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Date: Sun, 7 Jul 2002 15:41:13 -0700
From: Jon Mini <baka@elvis.mu.org>
To: Juli Mallett <jmallett@FreeBSD.ORG>
Cc: Mike Silbersack <silby@silby.com>,
	Alfred Perlstein <bright@mu.org>, net@FreeBSD.ORG
Subject: Re: the incredible shrinking socket
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References: <20020707083710.GM97638@elvis.mu.org> <20020707143846.A13771-100000@patrocles.silby.com> <20020707131421.A50599@FreeBSD.ORG>
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On Sun, Jul 07, 2002 at 01:14:21PM -0700, Juli Mallett wrote:
> * De: Mike Silbersack <silby@silby.com> [ Data: 2002-07-07 ]
> 	[ Subjecte: Re: the incredible shrinking socket ]
> > 
> > On Sun, 7 Jul 2002, Alfred Perlstein wrote:
> > 
> > > Some time ago I noticed that there appeared to be several members
> > > of struct socket that were either only used by listen sockets or
> > > only used by data sockets.
> > >
> > > I've taken a stab at unionizing the members and we wind up saving
> > > 28 bytes per socket on i386, and probably nearly double that on
> > > any 64 bit platform.  That's ~15%, which isn't too shabby.
> > 
> > Unions are ooogly.  Would it be possible to seperate listen-only
> > structures out into a seperate struct instead with a pointer to it?
> 
> If you're going to do that why not just end the struct with
> 	char foo[1];
> 
> And overlay the unique bits at the end?

Because that is even more oogly than a union.

-- 
Jonathan Mini <mini@freebsd.org>
http://www.freebsd.org/

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