Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754148AbXLMAOF (ORCPT ); Wed, 12 Dec 2007 19:14:05 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751248AbXLMANy (ORCPT ); Wed, 12 Dec 2007 19:13:54 -0500 Received: from sovereign.computergmbh.de ([85.214.69.204]:49358 "EHLO sovereign.computergmbh.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750912AbXLMANx (ORCPT ); Wed, 12 Dec 2007 19:13:53 -0500 Date: Thu, 13 Dec 2007 01:13:52 +0100 (CET) From: Jan Engelhardt To: Rene Herman cc: Linux Kernel Subject: Re: [RFT] Port 0x80 I/O speed In-Reply-To: Message-ID: References: <475F1DC6.5090403@keyaccess.nl> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1498 Lines: 40 On Dec 13 2007 00:54, Jan Engelhardt wrote: > >Transmeta TM5800 CPU with nominal frequency 933 MHz, but it has a >hardware(!) 'ondemand' governor over the range of frequencies that >the user allowed scaling over, irrespective of the software governor. >(That is, if the CPU can do 300,533 and 933 MHz, and setting the >min/max to 300/533 will cause the hardware to 'ondemand' between 300 >and 533 only. And that even if 'performance' is set on the software >side - so the only way to enforce 'performance' is to actually set >min=933.) > >00:46 takeshi:../cpu0/cpufreq # echo 300000 >scaling_min_freq >00:46 takeshi:../cpu0/cpufreq # echo 933000 >scaling_max_freq >00:42 takeshi:/dev/shm # for ((x=1;x<=10;++x)); do ./port80 ; done >cycles: out 1514, in 584 ^ most likely 300 MHz state >cycles: out 1371, in 516 ^ 533 MHz state >cycles: out 1291, in 472 ^ ?? >cycles: out 1304, in 437 ^ ?? >cycles: out 1308, in 410 ^ ?? >cycles: out 1315, in 419 ^ 933 MHz state >cycles: out 1315, in 419 >cycles: out 1314, in 419 >cycles: out 1315, in 420 >cycles: out 1315, in 419 ...this is in stark contrast to values of other users, where, skimming through the mails, higher cpu frequencies yields higher out/in values, but not so on TM5800. Highly interesting. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/