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From: songer@ei.ecn.purdue.edu (Christopher M Songer)
Newsgroups: comp.sys.next
Subject: Re: NX_VOID, Release 2.1 and Lighthouse Design
Message-ID: <1991Jun27.214855.6114@noose.ecn.purdue.edu>
Date: 27 Jun 91 21:48:55 GMT
References: <1991Jun26.023443.27660@ni.umd.edu> <1991Jun26.144145.11129@shaman.com> <1991Jun26.200004.1042@zardoz.club.cc.cmu.edu>
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In article <1991Jun26.200004.1042@zardoz.club.cc.cmu.edu> ddj@zardoz.club.cc.cmu.edu (Doug DeJulio) writes:
>
>I hope that this is not true.  I would like to see NeXT change from a
>Mach 2.5 based kernel to a Mach 3.0 based kernel.  A Macintosh
>emulator I'm working on would be much easier with some of the features
>of Mach 3.0 available (mainly external pagers).

                        ^^^^^^^^^^^^^^^^^^^^^^

>
>Of course, there's no reason that this change would have to break any
>software that works under Mach 2.5.
>-- 
>Doug DeJulio
>ddj@zardoz.club.cc.cmu.edu

YES!!!!!!!

(Let's say it again for emphasis, this is my personal pet NeXT peeve.)

YES!!!!!!!

External Pagers are crucial. They were a big performance hit under
2.5 and this is probably why they were left out of the NeXT version, but
regardless of whether NeXT goes to the 3.0 microkernel, PUT EXTERNAL
PAGERS IN NEXT MACH. There is so much you can do with them and, more
importantly, so much you can't do without them....

SYSV shared memory compatibility libs would be easy to do with external
pagers but rewriting code that uses SYSV shared memory is NOT easy! As
NeXT OS currently stands, one cannot do a set of SYSV shared memory
libraries. There are some coolo programs that use SYSV shm* calls. I'd
like to run some of them. So, I whole heartedly agree with Doug's comment.
An upgrade to the 3.0 microkernel would be fine, or patching the external
pagers into the current would be fine too -- either way, having external
pager would be a real boon!

-Chris