From mboxrd@z Thu Jan 1 00:00:00 1970 From: Srinivas Pandruvada Subject: Re: [PATCH 0/3] CPU Package temperarure thermal driver (v02) Date: Tue, 28 May 2013 08:17:38 -0700 Message-ID: <51A4CA92.5090203@linux.intel.com> References: <1368834123-9591-1-git-send-email-srinivas.pandruvada@linux.intel.com> <1369708711.1913.4.camel@rzhang1-mobl4> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mga02.intel.com ([134.134.136.20]:57076 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934389Ab3E1PMu (ORCPT ); Tue, 28 May 2013 11:12:50 -0400 In-Reply-To: <1369708711.1913.4.camel@rzhang1-mobl4> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Zhang Rui , tony.luck@intel.com Cc: linux-pm@vger.kernel.org, eduardo.valentin@ti.com, linux-edac@vger.kernel.org Tony Luck is the maintainer and he did review once and gave comments. Hi Tony, Do you have further comments? Thanks, Srinivas On 05/27/2013 07:38 PM, Zhang Rui wrote: > On Fri, 2013-05-17 at 16:42 -0700, Srinivas Pandruvada wrote: >> This driver register CPU digital temperature package level sensor as a >> thermal zone with two user mode configurable trip points. Once >> the trip point is violated, user mode can receive notification via thermal >> notification mechanism and can take any action to control temperature. >> > I'm okay with this patch set. > But I'm wondering who should take patch 1/3? > > thanks, > rui >> Changes: >> v02: >> Did majority of changes suggested by Eduardo Valentin. Main changes are: >> - Module parameters for rate control delay >> - Removed user space gov parameter in thermal_zone_register >> - Changes related to returning of errors values >> - Error code return values >> >> v01: >> First version for review >> >> Background: >> This set of changes were done to coretemp driver and posted to lm_sensors >> mailing list on 04/04/2013. This was reviewed by Guenter Roeck from lm-sensors >> and Zhang Rui (thermal maintainer). They were in agreement not to add notification >> mechanism to coretemp driver but use thermal sysfs. >> Guenter Roeck suggested to use approach like "db8500_thermal driver in drivers/thermal". >> So resubmitting the driver as a thermal zone driver. >> Previous discussion link: >> http://comments.gmane.org/gmane.linux.drivers.sensors/32182 >> " >> This is clear that there is reluctance in adding thresholds in coretemp sysfs, >> during previous attempts. Probably because of lake of use cases. >> But this time use case may be more compelling. >> >> We have many small form factor devices like ultrabooks, slate PCs in the market. >> Unfortunately these devices reach maximum temperature with relatively less >> workloads, causing BIOS to do thermal throttling. There are real performance >> issues due to aggressive BIOS action to control thermals and also thermal breakdown >> in some cases. >> >> Even the most expensive laptops, don't have correct ACPI thermal configuration, >> so that kernel thermal driver can act. In some case even the trip point is higher >> than critical temperature setting. >> >> Intel has developed several drivers, which can be used to cool the system very efficiently. >> They include RAPL based cooling driver, Powerclamp driver and P state driver. >> To utilize these cooling device a closed loop user mode program is required, which >> will utilize these method and dynamically compensate for high CPU temperatures, >> without relying on any configuration data. >> One such solution is developed is "Linux thermal daemon". More details can be >> obtained from >> "https://github.com/01org/thermal_daemon/blob/master/ThermalDaemon_Introduction.pdf". >> This daemon polls for cpu temperature and apply compensation once the CPU reach target >> temperature. >> >> This polling can be mostly avoided, by getting notification for the temperature, where >> it needs to wake up and get ready for apply compensation. In most of the normal use >> cases, there may not be any threshold events. So very minimal number of user space >> notification for thermal thresholds. >> >> Srinivas Pandruvada (3): >> x86, mcheck, therm_throt: Process package thresholds >> Thermal: CPU Package temperature thermal >> Thermal: Documentation for x86 package temperature thermal driver >> >> Documentation/thermal/x86_pkg_temperature_thermal | 47 ++ >> arch/x86/include/asm/mce.h | 7 + >> arch/x86/kernel/cpu/mcheck/therm_throt.c | 63 ++- >> drivers/thermal/Kconfig | 12 + >> drivers/thermal/Makefile | 2 +- >> drivers/thermal/x86_pkg_temp_thermal.c | 642 ++++++++++++++++++++++ >> 6 files changed, 768 insertions(+), 5 deletions(-) >> create mode 100644 Documentation/thermal/x86_pkg_temperature_thermal >> create mode 100644 drivers/thermal/x86_pkg_temp_thermal.c >> > > -- > To unsubscribe from this list: send the line "unsubscribe linux-pm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >