2023-03-22 19:36:27

by Rafael J. Wysocki

[permalink] [raw]
Subject: [PATCH v1] thermal: core: Clean up thermal_list_lock locking

From: Rafael J. Wysocki <[email protected]>

Once thermal_list_lock has been acquired in
__thermal_cooling_device_register(), it is not necessary to drop it
and take it again until all of the thermal zones have been updated,
so change the code accordingly.

No expected functional impact.

Signed-off-by: Rafael J. Wysocki <[email protected]>
---
drivers/thermal/thermal_core.c | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)

Index: linux-pm/drivers/thermal/thermal_core.c
===================================================================
--- linux-pm.orig/drivers/thermal/thermal_core.c
+++ linux-pm/drivers/thermal/thermal_core.c
@@ -826,8 +826,6 @@ static void bind_cdev(struct thermal_coo
const struct thermal_zone_params *tzp;
struct thermal_zone_device *pos = NULL;

- mutex_lock(&thermal_list_lock);
-
list_for_each_entry(pos, &thermal_tz_list, node) {
if (!pos->tzp && !pos->ops->bind)
continue;
@@ -854,8 +852,6 @@ static void bind_cdev(struct thermal_coo
tzp->tbp[i].weight);
}
}
-
- mutex_unlock(&thermal_list_lock);
}

/**
@@ -933,17 +929,17 @@ __thermal_cooling_device_register(struct

/* Add 'this' new cdev to the global cdev list */
mutex_lock(&thermal_list_lock);
+
list_add(&cdev->node, &thermal_cdev_list);
- mutex_unlock(&thermal_list_lock);

/* Update binding information for 'this' new cdev */
bind_cdev(cdev);

- mutex_lock(&thermal_list_lock);
list_for_each_entry(pos, &thermal_tz_list, node)
if (atomic_cmpxchg(&pos->need_update, 1, 0))
thermal_zone_device_update(pos,
THERMAL_EVENT_UNSPECIFIED);
+
mutex_unlock(&thermal_list_lock);

return cdev;




2023-04-01 20:50:32

by Daniel Lezcano

[permalink] [raw]
Subject: Re: [PATCH v1] thermal: core: Clean up thermal_list_lock locking

On 22/03/2023 20:34, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <[email protected]>
>
> Once thermal_list_lock has been acquired in
> __thermal_cooling_device_register(), it is not necessary to drop it
> and take it again until all of the thermal zones have been updated,
> so change the code accordingly.
>
> No expected functional impact.
>
> Signed-off-by: Rafael J. Wysocki <[email protected]>
> ---

Looks good to me, shall I pick it in my branch ?


> drivers/thermal/thermal_core.c | 8 ++------
> 1 file changed, 2 insertions(+), 6 deletions(-)
>
> Index: linux-pm/drivers/thermal/thermal_core.c
> ===================================================================
> --- linux-pm.orig/drivers/thermal/thermal_core.c
> +++ linux-pm/drivers/thermal/thermal_core.c
> @@ -826,8 +826,6 @@ static void bind_cdev(struct thermal_coo
> const struct thermal_zone_params *tzp;
> struct thermal_zone_device *pos = NULL;
>
> - mutex_lock(&thermal_list_lock);
> -
> list_for_each_entry(pos, &thermal_tz_list, node) {
> if (!pos->tzp && !pos->ops->bind)
> continue;
> @@ -854,8 +852,6 @@ static void bind_cdev(struct thermal_coo
> tzp->tbp[i].weight);
> }
> }
> -
> - mutex_unlock(&thermal_list_lock);
> }
>
> /**
> @@ -933,17 +929,17 @@ __thermal_cooling_device_register(struct
>
> /* Add 'this' new cdev to the global cdev list */
> mutex_lock(&thermal_list_lock);
> +
> list_add(&cdev->node, &thermal_cdev_list);
> - mutex_unlock(&thermal_list_lock);
>
> /* Update binding information for 'this' new cdev */
> bind_cdev(cdev);
>
> - mutex_lock(&thermal_list_lock);
> list_for_each_entry(pos, &thermal_tz_list, node)
> if (atomic_cmpxchg(&pos->need_update, 1, 0))
> thermal_zone_device_update(pos,
> THERMAL_EVENT_UNSPECIFIED);
> +
> mutex_unlock(&thermal_list_lock);
>
> return cdev;
>
>
>

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2023-04-03 17:52:13

by Rafael J. Wysocki

[permalink] [raw]
Subject: Re: [PATCH v1] thermal: core: Clean up thermal_list_lock locking

On Sat, Apr 1, 2023 at 10:45 PM Daniel Lezcano
<[email protected]> wrote:
>
> On 22/03/2023 20:34, Rafael J. Wysocki wrote:
> > From: Rafael J. Wysocki <[email protected]>
> >
> > Once thermal_list_lock has been acquired in
> > __thermal_cooling_device_register(), it is not necessary to drop it
> > and take it again until all of the thermal zones have been updated,
> > so change the code accordingly.
> >
> > No expected functional impact.
> >
> > Signed-off-by: Rafael J. Wysocki <[email protected]>
> > ---
>
> Looks good to me, shall I pick it in my branch ?

No, I;ll take care of it myself, thanks!

> > drivers/thermal/thermal_core.c | 8 ++------
> > 1 file changed, 2 insertions(+), 6 deletions(-)
> >
> > Index: linux-pm/drivers/thermal/thermal_core.c
> > ===================================================================
> > --- linux-pm.orig/drivers/thermal/thermal_core.c
> > +++ linux-pm/drivers/thermal/thermal_core.c
> > @@ -826,8 +826,6 @@ static void bind_cdev(struct thermal_coo
> > const struct thermal_zone_params *tzp;
> > struct thermal_zone_device *pos = NULL;
> >
> > - mutex_lock(&thermal_list_lock);
> > -
> > list_for_each_entry(pos, &thermal_tz_list, node) {
> > if (!pos->tzp && !pos->ops->bind)
> > continue;
> > @@ -854,8 +852,6 @@ static void bind_cdev(struct thermal_coo
> > tzp->tbp[i].weight);
> > }
> > }
> > -
> > - mutex_unlock(&thermal_list_lock);
> > }
> >
> > /**
> > @@ -933,17 +929,17 @@ __thermal_cooling_device_register(struct
> >
> > /* Add 'this' new cdev to the global cdev list */
> > mutex_lock(&thermal_list_lock);
> > +
> > list_add(&cdev->node, &thermal_cdev_list);
> > - mutex_unlock(&thermal_list_lock);
> >
> > /* Update binding information for 'this' new cdev */
> > bind_cdev(cdev);
> >
> > - mutex_lock(&thermal_list_lock);
> > list_for_each_entry(pos, &thermal_tz_list, node)
> > if (atomic_cmpxchg(&pos->need_update, 1, 0))
> > thermal_zone_device_update(pos,
> > THERMAL_EVENT_UNSPECIFIED);
> > +
> > mutex_unlock(&thermal_list_lock);
> >
> > return cdev;
> >
> >
> >
>
> --
> <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs
>
> Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook |
> <http://twitter.com/#!/linaroorg> Twitter |
> <http://www.linaro.org/linaro-blog/> Blog
>