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From: guy@sun.uucp (Guy Harris)
Newsgroups: net.unix,net.unix-wizards
Subject: Re: Help Measuring Fork/Exec Overhead
Message-ID: <2697@sun.uucp>
Date: Sat, 24-Aug-85 02:19:02 EDT
Article-I.D.: sun.2697
Posted: Sat Aug 24 02:19:02 1985
Date-Received: Sun, 25-Aug-85 12:48:16 EDT
References: <782@druak.UUCP> <907@brl-tgr.ARPA>
Organization: Sun Microsystems, Inc.
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Xref: watmath net.unix:5460 net.unix-wizards:14544

> UNIX System V Release 2 fork() overhead is fairly small if you
> don't modify much data in the child process, because it uses
> "copy on write" to avoid unnecessary copying of data from parent
> into the child process.

UNIX System V Release 2 VAX Version 2 (3B20 Version X, iAPX286 Version Y,
M68K version Z, etc., for some X, Y, Z, etc.) fork() overhead, anyway.
S5R2V1 still uses traditional UNIX code for fork() (as might *any* UNIX on a
non-paged machine, since there's not much point in copy-on-write if the
smallest unit that can be mapped is an entire segment).

	Guy Harris