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From: Wilko Bulte <wilko@yedi.iaf.nl>
Message-Id: <199708282110.XAA02694@yedi.iaf.nl>
Subject: Re: shared libraries?
To: andrew@zeta.org.au (Andrew Reilly)
Date: Thu, 28 Aug 1997 23:10:17 +0200 (MET DST)
Cc: toor@dyson.iquest.net, perlsta@sunyit.edu, hackers@FreeBSD.ORG
In-Reply-To: <199708280638.QAA18886@gurney.reilly.home> from "Andrew Reilly" at Aug 28, 97 04:38:48 pm
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As Andrew Reilly wrote...
> On 28 Aug, John S. Dyson wrote:
> > Believe it or not, shared libs often hurt more than help.  Even with an
> > ideal scheme that is prelinked, a program can take MORE memory, not less.
> > We share the .text of programs even without using shared libs.  In the
> > case of shells, shared libs are usually a loose.  A rule of thumb that I use
> > is (These are only my opinions):
> [list elided]

[del]

> Has anyone considered building a shared library use-analysis
> tool, to attempt to optimise the ordering of objects within
> the various shared libraries, so that the "most used" core
> of modules were concatenated, probably at the front, with
> less commonly used functions falling to the tail, so they
> would mostly not be paged in?

I think the SVR3 Unix libc_s was built using a reordering process like
this.

_     ____________________________________________________________________
 |   / o / /  _  Bulte  email: wilko@yedi.iaf.nl http://www.tcja.nl/~wilko
 |/|/ / / /( (_) Arnhem, The Netherlands - Do, or do not. There is no 'try'
----------------------------------------------------------------------Yoda