linux-kernel - Re: [PATCH v2 08/11] thermal: core: Introduce thermal_cdev_update

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Message-ID: <51bdabae-6464-4a11-8017-b97d51223466@arm.com>
Date: Tue, 22 Oct 2024 23:23:09 +0100
From: Lukasz Luba <lukasz.luba@....com>
To: "Rafael J. Wysocki" <rjw@...ysocki.net>
Cc: LKML <linux-kernel@...r.kernel.org>, Linux PM <linux-pm@...r.kernel.org>,
 Daniel Lezcano <daniel.lezcano@...aro.org>, Zhang Rui <rui.zhang@...el.com>,
 Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>
Subject: Re: [PATCH v2 08/11] thermal: core: Introduce
 thermal_cdev_update_nocheck()



On 10/10/24 23:16, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
> 
> Three thermal governors call __thermal_cdev_update() under the
> cdev lock without doing any checks, so in order to reduce the
> related code duplication, introduce a new helper function called
> thermal_cdev_update_nocheck() for them and make them use it.
> 
> No intentional functional impact.
> 
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
> ---
> 
> This is a resend of
> 
> https://lore.kernel.org/linux-pm/3791590.MHq7AAxBmi@rjwysocki.net/
> 
> ---
>   drivers/thermal/gov_bang_bang.c       |    4 +---
>   drivers/thermal/gov_fair_share.c      |    4 +---
>   drivers/thermal/gov_power_allocator.c |    5 ++---
>   drivers/thermal/thermal_core.h        |    1 +
>   drivers/thermal/thermal_helpers.c     |   13 +++++++++++++
>   5 files changed, 18 insertions(+), 9 deletions(-)
> 
> Index: linux-pm/drivers/thermal/gov_bang_bang.c
> ===================================================================
> --- linux-pm.orig/drivers/thermal/gov_bang_bang.c
> +++ linux-pm/drivers/thermal/gov_bang_bang.c
> @@ -30,9 +30,7 @@ static void bang_bang_set_instance_targe
>   
>   	dev_dbg(&instance->cdev->device, "target=%ld\n", instance->target);
>   
> -	mutex_lock(&instance->cdev->lock);
> -	__thermal_cdev_update(instance->cdev);
> -	mutex_unlock(&instance->cdev->lock);
> +	thermal_cdev_update_nocheck(instance->cdev);
>   }
>   
>   /**
> Index: linux-pm/drivers/thermal/gov_fair_share.c
> ===================================================================
> --- linux-pm.orig/drivers/thermal/gov_fair_share.c
> +++ linux-pm/drivers/thermal/gov_fair_share.c
> @@ -89,9 +89,7 @@ static void fair_share_throttle(struct t
>   		}
>   		instance->target = div_u64(dividend, divisor);
>   
> -		mutex_lock(&cdev->lock);
> -		__thermal_cdev_update(cdev);
> -		mutex_unlock(&cdev->lock);
> +		thermal_cdev_update_nocheck(cdev);
>   	}
>   }
>   
> 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
> @@ -322,9 +322,8 @@ power_actor_set_power(struct thermal_coo
>   		return ret;
>   
>   	instance->target = clamp_val(state, instance->lower, instance->upper);
> -	mutex_lock(&cdev->lock);
> -	__thermal_cdev_update(cdev);
> -	mutex_unlock(&cdev->lock);
> +
> +	thermal_cdev_update_nocheck(cdev);
>   
>   	return 0;
>   }
> Index: linux-pm/drivers/thermal/thermal_core.h
> ===================================================================
> --- linux-pm.orig/drivers/thermal/thermal_core.h
> +++ linux-pm/drivers/thermal/thermal_core.h
> @@ -213,6 +213,7 @@ static inline bool cdev_is_power_actor(s
>   }
>   
>   void thermal_cdev_update(struct thermal_cooling_device *);
> +void thermal_cdev_update_nocheck(struct thermal_cooling_device *cdev);
>   void __thermal_cdev_update(struct thermal_cooling_device *cdev);
>   
>   int get_tz_trend(struct thermal_zone_device *tz, const struct thermal_trip *trip);
> Index: linux-pm/drivers/thermal/thermal_helpers.c
> ===================================================================
> --- linux-pm.orig/drivers/thermal/thermal_helpers.c
> +++ linux-pm/drivers/thermal/thermal_helpers.c
> @@ -206,6 +206,19 @@ void thermal_cdev_update(struct thermal_
>   }
>   
>   /**
> + * thermal_cdev_update_nocheck() - Unconditionally update cooling device state
> + * @cdev: Target cooling device.
> + */
> +void thermal_cdev_update_nocheck(struct thermal_cooling_device *cdev)
> +{
> +	mutex_lock(&cdev->lock);
> +
> +	__thermal_cdev_update(cdev);
> +
> +	mutex_unlock(&cdev->lock);
> +}
> +
> +/**
>    * thermal_zone_get_slope - return the slope attribute of the thermal zone
>    * @tz: thermal zone device with the slope attribute
>    *
> 
> 
> 


Reviewed-by: Lukasz Luba <lukasz.luba@....com>