From owner-freebsd-stable@FreeBSD.ORG Mon Oct 16 23:30:25 2006 Return-Path: X-Original-To: freebsd-stable@freebsd.org Delivered-To: freebsd-stable@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 3855116A407 for ; Mon, 16 Oct 2006 23:30:25 +0000 (UTC) (envelope-from kstewart@owt.com) Received: from smtp.owt.com (smtp.owt.com [204.118.6.19]) by mx1.FreeBSD.org (Postfix) with ESMTP id E237043D58 for ; Mon, 16 Oct 2006 23:30:24 +0000 (GMT) (envelope-from kstewart@owt.com) Received: from topaz-out (owt-207-41-94-233.owt.com [207.41.94.233]) by smtp.owt.com (8.12.8/8.12.8) with ESMTP id k9GNUIhf015962; Mon, 16 Oct 2006 16:30:18 -0700 From: Kent Stewart To: "Nikolas Britton" Date: Mon, 16 Oct 2006 16:30:23 -0700 User-Agent: KMail/1.9.4 References: <20061013143130.GW491@dev.null.cz> <200610131347.41023.kstewart@owt.com> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200610161630.23776.kstewart@owt.com> Cc: freebsd-stable@freebsd.org Subject: Re: FreeBSD and "make -j# buildworld" usability X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 16 Oct 2006 23:30:25 -0000 On Monday 16 October 2006 12:46, Nikolas Britton wrote: > On 10/13/06, Kent Stewart wrote: > > On Friday 13 October 2006 07:31, Buki wrote: > > > Hi, > > > > > > I searched the archives and web a little but found many different > > > opinions on stability/usability of using make -j# with buildworld > > > (and buildkernel). > > > > > > So I am asking if it is a good idea to use make -j on production > > > boxes. > > > > I tested buildworlds with different values for -j. On single > > processors, using a script that basically looked like > > > > time make -j? ... > > > > yielded fastest builds when I didn't specify a value for -j. On > > dual cpu's a value around -j8 yielded the fastest build. > > That's odd, your results don't jive with this: > http://people.freebsd.org/~fsmp/SMP/akgraph-a/graph1.html His results are too old to use as a reference. My system was the next step up and is also too old to consider current. His cpus were Intel Pentium pro 200MHZ and the bus speed alone (66MHz) would make a big difference. Only having 64MB of memory may also skew the results. My system was 2 Intel pIII 866's and had 256-512MB of SDRAM or DDR memory. Kent > > Although that report is quite old... My general rule of thumb for -j > is n +1, where n equals the total number of cpu cores. This is > generally enough to keep to processor(s) occupied without over > stressing the system. Maybe n * 2 is more appropriate, can you post > the results from your test? -- Kent Stewart Richland, WA http://www.soyandina.com/ "I am Andean project". http://users.owt.com/kstewart/index.html