[PATCH v2 3/3] devfreq: move statistics to separate struct

Kamil Konieczny
2019-12-04T15:00:39Z

Count time and transitions between devfreq frequencies in separate struct
for improved code readability and maintenance.

Signed-off-by: Kamil Konieczny <k.konieczny@samsung.com>
---
Changes in v2:
squash three patches into one, do not modify devfreq_profile and separate stats
into devfreq_stats

drivers/devfreq/devfreq.c | 68 +++++++++++++++++++++++----------------
include/linux/devfreq.h | 31 ++++++++++++------
2 files changed, 62 insertions(+), 37 deletions(-)

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index 901af3b66a76..4d50c8f10bd2 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -198,6 +198,7 @@ static int set_freq_table(struct devfreq *devfreq)
*/
int devfreq_update_status(struct devfreq *devfreq, unsigned long freq)
{
+ struct devfreq_stats *stats = devfreq->stats;
int lev, prev_lev, ret = 0;
unsigned long long cur_time;

@@ -214,8 +215,8 @@ int devfreq_update_status(struct devfreq *devfreq, unsigned long freq)
goto out;
}

- devfreq->time_in_state[prev_lev] +=
- cur_time - devfreq->last_stat_updated;
+ stats->time_in_state[prev_lev] +=
+ cur_time - stats->last_stat_updated;

lev = devfreq_get_freq_level(devfreq, freq);
if (lev < 0) {
@@ -224,13 +225,12 @@ 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++;
+ stats->trans_table[(prev_lev * stats->max_state) + lev]++;
+ stats->total_trans++;
}

out:
- devfreq->last_stat_updated = cur_time;
+ stats->last_stat_updated = cur_time;
return ret;
}
EXPORT_SYMBOL(devfreq_update_status);
@@ -525,7 +525,7 @@ void devfreq_monitor_resume(struct devfreq *devfreq)
msecs_to_jiffies(devfreq->profile->polling_ms));

out_update:
- devfreq->last_stat_updated = get_jiffies_64();
+ devfreq->stats->last_stat_updated = get_jiffies_64();
devfreq->stop_polling = false;

if (devfreq->profile->get_cur_freq &&
@@ -735,28 +735,38 @@ struct devfreq *devfreq_add_device(struct device *dev,
goto err_out;
}

- devfreq->trans_table = devm_kzalloc(&devfreq->dev,
+ devfreq->stats = devm_kzalloc(&devfreq->dev, sizeof(*devfreq->stats),
+ GFP_KERNEL);
+ if (!devfreq->stats) {
+ mutex_unlock(&devfreq->lock);
+ err = -ENOMEM;
+ goto err_devfreq;
+ }
+
+ devfreq->stats->freq_table = devfreq->profile->freq_table;
+ devfreq->stats->max_state = devfreq->profile->max_state;
+ devfreq->stats->trans_table = devm_kzalloc(&devfreq->dev,
array3_size(sizeof(unsigned int),
- devfreq->profile->max_state,
- devfreq->profile->max_state),
+ devfreq->stats->max_state,
+ devfreq->stats->max_state),
GFP_KERNEL);
- if (!devfreq->trans_table) {
+ if (!devfreq->stats->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),
+ devfreq->stats->time_in_state = devm_kcalloc(&devfreq->dev,
+ devfreq->stats->max_state,
+ sizeof(*devfreq->stats->time_in_state),
GFP_KERNEL);
- if (!devfreq->time_in_state) {
+ if (!devfreq->stats->time_in_state) {
mutex_unlock(&devfreq->lock);
err = -ENOMEM;
goto err_devfreq;
}

- devfreq->last_stat_updated = get_jiffies_64();
+ devfreq->stats->last_stat_updated = get_jiffies_64();

srcu_init_notifier_head(&devfreq->transition_notifier_list);

@@ -1435,9 +1445,10 @@ static ssize_t trans_stat_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct devfreq *devfreq = to_devfreq(dev);
+ struct devfreq_stats *stats = devfreq->stats;
+ unsigned int max_state = stats->max_state;
ssize_t len;
int i, j;
- unsigned int max_state = devfreq->profile->max_state;

if (max_state == 0)
return sprintf(buf, "Not Supported.\n");
@@ -1454,28 +1465,28 @@ static ssize_t trans_stat_show(struct device *dev,
len += sprintf(buf + len, " :");
for (i = 0; i < max_state; i++)
len += sprintf(buf + len, "%10lu",
- devfreq->profile->freq_table[i]);
+ stats->freq_table[i]);

len += sprintf(buf + len, " time(ms)\n");

for (i = 0; i < max_state; i++) {
- if (devfreq->profile->freq_table[i]
+ if (stats->freq_table[i]
== devfreq->previous_freq) {
len += sprintf(buf + len, "*");
} else {
len += sprintf(buf + len, " ");
}
len += sprintf(buf + len, "%10lu:",
- devfreq->profile->freq_table[i]);
+ stats->freq_table[i]);
for (j = 0; j < max_state; j++)
len += sprintf(buf + len, "%10u",
- devfreq->trans_table[(i * max_state) + j]);
+ stats->trans_table[(i * max_state) + j]);
len += sprintf(buf + len, "%10llu\n", (u64)
- jiffies64_to_msecs(devfreq->time_in_state[i]));
+ jiffies64_to_msecs(stats->time_in_state[i]));
}

len += sprintf(buf + len, "Total transition : %u\n",
- devfreq->total_trans);
+ stats->total_trans);
return len;
}

@@ -1484,16 +1495,17 @@ static ssize_t trans_stat_store(struct device *dev,
const char *buf, size_t count)
{
struct devfreq *df = to_devfreq(dev);
- unsigned int cnt = df->profile->max_state;
+ struct devfreq_stats *stats = df->stats;
+ unsigned int cnt = stats->max_state;

if (cnt == 0)
return count;

mutex_lock(&df->lock);
- memset(df->time_in_state, 0, cnt * sizeof(u64));
- memset(df->trans_table, 0, cnt * cnt * sizeof(int));
- df->last_stat_updated = get_jiffies_64();
- df->total_trans = 0;
+ memset(stats->time_in_state, 0, cnt * sizeof(u64));
+ memset(stats->trans_table, 0, cnt * cnt * sizeof(int));
+ stats->last_stat_updated = get_jiffies_64();
+ stats->total_trans = 0;
mutex_unlock(&df->lock);

return count;
diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
index b81a86e47fb9..2715719924e7 100644
--- a/include/linux/devfreq.h
+++ b/include/linux/devfreq.h
@@ -106,6 +106,25 @@ struct devfreq_dev_profile {
unsigned int max_state;
};

+/**
+ * struct devfreq_stats - Devfreq's transitions stats counters
+ * @freq_table: List of frequencies 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_stat_updated: The last time stats were updated.
+ */
+struct devfreq_stats {
+ unsigned long *freq_table;
+ unsigned int max_state;
+
+ unsigned int total_trans;
+ unsigned int *trans_table;
+ u64 *time_in_state;
+ unsigned long long last_stat_updated;
+};
+
/**
* struct devfreq - Device devfreq structure
* @node: list node - contains the devices with devfreq that have been
@@ -131,10 +150,7 @@ 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_stat_updated: The last time stat updated
+ * @stats: Statistics of devfreq transitions and states times
* @transition_notifier_list: list head of DEVFREQ_TRANSITION_NOTIFIER notifier
*
* This structure stores the devfreq information for a give device.
@@ -171,11 +187,8 @@ 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_stat_updated;
+ /* information for device frequency transitions */
+ struct devfreq_stats *stats;

struct srcu_notifier_head transition_notifier_list;
};
--
2.24.0