Re: [PATCH V5] powercap/drivers/idle_injection: Add an idle injection framework

[Daniel Lezcano]

On 06/06/2018 14:23, Peter Zijlstra wrote:
> On Tue, Jun 05, 2018 at 11:16:40AM +0200, Daniel Lezcano wrote:
>> +	atomic_t idle_duration_ms;
>> +	atomic_t run_duration_ms;
> 
>> +	idle_duration_ms = atomic_read(&ii_dev->idle_duration_ms);
> 
>> +	run_duration_ms = atomic_read(&ii_dev->run_duration_ms);
> 
>> +	atomic_set(&ii_dev->run_duration_ms, run_duration_ms);
>> +	atomic_set(&ii_dev->idle_duration_ms, idle_duration_ms);
> 
>> +	*run_duration_ms = atomic_read(&ii_dev->run_duration_ms);
>> +	*idle_duration_ms = atomic_read(&ii_dev->idle_duration_ms);
> 
>> +	if (!atomic_read(&ii_dev->idle_duration_ms))
> 
>> +	if (!atomic_read(&ii_dev->run_duration_ms))
> 
> What is the point of atomic_t here ?!

idle_duration and run_duration can be changed from different places at
the same time. The atomic is here to ensure the read/write are consistent.

Do you think it is pointless ?




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