From mboxrd@z Thu Jan 1 00:00:00 1970 From: Zhang Rui Subject: Re: [PATCHv4 11/15] Thermal: Introduce a step_wise thermal governor Date: Tue, 18 Sep 2012 15:13:30 +0800 Message-ID: <1347952410.1682.1227.camel@rui.sh.intel.com> References: <1347946506-18449-1-git-send-email-durgadoss.r@intel.com> <1347946506-18449-12-git-send-email-durgadoss.r@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mga14.intel.com ([143.182.124.37]:59314 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756849Ab2IRHM4 (ORCPT ); Tue, 18 Sep 2012 03:12:56 -0400 In-Reply-To: <1347946506-18449-12-git-send-email-durgadoss.r@intel.com> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Durgadoss R Cc: lenb@kernel.org, linux-acpi@vger.kernel.org, eduardo.valentin@ti.com On =E4=BA=8C, 2012-09-18 at 11:05 +0530, Durgadoss R wrote: > This patch adds a simple step_wise governor to the > generic thermal layer. This algorithm throttles the > cooling devices in a linear fashion. If the 'trend' > is heating, it throttles by one step. And if the > thermal trend is cooling it de-throttles by one step. >=20 > This actually moves the throttling logic from thermal_sys.c > and puts inside step_wise.c, without any change. This is > always selected as the default governor. >=20 > Signed-off-by: Durgadoss R > --- > drivers/thermal/Kconfig | 7 ++ > drivers/thermal/Makefile | 1 + > drivers/thermal/step_wise.c | 194 +++++++++++++++++++++++++++++++++= ++++++++++ > 3 files changed, 202 insertions(+) > create mode 100644 drivers/thermal/step_wise.c >=20 > diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig > index 2200912..9f6a3aa 100644 > --- a/drivers/thermal/Kconfig > +++ b/drivers/thermal/Kconfig > @@ -4,6 +4,7 @@ > =20 > menuconfig THERMAL > tristate "Generic Thermal sysfs driver" > + select STEP_WISE > help > Generic Thermal Sysfs driver offers a generic mechanism for > thermal management. Usually it's made up of one or more thermal > @@ -59,3 +60,9 @@ config FAIR_SHARE > depends on THERMAL > help > Enable this to manage platform thermals using fair-share governor= =2E > + > +config STEP_WISE > + bool "Step_wise thermal governor" > + depends on THERMAL > + help > + Enable this to manage platform thermals using a simple linear if we always wants CONFIG_STEP_WISE built in, why bother to export this config option to users? IMO, something like menuconfig THERMAL tristate "Generic Thermal sysfs driver" select STEP_WISE config STEP_WISE bool depends on THERMAL is enough, SETP_WISE will always be selected. further more, we even do not need a config option for this governor, just "obj-y +=3D step_wise.o" in Makefile. another question would be, as this governor registration function is fs_initcall(), what if a platform thermal driver is registered and gets a thermal even= t before this governor being registered? thanks, rui > diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile > index 30540dd..4e53c00 100644 > --- a/drivers/thermal/Makefile > +++ b/drivers/thermal/Makefile > @@ -8,3 +8,4 @@ obj-$(CONFIG_SPEAR_THERMAL) +=3D spear_thermal.o > obj-$(CONFIG_RCAR_THERMAL) +=3D rcar_thermal.o > obj-$(CONFIG_EXYNOS_THERMAL) +=3D exynos_thermal.o > obj-$(CONFIG_FAIR_SHARE) +=3D fair_share.o > +obj-$(CONFIG_STEP_WISE) +=3D step_wise.o > diff --git a/drivers/thermal/step_wise.c b/drivers/thermal/step_wise.= c > new file mode 100644 > index 0000000..3f9cfcf > --- /dev/null > +++ b/drivers/thermal/step_wise.c > @@ -0,0 +1,194 @@ > +/* > + * step_wise.c - A step-by-step Thermal throttling governor > + * > + * Copyright (C) 2012 Intel Corp > + * Copyright (C) 2012 Durgadoss R > + * > + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~= ~~~~~~~~~~ > + * > + * This program is free software; you can redistribute it and/or mo= dify > + * it under the terms of the GNU General Public License as publishe= d 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 GN= U > + * General Public License for more details. > + * > + * You should have received a copy of the GNU General Public Licens= e 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" > + > +/* > + * If the temperature is higher than a trip point, > + * a. if the trend is THERMAL_TREND_RAISING, use higher cooling > + * state for this trip point > + * b. if the trend is THERMAL_TREND_DROPPING, use lower cooling > + * state for this trip point > + */ > +static unsigned long get_target_state(struct thermal_instance *insta= nce, > + enum thermal_trend trend) > +{ > + struct thermal_cooling_device *cdev =3D instance->cdev; > + unsigned long cur_state; > + > + cdev->ops->get_cur_state(cdev, &cur_state); > + > + if (trend =3D=3D THERMAL_TREND_RAISING) { > + cur_state =3D cur_state < instance->upper ? > + (cur_state + 1) : instance->upper; > + } else if (trend =3D=3D THERMAL_TREND_DROPPING) { > + cur_state =3D cur_state > instance->lower ? > + (cur_state - 1) : instance->lower; > + } > + > + return cur_state; > +} > + > +static void update_passive_instance(struct thermal_zone_device *tz, > + enum thermal_trip_type type, int value) > +{ > + /* > + * If value is +1, activate a passive instance. > + * If value is -1, deactivate a passive instance. > + */ > + if (type =3D=3D THERMAL_TRIP_PASSIVE || type =3D=3D THERMAL_TRIPS_N= ONE) > + tz->passive +=3D value; > +} > + > +static void update_instance_for_throttle(struct thermal_zone_device = *tz, > + int trip, enum thermal_trip_type trip_type, > + enum thermal_trend trend) > +{ > + struct thermal_instance *instance; > + > + list_for_each_entry(instance, &tz->thermal_instances, tz_node) { > + if (instance->trip !=3D trip) > + continue; > + > + instance->target =3D get_target_state(instance, trend); > + > + /* Activate a passive thermal instance */ > + if (instance->target =3D=3D THERMAL_NO_TARGET) > + update_passive_instance(tz, trip_type, 1); > + > + instance->cdev->updated =3D false; /* cdev needs update */ > + } > +} > + > +static void update_instance_for_dethrottle(struct thermal_zone_devic= e *tz, > + int trip, enum thermal_trip_type trip_type) > +{ > + struct thermal_instance *instance; > + struct thermal_cooling_device *cdev; > + unsigned long cur_state; > + > + list_for_each_entry(instance, &tz->thermal_instances, tz_node) { > + if (instance->trip !=3D trip || > + instance->target =3D=3D THERMAL_NO_TARGET) > + continue; > + > + cdev =3D instance->cdev; > + cdev->ops->get_cur_state(cdev, &cur_state); > + > + instance->target =3D cur_state > instance->lower ? > + (cur_state - 1) : THERMAL_NO_TARGET; > + > + /* Deactivate a passive thermal instance */ > + if (instance->target =3D=3D THERMAL_NO_TARGET) > + update_passive_instance(tz, trip_type, -1); > + > + cdev->updated =3D false; /* cdev needs update */ > + } > +} > + > +static void thermal_zone_trip_update(struct thermal_zone_device *tz,= int trip) > +{ > + long trip_temp; > + enum thermal_trip_type trip_type; > + enum thermal_trend trend; > + > + if (trip =3D=3D THERMAL_TRIPS_NONE) { > + trip_temp =3D tz->forced_passive; > + trip_type =3D THERMAL_TRIPS_NONE; > + } else { > + tz->ops->get_trip_temp(tz, trip, &trip_temp); > + tz->ops->get_trip_type(tz, trip, &trip_type); > + } > + > + trend =3D get_tz_trend(tz, trip); > + > + mutex_lock(&tz->lock); > + > + if (tz->temperature >=3D trip_temp) > + update_instance_for_throttle(tz, trip, trip_type, trend); > + else > + update_instance_for_dethrottle(tz, trip, trip_type); > + > + mutex_unlock(&tz->lock); > +} > + > +/** > + * step_wise_throttle - throttles devices asscciated with the given = zone > + * @tz - thermal_zone_device > + * @trip - the trip point > + * @trip_type - type of the trip point > + * > + * Throttling Logic: This uses the trend of the thermal zone to thro= ttle. > + * If the thermal zone is 'heating up' this throttles all the coolin= g > + * devices associated with the zone and its particular trip point, b= y one > + * step. If the zone is 'cooling down' it brings back the performanc= e of > + * the devices by one step. > + */ > +int step_wise_throttle(struct thermal_zone_device *tz, int trip) > +{ > + struct thermal_instance *instance; > + > + thermal_zone_trip_update(tz, trip); > + > + if (tz->forced_passive) > + thermal_zone_trip_update(tz, THERMAL_TRIPS_NONE); > + > + mutex_lock(&tz->lock); > + > + list_for_each_entry(instance, &tz->thermal_instances, tz_node) > + thermal_cdev_update(instance->cdev); > + > + mutex_unlock(&tz->lock); > + > + return 0; > +} > + > +struct thermal_governor thermal_gov_step_wise =3D { > + .name =3D DEFAULT_THERMAL_GOVERNOR, > + .throttle =3D step_wise_throttle, > + .owner =3D THIS_MODULE, > +}; > + > +static int __init thermal_gov_step_wise_init(void) > +{ > + return thermal_register_governor(&thermal_gov_step_wise); > +} > + > +static void __exit thermal_gov_step_wise_exit(void) > +{ > + thermal_unregister_governor(&thermal_gov_step_wise); > +} > + > +/* This should load after thermal framework */ > +fs_initcall(thermal_gov_step_wise_init); > +module_exit(thermal_gov_step_wise_exit); > + > +MODULE_AUTHOR("Durgadoss R"); > +MODULE_DESCRIPTION("A step-by-step thermal throttling governor"); > +MODULE_LICENSE("GPL"); -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html