Received: from maia.hub.org (maia-5.hub.org [200.46.204.29]) by mail.postgresql.org (Postfix) with ESMTP id D304F1337B96 for ; Mon, 20 Dec 2010 14:15:36 -0400 (AST) Received: from mail.postgresql.org ([200.46.204.86]) by maia.hub.org (mx1.hub.org [200.46.204.29]) (amavisd-maia, port 10024) with ESMTP id 93546-05 for ; Mon, 20 Dec 2010 18:15:28 +0000 (UTC) X-Greylist: delayed 00:15:42.958096 by SQLgrey-1.7.6 Received: from wizmail.org (wizmail.org [217.146.107.12]) by mail.postgresql.org (Postfix) with ESMTP id D328A1337B94 for ; Mon, 20 Dec 2010 14:15:27 -0400 (AST) Received: from ebony.jgh.adsl.wizards.co.uk ([217.146.123.59]) (from_AS 16353) by wizmail.org with esmtpsa (TLSv1:DHE-RSA-CAMELLIA256-SHA:256) (Exim 4.72) id 1PUk1U-0001yU-Sa (return-path ); Mon, 20 Dec 2010 17:59:49 +0000 Message-ID: <4D0F998E.7060007@wizmail.org> Date: Mon, 20 Dec 2010 17:59:42 +0000 From: Jeremy Harris User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.1.21) Gecko/20090320 Fedora/2.0.0.21-1.fc9 Thunderbird/2.0.0.21 Mnenhy/0.7.5.0 MIME-Version: 1.0 To: pgsql-performance@postgresql.org Subject: Re: CPU bound References: <4D0EFC02.7040004@vmsinfo.com> <20101220154847.GX10252@aart.is.rice.edu> In-Reply-To: <20101220154847.GX10252@aart.is.rice.edu> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit 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: 201012/257 X-Sequence-Number: 41709 On 2010-12-20 15:48, Kenneth Marshall wrote: >> And how exactly, given that the kernel does not know whether the CPU is >> active or waiting on ram, could an application do so? >> > > Exactly. I have only seen this data from hardware emulators. It would > be nice to have... :) There's no reason that the cpu hardware couldn't gather such, and IMHO it's be dead useful, at least at the outermost cache level (preferably separately at each level). But people have trouble understanding vmstat already.... Note that dtrace *can* get to the cpu performance counters, just that the kernel doesn't routinely account for all that info per-process as routine. I'd expect IBM to have equivalent facilities. -- Jeremy