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From: jik@athena.mit.edu (Jonathan I. Kamens)
Newsgroups: comp.unix.questions,comp.unix.internals
Subject: Re: why different swapping modes on executables?
Message-ID: <1991Mar12.031538.14460@athena.mit.edu>
Date: 12 Mar 91 03:15:38 GMT
References: <1991Mar12.012401.557@nowhere.uucp>
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In article <1991Mar12.012401.557@nowhere.uucp>, sking@nowhere.uucp (Steven King) writes:
|>         "A magic number of 0410 indicates thats the executable must
|>        be swapped through the private swapping store of the UNIX system,
|>        while the magic number of 0413 causes the system to attempt to
|>        page the text directly from the a.out file".
|> 
|>     While I think I understand what the difference is, I don't understand
|>  why the difference. Is there any advantage to one over the other? How
|>  does one, short of directly editing the binary, assign one or the other?
|>  ( the link editor doesn't offer any clues ) 

  Well, if you're installing a binary on an NFS server that lots of machines
are going to be using, you probably want the machines using it to copy the
binary into local swap space, because of the performance gain that will
result.  If, on the other hand, you're installing a binary on a local disk,
then you won't get any gain by copying the file into swap space, since that'll
just be another local disk (and me even be an NFS swap partition, which would
be worse).

  My ld(1) claims that "-z" causes 0413 to be used, and that's the default,
while "-n" causes 0410 to be used.

-- 
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