Messages in this thread | | | Subject | Re: [PATCHv5 01/10] Thermal: Do kfree in _unregister functions | From | Zhang Rui <> | Date | Mon, 03 Mar 2014 21:44:16 +0800 |
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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. >
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