Re: [PATCH 5/7] devfreq: move transition statistics to devfreq profile structure

[Chanwoo Choi]

Hi Bartlomiej,

On 11/15/19 3:10 AM, Bartlomiej Zolnierkiewicz wrote:
> 
> Hi Chanwoo,
> 
> On 11/14/19 3:02 AM, Chanwoo Choi wrote:
>> Hi Kamil,
>>
>> The devfreq_dev_profile structure have to only contain the each devfreq device
>> callback function/data which are used in the devfreq core.
>>
>> The generated information after registered the devfreq device
>> with devfreq_add_device() should be stored in the 'struct device'.
>>
>> The devfreq core need to split out the data between user input
>> data (struct devfreq_dev_profile) and the initialized/generated data
>> by core (struct devfreq). It is not same with cpufreq. cpufreq
> 
> How's about doing it the other way around -> moving 'freq_table' and
> 'max_state' from 'struct devfreq_dev_profile' to 'struct devfreq'?

I agree to move 'freq_table' and 'max_state' to 'struct devfreq
as I replied on patch7 from your reply. But, it have to be touched
with the ordering issue of freq_table on drivers/thermal/devfreq_cooling.c.

Regards,
Chanwoo Choi

> 
> They are both initialized/generated by the core during
> devfreq_add_device()->set_freq_table() for all in-kernel drivers.
> 
> Best regards,
> --
> Bartlomiej Zolnierkiewicz
> Samsung R&D Institute Poland
> Samsung Electronics 
> 
>> don't require the any structure like 'devfreq_dev_profile'.
>>
>> So, I can't agree.
>>
>> Thanks.
>> Chanwoo Choi
>>
>>
>> On 11/13/19 6:13 PM, Kamil Konieczny wrote:
>>> Move transition statistics to devfreq profile structure. This is for
>>> preparation for moving transition statistics into separate struct.
>>> It is safe to do as frequency table and maximum state information are
>>> already present in devfreq profile structure and there are no devfreq
>>> drivers using more than one instance of devfreq structure per devfreq
>>> profile one.
>>>
>>> It also makes devfreq code more similar to cpufreq one.
>>>
>>> Signed-off-by: Kamil Konieczny <k.konieczny@xxxxxxxxxxx>
>>> ---
>>>  drivers/devfreq/devfreq.c | 115 +++++++++++++++++++-------------------
>>>  include/linux/devfreq.h   |  25 ++++-----
>>>  2 files changed, 70 insertions(+), 70 deletions(-)
>>>
>>> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
>>> index 6e5a17f4c92c..70533b787744 100644
>>> --- a/drivers/devfreq/devfreq.c
>>> +++ b/drivers/devfreq/devfreq.c
>>> @@ -128,7 +128,7 @@ static int set_freq_table(struct devfreq *devfreq)
>>>  
>>>  	profile->max_state = count;
>>>  	profile->freq_table = devm_kcalloc(devfreq->dev.parent,
>>> -					profile->max_state,
>>> +					count,
>>>  					sizeof(*profile->freq_table),
>>>  					GFP_KERNEL);
>>>  	if (!profile->freq_table) {
>>> @@ -157,29 +157,30 @@ static int set_freq_table(struct devfreq *devfreq)
>>>   */
>>>  int devfreq_update_status(struct devfreq *devfreq, unsigned long freq)
>>>  {
>>> -	int lev, prev_lev, ret = 0;
>>> +	struct devfreq_dev_profile *profile = devfreq->profile;
>>>  	unsigned long long cur_time;
>>> +	int lev, prev_lev, ret = 0;
>>>  
>>>  	cur_time = get_jiffies_64();
>>>  
>>>  	/* Immediately exit if previous_freq is not initialized yet. */
>>>  	if (!devfreq->previous_freq) {
>>> -		spin_lock(&devfreq->stats_lock);
>>> -		devfreq->last_time = cur_time;
>>> -		spin_unlock(&devfreq->stats_lock);
>>> +		spin_lock(&profile->stats_lock);
>>> +		profile->last_time = cur_time;
>>> +		spin_unlock(&profile->stats_lock);
>>>  		return 0;
>>>  	}
>>>  
>>>  	prev_lev = devfreq_get_freq_level(devfreq, devfreq->previous_freq);
>>>  
>>> -	spin_lock(&devfreq->stats_lock);
>>> +	spin_lock(&profile->stats_lock);
>>>  	if (prev_lev < 0) {
>>>  		ret = prev_lev;
>>>  		goto out;
>>>  	}
>>>  
>>> -	devfreq->time_in_state[prev_lev] +=
>>> -			 cur_time - devfreq->last_time;
>>> +	profile->time_in_state[prev_lev] +=
>>> +			 cur_time - profile->last_time;
>>>  	lev = devfreq_get_freq_level(devfreq, freq);
>>>  	if (lev < 0) {
>>>  		ret = lev;
>>> @@ -187,14 +188,14 @@ int devfreq_update_status(struct devfreq *devfreq, unsigned long freq)
>>>  	}
>>>  
>>>  	if (lev != prev_lev) {
>>> -		devfreq->trans_table[(prev_lev *
>>> -				devfreq->profile->max_state) + lev]++;
>>> -		devfreq->total_trans++;
>>> +		profile->trans_table[(prev_lev *
>>> +				profile->max_state) + lev]++;
>>> +		profile->total_trans++;
>>>  	}
>>>  
>>>  out:
>>> -	devfreq->last_time = cur_time;
>>> -	spin_unlock(&devfreq->stats_lock);
>>> +	profile->last_time = cur_time;
>>> +	spin_unlock(&profile->stats_lock);
>>>  	return ret;
>>>  }
>>>  EXPORT_SYMBOL(devfreq_update_status);
>>> @@ -474,23 +475,23 @@ EXPORT_SYMBOL(devfreq_monitor_suspend);
>>>  void devfreq_monitor_resume(struct devfreq *devfreq)
>>>  {
>>>  	unsigned long freq;
>>> +	struct devfreq_dev_profile *profile = devfreq->profile;
>>>  
>>>  	mutex_lock(&devfreq->lock);
>>>  	if (!devfreq->stop_polling)
>>>  		goto out;
>>>  
>>> -	if (!delayed_work_pending(&devfreq->work) &&
>>> -			devfreq->profile->polling_ms)
>>> +	if (!delayed_work_pending(&devfreq->work) && profile->polling_ms)
>>>  		queue_delayed_work(devfreq_wq, &devfreq->work,
>>> -			msecs_to_jiffies(devfreq->profile->polling_ms));
>>> +			msecs_to_jiffies(profile->polling_ms));
>>>  
>>> -	spin_lock(&devfreq->stats_lock);
>>> -	devfreq->last_time = get_jiffies_64();
>>> -	spin_unlock(&devfreq->stats_lock);
>>> +	spin_lock(&profile->stats_lock);
>>> +	profile->last_time = get_jiffies_64();
>>> +	spin_unlock(&profile->stats_lock);
>>>  	devfreq->stop_polling = false;
>>>  
>>> -	if (devfreq->profile->get_cur_freq &&
>>> -		!devfreq->profile->get_cur_freq(devfreq->dev.parent, &freq))
>>> +	if (profile->get_cur_freq &&
>>> +	    !profile->get_cur_freq(devfreq->dev.parent, &freq))
>>>  		devfreq->previous_freq = freq;
>>>  
>>>  out:
>>> @@ -657,7 +658,7 @@ struct devfreq *devfreq_add_device(struct device *dev,
>>>  	devfreq->data = data;
>>>  	devfreq->nb.notifier_call = devfreq_notifier_call;
>>>  
>>> -	if (!devfreq->profile->max_state && !devfreq->profile->freq_table) {
>>> +	if (!profile->max_state && !profile->freq_table) {
>>>  		mutex_unlock(&devfreq->lock);
>>>  		err = set_freq_table(devfreq);
>>>  		if (err < 0)
>>> @@ -693,29 +694,29 @@ struct devfreq *devfreq_add_device(struct device *dev,
>>>  		goto err_out;
>>>  	}
>>>  
>>> -	devfreq->trans_table = devm_kzalloc(&devfreq->dev,
>>> -			array3_size(sizeof(unsigned int),
>>> -				    devfreq->profile->max_state,
>>> -				    devfreq->profile->max_state),
>>> -			GFP_KERNEL);
>>> -	if (!devfreq->trans_table) {
>>> +	profile->trans_table = devm_kzalloc(&devfreq->dev,
>>> +					    array3_size(sizeof(unsigned int),
>>> +							profile->max_state,
>>> +							profile->max_state),
>>> +					    GFP_KERNEL);
>>> +	if (!profile->trans_table) {
>>>  		mutex_unlock(&devfreq->lock);
>>>  		err = -ENOMEM;
>>>  		goto err_devfreq;
>>>  	}
>>>  
>>> -	devfreq->time_in_state = devm_kcalloc(&devfreq->dev,
>>> -			devfreq->profile->max_state,
>>> -			sizeof(*devfreq->time_in_state),
>>> -			GFP_KERNEL);
>>> -	if (!devfreq->time_in_state) {
>>> +	profile->time_in_state = devm_kcalloc(&devfreq->dev,
>>> +					      profile->max_state,
>>> +					      sizeof(*profile->time_in_state),
>>> +					      GFP_KERNEL);
>>> +	if (!profile->time_in_state) {
>>>  		mutex_unlock(&devfreq->lock);
>>>  		err = -ENOMEM;
>>>  		goto err_devfreq;
>>>  	}
>>>  
>>> -	devfreq->last_time = get_jiffies_64();
>>> -	spin_lock_init(&devfreq->stats_lock);
>>> +	profile->last_time = get_jiffies_64();
>>> +	spin_lock_init(&profile->stats_lock);
>>>  
>>>  	srcu_init_notifier_head(&devfreq->transition_notifier_list);
>>>  
>>> @@ -1402,9 +1403,10 @@ static ssize_t trans_stat_show(struct device *dev,
>>>  			       struct device_attribute *attr, char *buf)
>>>  {
>>>  	struct devfreq *devfreq = to_devfreq(dev);
>>> +	struct devfreq_dev_profile *profile = devfreq->profile;
>>>  	ssize_t len;
>>>  	int i, j;
>>> -	unsigned int max_state = devfreq->profile->max_state;
>>> +	unsigned int max_state = profile->max_state;
>>>  
>>>  	if (!devfreq->stop_polling &&
>>>  			devfreq_update_status(devfreq, devfreq->previous_freq))
>>> @@ -1415,46 +1417,45 @@ static ssize_t trans_stat_show(struct device *dev,
>>>  	len = sprintf(buf, "     From  :   To\n");
>>>  	len += sprintf(buf + len, "           :");
>>>  
>>> -	spin_lock(&devfreq->stats_lock);
>>> +	spin_lock(&profile->stats_lock);
>>>  	for (i = 0; i < max_state; i++)
>>>  		len += sprintf(buf + len, "%10lu",
>>> -				devfreq->profile->freq_table[i]);
>>> +				profile->freq_table[i]);
>>>  
>>>  	len += sprintf(buf + len, "   time(ms)\n");
>>>  
>>>  	for (i = 0; i < max_state; i++) {
>>> -		if (devfreq->profile->freq_table[i]
>>> -					== devfreq->previous_freq) {
>>> +		if (profile->freq_table[i] == devfreq->previous_freq)
>>>  			len += sprintf(buf + len, "*");
>>> -		} else {
>>> +		else
>>>  			len += sprintf(buf + len, " ");
>>> -		}
>>> +
>>>  		len += sprintf(buf + len, "%10lu:",
>>> -				devfreq->profile->freq_table[i]);
>>> +				profile->freq_table[i]);
>>>  		for (j = 0; j < max_state; j++)
>>>  			len += sprintf(buf + len, "%10u",
>>> -				devfreq->trans_table[(i * max_state) + j]);
>>> +				profile->trans_table[(i * max_state) + j]);
>>>  		len += sprintf(buf + len, "%10llu\n", (u64)
>>> -			jiffies64_to_msecs(devfreq->time_in_state[i]));
>>> +			jiffies64_to_msecs(profile->time_in_state[i]));
>>>  	}
>>>  
>>>  	len += sprintf(buf + len, "Total transition : %u\n",
>>> -					devfreq->total_trans);
>>> -	spin_unlock(&devfreq->stats_lock);
>>> +					profile->total_trans);
>>> +	spin_unlock(&profile->stats_lock);
>>>  	return len;
>>>  }
>>>  static DEVICE_ATTR_RO(trans_stat);
>>>  
>>> -static void defvreq_stats_clear_table(struct devfreq *devfreq)
>>> +static void defvreq_stats_clear_table(struct devfreq_dev_profile *profile)
>>>  {
>>> -	unsigned int count = devfreq->profile->max_state;
>>> -
>>> -	spin_lock(&devfreq->stats_lock);
>>> -	memset(devfreq->time_in_state, 0, count * sizeof(u64));
>>> -	memset(devfreq->trans_table, 0, count * count * sizeof(int));
>>> -	devfreq->last_time = get_jiffies_64();
>>> -	devfreq->total_trans = 0;
>>> -	spin_unlock(&devfreq->stats_lock);
>>> +	unsigned int count = profile->max_state;
>>> +
>>> +	spin_lock(&profile->stats_lock);
>>> +	memset(profile->time_in_state, 0, count * sizeof(u64));
>>> +	memset(profile->trans_table, 0, count * count * sizeof(int));
>>> +	profile->last_time = get_jiffies_64();
>>> +	profile->total_trans = 0;
>>> +	spin_unlock(&profile->stats_lock);
>>>  }
>>>  
>>>  static ssize_t trans_reset_store(struct device *dev,
>>> @@ -1464,7 +1465,7 @@ static ssize_t trans_reset_store(struct device *dev,
>>>  {
>>>  	struct devfreq *devfreq = to_devfreq(dev);
>>>  
>>> -	defvreq_stats_clear_table(devfreq);
>>> +	defvreq_stats_clear_table(devfreq->profile);
>>>  
>>>  	return count;
>>>  }
>>> diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
>>> index 2ddf25993f7d..4ceb2a517a9c 100644
>>> --- a/include/linux/devfreq.h
>>> +++ b/include/linux/devfreq.h
>>> @@ -91,6 +91,12 @@ struct devfreq_dev_status {
>>>   * @freq_table:		Optional list of frequencies to support statistics
>>>   *			and freq_table must be generated in ascending order.
>>>   * @max_state:		The size of freq_table.
>>> + * @total_trans:	Number of devfreq transitions
>>> + * @trans_table:	Statistics of devfreq transitions
>>> + * @time_in_state:	Statistics of devfreq states
>>> + * @last_time:		The last time stats were updated
>>> + * @stats_lock:		Lock protecting trans_table, time_in_state,
>>> + *			last_time and total_trans used for statistics
>>>   */
>>>  struct devfreq_dev_profile {
>>>  	unsigned long initial_freq;
>>> @@ -104,6 +110,12 @@ struct devfreq_dev_profile {
>>>  
>>>  	unsigned long *freq_table;
>>>  	unsigned int max_state;
>>> +	/* information for device frequency transition */
>>> +	unsigned int total_trans;
>>> +	unsigned int *trans_table;
>>> +	u64 *time_in_state;
>>> +	unsigned long long last_time;
>>> +	spinlock_t stats_lock;
>>>  };
>>>  
>>>  /**
>>> @@ -131,12 +143,6 @@ struct devfreq_dev_profile {
>>>   * @suspend_freq:	 frequency of a device set during suspend phase.
>>>   * @resume_freq:	 frequency of a device set in resume phase.
>>>   * @suspend_count:	 suspend requests counter for a device.
>>> - * @total_trans:	Number of devfreq transitions
>>> - * @trans_table:	Statistics of devfreq transitions
>>> - * @time_in_state:	Statistics of devfreq states
>>> - * @last_time:		The last time stats were updated
>>> - * @stats_lock:		Lock protecting trans_table, time_in_state, last_time
>>> - *			and total_trans used for statistics
>>>   * @transition_notifier_list: list head of DEVFREQ_TRANSITION_NOTIFIER notifier
>>>   *
>>>   * This structure stores the devfreq information for a give device.
>>> @@ -173,13 +179,6 @@ struct devfreq {
>>>  	unsigned long resume_freq;
>>>  	atomic_t suspend_count;
>>>  
>>> -	/* information for device frequency transition */
>>> -	unsigned int total_trans;
>>> -	unsigned int *trans_table;
>>> -	u64 *time_in_state;
>>> -	unsigned long long last_time;
>>> -	spinlock_t stats_lock;
>>> -
>>>  	struct srcu_notifier_head transition_notifier_list;
>>>  };
>>>  
>>>
> 
> 
>