*BSD News Article 73698


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From: Terry Lambert <terry@lambert.org>
Newsgroups: comp.os.linux.networking,comp.unix.bsd.netbsd.misc,comp.unix.bsd.freebsd.misc
Subject: Re: TCP latency
Date: Sun, 14 Jul 1996 17:49:58 -0700
Organization: Me
Lines: 24
Message-ID: <31E995B6.573A3461@lambert.org>
References: <4paedl$4bm@engnews2.eng.sun.com>
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	  <Du681x.2Gy@kroete2.freinet.de> <31DFEB02.41C67EA6@dyson.iquest.net>
	  <4rpdtn$30b@symiserver2.symantec.com> <x7ohlq78wt.fsf@oberon.di.fc.ul.pt>
	  <Pine.LNX.3.91.960709020017.19115I-100000@reflections.mindspring.com>
	  <4s12la$pm8@enomem.lkg.dec.com>
	  <m24tnf9f69.fsf@frob.mlm.extern.lrz-muenchen.de> <4sbhrq$msh@enomem.lkg.dec.com>
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Matt Thomas wrote:
] In article <m24tnf9f69.fsf@frob.mlm.extern.lrz-muenchen.de>,
]         Andi Kleen <andi@mlm.extern.lrz-muenchen.de> writes:
] 
] >I think a mmap() interface to sockets would be more elegant (and
] >you could do exactly the same thing)
] 
] I can't see how mmap() would map to a socket.  Unlike a file,
] you can't directly address portions of a communication stream.
] What would lseek do?  Sockets have semantics that are very
] sequential in nature.  mmap is not a good fit.
] 
] How would you use mmap on a pipe?

You would map the buffer into both the source and target
applications address spaces, and avoid the user->kernel->user
copies.


                                        Terry Lambert
                                        terry@lambert.org
---
Any opinions in this posting are my own and not those of my present
or previous employers.