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From: mangler@cit-vax.Caltech.Edu (System Mangler)
Newsgroups: comp.unix.wizards
Subject: Re: multiple-machine executables for Suns?
Message-ID: <3570@cit-vax.Caltech.Edu>
Date: Tue, 11-Aug-87 18:30:55 EDT
Article-I.D.: cit-vax.3570
Posted: Tue Aug 11 18:30:55 1987
Date-Received: Thu, 13-Aug-87 06:21:42 EDT
References: <1853@megaron.arizona.edu> <12646@sol.hi.UUCP> <24871@sun.uucp> <1857@megaron.arizona.edu>
Organization: California Institute of Technology
Lines: 21
Summary: Hybrid of Sun-2 and Sun-3 a.out

In article <1857@megaron.arizona.edu>, whm@arizona.edu (Bill Mitchell) writes:
> On the Suns however, if you want to have software on Sun-2s and Sun-3s, you
> can compile Sun-2 binaries and run them on Sun-3s, but you miss out on some
> of the good 68020 instructions.

The larger problem with running Sun-2 binaries is that Sun-3s cannot
demand-page them.  Thus before suntools can start at all, the entire
700K text segment has to be loaded, in our case from a Sun-2 serving
16 NFS clients.  Slowww...

One easy solution to this problem would be to add a hybrid a.out format,
using only 68010 instructions so that it will run on a Sun-2, but having
the text segment rounded to an 8K boundary instead of 2K, so that a Sun-3
can demand-page from the executable.  The cost in disk space would be
small, the improvement in response time would be dramatic, and it should
be trivial to implement, since the code is almost all there and in most
places you'd just be duplicating one of the cases of a switch statement.

Please?

Don Speck   speck@vlsi.caltech.edu  {rutgers,amdahl}!cristsommuOrga