From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pjotr Prins Subject: Re: OpenBLAS and performance Date: Wed, 20 Dec 2017 18:22:15 +0100 Message-ID: <20171220172215.GA7926@thebird.nl> References: <20171219104956.GB806@thebird.nl> <87tvwl7h4w.fsf@albion.it.manchester.ac.uk> <87h8sl78vp.fsf@albion.it.manchester.ac.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from eggs.gnu.org ([2001:4830:134:3::10]:59341) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eRi7C-00049A-Vm for guix-devel@gnu.org; Wed, 20 Dec 2017 12:25:11 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eRi7B-0003o5-W0 for guix-devel@gnu.org; Wed, 20 Dec 2017 12:25:10 -0500 Content-Disposition: inline In-Reply-To: <87h8sl78vp.fsf@albion.it.manchester.ac.uk> 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: Dave Love Cc: guix-devel@gnu.org On Wed, Dec 20, 2017 at 02:48:42PM +0000, Dave Love wrote: > I wrote: > > > If you do provide some sort of threaded version for Python, then as far > > as I remember it must use pthreads, not OpenMP, though you want the > > OpenMP version for other purposes, and I hadn't realized there wasn't > > one currently. > > I was confused. I see the only version of the library shipped is built > with pthreads. I think there should be serial, pthreads, and OpenMP > versions, as for Fedora. It may also be useful to provide the 64-bit > integer versions, like Fedora; that's useful for at least a flagship > chemistry program. I was just stating that the default openblas package does not perform well (it is single threaded, for one). If I compile for a target it makes a large difference. I don't know how we can make that available to others apart from having special packages like the one I made. Looks to me like python-numpy could benefit, but how we deploy that as a flavour - I have no idea. > I also remembered the problems with 0.2.20. I'll send a patch for the > wrong cache size used on some x86_64 when I get a chance. It is a stable release. So far no problems on my end using the latest git checkout of openblas. Pj. --