From owner-freebsd-stable@freebsd.org Mon Jan 23 11:07:47 2017 Return-Path: Delivered-To: freebsd-stable@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 08049CBD907 for ; Mon, 23 Jan 2017 11:07:47 +0000 (UTC) (envelope-from tech-lists@zyxst.net) Received: from out1-smtp.messagingengine.com (out1-smtp.messagingengine.com [66.111.4.25]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id D140CF7B for ; Mon, 23 Jan 2017 11:07:46 +0000 (UTC) (envelope-from tech-lists@zyxst.net) Received: from compute4.internal (compute4.nyi.internal [10.202.2.44]) by mailout.nyi.internal (Postfix) with ESMTP id A05812047A for ; Mon, 23 Jan 2017 06:07:45 -0500 (EST) Received: from frontend1 ([10.202.2.160]) by compute4.internal (MEProxy); Mon, 23 Jan 2017 06:07:45 -0500 DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; d=zyxst.net; h= content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to:x-me-sender :x-me-sender:x-sasl-enc:x-sasl-enc; s=mesmtp; bh=7oy4nJZ+yR9f48D Wv6a/So/0Cdg=; b=BfXxs+6KqxgthDG1d397NFWyn1EtDDqOfZOxaNaR3IYyxim wSw8mo2r1KGkskUzyu9e0lzInBCsKh1QblcFuGDiqdDuJhD6UtuL1w6EP0zuBcp3 yOMnCcZ2cTHslrq6l/uqc8djOw7paIKscpGjWEmN/aRA2VHQgxLdRxsb+mx0= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; d= messagingengine.com; h=content-transfer-encoding:content-type :date:from:in-reply-to:message-id:mime-version:references :subject:to:x-me-sender:x-me-sender:x-sasl-enc:x-sasl-enc; s= smtpout; bh=7oy4nJZ+yR9f48DWv6a/So/0Cdg=; b=kR4L8u4bfoUbCc8HfaSk 3pKrzc3YPoIWgbk5kvD4TXB30rWjoIXaJRvWgko/W3nzuytpqjT70C2Z3Mnsisr6 MphZ/Q4M4+z9QgwKYjxl+4qQpPJNd3PibxdyfXHS/G+voxEra+M+/EyjkmumGgVU kbmVpiGYVnMpht66f0qM8GQ= X-ME-Sender: X-Sasl-enc: 6ld40yUfu55aKVilr7105ilOP46rQNBvMq1H/R8+v+LA 1485169665 Received: from pumpkin.growveg.org (pumpkin.growveg.org [82.70.91.101]) by mail.messagingengine.com (Postfix) with ESMTPA id 4304E7E404 for ; Mon, 23 Jan 2017 06:07:45 -0500 (EST) Subject: Re: Building Kernel and World with -j To: freebsd-stable@freebsd.org References: From: tech-lists Message-ID: <693bfe80-fb44-4a3f-c0c3-6fd79a0055b3@zyxst.net> Date: Mon, 23 Jan 2017 11:07:37 +0000 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:45.0) Gecko/20100101 Thunderbird/45.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.23 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, 23 Jan 2017 11:07:47 -0000 On 23/01/2017 06:57, Walter Parker wrote: > Hi, > > For decades there has always been a warning not to do parallel builds of > the kernel or the world (Linux kernel builds also suggest not to do this). > > Every once in a while, I see people post about 5 minutes. This only way I > can see this happening is by doing a parallel build (-j 16 on a Xeon > Monster box). > > Are parallel builds safe? If not, what are actual risk factors and can they > be mitigated? I remember warnings to the effect that while buildworld and buildkernel was safe, installworld and installkernel were not. I use -j32 on i7 monster boxes. -- J.