Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!lavaca.uh.edu!uhnix1!sugar!ficc!peter From: peter@ficc.uu.net (Peter da Silva) Newsgroups: comp.arch Subject: Re: Why fork? (long, was Re: IBM PC prehistory) Message-ID: Date: 18 Jan 90 16:03:51 GMT References: <610@ssp11.idca.tds.philips.nl> <952@dms.UUCP> <1239@cirrusl.UUCP> Reply-To: peter@ficc.uu.net (Peter da Silva) Organization: Xenix Support, FICC Lines: 9 > Actually, the Berkley folks have a system call vfork(), which does the > fork/exec in one operation. But of course, it is not compatible with Sys V. I thought it sort of deferred the actual fork until the exec occurred, just duplicating the file table and other "cheap" resources. And of course once you have a VM system fork() is just fine and vfork() is a meaningless optimisation. Just mark all the data pages copy-on-write. So why didn't they put vfork() in 2BSD? -- _--_|\ Peter da Silva. +1 713 274 5180. . / \ \_.--._/ Xenix Support -- it's not just a job, it's an adventure! v "Have you hugged your wolf today?" `-_-'