From owner-freebsd-stable@FreeBSD.ORG Fri Oct 13 17:42:50 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 5CA2516A415 for ; Fri, 13 Oct 2006 17:42:50 +0000 (UTC) (envelope-from drosih@rpi.edu) Received: from smtp5.server.rpi.edu (smtp5.server.rpi.edu [128.113.2.225]) by mx1.FreeBSD.org (Postfix) with ESMTP id 1AC5243D70 for ; Fri, 13 Oct 2006 17:42:38 +0000 (GMT) (envelope-from drosih@rpi.edu) Received: from [128.113.24.47] (gilead.netel.rpi.edu [128.113.24.47]) by smtp5.server.rpi.edu (8.13.1/8.13.1) with ESMTP id k9DHgUp3019299; Fri, 13 Oct 2006 13:42:30 -0400 Mime-Version: 1.0 Message-Id: In-Reply-To: <20061013143130.GW491@dev.null.cz> References: <20061013143130.GW491@dev.null.cz> Date: Fri, 13 Oct 2006 13:42:29 -0400 To: Buki , freebsd-stable@freebsd.org From: Garance A Drosihn Content-Type: text/plain; charset="us-ascii" ; format="flowed" X-CanItPRO-Stream: default X-RPI-SA-Score: undef - spam-scanning disabled X-Scanned-By: CanIt (www . canit . ca) Cc: 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: Fri, 13 Oct 2006 17:42:50 -0000 At 4:31 PM +0200 10/13/06, 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. It depends on the target. There are no bugs in 'make -j' per se, but a makefile target has to pay attention to some extra details if that specific target is going to work reliably when using '-j'. You are asking about two different targets. It should be safe to use -j on 'make buildworld', and in fact I do that all the time. Most of my systems are dual-CPU or dual-core, and -j makes the buildworld go significantly faster. *Occasionally* that does not work (particularly if you are following the freebsd-current branch), but any problems in that target are fixed as soon as they are noticed. In the past it has not been safe to use -j on 'make buildkernel', so I never do that. You probably wouldn't gain all that much time by using -j on 'make buildkernel' -- or at least not as much time as you'll lose the first time it does not work right. So I'm sure you see plenty of people say "DON'T DO THAT!!" when it comes to -j and 'make buildkernel'. Some work is now being done so that -j can be reliably used on 'make buildkernel', but I don't think that has been completed yet. For now, my own opinion is that you're not going to save enough time with -j on buildkernel to justify the amount of time you'll lose if it does not work. That is my answer for today, but I expect -j for buildkernel will be more reliable as time goes on. -- Garance Alistair Drosehn = gad@gilead.netel.rpi.edu Senior Systems Programmer or gad@freebsd.org Rensselaer Polytechnic Institute or drosih@rpi.edu