From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753128AbZBHSgO (ORCPT ); Sun, 8 Feb 2009 13:36:14 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753124AbZBHSf6 (ORCPT ); Sun, 8 Feb 2009 13:35:58 -0500 Received: from an-out-0708.google.com ([209.85.132.249]:15269 "EHLO an-out-0708.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752988AbZBHSf5 (ORCPT ); Sun, 8 Feb 2009 13:35:57 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:user-agent:mime-version:newsgroups:to:cc :subject:references:in-reply-to:content-type :content-transfer-encoding; b=vDvscY2nWDmDZRK4InHLvshupD1eVngDbtWWTO3JA9dcltRsWWcwGJbrg49948W0LY RQ8RA3azIJw1COUhjHwn3Tx+Dr+DUeHBAJ6UjK+e6AWLghd5s0B0wZvVlxvTAS1T5Vr2 4WPsOcOweKYA2h+Gk5yxfO6zHaS+JsfPVC8H8= Message-ID: <498F2608.9030809@gmail.com> Date: Sun, 08 Feb 2009 12:35:52 -0600 From: Robert Hancock User-Agent: Thunderbird 2.0.0.19 (X11/20090105) MIME-Version: 1.0 Newsgroups: gmane.linux.kernel To: Thomas Renninger CC: davej@codemonkey.org.uk, mark.langsdorf@amd.com, cpufreq@vger.kernel.org, venkatesh.pallipadi@intel.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH 4/7] CPUFREQ: powernow-k8: Get transition latency from ACPI _PSS table References: <1233679606-1971-1-git-send-email-trenn@suse.de> <1233679606-1971-5-git-send-email-trenn@suse.de> In-Reply-To: <1233679606-1971-5-git-send-email-trenn@suse.de> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Thomas Renninger wrote: > From: Mark Langsdorf > > At this time, the PowerNow! driver for K8 uses an experimentally > derived formula to calculate transition latency. The value it > provides is orders of magnitude too large on modern systems. > This patch replaces the formula with ACPI _PSS latency values > for more accuracy and better performance. > > I've tested it on two 2nd generation Opteron systems, a 3rd > generation Operton system, and a Turion X2 without seeing any > stability problems. > > Signed-off-by: Mark Langsdorf > Signed-off-by: Thomas Renninger > --- > arch/x86/kernel/cpu/cpufreq/powernow-k8.c | 28 ++++++++++++++++++++++------ > 1 files changed, 22 insertions(+), 6 deletions(-) Hopefully somebody is pushing this for .29? This seems to make a big difference in system responsiveness on my Athlon X2 system.