From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.chez-thomas.org (hermes.mlbassoc.com [64.234.241.98]) by yocto-www.yoctoproject.org (Postfix) with ESMTP id 79E29E00559 for ; Mon, 31 Oct 2011 10:39:16 -0700 (PDT) Received: by mail.chez-thomas.org (Postfix, from userid 999) id D1CC7166019C; Mon, 31 Oct 2011 11:39:07 -0600 (MDT) X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on hermes.chez-thomas.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=4.0 tests=ALL_TRUSTED,BAYES_00 autolearn=unavailable version=3.3.2 Received: from hermes.chez-thomas.org (localhost.localdomain [127.0.0.1]) by mail.chez-thomas.org (Postfix) with ESMTP id 64B171660106; Mon, 31 Oct 2011 11:39:06 -0600 (MDT) Message-ID: <4EAEDD3A.9070601@mlbassoc.com> Date: Mon, 31 Oct 2011 11:39:06 -0600 From: Gary Thomas User-Agent: Mozilla/5.0 (X11; Linux i686; rv:7.0.1) Gecko/20110930 Thunderbird/7.0.1 MIME-Version: 1.0 To: "Robert P. J. Day" References: <4EAD7542.4070204@gna.org> <4EAED7B0.4050909@windriver.com> In-Reply-To: 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: Mon, 31 Oct 2011 17:39:17 -0000 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit 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. -- ------------------------------------------------------------ Gary Thomas | Consulting for the MLB Associates | Embedded world ------------------------------------------------------------