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From: mohta@necom830.cc.titech.ac.jp (Masataka Ohta)
Newsgroups: comp.unix.internals
Subject: Re: Shared Libraries YO!!!
Message-ID: <337@titccy.cc.titech.ac.jp>
Date: 19 Jun 91 08:06:45 GMT
References: <1991Jun10.154811.11965@infonode.ingr.com> <4945@skye.ed.ac.uk>
Sender: news@titccy.cc.titech.ac.jp
Distribution: comp
Organization: Tokyo Institute of Technology
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In article <4945@skye.ed.ac.uk>
	richard@aiai.UUCP (Richard Tobin) writes:

>>End of argument.
>
>I think not.

I think the argument might have end. Let's summaries.

So far, no one has shown any usable data on how much code is shared with
shared libraries under their usual load.

So, perhaps, shared libraries dose not help to decrease memory consumption
so much.

On the other hand, I showed a measurement result of increase of memory
consumption based on some configuration (not my own configuration
but other people's typical configuration).

As for the software upgrade flexibility, its only example, /etc/hosts to
DNS, was denied (note that Chris Torek's fact has nothing to do with
the denial, as it can be interpreted that people in Berkeley noticed the
necessity to change struct hostent after half year of experience with DNS)
and no other supporting fact has shown.

So, it should be concluded that there is no usable software upgrade
flexibility in shared libraries.

With shared libraries, disk consumption is surely decreased. So it might
be useful in some cases. But such cases are, I think, rare. If the environment
is networked and there is large shared servers (the case when shared libraries
is really shared with many programs), there is large disk for unshared user
data and the size of command files, which are already shared by networking,
matters little. Are there any natural and common configuration where disk
consumption really matters?

							Masataka Ohta