From patchwork Sat Sep 1 11:51:31 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: durgadoss.r@intel.com X-Patchwork-Id: 1395221 Return-Path: X-Original-To: patchwork-linux-acpi@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id B12C1DFABE for ; Sat, 1 Sep 2012 11:52:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755520Ab2IALwp (ORCPT ); Sat, 1 Sep 2012 07:52:45 -0400 Received: from mga14.intel.com ([143.182.124.37]:45763 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755530Ab2IALwo (ORCPT ); Sat, 1 Sep 2012 07:52:44 -0400 Received: from azsmga001.ch.intel.com ([10.2.17.19]) by azsmga102.ch.intel.com with ESMTP; 01 Sep 2012 04:52:44 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.80,351,1344236400"; d="scan'208";a="187697168" Received: from dr3-desktop.iind.intel.com ([10.223.107.36]) by azsmga001.ch.intel.com with ESMTP; 01 Sep 2012 04:52:41 -0700 From: Durgadoss R To: lenb@kernel.org, rui.zhang@intel.com Cc: linux-acpi@vger.kernel.org, eduardo.valentin@ti.com, Durgadoss R Subject: [PATCHv3 10/15] Thermal: Introduce fair_share thermal governor Date: Sat, 1 Sep 2012 17:21:31 +0530 Message-Id: <1346500296-25200-11-git-send-email-durgadoss.r@intel.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1346500296-25200-1-git-send-email-durgadoss.r@intel.com> References: <1346500296-25200-1-git-send-email-durgadoss.r@intel.com> Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org This patch introduces a simple 'weight' based governor named fair_share governor. Whenever the thermal framework gets notified of the trip point violation, this governor (if configured), throttles the cooling devices associated with a thermal zone. This mapping between a thermal zone and a cooling device and the effectiveness of cooling are provided in the platform layer. Signed-off-by: Durgadoss R --- drivers/thermal/Kconfig | 6 ++ drivers/thermal/Makefile | 3 +- drivers/thermal/fair_share.c | 133 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 141 insertions(+), 1 deletion(-) create mode 100644 drivers/thermal/fair_share.c diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig index 3ab2bd5..f5110c0 100644 --- a/drivers/thermal/Kconfig +++ b/drivers/thermal/Kconfig @@ -27,3 +27,9 @@ config SPEAR_THERMAL help Enable this to plug the SPEAr thermal sensor driver into the Linux thermal framework + +config FAIR_SHARE + bool "Fair-share thermal governor" + depends on THERMAL + help + Enable this to manage platform thermals using fair-share governor. diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile index a9fff0b..4ffe1a8 100644 --- a/drivers/thermal/Makefile +++ b/drivers/thermal/Makefile @@ -3,4 +3,5 @@ # obj-$(CONFIG_THERMAL) += thermal_sys.o -obj-$(CONFIG_SPEAR_THERMAL) += spear_thermal.o \ No newline at end of file +obj-$(CONFIG_SPEAR_THERMAL) += spear_thermal.o +obj-$(CONFIG_FAIR_SHARE) += fair_share.o diff --git a/drivers/thermal/fair_share.c b/drivers/thermal/fair_share.c new file mode 100644 index 0000000..5d3a7a3 --- /dev/null +++ b/drivers/thermal/fair_share.c @@ -0,0 +1,133 @@ +/* + * fair_share.c - A simple weight based Thermal governor + * + * Copyright (C) 2012 Intel Corp + * Copyright (C) 2012 Durgadoss R + * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2 of the License. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include + +#include "thermal_core.h" + +/** + * get_trip_level: - obtains the current trip level for a zone + * @tz: thermal zone device + */ +static int get_trip_level(struct thermal_zone_device *tz) +{ + int count = 0; + unsigned long trip_temp; + + if (tz->trips == 0 || !tz->ops->get_trip_temp) + return 0; + + for (count = 0; count < tz->trips; count++) { + tz->ops->get_trip_temp(tz, count, &trip_temp); + if (tz->temperature < trip_temp) + break; + } + return count; +} + +static long get_target_state(struct thermal_zone_device *tz, + struct thermal_cooling_device *cdev, int weight, int level) +{ + unsigned long max_state; + + cdev->ops->get_max_state(cdev, &max_state); + + return (long)(weight * level * max_state) / (100 * tz->trips); +} + +/** + * fair_share_throttle - throttles devices asscciated with the given zone + * @tz - thermal_zone_device + * + * Throttling Logic: This uses three parameters to calculate the new + * throttle state of the cooling devices associated with the given zone. + * + * Parameters used for Throttling: + * P1. max_state: Maximum throttle state exposed by the cooling device. + * P2. weight[i]/100: + * How 'effective' the 'i'th device is, in cooling the given zone. + * P3. cur_trip_level/max_no_of_trips: + * This describes the extent to which the devices should be throttled. + * We do not want to throttle too much when we trip a lower temperature, + * whereas the throttling is at full swing if we trip critical levels. + * (Heavily assumes the trip points are in ascending order) + * new_state of cooling device = P3 * P2 * P1 + */ +int fair_share_throttle(struct thermal_zone_device *tz, int trip) +{ + const struct thermal_zone_params *tzp; + struct thermal_cooling_device *cdev; + struct thermal_instance *instance; + int i; + int cur_trip_level = get_trip_level(tz); + + if (!tz->tzp || !tz->tzp->tbp) + return -EINVAL; + + tzp = tz->tzp; + + for (i = 0; i < tzp->num_tbps; i++) { + if (!tzp->tbp[i].cdev) + continue; + + cdev = tzp->tbp[i].cdev; + instance = get_thermal_instance(tz, cdev, trip); + if (!instance) + continue; + + instance->target = get_target_state(tz, cdev, + tzp->tbp[i].weight, cur_trip_level); + + instance->cdev->updated = false; + thermal_cdev_update(cdev); + } + return 0; +} + +struct thermal_governor thermal_gov_fair_share = { + .name = "fair_share", + .throttle = fair_share_throttle, + .owner = THIS_MODULE, +}; + +static int __init thermal_gov_fair_share_init(void) +{ + return thermal_register_governor(&thermal_gov_fair_share); +} + +static void __exit thermal_gov_fair_share_exit(void) +{ + thermal_unregister_governor(&thermal_gov_fair_share); +} + +/* This should load after thermal framework */ +fs_initcall(thermal_gov_fair_share_init); +module_exit(thermal_gov_fair_share_exit); + +MODULE_AUTHOR("Durgadoss R"); +MODULE_DESCRIPTION("A simple weight based thermal throttling governor"); +MODULE_LICENSE("GPL");