Path: utzoo!news-server.csri.toronto.edu!cs.utexas.edu!wuarchive!uunet!auspex!guy
From: guy@auspex.auspex.com (Guy Harris)
Newsgroups: comp.os.misc
Subject: Re: Operating system sizes
Keywords: kloc, operating system, size, source code
Message-ID: <6554@auspex.auspex.com>
Date: 11 Mar 91 18:36:59 GMT
References: <2551@sirius.ucs.adelaide.edu.au>
Organization: Auspex Systems, Santa Clara
Lines: 20

>SunOS 4.03, Sun - 440k.  This includes both the Sun 3 and Sun 4
>    versions.  For either one alone I would guess about 350k lines all
>    up.  RPC, TMPFS, DLL, NFS, YP, POSIX, SVID, XPG, C2, it's all fun
>    stuff, but not without its cost.  I guess one important thing to
>    note is the size of a basic Unix system is quite small in
>    comparison to the amount of extra stuff added to provide all the
>    functionality many people expect.  But is it all really necessary,
>    and does it have to be in the kernel?

No, not all of it does - which is why neither YP nor DLL, if by the
latter you mean "dynamically-linked libraries", *are* in the kernel. 
The YP client and server code, and the run-time loader, run in user
mode; they make use of services that are in the kernel (e.g., file
system access and network access in the case of YP, file system access
and "mmap()" in the case of the run-time loader), but aren't implemented
entirely in the kernel. 

You may also have included RFS in your count of source lines; you're not
obliged to include that as part of your system, if you don't need it. 
(The same is true of NFS.)