Received: from maia.hub.org (maia-2.hub.org [200.46.204.251]) by mail.postgresql.org (Postfix) with ESMTP id 047411337BFE for ; Thu, 14 Apr 2011 07:10:16 -0300 (ADT) Received: from mail.postgresql.org ([200.46.204.86]) by maia.hub.org (mx1.hub.org [200.46.204.251]) (amavisd-maia, port 10024) with ESMTP id 04806-01-3 for ; Thu, 14 Apr 2011 10:09:55 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from mx01.bfk.de (mx01.bfk.de [193.227.124.2]) by mail.postgresql.org (Postfix) with ESMTP id E43EB1337C54 for ; Thu, 14 Apr 2011 07:09:21 -0300 (ADT) Received: from mx00.int.bfk.de ([10.119.110.2]) by mx01.bfk.de with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) id 1QAJUG-0006QO-2I; Thu, 14 Apr 2011 10:09:20 +0000 Received: by bfk.de with local id 1QAJUF-0003f4-UZ; Thu, 14 Apr 2011 10:09:19 +0000 To: Jesper Krogh Cc: pgsql-performance@postgresql.org Subject: Re: Linux: more cores = less concurrency. References: <356731.11980.qm@web26005.mail.ukl.yahoo.com> <4DA35CF8.7050205@krogh.cc> From: Florian Weimer Date: Thu, 14 Apr 2011 10:09:19 +0000 In-Reply-To: <4DA35CF8.7050205@krogh.cc> (Jesper Krogh's message of "Mon\, 11 Apr 2011 21\:56\:40 +0200") Message-ID: <8239lli1ps.fsf@mid.bfk.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=-1.91 tagged_above=-10 required=5 tests=BAYES_00=-1.9, T_RP_MATCHES_RCVD=-0.01 X-Spam-Level: X-Archive-Number: 201104/212 X-Sequence-Number: 43274 * Jesper Krogh: > If you have a 1 socket system, all of your data can be fetched from > "local" ram seen from you cpu, on a 2 socket, 50% of your accesses > will be "way slower", 4 socket even worse. There are non-NUMA multi-socket systems, so this doesn't apply in all cases. (The E5320-based system is likely non-NUMA.) Speaking about NUMA, do you know if there are some non-invasive tools which can be used to monitor page migration and off-node memory accesses? --=20 Florian Weimer BFK edv-consulting GmbH http://www.bfk.de/ Kriegsstra=DFe 100 tel: +49-721-96201-1 D-76133 Karlsruhe fax: +49-721-96201-99