From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by yocto-www.yoctoproject.org (Postfix) with ESMTP id 2D02BE006BA for ; Tue, 15 Nov 2011 15:51:32 -0800 (PST) Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga102.jf.intel.com with ESMTP; 15 Nov 2011 15:51:31 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.67,352,1309762800"; d="scan'208";a="76048578" Received: from unknown (HELO envy.home) ([10.255.12.20]) by orsmga001.jf.intel.com with ESMTP; 15 Nov 2011 15:51:31 -0800 Message-ID: <4EC2FB03.4090701@linux.intel.com> Date: Tue, 15 Nov 2011 15:51:31 -0800 From: Darren Hart User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:7.0) Gecko/20110927 Thunderbird/7.0 MIME-Version: 1.0 To: "Rifenbark, Scott M" References: <4EAD7542.4070204@gna.org> <4EAED7B0.4050909@windriver.com> <4EAEDD3A.9070601@mlbassoc.com> <4EB2D044.7050207@linux.intel.com> <41DEA4B02DBDEF40A0F3B6D0DDB1237916EB04E7@ORSMSX101.amr.corp.intel.com> In-Reply-To: <41DEA4B02DBDEF40A0F3B6D0DDB1237916EB04E7@ORSMSX101.amr.corp.intel.com> X-Enigmail-Version: 1.3.3 Cc: "yocto@yoctoproject.org" Subject: Re: what's the proper value for BB_NUMBER_THREADS? X-BeenThere: yocto@yoctoproject.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: Discussion of all things Yocto List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 15 Nov 2011 23:51:32 -0000 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit On 11/15/2011 03:08 PM, Rifenbark, Scott M wrote: > I haven't heard more on this. Should I adjust the documents to > suggest 2x for both these variables? I think that's a reasonable thing to do, yes. -- Darren > > Scott > > -----Original Message----- From: yocto-bounces@yoctoproject.org > [mailto:yocto-bounces@yoctoproject.org] On Behalf Of Robert P. J. > Day Sent: Thursday, November 03, 2011 10:42 AM To: Darren Hart Cc: > yocto@yoctoproject.org Subject: Re: [yocto] what's the proper value > for BB_NUMBER_THREADS? > > On Thu, 3 Nov 2011, Darren Hart wrote: > >> >> >> On 10/31/2011 10:39 AM, Gary Thomas wrote: >>> On 2011-10-31 11:25, Robert P. J. Day wrote: >>>> On Mon, 31 Oct 2011, Mark Hatle wrote: >>>> >>>>> On 10/30/11 11:15 AM, Robert P. J. Day wrote: >>>>>> On Sun, 30 Oct 2011, Christian Gagneraud wrote: >>>>>> >>>>>>> On 30/10/11 15:32, Robert P. J. Day wrote: >>>>>>>> >>>>>>>> all the docs recommend twice the number of cores >>>>>>>> (AFAICT), yet the template local.conf file suggests >>>>>>>> that, for a quad core, the value of 4 would be >>>>>>>> appropriate. shouldn't that say 8? same with >>>>>>>> PARALLEL_MAKE? >>>>>>> >>>>>>> Hi Robert, >>>>>>> >>>>>>> The Poky ref manual says (rule of thumb) x2 for >>>>>>> BB_NUMBER_THREADS, and x1.5 for PARALLEL_MAKE. >>>>>> >>>>>> if that's the case, anyone object to my submitting a patch >>>>>> to update local.conf.sample appropriately? >>>>>> >>>>>> rday >>>>>> >>>>> >>>>> I agree the manual and local.conf files should match. The >>>>> issue seems to be that the perfect values are subjective. >>>>> Things like memory, disk speed, chipset latency, and of >>>>> course processor speed/cores all affect the optimal setting. >>>>> But we do need a consistent rule of thumb.. I myself usually >>>>> use x2 for both THREADS and MAKE. >>>> >>>> that's what i would normally use, assuming that having an >>>> overly high value for either of those settings can't possibly >>>> hurt. if that's the consensus, i can adjust the references to >>>> say 2x everywhere that i know of. just let me know. >>> >>> Look back in the archives - I think it was Richard that did a >>> fairly extensive study of this and he (whoever it was) found that >>> there were saturation points and trying to get beyond them had a >>> negative impact. >> >> 2x on each works well up to about 12 in my experience. Richard has >> found benefits using 24 on a similar system with more memory. >> However, if you aren't building on a monster machine, then 2x >> serves as a reasonable rule of thumb. > > since i vaguely recall that i was the one who asked about this, i can > submit a patch for this unless someone else already wants to. i can > see that the places to change would be in some of the docs, as well > as the comment in local.conf.sample. > > anyone else want to take care of that? anyone? bueller? > > rday > -- Darren Hart Intel Open Source Technology Center Yocto Project - Linux Kernel