Received: from makus.postgresql.org ([98.129.198.125]) by malur.postgresql.org with esmtp (Exim 4.72) (envelope-from ) id 1TJNOs-0000SV-P9 for pgsql-performance@postgresql.org; Wed, 03 Oct 2012 11:46:02 +0000 Received: from host36.ns3.it ([80.79.54.36] helo=mail.opinioni.net) by makus.postgresql.org with esmtp (Exim 4.72) (envelope-from ) id 1TJNOo-0003uf-J6 for pgsql-performance@postgresql.org; Wed, 03 Oct 2012 11:46:02 +0000 Received: from localhost (localhost [127.0.0.1]) by mail.opinioni.net (Postfix) with ESMTP id 5BEB04B0D2A for ; Wed, 3 Oct 2012 13:47:19 +0200 (CEST) Received: from mail.opinioni.net ([127.0.0.1]) by localhost (opinioni.net [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id XpEWibOu5AN0 for ; Wed, 3 Oct 2012 13:47:19 +0200 (CEST) Received: from [192.168.1.50] (78-134-6-72.v4.ngi.it [78.134.6.72]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.opinioni.net (Postfix) with ESMTPS id 3198B4B0D29 for ; Wed, 3 Oct 2012 13:47:19 +0200 (CEST) Message-ID: <506C2572.2040505@opinioni.net> Date: Wed, 03 Oct 2012 13:45:54 +0200 From: Andrea Suisani User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:15.0) Gecko/20120912 Thunderbird/15.0.1 MIME-Version: 1.0 To: pgsql-performance@postgresql.org Subject: Re: 20% performance drop on PostgreSQL 9.2 from kernel 3.5.3 to 3.6-rc5 on AMD chipsets References: <5058264D.5090702@opinioni.net> In-Reply-To: <5058264D.5090702@opinioni.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Pg-Spam-Score: -1.9 (-) X-Archive-Number: 201210/19 X-Sequence-Number: 47978 Hi On 09/18/2012 09:44 AM, Andrea Suisani wrote: > On 09/14/2012 10:45 AM, Daniel Farina wrote: >> On Fri, Sep 14, 2012 at 12:40 AM, Nikolay Ulyanitsky wrote: >>> Hi >>> I compiled the 3.6-rc5 kernel with the same config from 3.5.3 and got >>> the 15-20% performance drop of PostgreSQL 9.2 on AMD chipsets (880G, >>> 990X). > > [cut] > >>> Kernel config - http://pastebin.com/cFpg5JSJ >>> >>> Any ideas? >> >> Did you tell LKML? It seems like a kind of change that could be found >> using git bisect of Linux, albiet laboriously. > > > just a pointer to LKML thread: > > https://lkml.org/lkml/2012/9/14/99 [cut] today Jonathan Corbet has posted a good write-up on lwn.net "How 3.6 nearly broke PostgreSQL" http://lwn.net/SubscriberLink/518329/672d5c68286f9c18/ this is definitely a worth reading piece. Andrea