linux-kernel - Re: [PATCH 3/3] powercap/drivers/idle_inject: Specify the idle state to inject

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Date:   Tue, 24 Sep 2019 15:02:51 +0200
From:   Daniel Lezcano <daniel.lezcano@...aro.org>
To:     Mathieu Poirier <mathieu.poirier@...aro.org>
Cc:     rafael@...nel.org, linux-pm@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        "Rafael J. Wysocki" <rjw@...ysocki.net>
Subject: Re: [PATCH 3/3] powercap/drivers/idle_inject: Specify the idle state
 to inject


Hi Mathieu,

On 18/09/2019 21:35, Mathieu Poirier wrote:
> On Mon, Sep 09, 2019 at 04:50:15PM +0200, Daniel Lezcano wrote:
>> Currently the idle injection framework only allows to inject the
>> deepest idle state available on the system.
>>
>> Give the opportunity to specify which idle state we want to inject by
>> adding a new function helper to set the state and use it when calling
>> play_idle().
>>
>> There is no functional changes, the cpuidle state is the deepest one.
>>
>> Signed-off-by: Daniel Lezcano <daniel.lezcano@...aro.org>
>> ---

[ ... ]

>> +/**
>> + * idle_inject_set_state - set the idle state to inject
>> + * @state: an integer for the idle state to inject
>> + */
>> +void idle_inject_set_state(struct idle_inject_device *ii_dev, int state)
>> +{
>> +	if (state >= CPUIDLE_STATE_NOUSE && state < CPUIDLE_STATE_MAX)
>> +		WRITE_ONCE(ii_dev->state, state);
>> +}
>> +
>>  /**
>>   * idle_inject_start - start idle injections
>>   * @ii_dev: idle injection control device structure
>> @@ -298,6 +310,7 @@ struct idle_inject_device *idle_inject_register(struct cpumask *cpumask)
>>  	cpumask_copy(to_cpumask(ii_dev->cpumask), cpumask);
>>  	hrtimer_init(&ii_dev->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
>>  	ii_dev->timer.function = idle_inject_timer_fn;
>> +	ii_dev->state = cpuidle_find_deepest_state();
>>  
>>  	for_each_cpu(cpu, to_cpumask(ii_dev->cpumask)) {
>>  
>> diff --git a/include/linux/idle_inject.h b/include/linux/idle_inject.h
>> index a445cd1a36c5..e2b26b9ccd34 100644
>> --- a/include/linux/idle_inject.h
>> +++ b/include/linux/idle_inject.h
>> @@ -26,4 +26,7 @@ void idle_inject_set_duration(struct idle_inject_device *ii_dev,
>>  void idle_inject_get_duration(struct idle_inject_device *ii_dev,
>>  				 unsigned int *run_duration_us,
>>  				 unsigned int *idle_duration_us);
>> +
>> +void idle_inject_set_state(struct idle_inject_device *ii_dev, int state);
>> +
> 
> The above function is not used in this patch and as such should be introduce as
> part of future work.  Otherwise I agree that this patch does not carry any
> functional changes.
> 
> Without function idle_inject_set_state():

I was about to remove the function but actually it may not make sense as
the idle_inject is a framework providing the different API to do the
idle injection and the function is an helper to set the state value. It
comes with the addition of the state number in the structure.

Next patch is the idle cooling device and makes use of it.

Can I still consider your acked-by valid?

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