Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756532AbcCCDRI (ORCPT ); Wed, 2 Mar 2016 22:17:08 -0500 Received: from mail-pf0-f171.google.com ([209.85.192.171]:34558 "EHLO mail-pf0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754085AbcCCDRG (ORCPT ); Wed, 2 Mar 2016 22:17:06 -0500 Date: Wed, 2 Mar 2016 19:17:02 -0800 From: Eduardo Valentin To: Javi Merino Cc: linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, rui.zang@intel.com, Zhang Rui Subject: Re: [PATCH v3 4/4] thermal: show the sub thermal zones in sysfs Message-ID: <20160303031700.GB3379@localhost.localdomain> References: <1448464186-26289-1-git-send-email-javi.merino@arm.com> <1448464186-26289-5-git-send-email-javi.merino@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1448464186-26289-5-git-send-email-javi.merino@arm.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 10576 Lines: 293 On Wed, Nov 25, 2015 at 03:09:46PM +0000, Javi Merino wrote: > When a thermal zone is created that has sub thermal zones via > devicetree or via thermal_zone_add_subtz() expose that relationship in > sysfs. > > Cc: Zhang Rui > Cc: Eduardo Valentin > Signed-off-by: Javi Merino > --- > Documentation/thermal/sysfs-api.txt | 33 ++++++++++ > drivers/thermal/thermal_core.c | 125 ++++++++++++++++++++++++++++++++++++ > include/linux/thermal.h | 3 + > 3 files changed, 161 insertions(+) > > diff --git a/Documentation/thermal/sysfs-api.txt b/Documentation/thermal/sysfs-api.txt > index dda24a0bdeec..5636a531f0b1 100644 > --- a/Documentation/thermal/sysfs-api.txt > +++ b/Documentation/thermal/sysfs-api.txt > @@ -219,11 +219,16 @@ Thermal zone device sys I/F, created once it's registered: > |---temp: Current temperature > |---mode: Working mode of the thermal zone > |---policy: Thermal governor used for this zone > + |---aggregation_function: Function to use when aggregating the > + temperature of this zone's slave thermal zones > |---available_policies: Available thermal governors for this zone > |---trip_point_[0-*]_temp: Trip point temperature > |---trip_point_[0-*]_type: Trip point type > |---trip_point_[0-*]_hyst: Hysteresis value for this trip point > |---emul_temp: Emulated temperature set node > + |---subtz[0-*]: Slave thermal zones of this thermal zone > + |---subtz[0-*]_weight: Weight of the slave thermal zone on > + this thermal zone > |---sustainable_power: Sustainable dissipatable power > |---k_po: Proportional term during temperature overshoot > |---k_pu: Proportional term during temperature undershoot > @@ -296,6 +301,19 @@ policy > One of the various thermal governors used for a particular zone. > RW, Required > > +aggregation_function > + The aggregation function used to calculate the temperature of > + this thermal zone when it has sub thermal zones. It can > + either be "max" or "weighted_average". If it's "max", the > + temperature of this thermal zone is the maximum of the > + temperatures of the sub thermal zones. If > + aggregation_function is "weighted_average", the temperature of > + this thermal zone is the weighted average of the temperatures > + of the sub thermal zones. The weights are specified in > + subtz[0-*]_weights. The aggregation_function sysfs entry > + doesn't exist for thermal zones without sub thermal zones. > + RW, Optional > + > available_policies > Available thermal governors which can be used for a particular zone. > RO, Required > @@ -359,6 +377,21 @@ emul_temp > because userland can easily disable the thermal policy by simply > flooding this sysfs node with low temperature values. > > +subtz[0-*] > + sysfs link to the slave thermal zone device. > + RO, Optional > + > +subtz[0-*]_weight > + The influence of subtz[0-*] in this thermal zone. This > + parameter is only used when using "weighted_average" as the > + aggregation_function. When calculating the temperature of > + this thermal zone, the temperature of each of the thermal > + zone's slaves is multiplied by its weight. The result is > + divided by the sum of all weights. If all weights are 0, > + the temperature of this thermal zone is the average of the > + temperatures of the sub thermal zones. > + RW, Optional > + > sustainable_power > An estimate of the sustained power that can be dissipated by > the thermal zone. Used by the power allocator governor. For > diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c > index 98bdb63b3b95..2bb1af0a9349 100644 > --- a/drivers/thermal/thermal_core.c > +++ b/drivers/thermal/thermal_core.c > @@ -63,14 +63,23 @@ static struct thermal_governor *def_governor; > > /** > * struct thermal_zone_link - a link between "master" and "slave" thermal zones > + * @id: link number in the master thermal zone > + * @name: filename in the master thermal zone's sysfs directory > * @weight: weight of the @slave thermal zone in the master > * calculation. Used when the master thermal zone's > * aggregation function is THERMAL_AGG_WEIGHTED_AVG > + * @weight_attr_name: filename of the weight attribute in the master's thermal > + * zone sysfs directory > + * @weight_attr: device attribute for the weight entry in sysfs > * @slave: pointer to the slave thermal zone > * @node: list node in the master thermal zone's slave_tzs list. > */ > struct thermal_zone_link { > + int id; > + char name[THERMAL_NAME_LENGTH]; > int weight; > + char weight_attr_name[THERMAL_NAME_LENGTH]; Are you sure you need this? > + struct device_attribute weight_attr; > struct thermal_zone_device *slave; > struct list_head node; > }; > @@ -990,6 +999,45 @@ emul_temp_store(struct device *dev, struct device_attribute *attr, > static DEVICE_ATTR(emul_temp, S_IWUSR, NULL, emul_temp_store); > > static ssize_t > +agg_func_show(struct device *dev, struct device_attribute *devattr, char *buf) > +{ > + struct thermal_zone_device *tz = to_thermal_zone(dev); > + > + if (tz->slave_agg_function == THERMAL_AGG_MAX) > + return sprintf(buf, "max\n"); > + else if (tz->slave_agg_function == THERMAL_AGG_WEIGHTED_AVG) > + return sprintf(buf, "weighted_average\n"); > + else > + return sprintf(buf, "(invalid)\n"); > +} > + > +static ssize_t > +agg_func_store(struct device *dev, struct device_attribute *attr, > + const char *buf, size_t count) > +{ > + int ret = 0; > + struct thermal_zone_device *tz = to_thermal_zone(dev); > + char func_name[THERMAL_NAME_LENGTH]; > + > + snprintf(func_name, sizeof(func_name), "%s", buf); > + > + mutex_lock(&tz->lock); > + > + if (sysfs_streq(func_name, "max")) > + tz->slave_agg_function = THERMAL_AGG_MAX; > + else if (sysfs_streq(func_name, "weighted_average")) > + tz->slave_agg_function = THERMAL_AGG_WEIGHTED_AVG; > + else > + ret = -EINVAL; > + > + mutex_unlock(&tz->lock); > + > + return ret ? ret : count; > +} > +static DEVICE_ATTR(aggregation_function, S_IRUGO | S_IWUSR, agg_func_show, > + agg_func_store); > + > +static ssize_t > sustainable_power_show(struct device *dev, struct device_attribute *devattr, > char *buf) > { > @@ -1305,6 +1353,35 @@ thermal_cooling_device_weight_store(struct device *dev, > > return count; > } > + > +static ssize_t > +thermal_subtz_weight_show(struct device *dev, struct device_attribute *attr, > + char *buf) > +{ > + struct thermal_zone_link *link; > + > + link = container_of(attr, struct thermal_zone_link, weight_attr); > + > + return sprintf(buf, "%d\n", link->weight); > +} > + > +static ssize_t > +thermal_subtz_weight_store(struct device *dev, struct device_attribute *attr, > + const char *buf, size_t count) > +{ > + struct thermal_zone_link *link; > + int ret, weight; > + > + ret = kstrtoint(buf, 0, &weight); > + if (ret) > + return ret; > + > + link = container_of(attr, struct thermal_zone_link, weight_attr); > + link->weight = weight; > + > + return count; > +} > + Now thinking of this, I see how you could input: (0.25 * T0 - 2C) + (0.75 * T1 + 1C) //where T0 is sensor of subtz0 and T1 is sensor of subtz1 for example. Which is a typical case, from what I have been seeing. How about if we change weight to: (ak/bk)*Tk + ck ? > /* Device management */ > > /** > @@ -2135,6 +2212,47 @@ int thermal_zone_add_subtz(struct thermal_zone_device *tz, > link->weight = weight; > list_add_tail(&link->node, &tz->slave_tzs); > > + if (list_is_singular(&tz->slave_tzs)) { > + ret = device_create_file(&tz->device, > + &dev_attr_aggregation_function); > + if (ret) > + pr_warn("Failed to create aggregation_function sysfs file: %d\n", > + ret); > + /* > + * Fall through: we failed to create the sysfs file, but > + * it's not fatal > + */ > + } > + > + ret = get_idr(&tz->link_idr, NULL, &link->id); > + if (ret) { > + /* > + * Even if we can't create the symlink in sysfs, > + * we've linked the thermal zones, so return success > + */ > + ret = 0; > + goto unlock; > + } > + > + snprintf(link->name, ARRAY_SIZE(link->name), "subtz%d", link->id); > + ret = sysfs_create_link(&tz->device.kobj, &subtz->device.kobj, > + link->name); > + if (ret) > + pr_warn("Failed to create symlink to sub thermal zone: %d\n", > + ret); > + > + snprintf(link->weight_attr_name, THERMAL_NAME_LENGTH, "subtz%d_weight", > + link->id); > + sysfs_attr_init(&link->weight_attr.attr); > + link->weight_attr.attr.name = link->weight_attr_name; > + link->weight_attr.attr.mode = S_IWUSR | S_IRUGO; > + link->weight_attr.show = thermal_subtz_weight_show; > + link->weight_attr.store = thermal_subtz_weight_store; > + ret = device_create_file(&tz->device, &link->weight_attr); > + if (ret) > + pr_warn("Failed to create sub thermal zone weight: %d\n", > + ret); > + > ret = 0; > > unlock: > @@ -2166,6 +2284,10 @@ int thermal_zone_del_subtz(struct thermal_zone_device *tz, > > list_for_each_entry(link, &tz->slave_tzs, node) { > if (link->slave == subtz) { > + device_remove_file(&tz->device, &link->weight_attr); > + sysfs_remove_link(&tz->device.kobj, link->name); > + release_idr(&tz->link_idr, NULL, link->id); > + > list_del(&link->node); > kfree(link); > > @@ -2174,6 +2296,9 @@ int thermal_zone_del_subtz(struct thermal_zone_device *tz, > } > } > > + if (list_empty(&tz->slave_tzs)) > + device_remove_file(&tz->device, &dev_attr_aggregation_function); > + > mutex_unlock(&tz->lock); > > return ret; > diff --git a/include/linux/thermal.h b/include/linux/thermal.h > index dc3d2ab77ab6..f14884353230 100644 > --- a/include/linux/thermal.h > +++ b/include/linux/thermal.h > @@ -192,6 +192,8 @@ struct thermal_attr { > * @thermal_instances: list of &struct thermal_instance of this thermal zone > * @idr: &struct idr to generate unique id for this zone's cooling > * devices > + * @link_idr: &struct idr to generate unique ids for this zone's links to > + * other thermal zones > * @lock: lock to protect thermal_instances list > * @node: node in thermal_tz_list (in thermal_core.c) > * @poll_queue: delayed work for polling > @@ -221,6 +223,7 @@ struct thermal_zone_device { > void *governor_data; > struct list_head thermal_instances; > struct idr idr; > + struct idr link_idr; > struct mutex lock; > struct list_head node; > struct delayed_work poll_queue; > -- > 1.9.1 >