From owner-freebsd-hackers Mon Feb 12 22:47:52 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from level3.dynacom.net (level3.dynacom.net [206.107.213.213]) by hub.freebsd.org (Postfix) with SMTP id 725B337B491 for ; Mon, 12 Feb 2001 22:47:50 -0800 (PST) Received: (qmail 11442 invoked by uid 0); 13 Feb 2001 06:47:49 -0000 Received: from dsl1-160.dynacom.net (HELO urx.com) (206.159.132.160) by mail.urx.com with SMTP; 13 Feb 2001 06:47:49 -0000 Message-ID: <3A88D893.ED6442EA@urx.com> Date: Mon, 12 Feb 2001 22:47:47 -0800 From: Kent Stewart Reply-To: kstewart@urx.com Organization: Dynacom X-Mailer: Mozilla 4.76 [en] (Windows NT 5.0; U) X-Accept-Language: en MIME-Version: 1.0 To: Jordan Hubbard Cc: Danny Braniss , freebsd-hackers@FreeBSD.ORG Subject: Re: soft updates performance References: <81045.982046200@winston.osd.bsdi.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Jordan Hubbard wrote: > > > One other point that I would like to understand is why -j4 takes > > longer on all of my systems. That goes against what everyone claims > > should happen. > > With how many running processors? If you're running -j4 on a > uniprocessor system, you're only introducing competition for already > scarce CPU resources, though -j2 can be a speedup since this allows > one target build to run while another is in an I/O wait. I've only > seen a speedup with -j4 when using at least 2 CPUs. It was a uniprocessor system. The folklore has it doing more but all I ever saw it produce was more competition, which resulted in a longer running buildworld. Kent -- Kent Stewart Richland, WA mailto:kbstew99@hotmail.com http://kstewart.urx.com/kstewart/index.html FreeBSD News http://daily.daemonnews.org/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message