| Message ID | 1389916587-2541-2-git-send-email-durgadoss.r@intel.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Delegated to: | Zhang Rui |
| Headers | show |
Hi Durgadoss, On Fri, Jan 17, 2014 at 05:26:18AM +0530, Durgadoss R wrote: > Currently the thermal_release function does > kfree for all devices when they call device_unregister. > This makes code scattering i.e whenever we add new > devices (to thermal class) we need to add its > corresponding kfree in thermal_release function. > And the if-else is also growing lengthy. > > Instead, do all kfree() of devices in their own > _unregister functions. This makes the code look > clean and easy to maintain. > > Signed-off-by: Durgadoss R <durgadoss.r@intel.com> > --- > drivers/thermal/thermal_core.c | 17 +++++------------ > 1 file changed, 5 insertions(+), 12 deletions(-) > > diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c > index 338a88b..165afc6 100644 > --- a/drivers/thermal/thermal_core.c > +++ b/drivers/thermal/thermal_core.c > @@ -1042,18 +1042,7 @@ EXPORT_SYMBOL_GPL(thermal_zone_unbind_cooling_device); > > static void thermal_release(struct device *dev) > { > - struct thermal_zone_device *tz; > - struct thermal_cooling_device *cdev; > - > - if (!strncmp(dev_name(dev), "thermal_zone", > - sizeof("thermal_zone") - 1)) { > - tz = to_thermal_zone(dev); > - kfree(tz); > - } else if(!strncmp(dev_name(dev), "cooling_device", > - sizeof("cooling_device") - 1)){ > - cdev = to_cooling_device(dev); > - kfree(cdev); > - } > + /* No-op since kfree(dev) is done in _unregister functions */ > } > > static struct class thermal_class = { > @@ -1146,6 +1135,7 @@ __thermal_cooling_device_register(struct device_node *np, > unregister: > release_idr(&thermal_cdev_idr, &thermal_idr_lock, cdev->id); > device_unregister(&cdev->device); > + kfree(cdev); This is broken, you can not assume that you are holding the last reference. Please observe help text of DEBUG_KOBJECT_RELEASE config option, activate said option and try unregistering thermal device. Thanks.
On Tue, 2014-01-21 at 11:46 -0800, Dmitry Torokhov wrote: > Hi Durgadoss, > > On Fri, Jan 17, 2014 at 05:26:18AM +0530, Durgadoss R wrote: > > Currently the thermal_release function does > > kfree for all devices when they call device_unregister. > > This makes code scattering i.e whenever we add new > > devices (to thermal class) we need to add its > > corresponding kfree in thermal_release function. > > And the if-else is also growing lengthy. > > > > Instead, do all kfree() of devices in their own > > _unregister functions. This makes the code look > > clean and easy to maintain. > > > > Signed-off-by: Durgadoss R <durgadoss.r@intel.com> > > --- > > drivers/thermal/thermal_core.c | 17 +++++------------ > > 1 file changed, 5 insertions(+), 12 deletions(-) > > > > diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c > > index 338a88b..165afc6 100644 > > --- a/drivers/thermal/thermal_core.c > > +++ b/drivers/thermal/thermal_core.c > > @@ -1042,18 +1042,7 @@ EXPORT_SYMBOL_GPL(thermal_zone_unbind_cooling_device); > > > > static void thermal_release(struct device *dev) > > { > > - struct thermal_zone_device *tz; > > - struct thermal_cooling_device *cdev; > > - > > - if (!strncmp(dev_name(dev), "thermal_zone", > > - sizeof("thermal_zone") - 1)) { > > - tz = to_thermal_zone(dev); > > - kfree(tz); > > - } else if(!strncmp(dev_name(dev), "cooling_device", > > - sizeof("cooling_device") - 1)){ > > - cdev = to_cooling_device(dev); > > - kfree(cdev); > > - } > > + /* No-op since kfree(dev) is done in _unregister functions */ > > } > > > > static struct class thermal_class = { > > @@ -1146,6 +1135,7 @@ __thermal_cooling_device_register(struct device_node *np, > > unregister: > > release_idr(&thermal_cdev_idr, &thermal_idr_lock, cdev->id); > > device_unregister(&cdev->device); > > + kfree(cdev); > > This is broken, you can not assume that you are holding the last > reference. Please observe help text of DEBUG_KOBJECT_RELEASE config > option, activate said option and try unregistering thermal device. > agreed. If you think it is too complicated to support the different thermal components in thermal_release(), we can introduce per device .release() callback as well. thanks, rui > Thanks. > -- 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_core.c b/drivers/thermal/thermal_core.c index 338a88b..165afc6 100644 --- a/drivers/thermal/thermal_core.c +++ b/drivers/thermal/thermal_core.c @@ -1042,18 +1042,7 @@ EXPORT_SYMBOL_GPL(thermal_zone_unbind_cooling_device); static void thermal_release(struct device *dev) { - struct thermal_zone_device *tz; - struct thermal_cooling_device *cdev; - - if (!strncmp(dev_name(dev), "thermal_zone", - sizeof("thermal_zone") - 1)) { - tz = to_thermal_zone(dev); - kfree(tz); - } else if(!strncmp(dev_name(dev), "cooling_device", - sizeof("cooling_device") - 1)){ - cdev = to_cooling_device(dev); - kfree(cdev); - } + /* No-op since kfree(dev) is done in _unregister functions */ } static struct class thermal_class = { @@ -1146,6 +1135,7 @@ __thermal_cooling_device_register(struct device_node *np, unregister: release_idr(&thermal_cdev_idr, &thermal_idr_lock, cdev->id); device_unregister(&cdev->device); + kfree(cdev); return ERR_PTR(result); } @@ -1250,6 +1240,7 @@ void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev) release_idr(&thermal_cdev_idr, &thermal_idr_lock, cdev->id); device_unregister(&cdev->device); + kfree(cdev); return; } EXPORT_SYMBOL_GPL(thermal_cooling_device_unregister); @@ -1563,6 +1554,7 @@ struct thermal_zone_device *thermal_zone_device_register(const char *type, unregister: release_idr(&thermal_tz_idr, &thermal_idr_lock, tz->id); device_unregister(&tz->device); + kfree(tz); return ERR_PTR(result); } EXPORT_SYMBOL_GPL(thermal_zone_device_register); @@ -1630,6 +1622,7 @@ void thermal_zone_device_unregister(struct thermal_zone_device *tz) idr_destroy(&tz->idr); mutex_destroy(&tz->lock); device_unregister(&tz->device); + kfree(tz); return; } EXPORT_SYMBOL_GPL(thermal_zone_device_unregister);
Currently the thermal_release function does kfree for all devices when they call device_unregister. This makes code scattering i.e whenever we add new devices (to thermal class) we need to add its corresponding kfree in thermal_release function. And the if-else is also growing lengthy. Instead, do all kfree() of devices in their own _unregister functions. This makes the code look clean and easy to maintain. Signed-off-by: Durgadoss R <durgadoss.r@intel.com> --- drivers/thermal/thermal_core.c | 17 +++++------------ 1 file changed, 5 insertions(+), 12 deletions(-)