| Message ID | 1343292083-2047-14-git-send-email-rui.zhang@intel.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On Thursday, July 26, 2012, Zhang Rui wrote: > we need to go over all the thermal_instance list of a cooling device > to decide which cooling state to put the cooling device to. > > But at this time, as a cooling device may be referenced in multiple > thermal zones, we need to lock the list first in case > another thermal zone is updating this cooling device. > > Signed-off-by: Zhang Rui <rui.zhang@intel.com> Reviewed-by: Rafael J. Wysocki <rjw@sisk.pl> > --- > drivers/thermal/thermal_sys.c | 8 ++++++++ > include/linux/thermal.h | 1 + > 2 files changed, 9 insertions(+) > > diff --git a/drivers/thermal/thermal_sys.c b/drivers/thermal/thermal_sys.c > index 7f3a891..356a59d 100644 > --- a/drivers/thermal/thermal_sys.c > +++ b/drivers/thermal/thermal_sys.c > @@ -799,6 +799,7 @@ int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz, > goto remove_symbol_link; > > mutex_lock(&tz->lock); > + mutex_lock(&cdev->lock); > list_for_each_entry(pos, &tz->thermal_instances, tz_node) > if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) { > result = -EEXIST; > @@ -808,6 +809,7 @@ int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz, > list_add_tail(&dev->tz_node, &tz->thermal_instances); > list_add_tail(&dev->cdev_node, &cdev->thermal_instances); > } > + mutex_unlock(&cdev->lock); > mutex_unlock(&tz->lock); > > if (!result) > @@ -840,14 +842,17 @@ int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz, > struct thermal_instance *pos, *next; > > mutex_lock(&tz->lock); > + mutex_lock(&cdev->lock); > list_for_each_entry_safe(pos, next, &tz->thermal_instances, tz_node) { > if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) { > list_del(&pos->tz_node); > list_del(&pos->cdev_node); > + mutex_unlock(&cdev->lock); > mutex_unlock(&tz->lock); > goto unbind; > } > } > + mutex_unlock(&cdev->lock); > mutex_unlock(&tz->lock); > > return -ENODEV; > @@ -913,6 +918,7 @@ thermal_cooling_device_register(char *type, void *devdata, > } > > strcpy(cdev->type, type); > + mutex_init(&cdev->lock); > INIT_LIST_HEAD(&cdev->thermal_instances); > cdev->ops = ops; > cdev->updated = true; > @@ -1016,6 +1022,7 @@ static void thermal_cdev_do_update(struct thermal_cooling_device *cdev) > if (cdev->updated) > return; > > + mutex_lock(&cdev->lock); > /* Make sure cdev enters the deepest cooling state */ > list_for_each_entry(instance, &cdev->thermal_instances, cdev_node) { > if (instance->target == THERMAL_NO_TARGET) > @@ -1023,6 +1030,7 @@ static void thermal_cdev_do_update(struct thermal_cooling_device *cdev) > if (instance->target > target) > target = instance->target; > } > + mutex_unlock(&cdev->lock); > cdev->ops->set_cur_state(cdev, target); > cdev->updated = true; > } > diff --git a/include/linux/thermal.h b/include/linux/thermal.h > index 06fd04d..d02d06d 100644 > --- a/include/linux/thermal.h > +++ b/include/linux/thermal.h > @@ -95,6 +95,7 @@ struct thermal_cooling_device { > void *devdata; > const struct thermal_cooling_device_ops *ops; > bool updated; /* true if the cooling device does not need update */ > + struct mutex lock; /* protect thermal_instances list */ > struct list_head thermal_instances; > struct list_head node; > }; > -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hello Rui, On Thu, Jul 26, 2012 at 04:41:23PM +0800, Zhang Rui wrote: > we need to go over all the thermal_instance list of a cooling device > to decide which cooling state to put the cooling device to. > > But at this time, as a cooling device may be referenced in multiple > thermal zones, we need to lock the list first in case > another thermal zone is updating this cooling device. > > Signed-off-by: Zhang Rui <rui.zhang@intel.com> Reviewed-by: Eduardo Valentin <eduardo.valentin@ti.com> A minor comment bellow. > --- > drivers/thermal/thermal_sys.c | 8 ++++++++ > include/linux/thermal.h | 1 + > 2 files changed, 9 insertions(+) > > diff --git a/drivers/thermal/thermal_sys.c b/drivers/thermal/thermal_sys.c > index 7f3a891..356a59d 100644 > --- a/drivers/thermal/thermal_sys.c > +++ b/drivers/thermal/thermal_sys.c > @@ -799,6 +799,7 @@ int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz, > goto remove_symbol_link; > > mutex_lock(&tz->lock); > + mutex_lock(&cdev->lock); Why do you need to lock while going through the tz thermal_instances? > list_for_each_entry(pos, &tz->thermal_instances, tz_node) > if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) { > result = -EEXIST; > @@ -808,6 +809,7 @@ int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz, > list_add_tail(&dev->tz_node, &tz->thermal_instances); > list_add_tail(&dev->cdev_node, &cdev->thermal_instances); Locking the above operation should be enough, no? > } > + mutex_unlock(&cdev->lock); > mutex_unlock(&tz->lock); > > if (!result) > @@ -840,14 +842,17 @@ int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz, > struct thermal_instance *pos, *next; > > mutex_lock(&tz->lock); > + mutex_lock(&cdev->lock); > list_for_each_entry_safe(pos, next, &tz->thermal_instances, tz_node) { > if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) { > list_del(&pos->tz_node); > list_del(&pos->cdev_node); > + mutex_unlock(&cdev->lock); > mutex_unlock(&tz->lock); > goto unbind; > } > } > + mutex_unlock(&cdev->lock); > mutex_unlock(&tz->lock); > > return -ENODEV; > @@ -913,6 +918,7 @@ thermal_cooling_device_register(char *type, void *devdata, > } > > strcpy(cdev->type, type); > + mutex_init(&cdev->lock); > INIT_LIST_HEAD(&cdev->thermal_instances); > cdev->ops = ops; > cdev->updated = true; > @@ -1016,6 +1022,7 @@ static void thermal_cdev_do_update(struct thermal_cooling_device *cdev) > if (cdev->updated) > return; > > + mutex_lock(&cdev->lock); > /* Make sure cdev enters the deepest cooling state */ > list_for_each_entry(instance, &cdev->thermal_instances, cdev_node) { > if (instance->target == THERMAL_NO_TARGET) > @@ -1023,6 +1030,7 @@ static void thermal_cdev_do_update(struct thermal_cooling_device *cdev) > if (instance->target > target) > target = instance->target; > } > + mutex_unlock(&cdev->lock); > cdev->ops->set_cur_state(cdev, target); > cdev->updated = true; > } > diff --git a/include/linux/thermal.h b/include/linux/thermal.h > index 06fd04d..d02d06d 100644 > --- a/include/linux/thermal.h > +++ b/include/linux/thermal.h > @@ -95,6 +95,7 @@ struct thermal_cooling_device { > void *devdata; > const struct thermal_cooling_device_ops *ops; > bool updated; /* true if the cooling device does not need update */ > + struct mutex lock; /* protect thermal_instances list */ > struct list_head thermal_instances; > struct list_head node; > }; > -- > 1.7.9.5 > -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On ?, 2012-08-20 at 18:45 +0300, Eduardo Valentin wrote: > Hello Rui, > > On Thu, Jul 26, 2012 at 04:41:23PM +0800, Zhang Rui wrote: > > we need to go over all the thermal_instance list of a cooling device > > to decide which cooling state to put the cooling device to. > > > > But at this time, as a cooling device may be referenced in multiple > > thermal zones, we need to lock the list first in case > > another thermal zone is updating this cooling device. > > > > Signed-off-by: Zhang Rui <rui.zhang@intel.com> > > Reviewed-by: Eduardo Valentin <eduardo.valentin@ti.com> > > A minor comment bellow. > > > --- > > drivers/thermal/thermal_sys.c | 8 ++++++++ > > include/linux/thermal.h | 1 + > > 2 files changed, 9 insertions(+) > > > > diff --git a/drivers/thermal/thermal_sys.c b/drivers/thermal/thermal_sys.c > > index 7f3a891..356a59d 100644 > > --- a/drivers/thermal/thermal_sys.c > > +++ b/drivers/thermal/thermal_sys.c > > @@ -799,6 +799,7 @@ int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz, > > goto remove_symbol_link; > > > > mutex_lock(&tz->lock); > > + mutex_lock(&cdev->lock); > > Why do you need to lock while going through the tz thermal_instances? > > > list_for_each_entry(pos, &tz->thermal_instances, tz_node) > > if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) { > > result = -EEXIST; > > @@ -808,6 +809,7 @@ int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz, > > list_add_tail(&dev->tz_node, &tz->thermal_instances); > > list_add_tail(&dev->cdev_node, &cdev->thermal_instances); > > Locking the above operation should be enough, no? > we need to add this thermal_instance to the cooling device thermal_instance list. say, what if another thermal zone that references this cooling device is being unregistered at the same time? thanks, rui > > } > > + mutex_unlock(&cdev->lock); > > mutex_unlock(&tz->lock); > > > > if (!result) > > @@ -840,14 +842,17 @@ int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz, > > struct thermal_instance *pos, *next; > > > > mutex_lock(&tz->lock); > > + mutex_lock(&cdev->lock); > > list_for_each_entry_safe(pos, next, &tz->thermal_instances, tz_node) { > > if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) { > > list_del(&pos->tz_node); > > list_del(&pos->cdev_node); > > + mutex_unlock(&cdev->lock); > > mutex_unlock(&tz->lock); > > goto unbind; > > } > > } > > + mutex_unlock(&cdev->lock); > > mutex_unlock(&tz->lock); > > > > return -ENODEV; > > @@ -913,6 +918,7 @@ thermal_cooling_device_register(char *type, void *devdata, > > } > > > > strcpy(cdev->type, type); > > + mutex_init(&cdev->lock); > > INIT_LIST_HEAD(&cdev->thermal_instances); > > cdev->ops = ops; > > cdev->updated = true; > > @@ -1016,6 +1022,7 @@ static void thermal_cdev_do_update(struct thermal_cooling_device *cdev) > > if (cdev->updated) > > return; > > > > + mutex_lock(&cdev->lock); > > /* Make sure cdev enters the deepest cooling state */ > > list_for_each_entry(instance, &cdev->thermal_instances, cdev_node) { > > if (instance->target == THERMAL_NO_TARGET) > > @@ -1023,6 +1030,7 @@ static void thermal_cdev_do_update(struct thermal_cooling_device *cdev) > > if (instance->target > target) > > target = instance->target; > > } > > + mutex_unlock(&cdev->lock); > > cdev->ops->set_cur_state(cdev, target); > > cdev->updated = true; > > } > > diff --git a/include/linux/thermal.h b/include/linux/thermal.h > > index 06fd04d..d02d06d 100644 > > --- a/include/linux/thermal.h > > +++ b/include/linux/thermal.h > > @@ -95,6 +95,7 @@ struct thermal_cooling_device { > > void *devdata; > > const struct thermal_cooling_device_ops *ops; > > bool updated; /* true if the cooling device does not need update */ > > + struct mutex lock; /* protect thermal_instances list */ > > struct list_head thermal_instances; > > struct list_head node; > > }; > > -- > > 1.7.9.5 > > -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hello, On Tue, Aug 21, 2012 at 08:53:27AM +0800, Zhang Rui wrote: > On ?, 2012-08-20 at 18:45 +0300, Eduardo Valentin wrote: > > Hello Rui, > > > > On Thu, Jul 26, 2012 at 04:41:23PM +0800, Zhang Rui wrote: > > > we need to go over all the thermal_instance list of a cooling device > > > to decide which cooling state to put the cooling device to. > > > > > > But at this time, as a cooling device may be referenced in multiple > > > thermal zones, we need to lock the list first in case > > > another thermal zone is updating this cooling device. > > > > > > Signed-off-by: Zhang Rui <rui.zhang@intel.com> > > > > Reviewed-by: Eduardo Valentin <eduardo.valentin@ti.com> > > > > A minor comment bellow. > > > > > --- > > > drivers/thermal/thermal_sys.c | 8 ++++++++ > > > include/linux/thermal.h | 1 + > > > 2 files changed, 9 insertions(+) > > > > > > diff --git a/drivers/thermal/thermal_sys.c b/drivers/thermal/thermal_sys.c > > > index 7f3a891..356a59d 100644 > > > --- a/drivers/thermal/thermal_sys.c > > > +++ b/drivers/thermal/thermal_sys.c > > > @@ -799,6 +799,7 @@ int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz, > > > goto remove_symbol_link; > > > > > > mutex_lock(&tz->lock); > > > + mutex_lock(&cdev->lock); > > > > Why do you need to lock while going through the tz thermal_instances? > > > > > list_for_each_entry(pos, &tz->thermal_instances, tz_node) > > > if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) { > > > result = -EEXIST; > > > @@ -808,6 +809,7 @@ int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz, > > > list_add_tail(&dev->tz_node, &tz->thermal_instances); > > > list_add_tail(&dev->cdev_node, &cdev->thermal_instances); > > > > Locking the above operation should be enough, no? > > > we need to add this thermal_instance to the cooling device > thermal_instance list. > say, what if another thermal zone that references this cooling device is > being unregistered at the same time? Well yes, that part I got it. But do you need to lock the cdev->lock while doing the search under tz->thermal_instances? I believe you need to lock it only while adding it to cdev->thermal_instances. That would cover the situation you are talking about. > > thanks, > rui > > > > } > > > + mutex_unlock(&cdev->lock); > > > mutex_unlock(&tz->lock); > > > > > > if (!result) > > > @@ -840,14 +842,17 @@ int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz, > > > struct thermal_instance *pos, *next; > > > > > > mutex_lock(&tz->lock); > > > + mutex_lock(&cdev->lock); > > > list_for_each_entry_safe(pos, next, &tz->thermal_instances, tz_node) { > > > if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) { > > > list_del(&pos->tz_node); > > > list_del(&pos->cdev_node); > > > + mutex_unlock(&cdev->lock); > > > mutex_unlock(&tz->lock); > > > goto unbind; > > > } > > > } > > > + mutex_unlock(&cdev->lock); > > > mutex_unlock(&tz->lock); > > > > > > return -ENODEV; > > > @@ -913,6 +918,7 @@ thermal_cooling_device_register(char *type, void *devdata, > > > } > > > > > > strcpy(cdev->type, type); > > > + mutex_init(&cdev->lock); > > > INIT_LIST_HEAD(&cdev->thermal_instances); > > > cdev->ops = ops; > > > cdev->updated = true; > > > @@ -1016,6 +1022,7 @@ static void thermal_cdev_do_update(struct thermal_cooling_device *cdev) > > > if (cdev->updated) > > > return; > > > > > > + mutex_lock(&cdev->lock); > > > /* Make sure cdev enters the deepest cooling state */ > > > list_for_each_entry(instance, &cdev->thermal_instances, cdev_node) { > > > if (instance->target == THERMAL_NO_TARGET) > > > @@ -1023,6 +1030,7 @@ static void thermal_cdev_do_update(struct thermal_cooling_device *cdev) > > > if (instance->target > target) > > > target = instance->target; > > > } > > > + mutex_unlock(&cdev->lock); > > > cdev->ops->set_cur_state(cdev, target); > > > cdev->updated = true; > > > } > > > diff --git a/include/linux/thermal.h b/include/linux/thermal.h > > > index 06fd04d..d02d06d 100644 > > > --- a/include/linux/thermal.h > > > +++ b/include/linux/thermal.h > > > @@ -95,6 +95,7 @@ struct thermal_cooling_device { > > > void *devdata; > > > const struct thermal_cooling_device_ops *ops; > > > bool updated; /* true if the cooling device does not need update */ > > > + struct mutex lock; /* protect thermal_instances list */ > > > struct list_head thermal_instances; > > > struct list_head node; > > > }; > > > -- > > > 1.7.9.5 > > > > > -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/thermal/thermal_sys.c b/drivers/thermal/thermal_sys.c index 7f3a891..356a59d 100644 --- a/drivers/thermal/thermal_sys.c +++ b/drivers/thermal/thermal_sys.c @@ -799,6 +799,7 @@ int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz, goto remove_symbol_link; mutex_lock(&tz->lock); + mutex_lock(&cdev->lock); list_for_each_entry(pos, &tz->thermal_instances, tz_node) if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) { result = -EEXIST; @@ -808,6 +809,7 @@ int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz, list_add_tail(&dev->tz_node, &tz->thermal_instances); list_add_tail(&dev->cdev_node, &cdev->thermal_instances); } + mutex_unlock(&cdev->lock); mutex_unlock(&tz->lock); if (!result) @@ -840,14 +842,17 @@ int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz, struct thermal_instance *pos, *next; mutex_lock(&tz->lock); + mutex_lock(&cdev->lock); list_for_each_entry_safe(pos, next, &tz->thermal_instances, tz_node) { if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) { list_del(&pos->tz_node); list_del(&pos->cdev_node); + mutex_unlock(&cdev->lock); mutex_unlock(&tz->lock); goto unbind; } } + mutex_unlock(&cdev->lock); mutex_unlock(&tz->lock); return -ENODEV; @@ -913,6 +918,7 @@ thermal_cooling_device_register(char *type, void *devdata, } strcpy(cdev->type, type); + mutex_init(&cdev->lock); INIT_LIST_HEAD(&cdev->thermal_instances); cdev->ops = ops; cdev->updated = true; @@ -1016,6 +1022,7 @@ static void thermal_cdev_do_update(struct thermal_cooling_device *cdev) if (cdev->updated) return; + mutex_lock(&cdev->lock); /* Make sure cdev enters the deepest cooling state */ list_for_each_entry(instance, &cdev->thermal_instances, cdev_node) { if (instance->target == THERMAL_NO_TARGET) @@ -1023,6 +1030,7 @@ static void thermal_cdev_do_update(struct thermal_cooling_device *cdev) if (instance->target > target) target = instance->target; } + mutex_unlock(&cdev->lock); cdev->ops->set_cur_state(cdev, target); cdev->updated = true; } diff --git a/include/linux/thermal.h b/include/linux/thermal.h index 06fd04d..d02d06d 100644 --- a/include/linux/thermal.h +++ b/include/linux/thermal.h @@ -95,6 +95,7 @@ struct thermal_cooling_device { void *devdata; const struct thermal_cooling_device_ops *ops; bool updated; /* true if the cooling device does not need update */ + struct mutex lock; /* protect thermal_instances list */ struct list_head thermal_instances; struct list_head node; };
we need to go over all the thermal_instance list of a cooling device to decide which cooling state to put the cooling device to. But at this time, as a cooling device may be referenced in multiple thermal zones, we need to lock the list first in case another thermal zone is updating this cooling device. Signed-off-by: Zhang Rui <rui.zhang@intel.com> --- drivers/thermal/thermal_sys.c | 8 ++++++++ include/linux/thermal.h | 1 + 2 files changed, 9 insertions(+)