linux/drivers/cpufreq/cpufreq_stats.c
Rafael J. Wysocki 8bb7844286 Add suspend-related notifications for CPU hotplug
Since nonboot CPUs are now disabled after tasks and devices have been
frozen and the CPU hotplug infrastructure is used for this purpose, we need
special CPU hotplug notifications that will help the CPU-hotplug-aware
subsystems distinguish normal CPU hotplug events from CPU hotplug events
related to a system-wide suspend or resume operation in progress.  This
patch introduces such notifications and causes them to be used during
suspend and resume transitions.  It also changes all of the
CPU-hotplug-aware subsystems to take these notifications into consideration
(for now they are handled in the same way as the corresponding "normal"
ones).

[oleg@tv-sign.ru: cleanups]
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:56 -07:00

387 lines
9.4 KiB
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/kernel.h>
#include <linux/sysdev.h>
#include <linux/cpu.h>
#include <linux/sysfs.h>
#include <linux/cpufreq.h>
#include <linux/jiffies.h>
#include <linux/percpu.h>
#include <linux/kobject.h>
#include <linux/spinlock.h>
#include <linux/notifier.h>
#include <asm/cputime.h>
static spinlock_t cpufreq_stats_lock;
#define CPUFREQ_STATDEVICE_ATTR(_name,_mode,_show) \
static struct freq_attr _attr_##_name = {\
.attr = {.name = __stringify(_name), .owner = THIS_MODULE, \
.mode = _mode, }, \
.show = _show,\
};
struct cpufreq_stats {
unsigned int cpu;
unsigned int total_trans;
unsigned long long last_time;
unsigned int max_state;
unsigned int state_num;
unsigned int last_index;
cputime64_t *time_in_state;
unsigned int *freq_table;
#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
unsigned int *trans_table;
#endif
};
static struct cpufreq_stats *cpufreq_stats_table[NR_CPUS];
struct cpufreq_stats_attribute {
struct attribute attr;
ssize_t(*show) (struct cpufreq_stats *, char *);
};
static int
cpufreq_stats_update (unsigned int cpu)
{
struct cpufreq_stats *stat;
unsigned long long cur_time;
cur_time = get_jiffies_64();
spin_lock(&cpufreq_stats_lock);
stat = cpufreq_stats_table[cpu];
if (stat->time_in_state)
stat->time_in_state[stat->last_index] =
cputime64_add(stat->time_in_state[stat->last_index],
cputime_sub(cur_time, stat->last_time));
stat->last_time = cur_time;
spin_unlock(&cpufreq_stats_lock);
return 0;
}
static ssize_t
show_total_trans(struct cpufreq_policy *policy, char *buf)
{
struct cpufreq_stats *stat = cpufreq_stats_table[policy->cpu];
if (!stat)
return 0;
return sprintf(buf, "%d\n",
cpufreq_stats_table[stat->cpu]->total_trans);
}
static ssize_t
show_time_in_state(struct cpufreq_policy *policy, char *buf)
{
ssize_t len = 0;
int i;
struct cpufreq_stats *stat = cpufreq_stats_table[policy->cpu];
if (!stat)
return 0;
cpufreq_stats_update(stat->cpu);
for (i = 0; i < stat->state_num; i++) {
len += sprintf(buf + len, "%u %llu\n", stat->freq_table[i],
(unsigned long long)cputime64_to_clock_t(stat->time_in_state[i]));
}
return len;
}
#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
static ssize_t
show_trans_table(struct cpufreq_policy *policy, char *buf)
{
ssize_t len = 0;
int i, j;
struct cpufreq_stats *stat = cpufreq_stats_table[policy->cpu];
if (!stat)
return 0;
cpufreq_stats_update(stat->cpu);
len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n");
len += snprintf(buf + len, PAGE_SIZE - len, " : ");
for (i = 0; i < stat->state_num; i++) {
if (len >= PAGE_SIZE)
break;
len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
stat->freq_table[i]);
}
if (len >= PAGE_SIZE)
return len;
len += snprintf(buf + len, PAGE_SIZE - len, "\n");
for (i = 0; i < stat->state_num; i++) {
if (len >= PAGE_SIZE)
break;
len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ",
stat->freq_table[i]);
for (j = 0; j < stat->state_num; j++) {
if (len >= PAGE_SIZE)
break;
len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
stat->trans_table[i*stat->max_state+j]);
}
len += snprintf(buf + len, PAGE_SIZE - len, "\n");
}
return len;
}
CPUFREQ_STATDEVICE_ATTR(trans_table,0444,show_trans_table);
#endif
CPUFREQ_STATDEVICE_ATTR(total_trans,0444,show_total_trans);
CPUFREQ_STATDEVICE_ATTR(time_in_state,0444,show_time_in_state);
static struct attribute *default_attrs[] = {
&_attr_total_trans.attr,
&_attr_time_in_state.attr,
#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
&_attr_trans_table.attr,
#endif
NULL
};
static struct attribute_group stats_attr_group = {
.attrs = default_attrs,
.name = "stats"
};
static int
freq_table_get_index(struct cpufreq_stats *stat, unsigned int freq)
{
int index;
for (index = 0; index < stat->max_state; index++)
if (stat->freq_table[index] == freq)
return index;
return -1;
}
static void
cpufreq_stats_free_table (unsigned int cpu)
{
struct cpufreq_stats *stat = cpufreq_stats_table[cpu];
struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
if (policy && policy->cpu == cpu)
sysfs_remove_group(&policy->kobj, &stats_attr_group);
if (stat) {
kfree(stat->time_in_state);
kfree(stat);
}
cpufreq_stats_table[cpu] = NULL;
if (policy)
cpufreq_cpu_put(policy);
}
static int
cpufreq_stats_create_table (struct cpufreq_policy *policy,
struct cpufreq_frequency_table *table)
{
unsigned int i, j, count = 0, ret = 0;
struct cpufreq_stats *stat;
struct cpufreq_policy *data;
unsigned int alloc_size;
unsigned int cpu = policy->cpu;
if (cpufreq_stats_table[cpu])
return -EBUSY;
if ((stat = kzalloc(sizeof(struct cpufreq_stats), GFP_KERNEL)) == NULL)
return -ENOMEM;
data = cpufreq_cpu_get(cpu);
if (data == NULL) {
ret = -EINVAL;
goto error_get_fail;
}
if ((ret = sysfs_create_group(&data->kobj, &stats_attr_group)))
goto error_out;
stat->cpu = cpu;
cpufreq_stats_table[cpu] = stat;
for (i=0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
unsigned int freq = table[i].frequency;
if (freq == CPUFREQ_ENTRY_INVALID)
continue;
count++;
}
alloc_size = count * sizeof(int) + count * sizeof(cputime64_t);
#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
alloc_size += count * count * sizeof(int);
#endif
stat->max_state = count;
stat->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
if (!stat->time_in_state) {
ret = -ENOMEM;
goto error_out;
}
stat->freq_table = (unsigned int *)(stat->time_in_state + count);
#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
stat->trans_table = stat->freq_table + count;
#endif
j = 0;
for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
unsigned int freq = table[i].frequency;
if (freq == CPUFREQ_ENTRY_INVALID)
continue;
if (freq_table_get_index(stat, freq) == -1)
stat->freq_table[j++] = freq;
}
stat->state_num = j;
spin_lock(&cpufreq_stats_lock);
stat->last_time = get_jiffies_64();
stat->last_index = freq_table_get_index(stat, policy->cur);
spin_unlock(&cpufreq_stats_lock);
cpufreq_cpu_put(data);
return 0;
error_out:
cpufreq_cpu_put(data);
error_get_fail:
kfree(stat);
cpufreq_stats_table[cpu] = NULL;
return ret;
}
static int
cpufreq_stat_notifier_policy (struct notifier_block *nb, unsigned long val,
void *data)
{
int ret;
struct cpufreq_policy *policy = data;
struct cpufreq_frequency_table *table;
unsigned int cpu = policy->cpu;
if (val != CPUFREQ_NOTIFY)
return 0;
table = cpufreq_frequency_get_table(cpu);
if (!table)
return 0;
if ((ret = cpufreq_stats_create_table(policy, table)))
return ret;
return 0;
}
static int
cpufreq_stat_notifier_trans (struct notifier_block *nb, unsigned long val,
void *data)
{
struct cpufreq_freqs *freq = data;
struct cpufreq_stats *stat;
int old_index, new_index;
if (val != CPUFREQ_POSTCHANGE)
return 0;
stat = cpufreq_stats_table[freq->cpu];
if (!stat)
return 0;
old_index = freq_table_get_index(stat, freq->old);
new_index = freq_table_get_index(stat, freq->new);
cpufreq_stats_update(freq->cpu);
if (old_index == new_index)
return 0;
if (old_index == -1 || new_index == -1)
return 0;
spin_lock(&cpufreq_stats_lock);
stat->last_index = new_index;
#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
stat->trans_table[old_index * stat->max_state + new_index]++;
#endif
stat->total_trans++;
spin_unlock(&cpufreq_stats_lock);
return 0;
}
static int cpufreq_stat_cpu_callback(struct notifier_block *nfb,
unsigned long action, void *hcpu)
{
unsigned int cpu = (unsigned long)hcpu;
switch (action) {
case CPU_ONLINE:
case CPU_ONLINE_FROZEN:
cpufreq_update_policy(cpu);
break;
case CPU_DEAD:
case CPU_DEAD_FROZEN:
cpufreq_stats_free_table(cpu);
break;
}
return NOTIFY_OK;
}
static struct notifier_block cpufreq_stat_cpu_notifier =
{
.notifier_call = cpufreq_stat_cpu_callback,
};
static struct notifier_block notifier_policy_block = {
.notifier_call = cpufreq_stat_notifier_policy
};
static struct notifier_block notifier_trans_block = {
.notifier_call = cpufreq_stat_notifier_trans
};
static int
__init cpufreq_stats_init(void)
{
int ret;
unsigned int cpu;
spin_lock_init(&cpufreq_stats_lock);
if ((ret = cpufreq_register_notifier(&notifier_policy_block,
CPUFREQ_POLICY_NOTIFIER)))
return ret;
if ((ret = cpufreq_register_notifier(&notifier_trans_block,
CPUFREQ_TRANSITION_NOTIFIER))) {
cpufreq_unregister_notifier(&notifier_policy_block,
CPUFREQ_POLICY_NOTIFIER);
return ret;
}
register_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
for_each_online_cpu(cpu) {
cpufreq_stat_cpu_callback(&cpufreq_stat_cpu_notifier,
CPU_ONLINE, (void *)(long)cpu);
}
return 0;
}
static void
__exit cpufreq_stats_exit(void)
{
unsigned int cpu;
cpufreq_unregister_notifier(&notifier_policy_block,
CPUFREQ_POLICY_NOTIFIER);
cpufreq_unregister_notifier(&notifier_trans_block,
CPUFREQ_TRANSITION_NOTIFIER);
unregister_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
for_each_online_cpu(cpu) {
cpufreq_stat_cpu_callback(&cpufreq_stat_cpu_notifier,
CPU_DEAD, (void *)(long)cpu);
}
}
MODULE_AUTHOR ("Zou Nan hai <nanhai.zou@intel.com>");
MODULE_DESCRIPTION ("'cpufreq_stats' - A driver to export cpufreq stats"
"through sysfs filesystem");
MODULE_LICENSE ("GPL");
module_init(cpufreq_stats_init);
module_exit(cpufreq_stats_exit);