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

[Bartlomiej Zolnierkiewicz]

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'?

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;
>>  };
>>  
>>