From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: Re: [RESEND][PATCH] cpufreq: stats: Add 'load_table' sysfs file to show accumulated data of CPU Date: Wed, 12 Jun 2013 13:05:09 +0200 Message-ID: <2801243.ZfLEluCnpU@vostro.rjw.lan> References: <1370419882-16831-1-git-send-email-cw00.choi@samsung.com> <11735265.3zXb8Z81XT@vostro.rjw.lan> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7Bit Return-path: Received: from hydra.sisk.pl ([212.160.235.94]:34837 "EHLO hydra.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751382Ab3FLKz5 (ORCPT ); Wed, 12 Jun 2013 06:55:57 -0400 In-Reply-To: Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Viresh Kumar Cc: Chanwoo Choi , linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, cpufreq@vger.kernel.org, kyungmin.park@samsung.com, myungjoo.ham@samsung.com On Wednesday, June 12, 2013 09:32:16 AM Viresh Kumar wrote: > On 12 June 2013 03:44, Rafael J. Wysocki wrote: > > On Wednesday, June 05, 2013 05:11:22 PM Chanwoo Choi wrote: > >> This patch add new sysfs file to show previous accumulated data of CPU load > >> as following path. This sysfs file is used to judge the correct system state > >> or determine suitable system resource on user-space. > >> - /sys/devices/system/cpu/cpu0/cpufreq/stats/load_table > >> > >> This sysfs file include following data: > >> - Measurement point of time > >> - CPU frequency > >> - Per-CPU load > >> > >> Signed-off-by: Chanwoo Choi > >> Signed-off-by: Myungjoo Ham > >> Signed-off-by: Kyungmin Park > > > > Well, first of all, there is the "one value per file" rule for sysfs attributes > > which is evidently violated by this code. > > Even this was enclosed in CONFIG_CPU_FREQ_STAT_DETAILS, > so even sysfs isn't that bad as we already had something similar here. Yes, we did, and yes, it was a mistake. It should have been in debugfs from the very beginning. > > Second, this looks like a feature needed to handle one particular platform, so > > why do you want to add it to the cpufreq core? > > I really felt this would be useful to others. They can track the load on > all cores for some time and that will really be useful. People can > understand their loads and system more easily with this patch in. If it were in debugfs, I'd have no objections. Thanks, Rafael -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.