Received: from makus.postgresql.org (makus.postgresql.org [98.129.198.125]) by mail.postgresql.org (Postfix) with ESMTP id 1B1FF930E1F for ; Fri, 3 Aug 2012 20:15:48 -0300 (ADT) Received: from smtp.01.com ([199.36.142.181]) by makus.postgresql.org with esmtp (Exim 4.72) (envelope-from ) id 1SxR5v-0003UP-4c for pgsql-performance@postgresql.org; Fri, 03 Aug 2012 23:15:47 +0000 Received: from localhost (localhost.localdomain [127.0.0.1]) by smtp-out-1.01.com (Postfix) with ESMTP id 896A82942ED; Fri, 3 Aug 2012 18:15:34 -0500 (CDT) X-Virus-Scanned: amavisd-new at smtp-out-1.01.com Received: from smtp.01.com ([127.0.0.1]) by localhost (smtp-out-1.01.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id kUWwZ0kXpO+b; Fri, 3 Aug 2012 18:15:34 -0500 (CDT) Received: from smtp.01.com (localhost.localdomain [127.0.0.1]) by smtp-out-1.01.com (Postfix) with ESMTP id 61A5C29403E; Fri, 3 Aug 2012 18:15:34 -0500 (CDT) Received: from Sidney-Stratton.local (70-36-143-92.dsl.dynamic.sonic.net [70.36.143.92]) by smtp-out-1.01.com (Postfix) with ESMTPSA id 118BF294174; Fri, 3 Aug 2012 18:15:34 -0500 (CDT) Message-ID: <501C5B95.90400@agliodbs.com> Date: Fri, 03 Aug 2012 16:15:33 -0700 From: Josh Berkus Organization: PostgreSQL Experts Inc. User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:14.0) Gecko/20120713 Thunderbird/14.0 MIME-Version: 1.0 To: Scott Marlowe CC: pgsql-performance@postgresql.org Subject: Re: Linux memory zone reclaim References: <500616CB.3070408@2ndQuadrant.com> <501673680200002500049227@gw.wicourts.gov> <501C50FE.80905@agliodbs.com> In-Reply-To: X-Enigmail-Version: 1.4.3 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Pg-Spam-Score: -1.9 (-) X-Archive-Number: 201208/16 X-Sequence-Number: 47554 >> This is poor design on Linux's part, since even the distant RAM is >> faster than disk. For now, we've been disabling zone_reclaim entirely. > > I haven't run into this, but we were running ubuntu 10.04 LTS. What > kernel were you running when this happened? I'd love to see a test > case on this, as it seems like a major regression if it's on newer > kernels, and we're looking at running 12.04 LTS soon on one of our > bigger machines. Jeff Frost will have a blog up about it later; we're still collecting data. -- Josh Berkus PostgreSQL Experts Inc. http://pgexperts.com