blob: 6c552859d691a644092a4ebd3338a6ea95dac905 [file] [log] [blame]
/*
* drivers/cpufreq/cpufreq_interactive.c
*
* Copyright (C) 2010 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.
*
* Author: Mike Chan (mike@android.com)
*
*/
#include <linux/cpu.h>
#include <linux/cpumask.h>
#include <linux/cpufreq.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/rwsem.h>
#include <linux/sched.h>
#include <linux/tick.h>
#include <linux/time.h>
#include <linux/timer.h>
#include <linux/workqueue.h>
#include <linux/kthread.h>
#include <linux/slab.h>
#include <linux/kernel_stat.h>
#include <asm/cputime.h>
#define CREATE_TRACE_POINTS
#include <trace/events/cpufreq_interactive.h>
static int active_count;
struct cpufreq_interactive_cpuinfo {
struct timer_list cpu_timer;
struct timer_list cpu_slack_timer;
spinlock_t load_lock; /* protects the next 4 fields */
u64 time_in_idle;
u64 time_in_idle_timestamp;
u64 cputime_speedadj;
u64 cputime_speedadj_timestamp;
struct cpufreq_policy *policy;
struct cpufreq_frequency_table *freq_table;
unsigned int target_freq;
unsigned int floor_freq;
u64 floor_validate_time;
u64 hispeed_validate_time;
struct rw_semaphore enable_sem;
int governor_enabled;
};
static DEFINE_PER_CPU(struct cpufreq_interactive_cpuinfo, cpuinfo);
/* realtime thread handles frequency scaling */
static struct task_struct *speedchange_task;
static cpumask_t speedchange_cpumask;
static spinlock_t speedchange_cpumask_lock;
static struct mutex gov_lock;
/* Hi speed to bump to from lo speed when load burst (default max) */
static unsigned int hispeed_freq;
/* Go to hi speed when CPU load at or above this value. */
#define DEFAULT_GO_HISPEED_LOAD 99
static unsigned long go_hispeed_load = DEFAULT_GO_HISPEED_LOAD;
/* Sampling down factor to be applied to min_sample_time at max freq */
static unsigned int sampling_down_factor;
/* Target load. Lower values result in higher CPU speeds. */
#define DEFAULT_TARGET_LOAD 90
static unsigned int default_target_loads[] = {DEFAULT_TARGET_LOAD};
static spinlock_t target_loads_lock;
static unsigned int *target_loads = default_target_loads;
static int ntarget_loads = ARRAY_SIZE(default_target_loads);
/*
* The minimum amount of time to spend at a frequency before we can ramp down.
*/
#define DEFAULT_MIN_SAMPLE_TIME (80 * USEC_PER_MSEC)
static unsigned long min_sample_time = DEFAULT_MIN_SAMPLE_TIME;
/*
* The sample rate of the timer used to increase frequency
*/
#define DEFAULT_TIMER_RATE (20 * USEC_PER_MSEC)
static unsigned long timer_rate = DEFAULT_TIMER_RATE;
/*
* Wait this long before raising speed above hispeed, by default a single
* timer interval.
*/
#define DEFAULT_ABOVE_HISPEED_DELAY DEFAULT_TIMER_RATE
static unsigned int default_above_hispeed_delay[] = {
DEFAULT_ABOVE_HISPEED_DELAY };
static spinlock_t above_hispeed_delay_lock;
static unsigned int *above_hispeed_delay = default_above_hispeed_delay;
static int nabove_hispeed_delay = ARRAY_SIZE(default_above_hispeed_delay);
/* Non-zero means indefinite speed boost active */
static int boost_val;
/* Duration of a boot pulse in usecs */
static int boostpulse_duration_val = DEFAULT_MIN_SAMPLE_TIME;
/* End time of boost pulse in ktime converted to usecs */
static u64 boostpulse_endtime;
/*
* Max additional time to wait in idle, beyond timer_rate, at speeds above
* minimum before wakeup to reduce speed, or -1 if unnecessary.
*/
#define DEFAULT_TIMER_SLACK (4 * DEFAULT_TIMER_RATE)
static int timer_slack_val = DEFAULT_TIMER_SLACK;
static bool io_is_busy;
static int cpufreq_governor_interactive(struct cpufreq_policy *policy,
unsigned int event);
#ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_INTERACTIVE
static
#endif
struct cpufreq_governor cpufreq_gov_interactive = {
.name = "interactive",
.governor = cpufreq_governor_interactive,
.max_transition_latency = 10000000,
.owner = THIS_MODULE,
};
static inline cputime64_t get_cpu_idle_time_jiffy(unsigned int cpu,
cputime64_t *wall)
{
u64 idle_time;
u64 cur_wall_time;
u64 busy_time;
cur_wall_time = jiffies64_to_cputime64(get_jiffies_64());
busy_time = kcpustat_cpu(cpu).cpustat[CPUTIME_USER];
busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SYSTEM];
busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_IRQ];
busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SOFTIRQ];
busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL];
busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE];
idle_time = cur_wall_time - busy_time;
if (wall)
*wall = jiffies_to_usecs(cur_wall_time);
return jiffies_to_usecs(idle_time);
}
static inline cputime64_t get_cpu_idle_time(unsigned int cpu,
cputime64_t *wall)
{
u64 idle_time = get_cpu_idle_time_us(cpu, wall);
if (idle_time == -1ULL)
idle_time = get_cpu_idle_time_jiffy(cpu, wall);
else if (!io_is_busy)
idle_time += get_cpu_iowait_time_us(cpu, wall);
return idle_time;
}
static void cpufreq_interactive_timer_resched(
struct cpufreq_interactive_cpuinfo *pcpu)
{
unsigned long expires;
unsigned long flags;
spin_lock_irqsave(&pcpu->load_lock, flags);
pcpu->time_in_idle =
get_cpu_idle_time(smp_processor_id(),
&pcpu->time_in_idle_timestamp);
pcpu->cputime_speedadj = 0;
pcpu->cputime_speedadj_timestamp = pcpu->time_in_idle_timestamp;
expires = jiffies + usecs_to_jiffies(timer_rate);
mod_timer_pinned(&pcpu->cpu_timer, expires);
if (timer_slack_val >= 0 && pcpu->target_freq > pcpu->policy->min) {
expires += usecs_to_jiffies(timer_slack_val);
mod_timer_pinned(&pcpu->cpu_slack_timer, expires);
}
spin_unlock_irqrestore(&pcpu->load_lock, flags);
}
/* The caller shall take enable_sem write semaphore to avoid any timer race.
* The cpu_timer and cpu_slack_timer must be deactivated when calling this
* function.
*/
static void cpufreq_interactive_timer_start(int cpu)
{
struct cpufreq_interactive_cpuinfo *pcpu = &per_cpu(cpuinfo, cpu);
unsigned long expires = jiffies + usecs_to_jiffies(timer_rate);
unsigned long flags;
pcpu->cpu_timer.expires = expires;
add_timer_on(&pcpu->cpu_timer, cpu);
if (timer_slack_val >= 0 && pcpu->target_freq > pcpu->policy->min) {
expires += usecs_to_jiffies(timer_slack_val);
pcpu->cpu_slack_timer.expires = expires;
add_timer_on(&pcpu->cpu_slack_timer, cpu);
}
spin_lock_irqsave(&pcpu->load_lock, flags);
pcpu->time_in_idle =
get_cpu_idle_time(cpu, &pcpu->time_in_idle_timestamp);
pcpu->cputime_speedadj = 0;
pcpu->cputime_speedadj_timestamp = pcpu->time_in_idle_timestamp;
spin_unlock_irqrestore(&pcpu->load_lock, flags);
}
static unsigned int freq_to_above_hispeed_delay(unsigned int freq)
{
int i;
unsigned int ret;
unsigned long flags;
spin_lock_irqsave(&above_hispeed_delay_lock, flags);
for (i = 0; i < nabove_hispeed_delay - 1 &&
freq >= above_hispeed_delay[i+1]; i += 2)
;
ret = above_hispeed_delay[i];
spin_unlock_irqrestore(&above_hispeed_delay_lock, flags);
return ret;
}
static unsigned int freq_to_targetload(unsigned int freq)
{
int i;
unsigned int ret;
unsigned long flags;
spin_lock_irqsave(&target_loads_lock, flags);
for (i = 0; i < ntarget_loads - 1 && freq >= target_loads[i+1]; i += 2)
;
ret = target_loads[i];
spin_unlock_irqrestore(&target_loads_lock, flags);
return ret;
}
/*
* If increasing frequencies never map to a lower target load then
* choose_freq() will find the minimum frequency that does not exceed its
* target load given the current load.
*/
static unsigned int choose_freq(
struct cpufreq_interactive_cpuinfo *pcpu, unsigned int loadadjfreq)
{
unsigned int freq = pcpu->policy->cur;
unsigned int prevfreq, freqmin, freqmax;
unsigned int tl;
int index;
freqmin = 0;
freqmax = UINT_MAX;
do {
prevfreq = freq;
tl = freq_to_targetload(freq);
/*
* Find the lowest frequency where the computed load is less
* than or equal to the target load.
*/
if (cpufreq_frequency_table_target(
pcpu->policy, pcpu->freq_table, loadadjfreq / tl,
CPUFREQ_RELATION_L, &index))
break;
freq = pcpu->freq_table[index].frequency;
if (freq > prevfreq) {
/* The previous frequency is too low. */
freqmin = prevfreq;
if (freq >= freqmax) {
/*
* Find the highest frequency that is less
* than freqmax.
*/
if (cpufreq_frequency_table_target(
pcpu->policy, pcpu->freq_table,
freqmax - 1, CPUFREQ_RELATION_H,
&index))
break;
freq = pcpu->freq_table[index].frequency;
if (freq == freqmin) {
/*
* The first frequency below freqmax
* has already been found to be too
* low. freqmax is the lowest speed
* we found that is fast enough.
*/
freq = freqmax;
break;
}
}
} else if (freq < prevfreq) {
/* The previous frequency is high enough. */
freqmax = prevfreq;
if (freq <= freqmin) {
/*
* Find the lowest frequency that is higher
* than freqmin.
*/
if (cpufreq_frequency_table_target(
pcpu->policy, pcpu->freq_table,
freqmin + 1, CPUFREQ_RELATION_L,
&index))
break;
freq = pcpu->freq_table[index].frequency;
/*
* If freqmax is the first frequency above
* freqmin then we have already found that
* this speed is fast enough.
*/
if (freq == freqmax)
break;
}
}
/* If same frequency chosen as previous then done. */
} while (freq != prevfreq);
return freq;
}
static u64 update_load(int cpu)
{
struct cpufreq_interactive_cpuinfo *pcpu = &per_cpu(cpuinfo, cpu);
u64 now;
u64 now_idle;
unsigned int delta_idle;
unsigned int delta_time;
u64 active_time;
now_idle = get_cpu_idle_time(cpu, &now);
delta_idle = (unsigned int)(now_idle - pcpu->time_in_idle);
delta_time = (unsigned int)(now - pcpu->time_in_idle_timestamp);
if (delta_time <= delta_idle)
active_time = 0;
else
active_time = delta_time - delta_idle;
pcpu->cputime_speedadj += active_time * pcpu->policy->cur;
pcpu->time_in_idle = now_idle;
pcpu->time_in_idle_timestamp = now;
return now;
}
static void cpufreq_interactive_timer(unsigned long data)
{
u64 now;
unsigned int delta_time;
u64 cputime_speedadj;
int cpu_load;
struct cpufreq_interactive_cpuinfo *pcpu =
&per_cpu(cpuinfo, data);
unsigned int new_freq;
unsigned int loadadjfreq;
unsigned int index;
unsigned long flags;
bool boosted;
unsigned long mod_min_sample_time;
if (!down_read_trylock(&pcpu->enable_sem))
return;
if (!pcpu->governor_enabled)
goto exit;
spin_lock_irqsave(&pcpu->load_lock, flags);
now = update_load(data);
delta_time = (unsigned int)(now - pcpu->cputime_speedadj_timestamp);
cputime_speedadj = pcpu->cputime_speedadj;
spin_unlock_irqrestore(&pcpu->load_lock, flags);
if (WARN_ON_ONCE(!delta_time))
goto rearm;
do_div(cputime_speedadj, delta_time);
loadadjfreq = (unsigned int)cputime_speedadj * 100;
cpu_load = loadadjfreq / pcpu->target_freq;
boosted = boost_val || now < boostpulse_endtime;
if (cpu_load >= go_hispeed_load || boosted) {
if (pcpu->target_freq < hispeed_freq) {
new_freq = hispeed_freq;
} else {
new_freq = choose_freq(pcpu, loadadjfreq);
if (new_freq < hispeed_freq)
new_freq = hispeed_freq;
}
} else {
new_freq = choose_freq(pcpu, loadadjfreq);
}
if (pcpu->target_freq >= hispeed_freq &&
new_freq > pcpu->target_freq &&
now - pcpu->hispeed_validate_time <
freq_to_above_hispeed_delay(pcpu->target_freq)) {
trace_cpufreq_interactive_notyet(
data, cpu_load, pcpu->target_freq,
pcpu->policy->cur, new_freq);
goto rearm;
}
pcpu->hispeed_validate_time = now;
if (cpufreq_frequency_table_target(pcpu->policy, pcpu->freq_table,
new_freq, CPUFREQ_RELATION_L,
&index))
goto rearm;
new_freq = pcpu->freq_table[index].frequency;
/*
* Do not scale below floor_freq unless we have been at or above the
* floor frequency for the minimum sample time since last validated.
*/
if (pcpu->policy->cur == pcpu->policy->max) {
mod_min_sample_time = sampling_down_factor;
} else {
mod_min_sample_time = min_sample_time;
}
if (new_freq < pcpu->floor_freq) {
if (now - pcpu->floor_validate_time < mod_min_sample_time) {
trace_cpufreq_interactive_notyet(
data, cpu_load, pcpu->target_freq,
pcpu->policy->cur, new_freq);
goto rearm;
}
}
/*
* Update the timestamp for checking whether speed has been held at
* or above the selected frequency for a minimum of min_sample_time,
* if not boosted to hispeed_freq. If boosted to hispeed_freq then we
* allow the speed to drop as soon as the boostpulse duration expires
* (or the indefinite boost is turned off).
*/
if (!boosted || new_freq > hispeed_freq) {
pcpu->floor_freq = new_freq;
pcpu->floor_validate_time = now;
}
if (pcpu->target_freq == new_freq) {
trace_cpufreq_interactive_already(
data, cpu_load, pcpu->target_freq,
pcpu->policy->cur, new_freq);
goto rearm_if_notmax;
}
trace_cpufreq_interactive_target(data, cpu_load, pcpu->target_freq,
pcpu->policy->cur, new_freq);
pcpu->target_freq = new_freq;
spin_lock_irqsave(&speedchange_cpumask_lock, flags);
cpumask_set_cpu(data, &speedchange_cpumask);
spin_unlock_irqrestore(&speedchange_cpumask_lock, flags);
wake_up_process(speedchange_task);
rearm_if_notmax:
/*
* Already set max speed and don't see a need to change that,
* wait until next idle to re-evaluate, don't need timer.
*/
if (pcpu->target_freq == pcpu->policy->max)
goto exit;
rearm:
if (!timer_pending(&pcpu->cpu_timer))
cpufreq_interactive_timer_resched(pcpu);
exit:
up_read(&pcpu->enable_sem);
return;
}
static void cpufreq_interactive_idle_start(void)
{
struct cpufreq_interactive_cpuinfo *pcpu =
&per_cpu(cpuinfo, smp_processor_id());
int pending;
if (!down_read_trylock(&pcpu->enable_sem))
return;
if (!pcpu->governor_enabled) {
up_read(&pcpu->enable_sem);
return;
}
pending = timer_pending(&pcpu->cpu_timer);
if (pcpu->target_freq != pcpu->policy->min) {
/*
* Entering idle while not at lowest speed. On some
* platforms this can hold the other CPU(s) at that speed
* even though the CPU is idle. Set a timer to re-evaluate
* speed so this idle CPU doesn't hold the other CPUs above
* min indefinitely. This should probably be a quirk of
* the CPUFreq driver.
*/
if (!pending)
cpufreq_interactive_timer_resched(pcpu);
}
up_read(&pcpu->enable_sem);
}
static void cpufreq_interactive_idle_end(void)
{
struct cpufreq_interactive_cpuinfo *pcpu =
&per_cpu(cpuinfo, smp_processor_id());
if (!down_read_trylock(&pcpu->enable_sem))
return;
if (!pcpu->governor_enabled) {
up_read(&pcpu->enable_sem);
return;
}
/* Arm the timer for 1-2 ticks later if not already. */
if (!timer_pending(&pcpu->cpu_timer)) {
cpufreq_interactive_timer_resched(pcpu);
} else if (time_after_eq(jiffies, pcpu->cpu_timer.expires)) {
del_timer(&pcpu->cpu_timer);
del_timer(&pcpu->cpu_slack_timer);
cpufreq_interactive_timer(smp_processor_id());
}
up_read(&pcpu->enable_sem);
}
static int cpufreq_interactive_speedchange_task(void *data)
{
unsigned int cpu;
cpumask_t tmp_mask;
unsigned long flags;
struct cpufreq_interactive_cpuinfo *pcpu;
while (1) {
set_current_state(TASK_INTERRUPTIBLE);
spin_lock_irqsave(&speedchange_cpumask_lock, flags);
if (cpumask_empty(&speedchange_cpumask)) {
spin_unlock_irqrestore(&speedchange_cpumask_lock,
flags);
schedule();
if (kthread_should_stop())
break;
spin_lock_irqsave(&speedchange_cpumask_lock, flags);
}
set_current_state(TASK_RUNNING);
tmp_mask = speedchange_cpumask;
cpumask_clear(&speedchange_cpumask);
spin_unlock_irqrestore(&speedchange_cpumask_lock, flags);
for_each_cpu(cpu, &tmp_mask) {
unsigned int j;
unsigned int max_freq = 0;
pcpu = &per_cpu(cpuinfo, cpu);
if (!down_read_trylock(&pcpu->enable_sem))
continue;
if (!pcpu->governor_enabled) {
up_read(&pcpu->enable_sem);
continue;
}
for_each_cpu(j, pcpu->policy->cpus) {
struct cpufreq_interactive_cpuinfo *pjcpu =
&per_cpu(cpuinfo, j);
if (pjcpu->target_freq > max_freq)
max_freq = pjcpu->target_freq;
}
if (max_freq != pcpu->policy->cur)
__cpufreq_driver_target(pcpu->policy,
max_freq,
CPUFREQ_RELATION_H);
trace_cpufreq_interactive_setspeed(cpu,
pcpu->target_freq,
pcpu->policy->cur);
up_read(&pcpu->enable_sem);
}
}
return 0;
}
static void cpufreq_interactive_boost(void)
{
int i;
int anyboost = 0;
unsigned long flags;
struct cpufreq_interactive_cpuinfo *pcpu;
spin_lock_irqsave(&speedchange_cpumask_lock, flags);
for_each_online_cpu(i) {
pcpu = &per_cpu(cpuinfo, i);
if (pcpu->target_freq < hispeed_freq) {
pcpu->target_freq = hispeed_freq;
cpumask_set_cpu(i, &speedchange_cpumask);
pcpu->hispeed_validate_time =
ktime_to_us(ktime_get());
anyboost = 1;
}
/*
* Set floor freq and (re)start timer for when last
* validated.
*/
pcpu->floor_freq = hispeed_freq;
pcpu->floor_validate_time = ktime_to_us(ktime_get());
}
spin_unlock_irqrestore(&speedchange_cpumask_lock, flags);
if (anyboost)
wake_up_process(speedchange_task);
}
static int cpufreq_interactive_notifier(
struct notifier_block *nb, unsigned long val, void *data)
{
struct cpufreq_freqs *freq = data;
struct cpufreq_interactive_cpuinfo *pcpu;
int cpu;
unsigned long flags;
if (val == CPUFREQ_POSTCHANGE) {
pcpu = &per_cpu(cpuinfo, freq->cpu);
if (!down_read_trylock(&pcpu->enable_sem))
return 0;
if (!pcpu->governor_enabled) {
up_read(&pcpu->enable_sem);
return 0;
}
for_each_cpu(cpu, pcpu->policy->cpus) {
struct cpufreq_interactive_cpuinfo *pjcpu =
&per_cpu(cpuinfo, cpu);
if (cpu != freq->cpu) {
if (!down_read_trylock(&pjcpu->enable_sem))
continue;
if (!pjcpu->governor_enabled) {
up_read(&pjcpu->enable_sem);
continue;
}
}
spin_lock_irqsave(&pjcpu->load_lock, flags);
update_load(cpu);
spin_unlock_irqrestore(&pjcpu->load_lock, flags);
if (cpu != freq->cpu)
up_read(&pjcpu->enable_sem);
}
up_read(&pcpu->enable_sem);
}
return 0;
}
static struct notifier_block cpufreq_notifier_block = {
.notifier_call = cpufreq_interactive_notifier,
};
static unsigned int *get_tokenized_data(const char *buf, int *num_tokens)
{
const char *cp;
int i;
int ntokens = 1;
unsigned int *tokenized_data;
int err = -EINVAL;
cp = buf;
while ((cp = strpbrk(cp + 1, " :")))
ntokens++;
if (!(ntokens & 0x1))
goto err;
tokenized_data = kmalloc(ntokens * sizeof(unsigned int), GFP_KERNEL);
if (!tokenized_data) {
err = -ENOMEM;
goto err;
}
cp = buf;
i = 0;
while (i < ntokens) {
if (sscanf(cp, "%u", &tokenized_data[i++]) != 1)
goto err_kfree;
cp = strpbrk(cp, " :");
if (!cp)
break;
cp++;
}
if (i != ntokens)
goto err_kfree;
*num_tokens = ntokens;
return tokenized_data;
err_kfree:
kfree(tokenized_data);
err:
return ERR_PTR(err);
}
static ssize_t show_target_loads(
struct kobject *kobj, struct attribute *attr, char *buf)
{
int i;
ssize_t ret = 0;
unsigned long flags;
spin_lock_irqsave(&target_loads_lock, flags);
for (i = 0; i < ntarget_loads; i++)
ret += sprintf(buf + ret, "%u%s", target_loads[i],
i & 0x1 ? ":" : " ");
ret += sprintf(buf + --ret, "\n");
spin_unlock_irqrestore(&target_loads_lock, flags);
return ret;
}
static ssize_t store_target_loads(
struct kobject *kobj, struct attribute *attr, const char *buf,
size_t count)
{
int ntokens;
unsigned int *new_target_loads = NULL;
unsigned long flags;
new_target_loads = get_tokenized_data(buf, &ntokens);
if (IS_ERR(new_target_loads))
return PTR_RET(new_target_loads);
spin_lock_irqsave(&target_loads_lock, flags);
if (target_loads != default_target_loads)
kfree(target_loads);
target_loads = new_target_loads;
ntarget_loads = ntokens;
spin_unlock_irqrestore(&target_loads_lock, flags);
return count;
}
static struct global_attr target_loads_attr =
__ATTR(target_loads, S_IRUGO | S_IWUSR,
show_target_loads, store_target_loads);
static ssize_t show_above_hispeed_delay(
struct kobject *kobj, struct attribute *attr, char *buf)
{
int i;
ssize_t ret = 0;
unsigned long flags;
spin_lock_irqsave(&above_hispeed_delay_lock, flags);
for (i = 0; i < nabove_hispeed_delay; i++)
ret += sprintf(buf + ret, "%u%s", above_hispeed_delay[i],
i & 0x1 ? ":" : " ");
ret += sprintf(buf + --ret, "\n");
spin_unlock_irqrestore(&above_hispeed_delay_lock, flags);
return ret;
}
static ssize_t store_above_hispeed_delay(
struct kobject *kobj, struct attribute *attr, const char *buf,
size_t count)
{
int ntokens;
unsigned int *new_above_hispeed_delay = NULL;
unsigned long flags;
new_above_hispeed_delay = get_tokenized_data(buf, &ntokens);
if (IS_ERR(new_above_hispeed_delay))
return PTR_RET(new_above_hispeed_delay);
spin_lock_irqsave(&above_hispeed_delay_lock, flags);
if (above_hispeed_delay != default_above_hispeed_delay)
kfree(above_hispeed_delay);
above_hispeed_delay = new_above_hispeed_delay;
nabove_hispeed_delay = ntokens;
spin_unlock_irqrestore(&above_hispeed_delay_lock, flags);
return count;
}
static struct global_attr above_hispeed_delay_attr =
__ATTR(above_hispeed_delay, S_IRUGO | S_IWUSR,
show_above_hispeed_delay, store_above_hispeed_delay);
static ssize_t show_hispeed_freq(struct kobject *kobj,
struct attribute *attr, char *buf)
{
return sprintf(buf, "%u\n", hispeed_freq);
}
static ssize_t store_hispeed_freq(struct kobject *kobj,
struct attribute *attr, const char *buf,
size_t count)
{
int ret;
long unsigned int val;
ret = strict_strtoul(buf, 0, &val);
if (ret < 0)
return ret;
hispeed_freq = val;
return count;
}
static struct global_attr hispeed_freq_attr = __ATTR(hispeed_freq, 0644,
show_hispeed_freq, store_hispeed_freq);
static ssize_t show_sampling_down_factor(struct kobject *kobj,
struct attribute *attr, char *buf)
{
return sprintf(buf, "%u\n", sampling_down_factor);
}
static ssize_t store_sampling_down_factor(struct kobject *kobj,
struct attribute *attr, const char *buf,
size_t count)
{
int ret;
long unsigned int val;
ret = strict_strtoul(buf, 0, &val);
if (ret < 0)
return ret;
sampling_down_factor = val;
return count;
}
static struct global_attr sampling_down_factor_attr =
__ATTR(sampling_down_factor, 0644,
show_sampling_down_factor, store_sampling_down_factor);
static ssize_t show_go_hispeed_load(struct kobject *kobj,
struct attribute *attr, char *buf)
{
return sprintf(buf, "%lu\n", go_hispeed_load);
}
static ssize_t store_go_hispeed_load(struct kobject *kobj,
struct attribute *attr, const char *buf, size_t count)
{
int ret;
unsigned long val;
ret = strict_strtoul(buf, 0, &val);
if (ret < 0)
return ret;
go_hispeed_load = val;
return count;
}
static struct global_attr go_hispeed_load_attr = __ATTR(go_hispeed_load, 0644,
show_go_hispeed_load, store_go_hispeed_load);
static ssize_t show_min_sample_time(struct kobject *kobj,
struct attribute *attr, char *buf)
{
return sprintf(buf, "%lu\n", min_sample_time);
}
static ssize_t store_min_sample_time(struct kobject *kobj,
struct attribute *attr, const char *buf, size_t count)
{
int ret;
unsigned long val;
ret = strict_strtoul(buf, 0, &val);
if (ret < 0)
return ret;
min_sample_time = val;
return count;
}
static struct global_attr min_sample_time_attr = __ATTR(min_sample_time, 0644,
show_min_sample_time, store_min_sample_time);
static ssize_t show_timer_rate(struct kobject *kobj,
struct attribute *attr, char *buf)
{
return sprintf(buf, "%lu\n", timer_rate);
}
static ssize_t store_timer_rate(struct kobject *kobj,
struct attribute *attr, const char *buf, size_t count)
{
int ret;
unsigned long val;
ret = strict_strtoul(buf, 0, &val);
if (ret < 0)
return ret;
timer_rate = val;
return count;
}
static struct global_attr timer_rate_attr = __ATTR(timer_rate, 0644,
show_timer_rate, store_timer_rate);
static ssize_t show_timer_slack(
struct kobject *kobj, struct attribute *attr, char *buf)
{
return sprintf(buf, "%d\n", timer_slack_val);
}
static ssize_t store_timer_slack(
struct kobject *kobj, struct attribute *attr, const char *buf,
size_t count)
{
int ret;
unsigned long val;
ret = kstrtol(buf, 10, &val);
if (ret < 0)
return ret;
timer_slack_val = val;
return count;
}
define_one_global_rw(timer_slack);
static ssize_t show_boost(struct kobject *kobj, struct attribute *attr,
char *buf)
{
return sprintf(buf, "%d\n", boost_val);
}
static ssize_t store_boost(struct kobject *kobj, struct attribute *attr,
const char *buf, size_t count)
{
int ret;
unsigned long val;
ret = kstrtoul(buf, 0, &val);
if (ret < 0)
return ret;
boost_val = val;
if (boost_val) {
trace_cpufreq_interactive_boost("on");
cpufreq_interactive_boost();
} else {
trace_cpufreq_interactive_unboost("off");
}
return count;
}
define_one_global_rw(boost);
static ssize_t store_boostpulse(struct kobject *kobj, struct attribute *attr,
const char *buf, size_t count)
{
int ret;
unsigned long val;
ret = kstrtoul(buf, 0, &val);
if (ret < 0)
return ret;
boostpulse_endtime = ktime_to_us(ktime_get()) + boostpulse_duration_val;
trace_cpufreq_interactive_boost("pulse");
cpufreq_interactive_boost();
return count;
}
static struct global_attr boostpulse =
__ATTR(boostpulse, 0200, NULL, store_boostpulse);
static ssize_t show_boostpulse_duration(
struct kobject *kobj, struct attribute *attr, char *buf)
{
return sprintf(buf, "%d\n", boostpulse_duration_val);
}
static ssize_t store_boostpulse_duration(
struct kobject *kobj, struct attribute *attr, const char *buf,
size_t count)
{
int ret;
unsigned long val;
ret = kstrtoul(buf, 0, &val);
if (ret < 0)
return ret;
boostpulse_duration_val = val;
return count;
}
define_one_global_rw(boostpulse_duration);
static ssize_t show_io_is_busy(struct kobject *kobj,
struct attribute *attr, char *buf)
{
return sprintf(buf, "%u\n", io_is_busy);
}
static ssize_t store_io_is_busy(struct kobject *kobj,
struct attribute *attr, const char *buf, size_t count)
{
int ret;
unsigned long val;
ret = kstrtoul(buf, 0, &val);
if (ret < 0)
return ret;
io_is_busy = val;
return count;
}
static struct global_attr io_is_busy_attr = __ATTR(io_is_busy, 0644,
show_io_is_busy, store_io_is_busy);
static struct attribute *interactive_attributes[] = {
&target_loads_attr.attr,
&above_hispeed_delay_attr.attr,
&hispeed_freq_attr.attr,
&go_hispeed_load_attr.attr,
&min_sample_time_attr.attr,
&timer_rate_attr.attr,
&timer_slack.attr,
&boost.attr,
&boostpulse.attr,
&boostpulse_duration.attr,
&io_is_busy_attr.attr,
&sampling_down_factor_attr.attr,
NULL,
};
static struct attribute_group interactive_attr_group = {
.attrs = interactive_attributes,
.name = "interactive",
};
static int cpufreq_interactive_idle_notifier(struct notifier_block *nb,
unsigned long val,
void *data)
{
switch (val) {
case IDLE_START:
cpufreq_interactive_idle_start();
break;
case IDLE_END:
cpufreq_interactive_idle_end();
break;
}
return 0;
}
static struct notifier_block cpufreq_interactive_idle_nb = {
.notifier_call = cpufreq_interactive_idle_notifier,
};
static int cpufreq_governor_interactive(struct cpufreq_policy *policy,
unsigned int event)
{
int rc;
unsigned int j;
struct cpufreq_interactive_cpuinfo *pcpu;
struct cpufreq_frequency_table *freq_table;
switch (event) {
case CPUFREQ_GOV_START:
if (!cpu_online(policy->cpu))
return -EINVAL;
mutex_lock(&gov_lock);
freq_table =
cpufreq_frequency_get_table(policy->cpu);
if (!hispeed_freq)
hispeed_freq = policy->max;
for_each_cpu(j, policy->cpus) {
pcpu = &per_cpu(cpuinfo, j);
pcpu->policy = policy;
pcpu->target_freq = policy->cur;
pcpu->freq_table = freq_table;
pcpu->floor_freq = pcpu->target_freq;
pcpu->floor_validate_time =
ktime_to_us(ktime_get());
pcpu->hispeed_validate_time =
pcpu->floor_validate_time;
down_write(&pcpu->enable_sem);
cpufreq_interactive_timer_start(j);
pcpu->governor_enabled = 1;
up_write(&pcpu->enable_sem);
}
/*
* Do not register the idle hook and create sysfs
* entries if we have already done so.
*/
if (++active_count > 1) {
mutex_unlock(&gov_lock);
return 0;
}
rc = sysfs_create_group(cpufreq_global_kobject,
&interactive_attr_group);
if (rc) {
mutex_unlock(&gov_lock);
return rc;
}
idle_notifier_register(&cpufreq_interactive_idle_nb);
cpufreq_register_notifier(
&cpufreq_notifier_block, CPUFREQ_TRANSITION_NOTIFIER);
mutex_unlock(&gov_lock);
break;
case CPUFREQ_GOV_STOP:
mutex_lock(&gov_lock);
for_each_cpu(j, policy->cpus) {
pcpu = &per_cpu(cpuinfo, j);
down_write(&pcpu->enable_sem);
pcpu->governor_enabled = 0;
del_timer_sync(&pcpu->cpu_timer);
del_timer_sync(&pcpu->cpu_slack_timer);
up_write(&pcpu->enable_sem);
}
if (--active_count > 0) {
mutex_unlock(&gov_lock);
return 0;
}
cpufreq_unregister_notifier(
&cpufreq_notifier_block, CPUFREQ_TRANSITION_NOTIFIER);
idle_notifier_unregister(&cpufreq_interactive_idle_nb);
sysfs_remove_group(cpufreq_global_kobject,
&interactive_attr_group);
mutex_unlock(&gov_lock);
break;
case CPUFREQ_GOV_LIMITS:
if (policy->max < policy->cur)
__cpufreq_driver_target(policy,
policy->max, CPUFREQ_RELATION_H);
else if (policy->min > policy->cur)
__cpufreq_driver_target(policy,
policy->min, CPUFREQ_RELATION_L);
for_each_cpu(j, policy->cpus) {
pcpu = &per_cpu(cpuinfo, j);
/* hold write semaphore to avoid race */
down_write(&pcpu->enable_sem);
if (pcpu->governor_enabled == 0) {
up_write(&pcpu->enable_sem);
continue;
}
/* update target_freq firstly */
if (policy->max < pcpu->target_freq)
pcpu->target_freq = policy->max;
else if (policy->min > pcpu->target_freq)
pcpu->target_freq = policy->min;
/* Reschedule timer.
* Delete the timers, else the timer callback may
* return without re-arm the timer when failed
* acquire the semaphore. This race may cause timer
* stopped unexpectedly.
*/
del_timer_sync(&pcpu->cpu_timer);
del_timer_sync(&pcpu->cpu_slack_timer);
cpufreq_interactive_timer_start(j);
up_write(&pcpu->enable_sem);
}
break;
}
return 0;
}
static void cpufreq_interactive_nop_timer(unsigned long data)
{
}
static int __init cpufreq_interactive_init(void)
{
unsigned int i;
struct cpufreq_interactive_cpuinfo *pcpu;
struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };
/* Initalize per-cpu timers */
for_each_possible_cpu(i) {
pcpu = &per_cpu(cpuinfo, i);
init_timer_deferrable(&pcpu->cpu_timer);
pcpu->cpu_timer.function = cpufreq_interactive_timer;
pcpu->cpu_timer.data = i;
init_timer(&pcpu->cpu_slack_timer);
pcpu->cpu_slack_timer.function = cpufreq_interactive_nop_timer;
spin_lock_init(&pcpu->load_lock);
init_rwsem(&pcpu->enable_sem);
}
spin_lock_init(&target_loads_lock);
spin_lock_init(&speedchange_cpumask_lock);
spin_lock_init(&above_hispeed_delay_lock);
mutex_init(&gov_lock);
speedchange_task =
kthread_create(cpufreq_interactive_speedchange_task, NULL,
"cfinteractive");
if (IS_ERR(speedchange_task))
return PTR_ERR(speedchange_task);
sched_setscheduler_nocheck(speedchange_task, SCHED_FIFO, &param);
get_task_struct(speedchange_task);
/* NB: wake up so the thread does not look hung to the freezer */
wake_up_process(speedchange_task);
return cpufreq_register_governor(&cpufreq_gov_interactive);
}
#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_INTERACTIVE
fs_initcall(cpufreq_interactive_init);
#else
module_init(cpufreq_interactive_init);
#endif
static void __exit cpufreq_interactive_exit(void)
{
cpufreq_unregister_governor(&cpufreq_gov_interactive);
kthread_stop(speedchange_task);
put_task_struct(speedchange_task);
}
module_exit(cpufreq_interactive_exit);
MODULE_AUTHOR("Mike Chan <mike@android.com>");
MODULE_DESCRIPTION("'cpufreq_interactive' - A cpufreq governor for "
"Latency sensitive workloads");
MODULE_LICENSE("GPL");