64 lines
2.6 KiB
Groff
64 lines
2.6 KiB
Groff
.\" $NetBSD: kttcp.4,v 1.5 2008/04/30 13:10:54 martin Exp $
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.\"
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.\" Copyright (c) 2003 The NetBSD Foundation, Inc.
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.\" All rights reserved.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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.\" POSSIBILITY OF SUCH DAMAGE.
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.\"
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.Dd December 2, 2006
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.Dt KTTCP 4
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.Os
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.Sh NAME
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.Nm kttcp
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.Nd kernel support for testing network throughput
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.Sh SYNOPSIS
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.Cd "pseudo-device kttcp"
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.Sh DESCRIPTION
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This driver provides kernel support for testing network
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throughput from the perspective of the kernel.
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It is similar in spirit to the classic ttcp network benchmark
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program, the main difference being that with kttcp, the kernel is
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the source and sink of the data.
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.Pp
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Testing like this is useful for a few reasons:
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.Bl -enum
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.It
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This allows us to know what kind of performance we can
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expect from network applications that run in the kernel
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space, such as the NFS server or the NFS client.
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These applications don't have to move the data to/from userspace,
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and so benchmark programs which run in userspace don't give us an
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accurate model.
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.It
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Since data received is just thrown away, the receiver is very fast.
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This can provide better exercise for the sender at the other end.
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.It
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Since the
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.Nx
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kernel currently uses a run-to-completion
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scheduling model, kttcp provides a benchmark model where
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preemption of the benchmark program is not an issue.
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.El
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.Sh SEE ALSO
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.Pa pkgsrc/benchmarks/kttcp ,
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.Pa pkgsrc/benchmarks/ttcp
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