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![Dave Jones](/assets/img/avatar_default.png)
The hotplug CPU locking in cpufreq is horrendous. No-one seems to care enough to fix it, so just remove it so that the 99.9% of the real world users of this code can use cpufreq without being bothered by warnings. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dave Jones <davej@redhat.com>
385 lines
9.4 KiB
C
385 lines
9.4 KiB
C
/*
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* drivers/cpufreq/cpufreq_stats.c
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*
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* Copyright (C) 2003-2004 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>.
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* (C) 2004 Zou Nan hai <nanhai.zou@intel.com>.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/kernel.h>
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#include <linux/sysdev.h>
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#include <linux/cpu.h>
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#include <linux/sysfs.h>
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#include <linux/cpufreq.h>
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#include <linux/jiffies.h>
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#include <linux/percpu.h>
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#include <linux/kobject.h>
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#include <linux/spinlock.h>
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#include <linux/notifier.h>
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#include <asm/cputime.h>
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static spinlock_t cpufreq_stats_lock;
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#define CPUFREQ_STATDEVICE_ATTR(_name,_mode,_show) \
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static struct freq_attr _attr_##_name = {\
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.attr = {.name = __stringify(_name), .owner = THIS_MODULE, \
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.mode = _mode, }, \
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.show = _show,\
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};
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struct cpufreq_stats {
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unsigned int cpu;
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unsigned int total_trans;
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unsigned long long last_time;
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unsigned int max_state;
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unsigned int state_num;
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unsigned int last_index;
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cputime64_t *time_in_state;
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unsigned int *freq_table;
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#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
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unsigned int *trans_table;
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#endif
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};
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static struct cpufreq_stats *cpufreq_stats_table[NR_CPUS];
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struct cpufreq_stats_attribute {
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struct attribute attr;
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ssize_t(*show) (struct cpufreq_stats *, char *);
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};
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static int
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cpufreq_stats_update (unsigned int cpu)
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{
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struct cpufreq_stats *stat;
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unsigned long long cur_time;
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cur_time = get_jiffies_64();
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spin_lock(&cpufreq_stats_lock);
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stat = cpufreq_stats_table[cpu];
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if (stat->time_in_state)
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stat->time_in_state[stat->last_index] =
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cputime64_add(stat->time_in_state[stat->last_index],
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cputime_sub(cur_time, stat->last_time));
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stat->last_time = cur_time;
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spin_unlock(&cpufreq_stats_lock);
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return 0;
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}
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static ssize_t
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show_total_trans(struct cpufreq_policy *policy, char *buf)
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{
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struct cpufreq_stats *stat = cpufreq_stats_table[policy->cpu];
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if (!stat)
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return 0;
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return sprintf(buf, "%d\n",
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cpufreq_stats_table[stat->cpu]->total_trans);
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}
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static ssize_t
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show_time_in_state(struct cpufreq_policy *policy, char *buf)
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{
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ssize_t len = 0;
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int i;
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struct cpufreq_stats *stat = cpufreq_stats_table[policy->cpu];
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if (!stat)
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return 0;
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cpufreq_stats_update(stat->cpu);
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for (i = 0; i < stat->state_num; i++) {
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len += sprintf(buf + len, "%u %llu\n", stat->freq_table[i],
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(unsigned long long)cputime64_to_clock_t(stat->time_in_state[i]));
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}
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return len;
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}
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#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
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static ssize_t
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show_trans_table(struct cpufreq_policy *policy, char *buf)
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{
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ssize_t len = 0;
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int i, j;
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struct cpufreq_stats *stat = cpufreq_stats_table[policy->cpu];
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if (!stat)
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return 0;
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cpufreq_stats_update(stat->cpu);
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len += snprintf(buf + len, PAGE_SIZE - len, " From : To\n");
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len += snprintf(buf + len, PAGE_SIZE - len, " : ");
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for (i = 0; i < stat->state_num; i++) {
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if (len >= PAGE_SIZE)
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break;
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len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
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stat->freq_table[i]);
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}
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if (len >= PAGE_SIZE)
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return len;
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len += snprintf(buf + len, PAGE_SIZE - len, "\n");
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for (i = 0; i < stat->state_num; i++) {
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if (len >= PAGE_SIZE)
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break;
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len += snprintf(buf + len, PAGE_SIZE - len, "%9u: ",
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stat->freq_table[i]);
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for (j = 0; j < stat->state_num; j++) {
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if (len >= PAGE_SIZE)
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break;
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len += snprintf(buf + len, PAGE_SIZE - len, "%9u ",
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stat->trans_table[i*stat->max_state+j]);
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}
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len += snprintf(buf + len, PAGE_SIZE - len, "\n");
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}
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return len;
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}
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CPUFREQ_STATDEVICE_ATTR(trans_table,0444,show_trans_table);
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#endif
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CPUFREQ_STATDEVICE_ATTR(total_trans,0444,show_total_trans);
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CPUFREQ_STATDEVICE_ATTR(time_in_state,0444,show_time_in_state);
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static struct attribute *default_attrs[] = {
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&_attr_total_trans.attr,
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&_attr_time_in_state.attr,
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#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
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&_attr_trans_table.attr,
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#endif
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NULL
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};
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static struct attribute_group stats_attr_group = {
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.attrs = default_attrs,
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.name = "stats"
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};
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static int
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freq_table_get_index(struct cpufreq_stats *stat, unsigned int freq)
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{
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int index;
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for (index = 0; index < stat->max_state; index++)
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if (stat->freq_table[index] == freq)
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return index;
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return -1;
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}
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static void
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cpufreq_stats_free_table (unsigned int cpu)
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{
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struct cpufreq_stats *stat = cpufreq_stats_table[cpu];
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struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
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if (policy && policy->cpu == cpu)
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sysfs_remove_group(&policy->kobj, &stats_attr_group);
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if (stat) {
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kfree(stat->time_in_state);
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kfree(stat);
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}
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cpufreq_stats_table[cpu] = NULL;
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if (policy)
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cpufreq_cpu_put(policy);
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}
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static int
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cpufreq_stats_create_table (struct cpufreq_policy *policy,
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struct cpufreq_frequency_table *table)
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{
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unsigned int i, j, count = 0, ret = 0;
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struct cpufreq_stats *stat;
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struct cpufreq_policy *data;
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unsigned int alloc_size;
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unsigned int cpu = policy->cpu;
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if (cpufreq_stats_table[cpu])
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return -EBUSY;
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if ((stat = kzalloc(sizeof(struct cpufreq_stats), GFP_KERNEL)) == NULL)
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return -ENOMEM;
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data = cpufreq_cpu_get(cpu);
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if (data == NULL) {
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ret = -EINVAL;
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goto error_get_fail;
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}
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if ((ret = sysfs_create_group(&data->kobj, &stats_attr_group)))
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goto error_out;
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stat->cpu = cpu;
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cpufreq_stats_table[cpu] = stat;
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for (i=0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
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unsigned int freq = table[i].frequency;
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if (freq == CPUFREQ_ENTRY_INVALID)
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continue;
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count++;
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}
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alloc_size = count * sizeof(int) + count * sizeof(cputime64_t);
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#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
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alloc_size += count * count * sizeof(int);
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#endif
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stat->max_state = count;
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stat->time_in_state = kzalloc(alloc_size, GFP_KERNEL);
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if (!stat->time_in_state) {
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ret = -ENOMEM;
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goto error_out;
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}
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stat->freq_table = (unsigned int *)(stat->time_in_state + count);
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#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
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stat->trans_table = stat->freq_table + count;
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#endif
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j = 0;
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for (i = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) {
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unsigned int freq = table[i].frequency;
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if (freq == CPUFREQ_ENTRY_INVALID)
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continue;
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if (freq_table_get_index(stat, freq) == -1)
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stat->freq_table[j++] = freq;
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}
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stat->state_num = j;
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spin_lock(&cpufreq_stats_lock);
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stat->last_time = get_jiffies_64();
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stat->last_index = freq_table_get_index(stat, policy->cur);
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spin_unlock(&cpufreq_stats_lock);
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cpufreq_cpu_put(data);
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return 0;
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error_out:
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cpufreq_cpu_put(data);
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error_get_fail:
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kfree(stat);
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cpufreq_stats_table[cpu] = NULL;
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return ret;
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}
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static int
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cpufreq_stat_notifier_policy (struct notifier_block *nb, unsigned long val,
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void *data)
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{
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int ret;
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struct cpufreq_policy *policy = data;
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struct cpufreq_frequency_table *table;
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unsigned int cpu = policy->cpu;
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if (val != CPUFREQ_NOTIFY)
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return 0;
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table = cpufreq_frequency_get_table(cpu);
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if (!table)
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return 0;
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if ((ret = cpufreq_stats_create_table(policy, table)))
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return ret;
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return 0;
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}
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static int
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cpufreq_stat_notifier_trans (struct notifier_block *nb, unsigned long val,
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void *data)
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{
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struct cpufreq_freqs *freq = data;
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struct cpufreq_stats *stat;
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int old_index, new_index;
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if (val != CPUFREQ_POSTCHANGE)
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return 0;
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stat = cpufreq_stats_table[freq->cpu];
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if (!stat)
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return 0;
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old_index = freq_table_get_index(stat, freq->old);
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new_index = freq_table_get_index(stat, freq->new);
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cpufreq_stats_update(freq->cpu);
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if (old_index == new_index)
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return 0;
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if (old_index == -1 || new_index == -1)
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return 0;
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spin_lock(&cpufreq_stats_lock);
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stat->last_index = new_index;
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#ifdef CONFIG_CPU_FREQ_STAT_DETAILS
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stat->trans_table[old_index * stat->max_state + new_index]++;
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#endif
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stat->total_trans++;
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spin_unlock(&cpufreq_stats_lock);
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return 0;
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}
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static int cpufreq_stat_cpu_callback(struct notifier_block *nfb,
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unsigned long action, void *hcpu)
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{
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unsigned int cpu = (unsigned long)hcpu;
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switch (action) {
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case CPU_ONLINE:
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cpufreq_update_policy(cpu);
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break;
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case CPU_DEAD:
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cpufreq_stats_free_table(cpu);
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break;
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}
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return NOTIFY_OK;
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}
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static struct notifier_block cpufreq_stat_cpu_notifier =
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{
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.notifier_call = cpufreq_stat_cpu_callback,
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};
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static struct notifier_block notifier_policy_block = {
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.notifier_call = cpufreq_stat_notifier_policy
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};
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static struct notifier_block notifier_trans_block = {
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.notifier_call = cpufreq_stat_notifier_trans
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};
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static int
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__init cpufreq_stats_init(void)
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{
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int ret;
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unsigned int cpu;
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spin_lock_init(&cpufreq_stats_lock);
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if ((ret = cpufreq_register_notifier(¬ifier_policy_block,
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CPUFREQ_POLICY_NOTIFIER)))
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return ret;
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if ((ret = cpufreq_register_notifier(¬ifier_trans_block,
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CPUFREQ_TRANSITION_NOTIFIER))) {
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cpufreq_unregister_notifier(¬ifier_policy_block,
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CPUFREQ_POLICY_NOTIFIER);
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return ret;
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}
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register_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
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for_each_online_cpu(cpu) {
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cpufreq_stat_cpu_callback(&cpufreq_stat_cpu_notifier,
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CPU_ONLINE, (void *)(long)cpu);
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}
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return 0;
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}
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static void
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__exit cpufreq_stats_exit(void)
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{
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unsigned int cpu;
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cpufreq_unregister_notifier(¬ifier_policy_block,
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CPUFREQ_POLICY_NOTIFIER);
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cpufreq_unregister_notifier(¬ifier_trans_block,
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CPUFREQ_TRANSITION_NOTIFIER);
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unregister_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
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for_each_online_cpu(cpu) {
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cpufreq_stat_cpu_callback(&cpufreq_stat_cpu_notifier,
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CPU_DEAD, (void *)(long)cpu);
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}
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}
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MODULE_AUTHOR ("Zou Nan hai <nanhai.zou@intel.com>");
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MODULE_DESCRIPTION ("'cpufreq_stats' - A driver to export cpufreq stats"
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"through sysfs filesystem");
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MODULE_LICENSE ("GPL");
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module_init(cpufreq_stats_init);
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module_exit(cpufreq_stats_exit);
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