![Tejun Heo](/assets/img/avatar_default.png)
sysfs is now completely out of driver/module lifetime game. After deletion, a sysfs node doesn't access anything outside sysfs proper, so there's no reason to hold onto the attribute owners. Note that often the wrong modules were accounted for as owners leading to accessing removed modules. This patch kills now unnecessary attribute->owner. Note that with this change, userland holding a sysfs node does not prevent the backing module from being unloaded. For more info regarding lifetime rule cleanup, please read the following message. http://article.gmane.org/gmane.linux.kernel/510293 (tweaked by Greg to not delete the field just yet, to make it easier to merge things properly.) Signed-off-by: Tejun Heo <htejun@gmail.com> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
387 lines
9.4 KiB
C
387 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), .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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case CPU_ONLINE_FROZEN:
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cpufreq_update_policy(cpu);
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break;
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case CPU_DEAD:
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case CPU_DEAD_FROZEN:
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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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