From: Daniel Lezcano <daniel.lezcano@linaro.org>
To: "Rafael J. Wysocki" <rjw@rjwysocki.net>,
Linux PM <linux-pm@vger.kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
Linux ACPI <linux-acpi@vger.kernel.org>,
Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
Zhang Rui <rui.zhang@intel.com>,
Lukasz Luba <lukasz.luba@arm.com>,
"Rafael J. Wysocki" <rafael@kernel.org>
Subject: Re: [PATCH v1 07/13] thermal: gov_power_allocator: Use trip pointers instead of trip indices
Date: Wed, 27 Sep 2023 17:10:52 +0200 [thread overview]
Message-ID: <9f1374db-f866-ff52-e86c-99fecee24d1b@linaro.org> (raw)
In-Reply-To: <2590280.Lt9SDvczpP@kreacher>
On 21/09/2023 19:55, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>
> Eliminate the __thermal_zone_get_trip() usage that adds unnecessary
> overhead (due to pointless bounds checking and copying of trip point
> data) from the power allocator thermal governor and generally make it
> use trip pointers instead of trip indices where applicable.
Actually the __thermal_zone_get_trip() change was done on purpose to
replace the 'throttle' callback index parameter by the trip pointer and
removing those call to __thermal_zone_get_trip() while the code was
using the trip pointer.
IMO, the changes should focus on changing the trip_index parameter by
the trip pointer directly in the throttle ops. The pointer can be
retrieved in the handle_thermal_trip() function and passed around for
the rest of the actions on this trip point
> The general functionality is not expected to be changed.
>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> ---
> drivers/thermal/gov_power_allocator.c | 102 ++++++++++++----------------------
> 1 file changed, 38 insertions(+), 64 deletions(-)
>
> Index: linux-pm/drivers/thermal/gov_power_allocator.c
> ===================================================================
> --- linux-pm.orig/drivers/thermal/gov_power_allocator.c
> +++ linux-pm/drivers/thermal/gov_power_allocator.c
> @@ -16,8 +16,6 @@
>
> #include "thermal_core.h"
>
> -#define INVALID_TRIP -1
> -
> #define FRAC_BITS 10
> #define int_to_frac(x) ((x) << FRAC_BITS)
> #define frac_to_int(x) ((x) >> FRAC_BITS)
> @@ -55,23 +53,23 @@ static inline s64 div_frac(s64 x, s64 y)
> * @err_integral: accumulated error in the PID controller.
> * @prev_err: error in the previous iteration of the PID controller.
> * Used to calculate the derivative term.
> + * @sustainable_power: Sustainable power (heat) that this thermal zone can
> + * dissipate
> * @trip_switch_on: first passive trip point of the thermal zone. The
> * governor switches on when this trip point is crossed.
> * If the thermal zone only has one passive trip point,
> - * @trip_switch_on should be INVALID_TRIP.
> + * @trip_switch_on should be NULL.
> * @trip_max_desired_temperature: last passive trip point of the thermal
> * zone. The temperature we are
> * controlling for.
> - * @sustainable_power: Sustainable power (heat) that this thermal zone can
> - * dissipate
> */
> struct power_allocator_params {
> bool allocated_tzp;
> s64 err_integral;
> s32 prev_err;
> - int trip_switch_on;
> - int trip_max_desired_temperature;
> u32 sustainable_power;
> + const struct thermal_trip *trip_switch_on;
> + const struct thermal_trip *trip_max_desired_temperature;
> };
>
> /**
> @@ -90,14 +88,12 @@ static u32 estimate_sustainable_power(st
> u32 sustainable_power = 0;
> struct thermal_instance *instance;
> struct power_allocator_params *params = tz->governor_data;
> - const struct thermal_trip *trip_max_desired_temperature =
> - &tz->trips[params->trip_max_desired_temperature];
>
> list_for_each_entry(instance, &tz->thermal_instances, tz_node) {
> struct thermal_cooling_device *cdev = instance->cdev;
> u32 min_power;
>
> - if (instance->trip != trip_max_desired_temperature)
> + if (instance->trip != params->trip_max_desired_temperature)
> continue;
>
> if (!cdev_is_power_actor(cdev))
> @@ -116,24 +112,23 @@ static u32 estimate_sustainable_power(st
> * estimate_pid_constants() - Estimate the constants for the PID controller
> * @tz: thermal zone for which to estimate the constants
> * @sustainable_power: sustainable power for the thermal zone
> - * @trip_switch_on: trip point number for the switch on temperature
> + * @trip_switch_on: trip point for the switch on temperature
> * @control_temp: target temperature for the power allocator governor
> *
> * This function is used to update the estimation of the PID
> * controller constants in struct thermal_zone_parameters.
> */
> static void estimate_pid_constants(struct thermal_zone_device *tz,
> - u32 sustainable_power, int trip_switch_on,
> + u32 sustainable_power,
> + const struct thermal_trip *trip_switch_on,
> int control_temp)
> {
> - struct thermal_trip trip;
> u32 temperature_threshold = control_temp;
> int ret;
> s32 k_i;
>
> - ret = __thermal_zone_get_trip(tz, trip_switch_on, &trip);
> - if (!ret)
> - temperature_threshold -= trip.temperature;
> + if (trip_switch_on)
> + temperature_threshold -= trip_switch_on->temperature;
>
> /*
> * estimate_pid_constants() tries to find appropriate default
> @@ -386,7 +381,7 @@ static int allocate_power(struct thermal
> struct thermal_instance *instance;
> struct power_allocator_params *params = tz->governor_data;
> const struct thermal_trip *trip_max_desired_temperature =
> - &tz->trips[params->trip_max_desired_temperature];
> + params->trip_max_desired_temperature;
> u32 *req_power, *max_power, *granted_power, *extra_actor_power;
> u32 *weighted_req_power;
> u32 total_req_power, max_allocatable_power, total_weighted_req_power;
> @@ -513,46 +508,35 @@ static int allocate_power(struct thermal
> static void get_governor_trips(struct thermal_zone_device *tz,
> struct power_allocator_params *params)
> {
> - int i, last_active, last_passive;
> - bool found_first_passive;
> -
> - found_first_passive = false;
> - last_active = INVALID_TRIP;
> - last_passive = INVALID_TRIP;
> + const struct thermal_trip *last_active = NULL:
> + const struct thermal_trip *last_passive = NULL;
> + bool found_first_passive = false;
> + int i;
>
> for (i = 0; i < tz->num_trips; i++) {
> - struct thermal_trip trip;
> - int ret;
> + const struct thermal_trip *trip = &tz->trips[i];
>
> - ret = __thermal_zone_get_trip(tz, i, &trip);
> - if (ret) {
> - dev_warn(&tz->device,
> - "Failed to get trip point %d type: %d\n", i,
> - ret);
> - continue;
> - }
> -
> - if (trip.type == THERMAL_TRIP_PASSIVE) {
> + if (trip->type == THERMAL_TRIP_PASSIVE) {
> if (!found_first_passive) {
> - params->trip_switch_on = i;
> + params->trip_switch_on = trip;
> found_first_passive = true;
> } else {
> - last_passive = i;
> + last_passive = trip;
> }
> - } else if (trip.type == THERMAL_TRIP_ACTIVE) {
> - last_active = i;
> + } else if (trip->type == THERMAL_TRIP_ACTIVE) {
> + last_active = trip;
> } else {
> break;
> }
> }
>
> - if (last_passive != INVALID_TRIP) {
> + if (last_passive) {
> params->trip_max_desired_temperature = last_passive;
> } else if (found_first_passive) {
> params->trip_max_desired_temperature = params->trip_switch_on;
> - params->trip_switch_on = INVALID_TRIP;
> + params->trip_switch_on = NULL;
> } else {
> - params->trip_switch_on = INVALID_TRIP;
> + params->trip_switch_on = NULL;
> params->trip_max_desired_temperature = last_active;
> }
> }
> @@ -567,14 +551,12 @@ static void allow_maximum_power(struct t
> {
> struct thermal_instance *instance;
> struct power_allocator_params *params = tz->governor_data;
> - const struct thermal_trip *trip_max_desired_temperature =
> - &tz->trips[params->trip_max_desired_temperature];
> u32 req_power;
>
> list_for_each_entry(instance, &tz->thermal_instances, tz_node) {
> struct thermal_cooling_device *cdev = instance->cdev;
>
> - if ((instance->trip != trip_max_desired_temperature) ||
> + if (instance->trip != params->trip_max_desired_temperature ||
> (!cdev_is_power_actor(instance->cdev)))
> continue;
>
> @@ -636,7 +618,6 @@ static int power_allocator_bind(struct t
> {
> int ret;
> struct power_allocator_params *params;
> - struct thermal_trip trip;
>
> ret = check_power_actors(tz);
> if (ret)
> @@ -662,12 +643,13 @@ static int power_allocator_bind(struct t
> get_governor_trips(tz, params);
>
> if (tz->num_trips > 0) {
> - ret = __thermal_zone_get_trip(tz, params->trip_max_desired_temperature,
> - &trip);
> - if (!ret)
> + const struct thermal_trip *trip;
> +
> + trip = params->trip_max_desired_temperature;
> + if (trip)
> estimate_pid_constants(tz, tz->tzp->sustainable_power,
> params->trip_switch_on,
> - trip.temperature);
> + trip->temperature);
> }
>
> reset_pid_controller(params);
> @@ -697,11 +679,10 @@ static void power_allocator_unbind(struc
> tz->governor_data = NULL;
> }
>
> -static int power_allocator_throttle(struct thermal_zone_device *tz, int trip_id)
> +static int power_allocator_throttle(struct thermal_zone_device *tz, int trip_index)
> {
> struct power_allocator_params *params = tz->governor_data;
> - struct thermal_trip trip;
> - int ret;
> + const struct thermal_trip *trip = &tz->trips[trip_index];
> bool update;
>
> lockdep_assert_held(&tz->lock);
> @@ -710,12 +691,12 @@ static int power_allocator_throttle(stru
> * We get called for every trip point but we only need to do
> * our calculations once
> */
> - if (trip_id != params->trip_max_desired_temperature)
> + if (trip != params->trip_max_desired_temperature)
> return 0;
>
> - ret = __thermal_zone_get_trip(tz, params->trip_switch_on, &trip);
> - if (!ret && (tz->temperature < trip.temperature)) {
> - update = (tz->last_temperature >= trip.temperature);
> + trip = params->trip_switch_on;
> + if (trip && tz->temperature < trip->temperature) {
> + update = tz->last_temperature >= trip->temperature;
> tz->passive = 0;
> reset_pid_controller(params);
> allow_maximum_power(tz, update);
> @@ -724,14 +705,7 @@ static int power_allocator_throttle(stru
>
> tz->passive = 1;
>
> - ret = __thermal_zone_get_trip(tz, params->trip_max_desired_temperature, &trip);
> - if (ret) {
> - dev_warn(&tz->device, "Failed to get the maximum desired temperature: %d\n",
> - ret);
> - return ret;
> - }
> -
> - return allocate_power(tz, trip.temperature);
> + return allocate_power(tz, params->trip_max_desired_temperature->temperature);
> }
>
> static struct thermal_governor thermal_gov_power_allocator = {
>
>
>
--
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next prev parent reply other threads:[~2023-09-27 15:11 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-21 17:46 [PATCH v1 00/13] thermal: ACPI: More ACPI thermal improvements and modification of thermal instances Rafael J. Wysocki
2023-09-21 17:48 ` [PATCH v1 01/13] ACPI: thermal: Add device list to struct acpi_thermal_trip Rafael J. Wysocki
2023-09-26 15:17 ` Daniel Lezcano
2023-09-21 17:49 ` [PATCH v1 02/13] ACPI: thermal: Collapse trip devices update functions Rafael J. Wysocki
2023-09-26 17:18 ` Daniel Lezcano
2023-09-26 17:56 ` Rafael J. Wysocki
2023-09-26 18:04 ` Rafael J. Wysocki
2023-09-26 21:16 ` Daniel Lezcano
2023-09-26 21:33 ` Daniel Lezcano
2023-09-21 17:50 ` [PATCH v1 03/13] ACPI: thermal: Collapse trip devices update function wrappers Rafael J. Wysocki
2023-09-27 9:15 ` Daniel Lezcano
2023-09-21 17:51 ` [PATCH v1 04/13] ACPI: thermal: Merge trip initialization functions Rafael J. Wysocki
2023-09-27 11:58 ` Daniel Lezcano
2023-09-21 17:52 ` [PATCH v1 05/13] thermal: core: Store trip pointer in struct thermal_instance Rafael J. Wysocki
2023-09-27 14:56 ` Daniel Lezcano
2023-09-21 17:54 ` [PATCH v1 06/13] thermal: gov_fair_share: Rearrange get_trip_level() Rafael J. Wysocki
2023-09-27 15:00 ` Daniel Lezcano
2023-09-27 15:06 ` Rafael J. Wysocki
2023-09-27 15:37 ` Daniel Lezcano
2023-09-27 16:09 ` Rafael J. Wysocki
2023-09-21 17:55 ` [PATCH v1 07/13] thermal: gov_power_allocator: Use trip pointers instead of trip indices Rafael J. Wysocki
2023-09-27 15:10 ` Daniel Lezcano [this message]
2023-09-27 15:27 ` Rafael J. Wysocki
2023-09-27 15:46 ` Daniel Lezcano
2023-09-27 16:14 ` Rafael J. Wysocki
2023-09-21 17:56 ` [PATCH v1 08/13] thermal: gov_step_wise: Fold update_passive_instance() into its caller Rafael J. Wysocki
2023-09-21 17:58 ` [PATCH v1 09/13] thermal: core: Rename trip point index function arguments in governors Rafael J. Wysocki
2023-09-21 18:01 ` [PATCH v1 10/13] thermal: core: Allow trip pointers to be used for cooling device binding Rafael J. Wysocki
2023-09-28 7:10 ` Daniel Lezcano
2023-09-28 10:38 ` Rafael J. Wysocki
2023-09-28 13:31 ` Daniel Lezcano
2023-09-21 18:02 ` [PATCH v1 11/13] ACPI: thermal: Do not use trip indices " Rafael J. Wysocki
2023-09-28 7:24 ` Daniel Lezcano
2023-09-21 18:04 ` [PATCH v1 12/13] ACPI: thermal: Drop critical_valid and hot_valid trip flags Rafael J. Wysocki
2023-09-28 7:25 ` Daniel Lezcano
2023-09-21 18:06 ` [PATCH v1 13/13] ACPI: thermal: Rename structure fields holding temperature in deci-Kelvin Rafael J. Wysocki
2023-09-28 7:28 ` Daniel Lezcano
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