From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761585AbXKHRUH (ORCPT ); Thu, 8 Nov 2007 12:20:07 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759962AbXKHRTw (ORCPT ); Thu, 8 Nov 2007 12:19:52 -0500 Received: from turing-police.cc.vt.edu ([128.173.14.107]:40640 "EHLO turing-police.cc.vt.edu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760662AbXKHRTv (ORCPT ); Thu, 8 Nov 2007 12:19:51 -0500 X-Mailer: exmh version 2.7.2 01/07/2005 with nmh-1.2 To: Andrew Morton , Mark Gross Cc: linux-kernel@vger.kernel.org Subject: 2.6.23-mm1 breaks C-state support on Intel T7200 x86_64 From: Valdis.Kletnieks@vt.edu Mime-Version: 1.0 Content-Type: multipart/signed; boundary="==_Exmh_1194542384_3143P"; micalg=pgp-sha1; protocol="application/pgp-signature" Content-Transfer-Encoding: 7bit Date: Thu, 08 Nov 2007 12:19:44 -0500 Message-ID: <3624.1194542384@turing-police.cc.vt.edu> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org --==_Exmh_1194542384_3143P Content-Type: text/plain; charset=us-ascii (Sorry for not reporting this sooner - I haven't been running off battery much in the last 3 weeks, so I didn't notice it till now...) Dell Latitude D820 laptop, T7200 Core2 Duo CPU, x86_64 kernel. As reported by 'powertop' on a basically idle machine: 2.6.23-mm1: Cn Avg residency P-states (frequencies) C0 (cpu running) (100.0%) 2.00 Ghz 0.8% C1 0.0ms ( 0.0%) 1.67 Ghz 0.0% C2 0.0ms ( 0.0%) 1333 Mhz 0.0% C3 0.0ms ( 0.0%) 1000 Mhz 99.2% 2.6.23-rc8-mm2: Cn Avg residency P-states (frequencies) C0 (cpu running) ( 0.3%) 2.00 Ghz 0.0% C1 0.0ms ( 0.0%) 1.67 Ghz 0.0% C2 0.0ms ( 0.0%) 1333 Mhz 0.0% C3 31.5ms (99.7%) 1000 Mhz 100.0% In addition, the ACPI power estimate reported about 25 watts for 23-mm1, but only 21 watts for -rc8-mm2, a significant regression. I bisected this down to this set of patches: pm-qos-infrastructure-and-interface.patch pm-qos-infrastructure-and-interface-fix.patch pm-qos-infrastructure-and-interface-vs-git-acpi.patch pm-qos-infrastructure-and-interface-vs-git-acpi-2.patch latencyc-use-qos-infrastructure.patch The patch says: To register the default pm_qos target for the specific parameter, the process must open one of /dev/[cpu_dma_latency, network_latency, network_throughput] As long as the device node is held open that process has a registered requirement on the parameter. The name of the requirement is "process_" derived from the current->pid from within the open system call. I shouldn't have to have a process open a /dev/file, write a number, and then stay around forever so the file doesn't close in order to get the same behavior I was getting by default before. What needs to happen to get this to not be a behavior regression/change? --==_Exmh_1194542384_3143P Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (GNU/Linux) Comment: Exmh version 2.5 07/13/2001 iD8DBQFHM0UwcC3lWbTT17ARAht9AKCGHKp43NZXYB6rZwGk4vaWJHeU9wCgzqG3 iF9ZKXsWsXlvnvj+Pu8/r7k= =XTrD -----END PGP SIGNATURE----- --==_Exmh_1194542384_3143P--