From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eduardo Valentin Subject: Re: [PATCH 1/1] drivers: acpi: add CPU id to cooling device type of processor driver Date: Wed, 4 May 2016 20:06:46 -0700 Message-ID: <20160505030645.GA2158@localhost.localdomain> References: <1462251879-7224-1-git-send-email-edubezval@gmail.com> <1462398872.14904.29.camel@linux.intel.com> <2680812.8DqCpBTJz8@vostro.rjw.lan> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-pf0-f174.google.com ([209.85.192.174]:33632 "EHLO mail-pf0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755313AbcEEDGw (ORCPT ); Wed, 4 May 2016 23:06:52 -0400 Content-Disposition: inline In-Reply-To: <2680812.8DqCpBTJz8@vostro.rjw.lan> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: "Rafael J. Wysocki" Cc: Srinivas Pandruvada , "Rafael J. Wysocki" , Rui Zhang , Linux PM , Len Brown , ACPI Devel Maling List , Linux Kernel Mailing List On Thu, May 05, 2016 at 12:00:57AM +0200, Rafael J. Wysocki wrote: > On Wednesday, May 04, 2016 02:54:32 PM Srinivas Pandruvada wrote: > > On Wed, 2016-05-04 at 23:49 +0200, Rafael J. Wysocki wrote: > > > On Tue, May 3, 2016 at 7:04 AM, Eduardo Valentin > > > wrote: > > > > > > > > Currently, in an ACPI based system, the processor driver registers > > > > one cooling device per processor. However, the cooling device type > > > > is the same for each processor. For example, on a system with four > > > > processors, the sysfs reading of each cooling device would look > > > > like: > > > > ebv@besouro ~ $ cat /sys/class/thermal/cooling_device*/type > > > > Processor > > > > Processor > > > > Processor > > > > Processor > > > > > > > > which turns out to fine. But, some parts of the thermal code may > > > > use > > > > type to identify participating devices in a thermal zone. Besides, > > > > adding notifications to user space may cause the production of > > > > messages > > > > that may confuse the listener. > > > > > > > > For this reason, this patch adds the processor ID cooling device > > > > type. > > > > After this change, the cooling device listing in the same previous > > > > example > > > > would look like this: > > > > ebv@besouro ~ $ cat /sys/class/thermal/cooling_device*/type > > > > Processor.0 > > > > Processor.1 > > > > Processor.2 > > > > Processor.3 > > > > > > > > allowing an easier identification of cooling device target. > > > > > > Is it not going to confuse any user space scripts or similar? > > > > Yes, it will. > > In that case the patch cannot be applied. In fact, we shall never brake userspace. Srinivas, could you please elaborate a bit more on how this would break userspace? How different would it be having an extra id? Are you expecting "Processor" string in daemon? BR, > > Thanks, > Rafael >