Received: from maia.hub.org (maia-3.hub.org [200.46.204.243]) by mail.postgresql.org (Postfix) with ESMTP id D3AB01337B67 for ; Mon, 11 Apr 2011 16:42:54 -0300 (ADT) Received: from mail.postgresql.org ([200.46.204.86]) by maia.hub.org (mx1.hub.org [200.46.204.243]) (amavisd-maia, port 10024) with ESMTP id 53710-07 for ; Mon, 11 Apr 2011 19:42:47 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from nm4-vm0.bullet.mail.ukl.yahoo.com (nm4-vm0.bullet.mail.ukl.yahoo.com [217.146.183.230]) by mail.postgresql.org (Postfix) with SMTP id 368C91337999 for ; Mon, 11 Apr 2011 16:42:46 -0300 (ADT) Received: from [217.146.183.210] by nm4.bullet.mail.ukl.yahoo.com with NNFMP; 11 Apr 2011 19:42:46 -0000 Received: from [217.146.183.176] by tm3.bullet.mail.ukl.yahoo.com with NNFMP; 11 Apr 2011 19:42:46 -0000 Received: from [127.0.0.1] by omp1017.mail.ukl.yahoo.com with NNFMP; 11 Apr 2011 19:42:46 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 477076.75143.bm@omp1017.mail.ukl.yahoo.com Received: (qmail 14109 invoked by uid 60001); 11 Apr 2011 19:42:46 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.co.uk; s=s1024; t=1302550966; bh=kQYj9B0pPMoiF5SKvr7jRK9GFs4inL2Zq4G8+bdaZY0=; h=Message-ID:X-YMail-OSG:Received:X-Mailer:Date:From:Subject:To:Cc:In-Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding; b=uyYgJfDGHc7ZOV87akjjz7HMAqJYIc42QedMHAWMSMQ50N4QUE4Jh+ghmmTusC/hEqKY0I1cIN/ClDkNdlPSYYvb9HtgAbN1nJxadm2Ai5F6QyNTab+0+pvxxv/vUiHSj7uMS4K0GQcRvjALQOuVM+h6J7u69R973KpFS+KKAOs= DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.co.uk; h=Message-ID:X-YMail-OSG:Received:X-Mailer:Date:From:Subject:To:Cc:In-Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding; b=MTrP8oo92fqj9gGxMRRtDuEjt0rr37SFlKGCuuFZ1vh1zKZ0GfoSH+e8kRg2VNHxWYboOJJpveclMK8wFnFrKLD6OVeGsX0ZevJ37jNapOqFEOPbvZwWPdecv5PWKqDDyTadLjw/4YAt++xCFnGUV0TiHwIw7zsDEl3CEgUtEX4=; Message-ID: <356731.11980.qm@web26005.mail.ukl.yahoo.com> X-YMail-OSG: SdXQdHYVM1mN9tNB3UzzotHj377ZgOBhj6xkZ3QboHuHRDb xeecKp4pxpQtxl8OdaU5HBSCToQ2LRSLcJ60luT2JoYzhSbgRmrgP1vnpU4n r97quSwQNH9lbwxKEzu82BPNJSQ_Iwq62CzbDKwWMu5l5HspY3MxrzH.c8Eb rKkWWh3z3dAfoOCHzOC1U5NERtdXR_2m.N1pPQe3my.AMxxNmQ5_7jhi4o9_ FZKZTmGJTgvRlZIMcnVFDyBeuaPxqeMzgMQhgyckDSReWKIIUP0SE9.gVexb dKzcmB.28Dr2OndUBmDX3ytRacbuHFgOjF6kzj0zpRiWc0FxF7IXj3H.snu0 SyFCWXvGY7NZ_c0IxontPJA4Aeg-- Received: from [81.98.134.44] by web26005.mail.ukl.yahoo.com via HTTP; Mon, 11 Apr 2011 20:42:46 BST X-Mailer: YahooMailClassic/12.0.2 YahooMailWebService/0.8.109.295617 Date: Mon, 11 Apr 2011 20:42:46 +0100 (BST) From: Glyn Astill Subject: Re: Linux: more cores = less concurrency. To: Scott Marlowe Cc: Kevin Grittner , "Joshua D. Drake" , pgsql-performance@postgresql.org In-Reply-To: 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=-1.898 tagged_above=-10 required=5 tests=BAYES_00=-1.9, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, RFC_ABUSE_POST=0.001 X-Spam-Level: X-Archive-Number: 201104/116 X-Sequence-Number: 43178 --- On Mon, 11/4/11, Scott Marlowe wrote:=0A=0A> = Just FYI, in synthetic pgbench type benchmarks, a 48 core=0A> AMD Magny=0A>= Cours with LSI HW RAID and 34 15k6 Hard drives scales=0A> almost linearly= =0A> up to 48 or so threads, getting into the 7000+ tps=0A> range.=A0 With = SW=0A> RAID it gets into the 5500 tps range.=0A> =0A=0AI'll have to try wit= h the synthetic benchmarks next then, but somethings definately going off h= ere. I'm seeing no disk activity at all as they're selects and all pages a= re in ram.=0A =0AI was wondering if anyone had any deeper knowledge of any = kernel tunables, or anything else for that matter.=0A=0AA wild guess is som= ething like multiple cores contending for cpu cache, cpu affinity, or some = kind of contention in the kernel, alas a little out of my depth.=0A=0AIt's = pretty sickening to think I can't get anything else out of more than 8 core= s.