From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Bavier Subject: Re: OpenBLAS and performance Date: Wed, 20 Dec 2017 13:02:41 -0600 Message-ID: <20171220130241.52f733aa@centurylink.net> References: <20171219104956.GB806@thebird.nl> <87tvwl7h4w.fsf@albion.it.manchester.ac.uk> <87h8sl78vp.fsf@albion.it.manchester.ac.uk> <20171220172215.GA7926@thebird.nl> <87d139xo3v.fsf@elephly.net> <20171220192802.GA8426@thebird.nl> <87bmitxj81.fsf@elephly.net> <20171220203215.GA8737@thebird.nl> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: Received: from eggs.gnu.org ([2001:4830:134:3::10]:47192) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eRod2-000486-0L for guix-devel@gnu.org; Wed, 20 Dec 2017 19:22:29 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eRocx-0006CL-Vj for guix-devel@gnu.org; Wed, 20 Dec 2017 19:22:27 -0500 Received: from mail.centurylink.net ([205.219.233.9]:15315 helo=smtp.centurylink.net) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eRocx-0006BY-QK for guix-devel@gnu.org; Wed, 20 Dec 2017 19:22:23 -0500 In-Reply-To: <20171220203215.GA8737@thebird.nl> List-Id: "Development of GNU Guix and the GNU System distribution." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: guix-devel-bounces+gcggd-guix-devel=m.gmane.org@gnu.org Sender: "Guix-devel" To: Pjotr Prins Cc: guix-devel@gnu.org, Dave Love On Wed, 20 Dec 2017 21:32:15 +0100 Pjotr Prins wrote: > On Wed, Dec 20, 2017 at 09:00:46PM +0100, Ricardo Wurmus wrote: > > > I do think we need to default to a conservative openblas for general > > > use. Question is how we make it fly on dedicated hardware. > > > > Have you tried preloading the special library with LD_PRELOAD? > > It is not a question of what I can do. It is a question of how we give > other people the benefit of optimized libs in an elegant way. Related only to this specific case of BLAS libraries, and not to the general idea of optimized libraries: I recently discovered "FlexiBLAS" from the Max Planck Institute https://www.mpi-magdeburg.mpg.de/projects/flexiblas which I thought might be useful for Guix. It lets one choose the desired BLAS backend at runtime via a configuration file or environment variables. In it's current state it needs a little configuration before use, but I think with a little work we could make picking a BLAS implementation as easy as, e.g. guix package -i python-numpy openblas-haswellp or guix package -i python-numpy atlas-24 where the python-numpy package is the same in both cases, built with a "flexiblas" input. > Performance matters in some circles. This should let people choose the BLAS implementation that is best for their hardware/application. It could also let Guix packages use vendor-supplied BLAS libraries. Just a thought, `~Eric