Re: [RFCv7 PATCH 03/10] sched: scheduler-driven cpu frequency selection

[Rafael J. Wysocki]

On Tue, Mar 1, 2016 at 1:57 PM, Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
> On Sat, Feb 27, 2016 at 01:08:02AM +0100, Rafael J. Wysocki wrote:
>> @@ -95,18 +98,20 @@ EXPORT_SYMBOL_GPL(cpufreq_set_update_uti
>>   *
>>   * This function is called by the scheduler on every invocation of
>>   * update_load_avg() on the CPU whose utilization is being updated.
>> + *
>> + * It can only be called from RCU-sched read-side critical sections.
>>   */
>>  void cpufreq_update_util(u64 time, unsigned long util, unsigned long max)
>>  {
>>       struct update_util_data *data;
>>
>> -     rcu_read_lock();
>> -
>
> Maybe, just because I'm paranoid, add something like:
>
> #ifdef CONFIG_LOCKDEP
>         WARN_ON(debug_locks && !rcu_read_lock_sched_held());
> #endif

OK