165 lines
6.6 KiB
Perl
165 lines
6.6 KiB
Perl
|
.\" Copyright (c) 1985 The Regents of the University of California.
|
||
|
|
.\" All rights reserved.
|
||
|
|
.\"
|
||
|
|
.\" Redistribution and use in source and binary forms, with or without
|
||
|
|
.\" modification, are permitted provided that the following conditions
|
||
|
|
.\" are met:
|
||
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
||
|
|
.\" notice, this list of conditions and the following disclaimer.
|
||
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
||
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
||
|
|
.\" documentation and/or other materials provided with the distribution.
|
||
|
|
.\" 3. All advertising materials mentioning features or use of this software
|
||
|
|
.\" must display the following acknowledgement:
|
||
|
|
.\" This product includes software developed by the University of
|
||
|
|
.\" California, Berkeley and its contributors.
|
||
|
|
.\" 4. Neither the name of the University nor the names of its contributors
|
||
|
|
.\" may be used to endorse or promote products derived from this software
|
||
|
|
.\" without specific prior written permission.
|
||
|
|
.\"
|
||
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
||
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
||
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
||
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
||
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
||
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
||
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
||
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
||
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
||
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
||
|
|
.\" SUCH DAMAGE.
|
||
|
|
.\"
|
||
|
|
.\" @(#)7.t 5.1 (Berkeley) 4/17/91
|
||
|
|
.\"
|
||
|
|
.ds RH Conclusions
|
||
|
|
.NH
|
||
|
|
Conclusions
|
||
|
|
.PP
|
||
|
|
4.2BSD, while functionally superior to 4.1BSD, lacked much of the
|
||
|
|
performance tuning required of a good system. We found that
|
||
|
|
the distributed system spent 10-20% more time in the kernel than
|
||
|
|
4.1BSD. This added overhead combined with problems with several
|
||
|
|
user programs severely limited the overall performance of the
|
||
|
|
system in a general timesharing environment.
|
||
|
|
.PP
|
||
|
|
Changes made to the system since the 4.2BSD distribution have
|
||
|
|
eliminated most of the
|
||
|
|
added system overhead by replacing old algorithms
|
||
|
|
or introducing additional cacheing schemes.
|
||
|
|
The combined caches added to the name translation process
|
||
|
|
reduce the average cost of translating a pathname to an inode by more than 50%.
|
||
|
|
These changes reduce the percentage of time spent running
|
||
|
|
in the system by nearly 9%.
|
||
|
|
.PP
|
||
|
|
The use of silo input on terminal ports only when necessary
|
||
|
|
has allowed the system to avoid a large amount of software interrupt
|
||
|
|
processing. Observations show that the system is forced to
|
||
|
|
field about 25% fewer interrupts than before.
|
||
|
|
.PP
|
||
|
|
The kernel
|
||
|
|
changes, combined with many bug fixes, make the system much more
|
||
|
|
responsive in a general timesharing environment.
|
||
|
|
The 4.3BSD Berkeley UNIX system now appears
|
||
|
|
capable of supporting loads at least as large as those supported under
|
||
|
|
4.1BSD while providing all the new interprocess communication, networking,
|
||
|
|
and file system facilities.
|
||
|
|
.nr H2 1
|
||
|
|
.ds RH Acknowledgements
|
||
|
|
.SH
|
||
|
|
\s+2Acknowledgements\s0
|
||
|
|
.PP
|
||
|
|
We would like to thank Robert Elz for sharing his ideas and
|
||
|
|
his code for cacheing system wide names and searching the process table.
|
||
|
|
We thank Alan Smith for initially suggesting the use of a
|
||
|
|
capability based cache.
|
||
|
|
We also acknowledge
|
||
|
|
George Goble who dropped many of our changes
|
||
|
|
into his production system and reported back fixes to the
|
||
|
|
disasters that they caused.
|
||
|
|
The buffer cache read-ahead trace package was based
|
||
|
|
on a program written by Jim Lawson. Ralph Campbell
|
||
|
|
implemented several of the C library changes. The original
|
||
|
|
version of the Internet daemon was written by Bill Joy.
|
||
|
|
In addition,
|
||
|
|
we would like to thank the many other people that contributed
|
||
|
|
ideas, information, and work while the system was undergoing change.
|
||
|
|
.ds RH References
|
||
|
|
.nr H2 1
|
||
|
|
.sp 2
|
||
|
|
.SH
|
||
|
|
\s+2References\s-2
|
||
|
|
.LP
|
||
|
|
.IP [Cabrera84] 20
|
||
|
|
Luis Felipe Cabrera, Eduard Hunter, Michael J. Karels, and David Mosher,
|
||
|
|
``A User-Process Oriented Performance Study of Ethernet Networking Under
|
||
|
|
Berkeley UNIX 4.2BSD,''
|
||
|
|
Research Report No. UCB/CSD 84/217, University of California,
|
||
|
|
Berkeley, December 1984.
|
||
|
|
.IP [Cabrera85] 20
|
||
|
|
Luis Felipe Cabrera, Michael J. Karels, and David Mosher,
|
||
|
|
``The Impact of Buffer Management on Networking Software Performance
|
||
|
|
in Berkeley UNIX 4.2BSD: A Case Study,''
|
||
|
|
Proceedings of the Summer Usenix Conference, Portland, Oregon,
|
||
|
|
June 1985, pp. 507-517.
|
||
|
|
.IP [GADS85] 20
|
||
|
|
GADS (Gateway Algorithms and Data Structures Task Force),
|
||
|
|
``Toward an Internet Standard for Subnetting,'' RFC-940,
|
||
|
|
Network Information Center, SRI International,
|
||
|
|
April 1985.
|
||
|
|
.IP [Joy80] 20
|
||
|
|
Joy, William,
|
||
|
|
``Comments on the performance of UNIX on the VAX'',
|
||
|
|
Computer System Research Group, U.C. Berkeley.
|
||
|
|
April 1980.
|
||
|
|
.IP [Kashtan80] 20
|
||
|
|
Kashtan, David L.,
|
||
|
|
``UNIX and VMS, Some Performance Comparisons'',
|
||
|
|
SRI International. February 1980.
|
||
|
|
.IP [Lankford84] 20
|
||
|
|
Jeffrey Lankford,
|
||
|
|
``UNIX System V and 4BSD Performance,''
|
||
|
|
\fIProceedings of the Salt Lake City Usenix Conference\fP,
|
||
|
|
pp 228-236, June 1984.
|
||
|
|
.IP [Leffler84] 20
|
||
|
|
Sam Leffler, Mike Karels, and M. Kirk McKusick,
|
||
|
|
``Measuring and Improving the Performance of 4.2BSD,''
|
||
|
|
\fIProceedings of the Salt Lake City Usenix Conference\fP,
|
||
|
|
pp 237-252, June 1984.
|
||
|
|
.IP [McKusick85]
|
||
|
|
M. Kirk McKusick, Mike Karels, and Samual Leffler,
|
||
|
|
``Performance Improvements and Functional Enhancements in 4.3BSD''
|
||
|
|
\fIProceedings of the Portland Usenix Conference\fP,
|
||
|
|
pp 519-531, June 1985.
|
||
|
|
.IP [Mockapetris83] 20
|
||
|
|
Paul Mockapetris, ``Domain Names \- Implementation and Schedule,''
|
||
|
|
Network Information Center, SRI International,
|
||
|
|
RFC-883,
|
||
|
|
November 1983.
|
||
|
|
.IP [Mogul84] 20
|
||
|
|
Jeffrey Mogul, ``Broadcasting Internet Datagrams,'' RFC-919,
|
||
|
|
Network Information Center, SRI International,
|
||
|
|
October 1984.
|
||
|
|
.IP [Mosher80] 20
|
||
|
|
Mosher, David,
|
||
|
|
``UNIX Performance, an Introspection'',
|
||
|
|
Presented at the Boulder, Colorado Usenix Conference, January 1980.
|
||
|
|
Copies of the paper are available from
|
||
|
|
Computer System Research Group, U.C. Berkeley.
|
||
|
|
.IP [Nagle84] 20
|
||
|
|
John Nagle, ``Congestion Control in IP/TCP Internetworks,'' RFC-896,
|
||
|
|
Network Information Center, SRI International,
|
||
|
|
January 1984.
|
||
|
|
.IP [Ritchie74] 20
|
||
|
|
Ritchie, D. M. and Thompson, K.,
|
||
|
|
``The UNIX Time-Sharing System'',
|
||
|
|
CACM 17, 7. July 1974. pp 365-375
|
||
|
|
.IP [Shannon83] 20
|
||
|
|
Shannon, W.,
|
||
|
|
private communication,
|
||
|
|
July 1983
|
||
|
|
.IP [Walsh84] 20
|
||
|
|
Robert Walsh and Robert Gurwitz,
|
||
|
|
``Converting BBN TCP/IP to 4.2BSD,''
|
||
|
|
\fIProceedings of the Salt Lake City Usenix Conference\fP,
|
||
|
|
pp 52-61, June 1984.
|