From owner-freebsd-questions@FreeBSD.ORG Thu Dec 1 21:26:44 2005 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id E928916A41F for ; Thu, 1 Dec 2005 21:26:44 +0000 (GMT) (envelope-from kris@obsecurity.org) Received: from elvis.mu.org (elvis.mu.org [192.203.228.196]) by mx1.FreeBSD.org (Postfix) with ESMTP id B1F1443D60 for ; Thu, 1 Dec 2005 21:26:39 +0000 (GMT) (envelope-from kris@obsecurity.org) Received: from obsecurity.dyndns.org (elvis.mu.org [192.203.228.196]) by elvis.mu.org (Postfix) with ESMTP id E4D321A4DA1; Thu, 1 Dec 2005 13:26:38 -0800 (PST) Received: by obsecurity.dyndns.org (Postfix, from userid 1000) id 49C1B515B4; Thu, 1 Dec 2005 16:26:38 -0500 (EST) Date: Thu, 1 Dec 2005 16:26:38 -0500 From: Kris Kennaway To: Jose Borquez Message-ID: <20051201212638.GB6690@xor.obsecurity.org> References: <438F68ED.7000709@sbcglobal.net> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="eJnRUKwClWJh1Khz" Content-Disposition: inline In-Reply-To: <438F68ED.7000709@sbcglobal.net> User-Agent: Mutt/1.4.2.1i Cc: FreeBSD Questions Subject: Re: make buildworld run twice as fast X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 01 Dec 2005 21:26:45 -0000 --eJnRUKwClWJh1Khz Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Dec 01, 2005 at 01:19:41PM -0800, Jose Borquez wrote: > I recently rebuilt my FreeBSD system from sources and it took around 2=20 > hours on an old PIII 800MHz pc to run "make buildworld". If I include=20 > the -j option to run multiple processes as once such as "make -j2=20 > buildworld" does that mean it would finish in half the time? No, that would only be true if you were using less than 50% of your resources (e.g. CPU) - for example, if your system has 2 CPUs. Otherwise, on a single CPU machine you are already using close to 100% of CPU, but you may still achieve a few percent speed-up since e.g. one compiler process can be running while another process is blocked waiting for disk I/O. However, this is balanced against increased kernel overhead and memory use. Kris --eJnRUKwClWJh1Khz Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2 (FreeBSD) iD8DBQFDj2qNWry0BWjoQKURAnPzAKCG0Njt9aQD04Umw2BISZXL5BqfAwCfcDuF g5HlQoBiQnp4hQNubh+Q7Wk= =B59r -----END PGP SIGNATURE----- --eJnRUKwClWJh1Khz--