From owner-cvs-src@FreeBSD.ORG Tue Jun 17 18:36:06 2008 Return-Path: Delivered-To: cvs-src@FreeBSD.ORG Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id DFDDB106567E; Tue, 17 Jun 2008 18:36:06 +0000 (UTC) (envelope-from ceri@submonkey.net) Received: from shrike.submonkey.net (cpc4-cdif1-0-0-cust805.cdif.cable.ntl.com [82.15.31.38]) by mx1.freebsd.org (Postfix) with ESMTP id 7673A8FC18; Tue, 17 Jun 2008 18:36:05 +0000 (UTC) (envelope-from ceri@submonkey.net) Received: from ceri by shrike.submonkey.net with local (Exim 4.69 (FreeBSD)) (envelope-from ) id 1K8g2F-00057R-F2; Tue, 17 Jun 2008 19:36:03 +0100 Date: Tue, 17 Jun 2008 19:36:03 +0100 From: Ceri Davies To: Maxim Sobolev , Ed Schouten , David Xu , src-committers@FreeBSD.ORG, cvs-src@FreeBSD.ORG, cvs-all@FreeBSD.ORG Message-ID: <20080617183603.GD24940@submonkey.net> References: <200806170633.m5H6XMJH084600@repoman.freebsd.org> <20080617134828.GA30076@zim.MIT.EDU> <20080617140600.GE1176@hoeg.nl> <4857D508.8070907@FreeBSD.org> <20080617170755.GA30958@zim.MIT.EDU> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="4ZLFUWh1odzi/v6L" Content-Disposition: inline In-Reply-To: <20080617170755.GA30958@zim.MIT.EDU> X-PGP: finger ceri@FreeBSD.org User-Agent: Mutt/1.5.17 (2007-11-01) Sender: Ceri Davies Cc: Subject: Re: cvs commit: src/include Makefile spawn.h unistd.h src/lib/libc/gen Makefile.inc Symbol.map exec.3 exec.c posix_spawn.c X-BeenThere: cvs-src@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: CVS commit messages for the src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 17 Jun 2008 18:36:07 -0000 --4ZLFUWh1odzi/v6L Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Jun 17, 2008 at 01:07:55PM -0400, David Schultz wrote: > On Tue, Jun 17, 2008, Maxim Sobolev wrote: > > Ed Schouten wrote: > > >* David Schultz wrote: > > >>I have no objections to this, but doesn't it defeat the whole > > >>purpose to implement posix_spawn() as a library function that just > > >>calls fork/exec? > > > > > >When (if?) applications start to use posix_spawn() we may decide to mo= ve > > >it into the kernel at any time. It should be okay for now. > >=20 > > Are there any benefits of doing it in the kernel vs. doing it via fork+= exec? >=20 > The only reason spawn exists is to better support platforms where > fork is slow, so implementing it in terms of fork/exec defeats the > purpose and potentially tricks configure scripts into making > incorrect assumptions about performance tradeoffs. It also helps on platforms like Solaris which refuse to overcommit, where a large process, say a 4GB JVM, would otherwise need another 4GB of swap free in order for fork to succeed. Ceri --=20 That must be wonderful! I don't understand it at all. -- Moliere --4ZLFUWh1odzi/v6L Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (FreeBSD) iD8DBQFIWAQSocfcwTS3JF8RAkXYAJwPFtiRK1KEtaFn2V1qEr/XuZuwKwCghrPQ Y6mnByEkN6DQRB4Auh8WN8I= =c1AZ -----END PGP SIGNATURE----- --4ZLFUWh1odzi/v6L--