From owner-freebsd-stable@FreeBSD.ORG Mon Feb 10 14:57:13 2014 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 03DE1BF for ; Mon, 10 Feb 2014 14:57:13 +0000 (UTC) Received: from ozzie.tundraware.com (ozzie.tundraware.com [75.145.138.73]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id A1EA31501 for ; Mon, 10 Feb 2014 14:57:12 +0000 (UTC) Received: from [10.219.131.92] ([66.175.245.1]) (authenticated bits=0) by ozzie.tundraware.com (8.14.8/8.14.8) with ESMTP id s1AEuwSL058171 (version=TLSv1/SSLv3 cipher=DHE-RSA-CAMELLIA256-SHA bits=256 verify=NO) for ; Mon, 10 Feb 2014 08:56:59 -0600 (CST) (envelope-from tundra@tundraware.com) Message-ID: <52F8E8C6.2060909@tundraware.com> Date: Mon, 10 Feb 2014 08:57:10 -0600 From: Tim Daneliuk User-Agent: Mozilla/5.0 (X11; Linux i686; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 MIME-Version: 1.0 To: freebsd-stable@freebsd.org Subject: Re: And Here I Thought buildworld/makeworld Was IO Bound References: <52F84AF8.8050007@tundraware.com> <52F86768.9000109@googlemail.com> In-Reply-To: <52F86768.9000109@googlemail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.4.3 (ozzie.tundraware.com [75.145.138.73]); Mon, 10 Feb 2014 08:56:59 -0600 (CST) X-TundraWare-MailScanner-Information: Please contact the ISP for more information X-TundraWare-MailScanner-ID: s1AEuwSL058171 X-TundraWare-MailScanner: Found to be clean X-TundraWare-MailScanner-From: tundra@tundraware.com X-Spam-Status: No X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.17 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, 10 Feb 2014 14:57:13 -0000 On 02/09/2014 11:45 PM, army.of.root wrote: > Am 10/02/14 04:43, schrieb Tim Daneliuk: >> For some years now, I have been doing nightly builds of -STABLE >> on an old Pentium D machine with 2G of memory. Buildworld + 2 >> different kernels was taking in the neighborhood of 3 1/2 hours or so >> to run. >> >> I then upgraded the Mobo/CPU to a Haswell Quadcore I5-4570 and, sure >> enough, the build time for all the above came down to 30-35 mins or so. >> >> "So", says I, "I'll bet a faster drive would help considering all the >> scribbling to the disk the compilers and makes do". So, I upgdared to >> a Kingston SSD Now 300, 120G hard drive and he time to do the above >> went down to .... wait, it's still about 30-35 mins ???? >> >> So, I've tried fiddling with different values for -j on the make >> command line to little avail. Well, -j8 and -j16 show no real >> difference here. >> >> So is the bounding function here actually CPU not IO? Am I missing >> something? >> >> Thanks, >> >> P.S. Trying now with no -j arg on make invocation. > > Hi, > > the new machine has a lot more memory, I assume. Yes, 8G as opposed to 2G. I suppose I could bump it out to 16G and see if this makes any material difference with even more cache space. > The build probably will not even hit the disk due to caching. Well ... it has to hit the disk sooner or later. But, if the frequency of physical writes is low because of aggregated IO from the cache, I guess that would tend to make the whole business more CPU bound than IO bound. I just found this surprising. > > Also remember, the build process spawns probably millions of processes and that alone takes some time. > > And 30min sounds pretty great to me :D Yeah, I wonder what other people are seeing for a full buildworld/kernel and/or what the master machines at FreeBSD.org do in this regards. Would anyone else care to share with the class? > > Best regards -- ---------------------------------------------------------------------------- Tim Daneliuk tundra@tundraware.com PGP Key: http://www.tundraware.com/PGP/