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

From: Bartlomiej Zolnierkiewicz
Date: Thu Nov 14 2019 - 13:11:06 EST



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;
>> };
>>
>>