On Thu, Feb 21, 2019 at 12:49:40AM -0500, Joel Fernandes (Google) wrote:
> @@ -34,8 +34,12 @@ void cpufreq_add_update_util_hook(int cpu, struct
> update_util_data *data,
> if (WARN_ON(!data || !func))
> return;
>
> - if (WARN_ON(per_cpu(cpufreq_update_util_data, cpu)))
> + rcu_read_lock();
> + if (WARN_ON(rcu_dereference(per_cpu(cpufreq_update_util_data, cpu)))) {
> + rcu_read_unlock();
> return;
> + }
> + rcu_read_unlock();
>
> data->func = func;
> rcu_assign_pointer(per_cpu(cpufreq_update_util_data, cpu), data);
This doesn't make any kind of sense to me.
