Hi Daniel,
On 6/1/20 10:44 PM, Daniel Lezcano wrote:
On 27/05/2020 11:58, Lukasz Luba wrote:
Add support for other devices than CPUs. The registration function does not require a valid cpumask pointer and is ready to handle new devices. Some of the internal structures has been reorganized in order to keep consistent view (like removing per_cpu pd pointers).
Signed-off-by: Lukasz Luba lukasz.luba@arm.com
[ ... ]
} EXPORT_SYMBOL_GPL(em_register_perf_domain);
+/**
- em_dev_unregister_perf_domain() - Unregister Energy Model (EM) for a device
- @dev : Device for which the EM is registered
- Try to unregister the EM for the specified device (but not a CPU).
- */
+void em_dev_unregister_perf_domain(struct device *dev) +{
- if (IS_ERR_OR_NULL(dev) || !dev->em_pd)
return;- if (_is_cpu_device(dev))
return;- mutex_lock(&em_pd_mutex);
Is the mutex really needed?
I just wanted to align this unregister code with register. Since there is debugfs dir lookup and the device's EM existence checks I thought it wouldn't harm just to lock for a while and make sure the registration path is not used. These two paths shouldn't affect each other, but with modules loading/unloading I wanted to play safe. I can change it maybe to just dmb() and the end of the function if it's a big performance problem in this unloading path. What do you think?
If this function is called that means there is no more user of the em_pd, no?
True, that EM users should already be unregistered i.e. thermal cooling.
- em_debug_remove_pd(dev);
- kfree(dev->em_pd->table);
- kfree(dev->em_pd);
- dev->em_pd = NULL;
- mutex_unlock(&em_pd_mutex);
+} +EXPORT_SYMBOL_GPL(em_dev_unregister_perf_domain);
Thank you for reviewing this.
Regards, Lukasz