Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756188Ab2BGS0G (ORCPT ); Tue, 7 Feb 2012 13:26:06 -0500 Received: from mail-lpp01m020-f174.google.com ([209.85.217.174]:39953 "EHLO mail-lpp01m020-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753706Ab2BGS0E (ORCPT ); Tue, 7 Feb 2012 13:26:04 -0500 MIME-Version: 1.0 In-Reply-To: <20120207001818.GB30840@kroah.com> References: <1326878467-17766-1-git-send-email-amit.kachhap@linaro.org> <20120206165658.GA28687@atrey.karlin.mff.cuni.cz> <20120206170348.GA19749@kroah.com> <20120207001818.GB30840@kroah.com> Date: Tue, 7 Feb 2012 10:26:02 -0800 Message-ID: Subject: Re: [linux-pm] [RFC PATCH] thermal: Add support to report cooling statistics achieved by cooling devices From: Amit Kachhap To: Greg KH Cc: Pavel Machek , linux-pm@lists.linux-foundation.org, linaro-dev@lists.linaro.org, patches@linaro.org, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, rob.lee@linaro.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2259 Lines: 56 On 6 February 2012 16:18, Greg KH wrote: > On Mon, Feb 06, 2012 at 03:16:17PM -0800, Amit Kachhap wrote: >> On 6 February 2012 09:03, Greg KH wrote: >> > On Mon, Feb 06, 2012 at 05:56:58PM +0100, Pavel Machek wrote: >> >> Hi! >> >> >> >> > Add a sysfs node code to report effective cooling of all cooling devices >> >> > attached to each trip points of a thermal zone. The cooling data reported >> >> > will be absolute if the higher temperature trip points are arranged first >> >> > otherwise the cooling stats is the cumulative effect of the earlier >> >> > invoked cooling handlers. >> >> > >> >> > The basic assumption is that cooling devices will bring down the temperature >> >> > in a symmetric manner and those statistics can be stored back and used for >> >> > further tuning of the system. >> >> >> >> /sys fs should be one-value-per-file, talk to gregkh. >> > >> > That's correct. >> > >> > Why not use debugfs for this instead? >> > >> > thanks, >> > >> > greg k-h >> >> Thanks Greg/Pavel for looking into the patch. >> Basically I checked the places where single sysfs entry is showing >> more then 1 output. And >> 1) /sys/devices/system/cpu/cpu0/cpufreq/stats/time_in_state >> 2) /sys/devices/system/cpu/cpu0/cpufreq/stats/trans_table >> are the places where the output is more than 1 value. > > Yes, those are two known-bad files, whose files will change soon and > move to debugfs. > > Just because you found 2, instead of the thousands of other properly > formatted files, does not mean you are allowed to create something like > this. > >> Anyway I can enclose this sysfs inside CONFIG_THERMAL_COOLING_STATS macro. > > No, you can not create it at all in sysfs, if you really need such a > large single file, use debugfs instead, that is what it is there for. > > Again, one-value-per-file is the sysfs rule, and has been for a decade > now, please don't think this is a new thing. > > greg k-h Ok I will follow one-value-per-file rule for sysfs file. Thanks -- 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/