https://github.com/torvalds/linux
Tip revision: b2cd1df66037e7c4697c7e40496bf7e4a5e16a2d authored by Linus Torvalds on 07 January 2018, 22:22:41 UTC
Linux 4.15-rc7
Linux 4.15-rc7
Tip revision: b2cd1df
cpufreq_stats.c
/*
* drivers/cpufreq/cpufreq_stats.c
*
* Copyright (C) 2003-2004 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
* (C) 2004 Zou Nan hai <nanhai.zou@intel.com>.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/cpu.h>
#include <linux/cpufreq.h>
#include <linux/module.h>
#include <linux/slab.h>
static DEFINE_SPINLOCK(cpufreq_stats_lock);
struct cpufreq_stats {
unsigned int total_trans;
unsigned long long last_time;
unsigned int max_state;
unsigned int state_num;
unsigned int last_index;
u64 *time_in_state;
unsigned int *freq_table;
unsigned int *trans_table;
};
static int cpufreq_stats_update(struct cpufreq_stats *stats)
{
unsigned long long cur_time = get_jiffies_64();
spin_lock(&cpufreq_stats_lock);
stats->time_in_state[stats->last_index] += cur_time - stats->last_time;
stats->last_time = cur_time;
spin_unlock(&cpufreq_stats_lock);
return 0;
}
static void cpufreq_stats_clear_table(struct cpufreq_stats *stats)
{
unsigned int count = stats->max_state;
memset(stats->time_in_state, 0, count * sizeof(u64));
memset(stats->trans_table, 0, count * count * sizeof(int));
stats->last_time = get_jiffies_64();
stats->total_trans = 0;
}
static ssize_t show_total_trans(struct cpufreq_policy *policy, char *buf)
{
return sprintf(buf, "%d\n", policy->stats->total_trans);
}
static ssize_t show_time_in_state(struct cpufreq_policy *policy, char *buf)
{
struct cpufreq_stats *stats = policy->stats;
ssize_t len = 0;
int i;
if (policy->fast_switch_enabled)
return 0;
cpufreq_stats_update(stats);
for (i = 0; i < stats->state_num; i++) {
len += sprintf(buf + len, "%u %llu\n", stats->freq_table[i],
(unsigned long long)
jiffies_64_to_clock_t(stats->time_in_state[i]));
}
return len;
}
static ssize_t store_reset(struct cpufreq_policy *policy, const char *buf,
size_t count)
{
/* We don't care what is written to the attribute. */
cpufreq_stats_clear_table(policy->stats);
return count;
}
static ssize_t show_trans_table(struct cpufreq_policy *policy, char *buf)
{
struct cpufreq_stats *stats = policy->stats;
ssize_t len = 0;
int i, j;
if (policy->fast_switch_enabled)
return 0;
len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n");
len += snprintf(buf + len, PAGE_SIZE - len, " : ");
for (i = 0; i < stats->state_num; i++) {
if (len >= PAGE_SIZE)
break;
len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
stats->freq_table[i]);
}
if (len >= PAGE_SIZE)
return PAGE_SIZE;
len += snprintf(buf + len, PAGE_SIZE - len, "\n");
for (i = 0; i < stats->state_num; i++) {
if (len >= PAGE_SIZE)
break;
len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ",
stats->freq_table[i]);
for (j = 0; j < stats->state_num; j++) {
if (len >= PAGE_SIZE)
break;
len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
stats->trans_table[i*stats->max_state+j]);
}
if (len >= PAGE_SIZE)
break;
len += snprintf(buf + len, PAGE_SIZE - len, "\n");
}
if (len >= PAGE_SIZE) {
pr_warn_once("cpufreq transition table exceeds PAGE_SIZE. Disabling\n");
return -EFBIG;
}
return len;
}
cpufreq_freq_attr_ro(trans_table);
cpufreq_freq_attr_ro(total_trans);
cpufreq_freq_attr_ro(time_in_state);
cpufreq_freq_attr_wo(reset);
static struct attribute *default_attrs[] = {
&total_trans.attr,
&time_in_state.attr,
&reset.attr,
&trans_table.attr,
NULL
};
static const struct attribute_group stats_attr_group = {
.attrs = default_attrs,
.name = "stats"
};
static int freq_table_get_index(struct cpufreq_stats *stats, unsigned int freq)
{
int index;
for (index = 0; index < stats->max_state; index++)
if (stats->freq_table[index] == freq)
return index;
return -1;
}
void cpufreq_stats_free_table(struct cpufreq_policy *policy)
{
struct cpufreq_stats *stats = policy->stats;
/* Already freed */
if (!stats)
return;
pr_debug("%s: Free stats table\n", __func__);
sysfs_remove_group(&policy->kobj, &stats_attr_group);
kfree(stats->time_in_state);
kfree(stats);
policy->stats = NULL;
}
void cpufreq_stats_create_table(struct cpufreq_policy *policy)
{
unsigned int i = 0, count = 0, ret = -ENOMEM;
struct cpufreq_stats *stats;
unsigned int alloc_size;
struct cpufreq_frequency_table *pos;
count = cpufreq_table_count_valid_entries(policy);
if (!count)
return;
/* stats already initialized */
if (policy->stats)
return;
stats = kzalloc(sizeof(*stats), GFP_KERNEL);
if (!stats)
return;
alloc_size = count * sizeof(int) + count * sizeof(u64);
alloc_size += count * count * sizeof(int);
/* Allocate memory for time_in_state/freq_table/trans_table in one go */
stats->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
if (!stats->time_in_state)
goto free_stat;
stats->freq_table = (unsigned int *)(stats->time_in_state + count);
stats->trans_table = stats->freq_table + count;
stats->max_state = count;
/* Find valid-unique entries */
cpufreq_for_each_valid_entry(pos, policy->freq_table)
if (freq_table_get_index(stats, pos->frequency) == -1)
stats->freq_table[i++] = pos->frequency;
stats->state_num = i;
stats->last_time = get_jiffies_64();
stats->last_index = freq_table_get_index(stats, policy->cur);
policy->stats = stats;
ret = sysfs_create_group(&policy->kobj, &stats_attr_group);
if (!ret)
return;
/* We failed, release resources */
policy->stats = NULL;
kfree(stats->time_in_state);
free_stat:
kfree(stats);
}
void cpufreq_stats_record_transition(struct cpufreq_policy *policy,
unsigned int new_freq)
{
struct cpufreq_stats *stats = policy->stats;
int old_index, new_index;
if (!stats) {
pr_debug("%s: No stats found\n", __func__);
return;
}
old_index = stats->last_index;
new_index = freq_table_get_index(stats, new_freq);
/* We can't do stats->time_in_state[-1]= .. */
if (old_index == -1 || new_index == -1 || old_index == new_index)
return;
cpufreq_stats_update(stats);
stats->last_index = new_index;
stats->trans_table[old_index * stats->max_state + new_index]++;
stats->total_trans++;
}