From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay1.mentorg.com (relay1.mentorg.com [192.94.38.131]) by mx1.pokylinux.org (Postfix) with ESMTP id 6AFF54C800A9 for ; Mon, 20 Jun 2011 17:57:30 -0500 (CDT) Received: from svr-orw-exc-10.mgc.mentorg.com ([147.34.98.58]) by relay1.mentorg.com with esmtp id 1QYnPN-0006RC-LJ from Tom_Rini@mentor.com for poky@yoctoproject.org; Mon, 20 Jun 2011 15:57:29 -0700 Received: from SVR-ORW-FEM-05.mgc.mentorg.com ([147.34.97.43]) by SVR-ORW-EXC-10.mgc.mentorg.com with Microsoft SMTPSVC(6.0.3790.4675); Mon, 20 Jun 2011 15:52:19 -0700 Received: from [172.30.80.125] (147.34.91.1) by svr-orw-fem-05.mgc.mentorg.com (147.34.97.43) with Microsoft SMTP Server id 14.1.289.1; Mon, 20 Jun 2011 15:57:29 -0700 Message-ID: <4DFFD045.3020003@mentor.com> Date: Mon, 20 Jun 2011 15:57:09 -0700 From: Tom Rini Organization: Mentor Graphics Corporation User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2.17) Gecko/20110424 Lightning/1.0b2 Thunderbird/3.1.10 MIME-Version: 1.0 To: References: <85e22915241def8ef365762345942443c0828025.1308366864.git.josh@linux.intel.com> <4DFC19AC.2010002@linux.intel.com> In-Reply-To: <4DFC19AC.2010002@linux.intel.com> X-Enigmail-Version: 1.1.1 X-OriginalArrivalTime: 20 Jun 2011 22:52:19.0579 (UTC) FILETIME=[B5A4ECB0:01CC2F9C] Subject: Re: [RFC PATCH 1/1] local.conf.sample: update suggestions for BB_NUMBER_THREADS and PARALLEL_MAKE X-BeenThere: poky@yoctoproject.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: Poky build system developer discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 20 Jun 2011 22:57:30 -0000 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit On 06/17/2011 08:21 PM, Darren Hart wrote: > > > On 06/17/2011 08:16 PM, Joshua Lock wrote: >> It's been suggested that BB_NUMBER_THREADS should be 2 * the number of cores >> and PARALLEL_MAKE should be equal to the number of cores available on the >> build machine. >> >> Update local.conf.sample to suggest this. >> >> Signed-off-by: Joshua Lock >> --- >> meta-yocto/conf/local.conf.sample | 4 +++- >> 1 files changed, 3 insertions(+), 1 deletions(-) >> >> diff --git a/meta-yocto/conf/local.conf.sample b/meta-yocto/conf/local.conf.sample >> index ea32b81..43d06e6 100644 >> --- a/meta-yocto/conf/local.conf.sample >> +++ b/meta-yocto/conf/local.conf.sample >> @@ -9,7 +9,9 @@ CONF_VERSION = "1" >> #SSTATE_DIR ?= "${TOPDIR}/sstate-cache" >> >> # Uncomment and set to allow bitbake to execute multiple tasks at once. >> -# For a quadcore, BB_NUMBER_THREADS = "4", PARALLEL_MAKE = "-j 4" would >> +# Recommended values are twice the number of processor cores for >> +# BB_NUMBER_THREADS and the number of processor cores for PARALLEL_MAKE >> +# For a quadcore, BB_NUMBER_THREADS = "8", PARALLEL_MAKE = "-j 4" would > > Hrm, where is this coming from? In my experience it works better the > other way around. We probably also need to be explicit about cores > versus threads. On my older quad-core AMD box, -j 6 / 4 threads is where it's at, and our testing / poking around on other hardware bears that out (for example my Dell M4400 laptop is -j 3 / 2 threads). That said, for much more beefy configurations, we use -j 16, and 12 threads (on an 8 core machine with 12GB mem). I think perhaps the best change here is to keep it at 1:1 in the sample (since we've also run into older hardware too) and explain that anywhere between 1:1 and 2*core:2*core could work best depending on setup, ymmv, etc. -- Tom Rini Mentor Graphics Corporation