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Date: Sat, 14 May 2022 14:19:32 +0000
From: Junwen Wu <wudaemon@....com>
To: rafael@...nel.org, daniel.lezcano@...aro.org, amitk@...nel.org,
rui.zhang@...el.com
Cc: linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org,
Junwen Wu <wudaemon@....com>
Subject: [PATCH v2] thermal/core: Make trans_table tunnable to avoid some needless zero output
Very high cooling device max state value make trans_table node
prompt File too large. We introduce show_state node, tunnable
by user,thus trans_table only show show_state'th trans count to
the max trans count, in this way trans_table_show's buffer is
always less than PAGE_SIZE and shows the important changes.
Signed-off-by: Junwen Wu <wudaemon@....com>
---
drivers/thermal/thermal_sysfs.c | 111 +++++++++++++++++++++++++-------
1 file changed, 86 insertions(+), 25 deletions(-)
diff --git a/drivers/thermal/thermal_sysfs.c b/drivers/thermal/thermal_sysfs.c
index f154bada2906..bb8627aa49b7 100644
--- a/drivers/thermal/thermal_sysfs.c
+++ b/drivers/thermal/thermal_sysfs.c
@@ -656,6 +656,7 @@ struct cooling_dev_stats {
spinlock_t lock;
unsigned int total_trans;
unsigned long state;
+ unsigned long show_state;
unsigned long max_states;
ktime_t last_time;
ktime_t *time_in_state;
@@ -752,38 +753,93 @@ reset_store(struct device *dev, struct device_attribute *attr, const char *buf,
return count;
}
-static ssize_t trans_table_show(struct device *dev,
- struct device_attribute *attr, char *buf)
+static ssize_t
+show_state_store(struct device *dev, struct device_attribute *attr, const char *buf,
+ size_t count)
{
struct thermal_cooling_device *cdev = to_cooling_device(dev);
struct cooling_dev_stats *stats = cdev->stats;
- ssize_t len = 0;
- int i, j;
+ unsigned long state;
+ ssize_t ret;
- len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n");
- len += snprintf(buf + len, PAGE_SIZE - len, " : ");
- for (i = 0; i < stats->max_states; i++) {
- if (len >= PAGE_SIZE)
- break;
- len += snprintf(buf + len, PAGE_SIZE - len, "state%2u ", i);
- }
- if (len >= PAGE_SIZE)
- return PAGE_SIZE;
+ spin_lock(&stats->lock);
+
+ ret = kstrtoul(buf, 10, &state);
+ if (ret || (state > stats->max_states))
+ goto unlock;
- len += snprintf(buf + len, PAGE_SIZE - len, "\n");
+ stats->show_state = state;
+unlock:
+ spin_unlock(&stats->lock);
- for (i = 0; i < stats->max_states; i++) {
- if (len >= PAGE_SIZE)
- break;
+ return count;
+}
+
+static ssize_t
+show_state_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct thermal_cooling_device *cdev = to_cooling_device(dev);
+ struct cooling_dev_stats *stats = cdev->stats;
+
+ return sprintf(buf, "%lu\n", stats->show_state);
+}
- len += snprintf(buf + len, PAGE_SIZE - len, "state%2u:", i);
+/* find the kth largest in nums array*/
+static int find_show_state(int *nums, int numsSize, int k, unsigned int *max_value)
+{
+ int i, l, r, mid, cnt = 0, min = INT_MAX, max = 0;
- for (j = 0; j < stats->max_states; j++) {
- if (len >= PAGE_SIZE)
- break;
- len += snprintf(buf + len, PAGE_SIZE - len, "%8u ",
- stats->trans_table[i * stats->max_states + j]);
+ for (i = 0; i < numsSize; i++) {
+ min = nums[i] < min ? nums[i] : min;
+ max = nums[i] > max ? nums[i] : max;
+ }
+ l = min;
+ r = max;
+ while (l < r) {
+ mid = r - (r - l) / 2;
+ for (i = 0; i < numsSize; i++) {
+ if (nums[i] >= mid)
+ cnt++;
+ }
+ if (cnt < k) {
+ r = mid - 1;
+ cnt = 0;
+ } else {
+ l = mid;
+ cnt = 0;
}
+ }
+
+ *max_value = max;
+
+ return l;
+}
+
+
+
+static ssize_t trans_table_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct thermal_cooling_device *cdev = to_cooling_device(dev);
+ struct cooling_dev_stats *stats = cdev->stats;
+ unsigned int show_state_value = 0;
+ unsigned int max_state_value = 0;
+ ssize_t len = 0;
+ int i, j;
+
+ len += snprintf(buf + len, PAGE_SIZE - len, " From : Index_change\n");
+ for (i = 0; i < stats->max_states; i++) {
+ show_state_value = find_show_state(&stats->trans_table[i * stats->max_states],
+ stats->max_states, stats->show_state, &max_state_value);
+ if (max_state_value)
+ len += snprintf(buf + len, PAGE_SIZE - len, "state%2u:", i);
+ else
+ continue;
+ for (j = 0; j < stats->max_states; j++)
+ if (stats->trans_table[i * stats->max_states + j] && (show_state_value <=
+ stats->trans_table[i * stats->max_states + j]))
+ len += snprintf(buf + len, PAGE_SIZE - len, " ->%u(%u)", j,
+ stats->trans_table[i * stats->max_states + j]);
if (len >= PAGE_SIZE)
break;
len += snprintf(buf + len, PAGE_SIZE - len, "\n");
@@ -793,6 +849,7 @@ static ssize_t trans_table_show(struct device *dev,
pr_warn_once("Thermal transition table exceeds PAGE_SIZE. Disabling\n");
return -EFBIG;
}
+
return len;
}
@@ -800,12 +857,14 @@ static DEVICE_ATTR_RO(total_trans);
static DEVICE_ATTR_RO(time_in_state_ms);
static DEVICE_ATTR_WO(reset);
static DEVICE_ATTR_RO(trans_table);
+static DEVICE_ATTR_RW(show_state);
static struct attribute *cooling_device_stats_attrs[] = {
&dev_attr_total_trans.attr,
&dev_attr_time_in_state_ms.attr,
&dev_attr_reset.attr,
&dev_attr_trans_table.attr,
+ &dev_attr_show_state.attr,
NULL
};
@@ -829,7 +888,7 @@ static void cooling_device_stats_setup(struct thermal_cooling_device *cdev)
var += sizeof(*stats->time_in_state) * states;
var += sizeof(*stats->trans_table) * states * states;
- stats = kzalloc(var, GFP_KERNEL);
+ stats = kvzalloc(var, GFP_KERNEL);
if (!stats)
return;
@@ -838,6 +897,8 @@ static void cooling_device_stats_setup(struct thermal_cooling_device *cdev)
cdev->stats = stats;
stats->last_time = ktime_get();
stats->max_states = states;
+ /* default set show_state = max_states/2 */
+ stats->show_state = states / 2;
spin_lock_init(&stats->lock);
@@ -848,7 +909,7 @@ static void cooling_device_stats_setup(struct thermal_cooling_device *cdev)
static void cooling_device_stats_destroy(struct thermal_cooling_device *cdev)
{
- kfree(cdev->stats);
+ kvfree(cdev->stats);
cdev->stats = NULL;
}
--
2.25.1
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