currently at least THREE paging
mechanisms on many UNIXs now.  (1) VM paging to swap device, (2) read-only
paging of text from the executable file image, (3) mmap() rw paging to a file.
That doesn't include zero-fill or other features that would be utilitized 
anyway.

	Frankly, I would rather see just one mechanism: rw paging to a file.

Now, unfortunately, you can't ro-page the text (code) segment directly from
an Amiga executable due to the relocation information but that doesn't preclude
combing (1), (2), and (3) to (3).  P.S. the specs on mmap() do allow for
the file to grow, of course.  See my original posting.

				-Matt