+++ /dev/null
-/*
- * CPUFreq hotplug governor
- *
- * Copyright (C) 2010 Texas Instruments, Inc.
- * Mike Turquette <mturquette@ti.com>
- * Santosh Shilimkar <santosh.shilimkar@ti.com>
- *
- * Based on ondemand governor
- * Copyright (C) 2001 Russell King
- * (C) 2003 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>,
- * Jun Nakajima <jun.nakajima@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/module.h>
-#include <linux/init.h>
-#include <linux/cpufreq.h>
-#include <linux/cpu.h>
-#include <linux/jiffies.h>
-#include <linux/kernel_stat.h>
-#include <linux/mutex.h>
-#include <linux/hrtimer.h>
-#include <linux/tick.h>
-#include <linux/ktime.h>
-#include <linux/sched.h>
-#include <linux/err.h>
-#include <linux/slab.h>
-
-/* greater than 80% avg load across online CPUs increases frequency */
-#define DEFAULT_UP_FREQ_MIN_LOAD (80)
-
-/* Keep 10% of idle under the up threshold when decreasing the frequency */
-#define DEFAULT_FREQ_DOWN_DIFFERENTIAL (10)
-
-/* less than 35% avg load across online CPUs decreases frequency */
-#define DEFAULT_DOWN_FREQ_MAX_LOAD (35)
-
-/* default sampling period (uSec) is bogus; 10x ondemand's default for x86 */
-#define DEFAULT_SAMPLING_PERIOD (100000)
-
-/* default number of sampling periods to average before hotplug-in decision */
-#define DEFAULT_HOTPLUG_IN_SAMPLING_PERIODS (5)
-
-/* default number of sampling periods to average before hotplug-out decision */
-#define DEFAULT_HOTPLUG_OUT_SAMPLING_PERIODS (20)
-
-static void do_dbs_timer(struct work_struct *work);
-static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
- unsigned int event);
-
-#ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_HOTPLUG
-static
-#endif
-struct cpufreq_governor cpufreq_gov_hotplug = {
- .name = "hotplug",
- .governor = cpufreq_governor_dbs,
- .owner = THIS_MODULE,
-};
-
-struct cpu_dbs_info_s {
- cputime64_t prev_cpu_idle;
- cputime64_t prev_cpu_wall;
- cputime64_t prev_cpu_nice;
- struct cpufreq_policy *cur_policy;
- struct delayed_work work;
- struct cpufreq_frequency_table *freq_table;
- int cpu;
- /*
- * percpu mutex that serializes governor limit change with
- * do_dbs_timer invocation. We do not want do_dbs_timer to run
- * when user is changing the governor or limits.
- */
- struct mutex timer_mutex;
-};
-static DEFINE_PER_CPU(struct cpu_dbs_info_s, hp_cpu_dbs_info);
-
-static unsigned int dbs_enable; /* number of CPUs using this policy */
-
-/*
- * dbs_mutex protects data in dbs_tuners_ins from concurrent changes on
- * different CPUs. It protects dbs_enable in governor start/stop.
- */
-static DEFINE_MUTEX(dbs_mutex);
-
-static struct workqueue_struct *khotplug_wq;
-
-static struct dbs_tuners {
- unsigned int sampling_rate;
- unsigned int up_threshold;
- unsigned int down_differential;
- unsigned int down_threshold;
- unsigned int hotplug_in_sampling_periods;
- unsigned int hotplug_out_sampling_periods;
- unsigned int hotplug_load_index;
- unsigned int *hotplug_load_history;
- unsigned int ignore_nice;
- unsigned int io_is_busy;
-} dbs_tuners_ins = {
- .sampling_rate = DEFAULT_SAMPLING_PERIOD,
- .up_threshold = DEFAULT_UP_FREQ_MIN_LOAD,
- .down_differential = DEFAULT_FREQ_DOWN_DIFFERENTIAL,
- .down_threshold = DEFAULT_DOWN_FREQ_MAX_LOAD,
- .hotplug_in_sampling_periods = DEFAULT_HOTPLUG_IN_SAMPLING_PERIODS,
- .hotplug_out_sampling_periods = DEFAULT_HOTPLUG_OUT_SAMPLING_PERIODS,
- .hotplug_load_index = 0,
- .ignore_nice = 0,
- .io_is_busy = 0,
-};
-
-/*
- * A corner case exists when switching io_is_busy at run-time: comparing idle
- * times from a non-io_is_busy period to an io_is_busy period (or vice-versa)
- * will misrepresent the actual change in system idleness. We ignore this
- * corner case: enabling io_is_busy might cause freq increase and disabling
- * might cause freq decrease, which probably matches the original intent.
- */
-static inline cputime64_t get_cpu_idle_time(unsigned int cpu, cputime64_t *wall)
-{
- u64 idle_time;
- u64 iowait_time;
-
- /* cpufreq-hotplug always assumes CONFIG_NO_HZ */
- idle_time = get_cpu_idle_time_us(cpu, wall);
-
- /* add time spent doing I/O to idle time */
- if (dbs_tuners_ins.io_is_busy) {
- iowait_time = get_cpu_iowait_time_us(cpu, wall);
- /* cpufreq-hotplug always assumes CONFIG_NO_HZ */
- if (iowait_time != -1ULL && idle_time >= iowait_time)
- idle_time -= iowait_time;
- }
-
- return idle_time;
-}
-
-/************************** sysfs interface ************************/
-
-/* XXX look at global sysfs macros in cpufreq.h, can those be used here? */
-
-/* cpufreq_hotplug Governor Tunables */
-#define show_one(file_name, object) \
-static ssize_t show_##file_name \
-(struct kobject *kobj, struct attribute *attr, char *buf) \
-{ \
- return sprintf(buf, "%u\n", dbs_tuners_ins.object); \
-}
-show_one(sampling_rate, sampling_rate);
-show_one(up_threshold, up_threshold);
-show_one(down_differential, down_differential);
-show_one(down_threshold, down_threshold);
-show_one(hotplug_in_sampling_periods, hotplug_in_sampling_periods);
-show_one(hotplug_out_sampling_periods, hotplug_out_sampling_periods);
-show_one(ignore_nice_load, ignore_nice);
-show_one(io_is_busy, io_is_busy);
-
-static ssize_t store_sampling_rate(struct kobject *a, struct attribute *b,
- const char *buf, size_t count)
-{
- unsigned int input;
- int ret;
- ret = sscanf(buf, "%u", &input);
- if (ret != 1)
- return -EINVAL;
-
- mutex_lock(&dbs_mutex);
- dbs_tuners_ins.sampling_rate = input;
- mutex_unlock(&dbs_mutex);
-
- return count;
-}
-
-static ssize_t store_up_threshold(struct kobject *a, struct attribute *b,
- const char *buf, size_t count)
-{
- unsigned int input;
- int ret;
- ret = sscanf(buf, "%u", &input);
-
- if (ret != 1 || input <= dbs_tuners_ins.down_threshold) {
- return -EINVAL;
- }
-
- mutex_lock(&dbs_mutex);
- dbs_tuners_ins.up_threshold = input;
- mutex_unlock(&dbs_mutex);
-
- return count;
-}
-
-static ssize_t store_down_differential(struct kobject *a, struct attribute *b,
- const char *buf, size_t count)
-{
- unsigned int input;
- int ret;
- ret = sscanf(buf, "%u", &input);
-
- if (ret != 1 || input >= dbs_tuners_ins.up_threshold)
- return -EINVAL;
-
- mutex_lock(&dbs_mutex);
- dbs_tuners_ins.down_differential = input;
- mutex_unlock(&dbs_mutex);
-
- return count;
-}
-
-static ssize_t store_down_threshold(struct kobject *a, struct attribute *b,
- const char *buf, size_t count)
-{
- unsigned int input;
- int ret;
- ret = sscanf(buf, "%u", &input);
-
- if (ret != 1 || input >= dbs_tuners_ins.up_threshold) {
- return -EINVAL;
- }
-
- mutex_lock(&dbs_mutex);
- dbs_tuners_ins.down_threshold = input;
- mutex_unlock(&dbs_mutex);
-
- return count;
-}
-
-static ssize_t store_hotplug_in_sampling_periods(struct kobject *a,
- struct attribute *b, const char *buf, size_t count)
-{
- unsigned int input;
- unsigned int *temp;
- unsigned int max_windows;
- int ret;
- ret = sscanf(buf, "%u", &input);
-
- if (ret != 1)
- return -EINVAL;
-
- /* already using this value, bail out */
- if (input == dbs_tuners_ins.hotplug_in_sampling_periods)
- return count;
-
- mutex_lock(&dbs_mutex);
- ret = count;
- max_windows = max(dbs_tuners_ins.hotplug_in_sampling_periods,
- dbs_tuners_ins.hotplug_out_sampling_periods);
-
- /* no need to resize array */
- if (input <= max_windows) {
- dbs_tuners_ins.hotplug_in_sampling_periods = input;
- goto out;
- }
-
- /* resize array */
- temp = kmalloc((sizeof(unsigned int) * input), GFP_KERNEL);
-
- if (!temp || IS_ERR(temp)) {
- ret = -ENOMEM;
- goto out;
- }
-
- memcpy(temp, dbs_tuners_ins.hotplug_load_history,
- (max_windows * sizeof(unsigned int)));
- kfree(dbs_tuners_ins.hotplug_load_history);
-
- /* replace old buffer, old number of sampling periods & old index */
- dbs_tuners_ins.hotplug_load_history = temp;
- dbs_tuners_ins.hotplug_in_sampling_periods = input;
- dbs_tuners_ins.hotplug_load_index = max_windows;
-out:
- mutex_unlock(&dbs_mutex);
-
- return ret;
-}
-
-static ssize_t store_hotplug_out_sampling_periods(struct kobject *a,
- struct attribute *b, const char *buf, size_t count)
-{
- unsigned int input;
- unsigned int *temp;
- unsigned int max_windows;
- int ret;
- ret = sscanf(buf, "%u", &input);
-
- if (ret != 1)
- return -EINVAL;
-
- /* already using this value, bail out */
- if (input == dbs_tuners_ins.hotplug_out_sampling_periods)
- return count;
-
- mutex_lock(&dbs_mutex);
- ret = count;
- max_windows = max(dbs_tuners_ins.hotplug_in_sampling_periods,
- dbs_tuners_ins.hotplug_out_sampling_periods);
-
- /* no need to resize array */
- if (input <= max_windows) {
- dbs_tuners_ins.hotplug_out_sampling_periods = input;
- goto out;
- }
-
- /* resize array */
- temp = kmalloc((sizeof(unsigned int) * input), GFP_KERNEL);
-
- if (!temp || IS_ERR(temp)) {
- ret = -ENOMEM;
- goto out;
- }
-
- memcpy(temp, dbs_tuners_ins.hotplug_load_history,
- (max_windows * sizeof(unsigned int)));
- kfree(dbs_tuners_ins.hotplug_load_history);
-
- /* replace old buffer, old number of sampling periods & old index */
- dbs_tuners_ins.hotplug_load_history = temp;
- dbs_tuners_ins.hotplug_out_sampling_periods = input;
- dbs_tuners_ins.hotplug_load_index = max_windows;
-out:
- mutex_unlock(&dbs_mutex);
-
- return ret;
-}
-
-static ssize_t store_ignore_nice_load(struct kobject *a, struct attribute *b,
- const char *buf, size_t count)
-{
- unsigned int input;
- int ret;
-
- unsigned int j;
-
- ret = sscanf(buf, "%u", &input);
- if (ret != 1)
- return -EINVAL;
-
- if (input > 1)
- input = 1;
-
- mutex_lock(&dbs_mutex);
- if (input == dbs_tuners_ins.ignore_nice) { /* nothing to do */
- mutex_unlock(&dbs_mutex);
- return count;
- }
- dbs_tuners_ins.ignore_nice = input;
-
- /* we need to re-evaluate prev_cpu_idle */
- for_each_online_cpu(j) {
- struct cpu_dbs_info_s *dbs_info;
- dbs_info = &per_cpu(hp_cpu_dbs_info, j);
- dbs_info->prev_cpu_idle = get_cpu_idle_time(j,
- &dbs_info->prev_cpu_wall);
- if (dbs_tuners_ins.ignore_nice)
- dbs_info->prev_cpu_nice = kstat_cpu(j).cpustat.nice;
-
- }
- mutex_unlock(&dbs_mutex);
-
- return count;
-}
-
-static ssize_t store_io_is_busy(struct kobject *a, struct attribute *b,
- const char *buf, size_t count)
-{
- unsigned int input;
- int ret;
-
- ret = sscanf(buf, "%u", &input);
- if (ret != 1)
- return -EINVAL;
-
- mutex_lock(&dbs_mutex);
- dbs_tuners_ins.io_is_busy = !!input;
- mutex_unlock(&dbs_mutex);
-
- return count;
-}
-
-define_one_global_rw(sampling_rate);
-define_one_global_rw(up_threshold);
-define_one_global_rw(down_differential);
-define_one_global_rw(down_threshold);
-define_one_global_rw(hotplug_in_sampling_periods);
-define_one_global_rw(hotplug_out_sampling_periods);
-define_one_global_rw(ignore_nice_load);
-define_one_global_rw(io_is_busy);
-
-static struct attribute *dbs_attributes[] = {
- &sampling_rate.attr,
- &up_threshold.attr,
- &down_differential.attr,
- &down_threshold.attr,
- &hotplug_in_sampling_periods.attr,
- &hotplug_out_sampling_periods.attr,
- &ignore_nice_load.attr,
- &io_is_busy.attr,
- NULL
-};
-
-static struct attribute_group dbs_attr_group = {
- .attrs = dbs_attributes,
- .name = "hotplug",
-};
-
-/************************** sysfs end ************************/
-
-static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info)
-{
- /* combined load of all enabled CPUs */
- unsigned int total_load = 0;
- /* single largest CPU load percentage*/
- unsigned int max_load = 0;
- /* largest CPU load in terms of frequency */
- unsigned int max_load_freq = 0;
- /* average load across all enabled CPUs */
- unsigned int avg_load = 0;
- /* average load across multiple sampling periods for hotplug events */
- unsigned int hotplug_in_avg_load = 0;
- unsigned int hotplug_out_avg_load = 0;
- /* number of sampling periods averaged for hotplug decisions */
- unsigned int periods;
-
- struct cpufreq_policy *policy;
- unsigned int i, j;
-
- policy = this_dbs_info->cur_policy;
-
- /*
- * cpu load accounting
- * get highest load, total load and average load across all CPUs
- */
- for_each_cpu(j, policy->cpus) {
- unsigned int load;
- unsigned int idle_time, wall_time;
- cputime64_t cur_wall_time, cur_idle_time;
- struct cpu_dbs_info_s *j_dbs_info;
-
- j_dbs_info = &per_cpu(hp_cpu_dbs_info, j);
-
- /* update both cur_idle_time and cur_wall_time */
- cur_idle_time = get_cpu_idle_time(j, &cur_wall_time);
-
- /* how much wall time has passed since last iteration? */
- wall_time = (unsigned int) cputime64_sub(cur_wall_time,
- j_dbs_info->prev_cpu_wall);
- j_dbs_info->prev_cpu_wall = cur_wall_time;
-
- /* how much idle time has passed since last iteration? */
- idle_time = (unsigned int) cputime64_sub(cur_idle_time,
- j_dbs_info->prev_cpu_idle);
- j_dbs_info->prev_cpu_idle = cur_idle_time;
-
- if (unlikely(!wall_time || wall_time < idle_time))
- continue;
-
- /* load is the percentage of time not spent in idle */
- load = 100 * (wall_time - idle_time) / wall_time;
-
- /* keep track of combined load across all CPUs */
- total_load += load;
-
- /* keep track of highest single load across all CPUs */
- if (load > max_load)
- max_load = load;
- }
-
- /* use the max load in the OPP freq change policy */
- max_load_freq = max_load * policy->cur;
-
- /* calculate the average load across all related CPUs */
- avg_load = total_load / num_online_cpus();
-
-
- /*
- * hotplug load accounting
- * average load over multiple sampling periods
- */
-
- /* how many sampling periods do we use for hotplug decisions? */
- periods = max(dbs_tuners_ins.hotplug_in_sampling_periods,
- dbs_tuners_ins.hotplug_out_sampling_periods);
-
- /* store avg_load in the circular buffer */
- dbs_tuners_ins.hotplug_load_history[dbs_tuners_ins.hotplug_load_index]
- = avg_load;
-
- /* compute average load across in & out sampling periods */
- for (i = 0, j = dbs_tuners_ins.hotplug_load_index;
- i < periods; i++, j--) {
- if (i < dbs_tuners_ins.hotplug_in_sampling_periods)
- hotplug_in_avg_load +=
- dbs_tuners_ins.hotplug_load_history[j];
- if (i < dbs_tuners_ins.hotplug_out_sampling_periods)
- hotplug_out_avg_load +=
- dbs_tuners_ins.hotplug_load_history[j];
-
- if (j == 0)
- j = periods;
- }
-
- hotplug_in_avg_load = hotplug_in_avg_load /
- dbs_tuners_ins.hotplug_in_sampling_periods;
-
- hotplug_out_avg_load = hotplug_out_avg_load /
- dbs_tuners_ins.hotplug_out_sampling_periods;
-
- /* return to first element if we're at the circular buffer's end */
- if (++dbs_tuners_ins.hotplug_load_index == periods)
- dbs_tuners_ins.hotplug_load_index = 0;
-
- /* check if auxiliary CPU is needed based on avg_load */
- if (avg_load > dbs_tuners_ins.up_threshold) {
- /* should we enable auxillary CPUs? */
- if (num_online_cpus() < 2 && hotplug_in_avg_load >
- dbs_tuners_ins.up_threshold) {
- /* hotplug with cpufreq is nasty
- * a call to cpufreq_governor_dbs may cause a lockup.
- * wq is not running here so its safe.
- */
- mutex_unlock(&this_dbs_info->timer_mutex);
- cpu_up(1);
- mutex_lock(&this_dbs_info->timer_mutex);
- goto out;
- }
- }
-
- /* check for frequency increase based on max_load */
- if (max_load > dbs_tuners_ins.up_threshold) {
- /* increase to highest frequency supported */
- if (policy->cur < policy->max)
- __cpufreq_driver_target(policy, policy->max,
- CPUFREQ_RELATION_H);
-
- goto out;
- }
-
- /* check for frequency decrease */
- if (avg_load < dbs_tuners_ins.down_threshold) {
- /* are we at the minimum frequency already? */
- if (policy->cur == policy->min) {
- /* should we disable auxillary CPUs? */
- if (num_online_cpus() > 1 && hotplug_out_avg_load <
- dbs_tuners_ins.down_threshold) {
- mutex_unlock(&this_dbs_info->timer_mutex);
- cpu_down(1);
- mutex_lock(&this_dbs_info->timer_mutex);
- }
- goto out;
- }
- }
-
- /*
- * go down to the lowest frequency which can sustain the load by
- * keeping 30% of idle in order to not cross the up_threshold
- */
- if ((max_load_freq <
- (dbs_tuners_ins.up_threshold - dbs_tuners_ins.down_differential) *
- policy->cur) && (policy->cur > policy->min)) {
- unsigned int freq_next;
- freq_next = max_load_freq /
- (dbs_tuners_ins.up_threshold -
- dbs_tuners_ins.down_differential);
-
- if (freq_next < policy->min)
- freq_next = policy->min;
-
- __cpufreq_driver_target(policy, freq_next,
- CPUFREQ_RELATION_L);
- }
-out:
- return;
-}
-
-static void do_dbs_timer(struct work_struct *work)
-{
- struct cpu_dbs_info_s *dbs_info =
- container_of(work, struct cpu_dbs_info_s, work.work);
- unsigned int cpu = dbs_info->cpu;
-
- /* We want all related CPUs to do sampling nearly on same jiffy */
- int delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate);
-
- mutex_lock(&dbs_info->timer_mutex);
- dbs_check_cpu(dbs_info);
- queue_delayed_work_on(cpu, khotplug_wq, &dbs_info->work, delay);
- mutex_unlock(&dbs_info->timer_mutex);
-}
-
-static inline void dbs_timer_init(struct cpu_dbs_info_s *dbs_info)
-{
- /* We want all related CPUs to do sampling nearly on same jiffy */
- int delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate);
- delay -= jiffies % delay;
-
- INIT_DELAYED_WORK_DEFERRABLE(&dbs_info->work, do_dbs_timer);
- queue_delayed_work_on(dbs_info->cpu, khotplug_wq, &dbs_info->work,
- delay);
-}
-
-static inline void dbs_timer_exit(struct cpu_dbs_info_s *dbs_info)
-{
- cancel_delayed_work_sync(&dbs_info->work);
-}
-
-static int cpufreq_governor_dbs(struct cpufreq_policy *policy,
- unsigned int event)
-{
- unsigned int cpu = policy->cpu;
- struct cpu_dbs_info_s *this_dbs_info;
- unsigned int i, j, max_periods;
- int rc;
-
- this_dbs_info = &per_cpu(hp_cpu_dbs_info, cpu);
-
- switch (event) {
- case CPUFREQ_GOV_START:
- if ((!cpu_online(cpu)) || (!policy->cur))
- return -EINVAL;
-
- mutex_lock(&dbs_mutex);
- dbs_enable++;
- for_each_cpu(j, policy->cpus) {
- struct cpu_dbs_info_s *j_dbs_info;
- j_dbs_info = &per_cpu(hp_cpu_dbs_info, j);
- j_dbs_info->cur_policy = policy;
-
- j_dbs_info->prev_cpu_idle = get_cpu_idle_time(j,
- &j_dbs_info->prev_cpu_wall);
- if (dbs_tuners_ins.ignore_nice) {
- j_dbs_info->prev_cpu_nice =
- kstat_cpu(j).cpustat.nice;
- }
-
- max_periods = max(DEFAULT_HOTPLUG_IN_SAMPLING_PERIODS,
- DEFAULT_HOTPLUG_OUT_SAMPLING_PERIODS);
- dbs_tuners_ins.hotplug_load_history = kmalloc(
- (sizeof(unsigned int) * max_periods),
- GFP_KERNEL);
- if (!dbs_tuners_ins.hotplug_load_history) {
- WARN_ON(1);
- return -ENOMEM;
- }
- for (i = 0; i < max_periods; i++)
- dbs_tuners_ins.hotplug_load_history[i] = 50;
- }
- this_dbs_info->cpu = cpu;
- this_dbs_info->freq_table = cpufreq_frequency_get_table(cpu);
- /*
- * Start the timerschedule work, when this governor
- * is used for first time
- */
- if (dbs_enable == 1) {
- rc = sysfs_create_group(cpufreq_global_kobject,
- &dbs_attr_group);
- if (rc) {
- mutex_unlock(&dbs_mutex);
- return rc;
- }
- }
- mutex_unlock(&dbs_mutex);
-
- mutex_init(&this_dbs_info->timer_mutex);
- dbs_timer_init(this_dbs_info);
- break;
-
- case CPUFREQ_GOV_STOP:
- dbs_timer_exit(this_dbs_info);
-
- mutex_lock(&dbs_mutex);
- mutex_destroy(&this_dbs_info->timer_mutex);
- dbs_enable--;
- mutex_unlock(&dbs_mutex);
- if (!dbs_enable)
- sysfs_remove_group(cpufreq_global_kobject,
- &dbs_attr_group);
- kfree(dbs_tuners_ins.hotplug_load_history);
- /*
- * XXX BIG CAVEAT: Stopping the governor with CPU1 offline
- * will result in it remaining offline until the user onlines
- * it again. It is up to the user to do this (for now).
- */
- break;
-
- case CPUFREQ_GOV_LIMITS:
- mutex_lock(&this_dbs_info->timer_mutex);
- if (policy->max < this_dbs_info->cur_policy->cur)
- __cpufreq_driver_target(this_dbs_info->cur_policy,
- policy->max, CPUFREQ_RELATION_H);
- else if (policy->min > this_dbs_info->cur_policy->cur)
- __cpufreq_driver_target(this_dbs_info->cur_policy,
- policy->min, CPUFREQ_RELATION_L);
- mutex_unlock(&this_dbs_info->timer_mutex);
- break;
- }
- return 0;
-}
-
-static int __init cpufreq_gov_dbs_init(void)
-{
- int err;
- cputime64_t wall;
- u64 idle_time;
- int cpu = get_cpu();
-
- idle_time = get_cpu_idle_time_us(cpu, &wall);
- put_cpu();
- if (idle_time != -1ULL) {
- dbs_tuners_ins.up_threshold = DEFAULT_UP_FREQ_MIN_LOAD;
- } else {
- pr_err("cpufreq-hotplug: %s: assumes CONFIG_NO_HZ\n",
- __func__);
- return -EINVAL;
- }
-
- khotplug_wq = create_workqueue("khotplug");
- if (!khotplug_wq) {
- pr_err("Creation of khotplug failed\n");
- return -EFAULT;
- }
- err = cpufreq_register_governor(&cpufreq_gov_hotplug);
- if (err)
- destroy_workqueue(khotplug_wq);
-
- return err;
-}
-
-static void __exit cpufreq_gov_dbs_exit(void)
-{
- cpufreq_unregister_governor(&cpufreq_gov_hotplug);
- destroy_workqueue(khotplug_wq);
-}
-
-MODULE_AUTHOR("Mike Turquette <mturquette@ti.com>");
-MODULE_DESCRIPTION("'cpufreq_hotplug' - cpufreq governor for dynamic frequency scaling and CPU hotplugging");
-MODULE_LICENSE("GPL");
-
-#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_HOTPLUG
-fs_initcall(cpufreq_gov_dbs_init);
-#else
-module_init(cpufreq_gov_dbs_init);
-#endif
-module_exit(cpufreq_gov_dbs_exit);
projects / firefly-linux-kernel-4.4.55.git / commitdiff