Received: from maia.hub.org (maia-2.hub.org [200.46.204.251]) by mail.postgresql.org (Postfix) with ESMTP id 0586F1337990 for ; Mon, 11 Apr 2011 18:30:11 -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 93195-05 for ; Mon, 11 Apr 2011 21:29:46 +0000 (UTC) X-Greylist: delayed 00:08:12.415698 by SQLgrey-1.7.6 Received: from eagle.jhcloos.com (eagle.jhcloos.com [207.210.242.212]) by mail.postgresql.org (Postfix) with ESMTP id ADC7A133740B for ; Mon, 11 Apr 2011 18:29:46 -0300 (ADT) Received: by eagle.jhcloos.com (Postfix, from userid 10) id 72C5940175; Mon, 11 Apr 2011 21:21:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=jhcloos.com; s=eagle; t=1302556892; bh=xSa8HTAGA/6CgxOPhGxMP0WjxBAn3KGK+kDOAGMfi+s=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=Hi9bQYHl/GIIYyZcUdAybbLXS+O7bAxVZxeTdOjHVpCtxbpczPmJWLZOjpEqXupw3 HyT/NIePUQQLfl3cTzIjScUo4fTVuKu+WOZTErcIBxN1Nbzf6wi09txZ8C3xC196o0 XjkPLM1cHUUCdOUPwvjQuBvXXO3RgZmHv7HQd3Dc= Received: by carbon.jhcloos.org (Postfix, from userid 500) id 24C12260042; Mon, 11 Apr 2011 20:39:46 +0000 (UTC) From: James Cloos To: Glyn Astill Cc: Steve Clark , david@lang.hm, Scott Marlowe , "Joshua D. Drake" , Kevin Grittner , pgsql-performance@postgresql.org Subject: Re: Linux: more cores = less concurrency. In-Reply-To: <976931.36062.qm@web26004.mail.ukl.yahoo.com> (Glyn Astill's message of "Mon, 11 Apr 2011 21:17:04 +0100 (BST)") References: <976931.36062.qm@web26004.mail.ukl.yahoo.com> User-Agent: Gnus/5.110016 (No Gnus v0.16) Emacs/24.0.50 (gnu/linux) Face: iVBORw0KGgoAAAANSUhEUgAAABAAAAAQAgMAAABinRfyAAAACVBMVEX///8ZGXBQKKnCrDQ3 AAAAJElEQVQImWNgQAAXzwQg4SKASgAlXIEEiwsSIYBEcLaAtMEAADJnB+kKcKioAAAAAElFTkSu QmCC Copyright: Copyright 2011 James Cloos OpenPGP: ED7DAEA6; url=http://jhcloos.com/public_key/0xED7DAEA6.asc OpenPGP-Fingerprint: E9E9 F828 61A4 6EA9 0F2B 63E7 997A 9F17 ED7D AEA6 Date: Mon, 11 Apr 2011 16:39:46 -0400 Message-ID: Lines: 14 MIME-Version: 1.0 Content-Type: text/plain X-Hashcash: 1:30:110411:glynastill@yahoo.co.uk::1S/U2VMOIolsVeUI:00000000000000000000000000000000000000G61K+ X-Hashcash: 1:30:110411:sclark@netwolves.com::ne46dxOMRi2dmsJw:0000000000000000000000000000000000000000e/4PZ X-Hashcash: 1:30:110411:david@lang.hm::P5Q4YaBi6RiB/U+3:000YMz1q X-Hashcash: 1:30:110411:scott.marlowe@gmail.com::7s/g5BlWqjDj7o7D:0000000000000000000000000000000000000esMHo X-Hashcash: 1:30:110411:jd@commandprompt.com::/uiaxuLJohE1jJMx:0000000000000000000000000000000000000000JHKfs X-Hashcash: 1:30:110411:kevin.grittner@wicourts.gov::+rAYBAQcgkbzVYlH:000000000000000000000000000000000APWzT X-Hashcash: 1:30:110411:pgsql-performance@postgresql.org::h7UtcnSBseZTrDrN:0000000000000000000000000000Cjerd 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: 201104/125 X-Sequence-Number: 43187 >>>>> "GA" == Glyn Astill writes: GA> I was hoping someone had seen this sort of behaviour before, GA> and could offer some sort of explanation or advice. Jesper's reply is probably most on point as to the reason. I know that recent Opterons use some of their cache to better manage cache-coherency. I presum recent Xeons do so, too, but perhaps yours are not recent enough for that? -JimC -- James Cloos OpenPGP: 1024D/ED7DAEA6