blob: 4df55b323fc18c8ca1971162d54d25b188299866 [file] [log] [blame] [edit]
/* drivers/cpufreq/cpufreq_times.c
*
* Copyright (C) 2018 Google, Inc.
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#include <linux/cpufreq.h>
#include <linux/cpufreq_times.h>
#include <linux/jiffies.h>
#include <linux/sched.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/threads.h>
static DEFINE_SPINLOCK(task_time_in_state_lock); /* task->time_in_state */
/**
* struct cpu_freqs - per-cpu frequency information
* @offset: start of these freqs' stats in task time_in_state array
* @max_state: number of entries in freq_table
* @last_index: index in freq_table of last frequency switched to
* @freq_table: list of available frequencies
*/
struct cpu_freqs {
unsigned int offset;
unsigned int max_state;
unsigned int last_index;
unsigned int freq_table[0];
};
static struct cpu_freqs *all_freqs[NR_CPUS];
static unsigned int next_offset;
void cpufreq_task_times_init(struct task_struct *p)
{
unsigned long flags;
spin_lock_irqsave(&task_time_in_state_lock, flags);
p->time_in_state = NULL;
spin_unlock_irqrestore(&task_time_in_state_lock, flags);
p->max_state = 0;
}
void cpufreq_task_times_alloc(struct task_struct *p)
{
void *temp;
unsigned long flags;
unsigned int max_state = READ_ONCE(next_offset);
/* We use one array to avoid multiple allocs per task */
temp = kcalloc(max_state, sizeof(p->time_in_state[0]), GFP_ATOMIC);
if (!temp)
return;
spin_lock_irqsave(&task_time_in_state_lock, flags);
p->time_in_state = temp;
spin_unlock_irqrestore(&task_time_in_state_lock, flags);
p->max_state = max_state;
}
/* Caller must hold task_time_in_state_lock */
static int cpufreq_task_times_realloc_locked(struct task_struct *p)
{
void *temp;
unsigned int max_state = READ_ONCE(next_offset);
temp = krealloc(p->time_in_state, max_state * sizeof(u64), GFP_ATOMIC);
if (!temp)
return -ENOMEM;
p->time_in_state = temp;
memset(p->time_in_state + p->max_state, 0,
(max_state - p->max_state) * sizeof(u64));
p->max_state = max_state;
return 0;
}
void cpufreq_task_times_exit(struct task_struct *p)
{
unsigned long flags;
void *temp;
if (!p->time_in_state)
return;
spin_lock_irqsave(&task_time_in_state_lock, flags);
temp = p->time_in_state;
p->time_in_state = NULL;
spin_unlock_irqrestore(&task_time_in_state_lock, flags);
kfree(temp);
}
int proc_time_in_state_show(struct seq_file *m, struct pid_namespace *ns,
struct pid *pid, struct task_struct *p)
{
unsigned int cpu, i;
u64 cputime;
unsigned long flags;
struct cpu_freqs *freqs;
struct cpu_freqs *last_freqs = NULL;
spin_lock_irqsave(&task_time_in_state_lock, flags);
for_each_possible_cpu(cpu) {
freqs = all_freqs[cpu];
if (!freqs || freqs == last_freqs)
continue;
last_freqs = freqs;
seq_printf(m, "cpu%u\n", cpu);
for (i = 0; i < freqs->max_state; i++) {
cputime = 0;
if (freqs->offset + i < p->max_state &&
p->time_in_state)
cputime = p->time_in_state[freqs->offset + i];
seq_printf(m, "%u %lu\n", freqs->freq_table[i],
(unsigned long)nsec_to_clock_t(cputime));
}
}
spin_unlock_irqrestore(&task_time_in_state_lock, flags);
return 0;
}
void cpufreq_acct_update_power(struct task_struct *p, u64 cputime)
{
unsigned long flags;
unsigned int state;
struct cpu_freqs *freqs = all_freqs[task_cpu(p)];
if (!freqs || is_idle_task(p) || p->flags & PF_EXITING)
return;
state = freqs->offset + READ_ONCE(freqs->last_index);
spin_lock_irqsave(&task_time_in_state_lock, flags);
if ((state < p->max_state || !cpufreq_task_times_realloc_locked(p)) &&
p->time_in_state)
p->time_in_state[state] += cputime;
spin_unlock_irqrestore(&task_time_in_state_lock, flags);
}
static int cpufreq_times_get_index(struct cpu_freqs *freqs, unsigned int freq)
{
int index;
for (index = 0; index < freqs->max_state; ++index) {
if (freqs->freq_table[index] == freq)
return index;
}
return -1;
}
void cpufreq_times_create_policy(struct cpufreq_policy *policy)
{
int cpu, index = 0;
unsigned int count = 0;
struct cpufreq_frequency_table *pos, *table;
struct cpu_freqs *freqs;
void *tmp;
if (all_freqs[policy->cpu])
return;
table = policy->freq_table;
if (!table)
return;
cpufreq_for_each_valid_entry(pos, table)
count++;
tmp = kzalloc(sizeof(*freqs) + sizeof(freqs->freq_table[0]) * count,
GFP_KERNEL);
if (!tmp)
return;
freqs = tmp;
freqs->max_state = count;
cpufreq_for_each_valid_entry(pos, table)
freqs->freq_table[index++] = pos->frequency;
index = cpufreq_times_get_index(freqs, policy->cur);
if (index >= 0)
WRITE_ONCE(freqs->last_index, index);
freqs->offset = next_offset;
WRITE_ONCE(next_offset, freqs->offset + count);
for_each_cpu(cpu, policy->related_cpus)
all_freqs[cpu] = freqs;
}
void cpufreq_times_record_transition(struct cpufreq_policy *policy,
unsigned int new_freq)
{
int index;
struct cpu_freqs *freqs = all_freqs[policy->cpu];
if (!freqs)
return;
index = cpufreq_times_get_index(freqs, new_freq);
if (index >= 0)
WRITE_ONCE(freqs->last_index, index);
}