Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84 SMI; site sun.uucp Path: utzoo!watmath!clyde!bonnie!akgua!whuxlm!harpo!decvax!decwrl!sun!guy 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. Lines: 12 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