| /* |
| * drivers/cpufreq/cpufreq_ondemand.c |
| * |
| * 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/input.h> |
| #include <linux/workqueue.h> |
| #include <linux/slab.h> |
| |
| /* |
| * dbs is used in this file as a shortform for demandbased switching |
| * It helps to keep variable names smaller, simpler |
| */ |
| |
| #define DEF_FREQUENCY_DOWN_DIFFERENTIAL (10) |
| #define DEF_FREQUENCY_UP_THRESHOLD (80) |
| #define DEF_SAMPLING_DOWN_FACTOR (1) |
| #define MAX_SAMPLING_DOWN_FACTOR (100000) |
| #define MICRO_FREQUENCY_DOWN_DIFFERENTIAL (3) |
| #define MICRO_FREQUENCY_UP_THRESHOLD (95) |
| #define MICRO_FREQUENCY_MIN_SAMPLE_RATE (10000) |
| #define MIN_FREQUENCY_UP_THRESHOLD (11) |
| #define MAX_FREQUENCY_UP_THRESHOLD (100) |
| #define MIN_FREQUENCY_DOWN_DIFFERENTIAL (1) |
| |
| /* |
| * The polling frequency of this governor depends on the capability of |
| * the processor. Default polling frequency is 1000 times the transition |
| * latency of the processor. The governor will work on any processor with |
| * transition latency <= 10mS, using appropriate sampling |
| * rate. |
| * For CPUs with transition latency > 10mS (mostly drivers with CPUFREQ_ETERNAL) |
| * this governor will not work. |
| * All times here are in uS. |
| */ |
| #define MIN_SAMPLING_RATE_RATIO (2) |
| |
| static unsigned int min_sampling_rate; |
| |
| #define LATENCY_MULTIPLIER (1000) |
| #define MIN_LATENCY_MULTIPLIER (100) |
| #define TRANSITION_LATENCY_LIMIT (10 * 1000 * 1000) |
| |
| #define POWERSAVE_BIAS_MAXLEVEL (1000) |
| #define POWERSAVE_BIAS_MINLEVEL (-1000) |
| |
| 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_ONDEMAND |
| static |
| #endif |
| struct cpufreq_governor cpufreq_gov_ondemand = { |
| .name = "ondemand", |
| .governor = cpufreq_governor_dbs, |
| .max_transition_latency = TRANSITION_LATENCY_LIMIT, |
| .owner = THIS_MODULE, |
| }; |
| |
| /* Sampling types */ |
| enum {DBS_NORMAL_SAMPLE, DBS_SUB_SAMPLE}; |
| |
| struct cpu_dbs_info_s { |
| cputime64_t prev_cpu_idle; |
| cputime64_t prev_cpu_iowait; |
| 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; |
| unsigned int freq_lo; |
| unsigned int freq_lo_jiffies; |
| unsigned int freq_hi_jiffies; |
| unsigned int rate_mult; |
| unsigned int prev_load; |
| unsigned int max_load; |
| int cpu; |
| unsigned int sample_type:1; |
| /* |
| * 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, od_cpu_dbs_info); |
| |
| static inline void dbs_timer_init(struct cpu_dbs_info_s *dbs_info); |
| static inline void dbs_timer_exit(struct cpu_dbs_info_s *dbs_info); |
| |
| static unsigned int dbs_enable; /* number of CPUs using this policy */ |
| |
| /* |
| * dbs_mutex protects dbs_enable in governor start/stop. |
| */ |
| static DEFINE_MUTEX(dbs_mutex); |
| |
| static struct workqueue_struct *input_wq; |
| |
| struct dbs_work_struct { |
| struct work_struct work; |
| unsigned int cpu; |
| }; |
| |
| static DEFINE_PER_CPU(struct dbs_work_struct, dbs_refresh_work); |
| |
| static struct dbs_tuners { |
| unsigned int sampling_rate; |
| unsigned int up_threshold; |
| unsigned int up_threshold_multi_core; |
| unsigned int down_differential; |
| unsigned int down_differential_multi_core; |
| unsigned int optimal_freq; |
| unsigned int up_threshold_any_cpu_load; |
| unsigned int sync_freq; |
| unsigned int ignore_nice; |
| unsigned int sampling_down_factor; |
| int powersave_bias; |
| unsigned int io_is_busy; |
| } dbs_tuners_ins = { |
| .up_threshold_multi_core = DEF_FREQUENCY_UP_THRESHOLD, |
| .up_threshold = DEF_FREQUENCY_UP_THRESHOLD, |
| .sampling_down_factor = DEF_SAMPLING_DOWN_FACTOR, |
| .down_differential = DEF_FREQUENCY_DOWN_DIFFERENTIAL, |
| .down_differential_multi_core = MICRO_FREQUENCY_DOWN_DIFFERENTIAL, |
| .up_threshold_any_cpu_load = DEF_FREQUENCY_UP_THRESHOLD, |
| .ignore_nice = 0, |
| .powersave_bias = 0, |
| .sync_freq = 0, |
| .optimal_freq = 0, |
| }; |
| |
| static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *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, NULL); |
| |
| if (idle_time == -1ULL) |
| return get_cpu_idle_time_jiffy(cpu, wall); |
| else |
| idle_time += get_cpu_iowait_time_us(cpu, wall); |
| |
| return idle_time; |
| } |
| |
| static inline cputime64_t get_cpu_iowait_time(unsigned int cpu, cputime64_t *wall) |
| { |
| u64 iowait_time = get_cpu_iowait_time_us(cpu, wall); |
| |
| if (iowait_time == -1ULL) |
| return 0; |
| |
| return iowait_time; |
| } |
| |
| /* |
| * Find right freq to be set now with powersave_bias on. |
| * Returns the freq_hi to be used right now and will set freq_hi_jiffies, |
| * freq_lo, and freq_lo_jiffies in percpu area for averaging freqs. |
| */ |
| static unsigned int powersave_bias_target(struct cpufreq_policy *policy, |
| unsigned int freq_next, |
| unsigned int relation) |
| { |
| unsigned int freq_req, freq_avg; |
| unsigned int freq_hi, freq_lo; |
| unsigned int index = 0; |
| unsigned int jiffies_total, jiffies_hi, jiffies_lo; |
| int freq_reduc; |
| struct cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info, |
| policy->cpu); |
| |
| if (!dbs_info->freq_table) { |
| dbs_info->freq_lo = 0; |
| dbs_info->freq_lo_jiffies = 0; |
| return freq_next; |
| } |
| |
| cpufreq_frequency_table_target(policy, dbs_info->freq_table, freq_next, |
| relation, &index); |
| freq_req = dbs_info->freq_table[index].frequency; |
| freq_reduc = freq_req * dbs_tuners_ins.powersave_bias / 1000; |
| freq_avg = freq_req - freq_reduc; |
| |
| /* Find freq bounds for freq_avg in freq_table */ |
| index = 0; |
| cpufreq_frequency_table_target(policy, dbs_info->freq_table, freq_avg, |
| CPUFREQ_RELATION_H, &index); |
| freq_lo = dbs_info->freq_table[index].frequency; |
| index = 0; |
| cpufreq_frequency_table_target(policy, dbs_info->freq_table, freq_avg, |
| CPUFREQ_RELATION_L, &index); |
| freq_hi = dbs_info->freq_table[index].frequency; |
| |
| /* Find out how long we have to be in hi and lo freqs */ |
| if (freq_hi == freq_lo) { |
| dbs_info->freq_lo = 0; |
| dbs_info->freq_lo_jiffies = 0; |
| return freq_lo; |
| } |
| jiffies_total = usecs_to_jiffies(dbs_tuners_ins.sampling_rate); |
| jiffies_hi = (freq_avg - freq_lo) * jiffies_total; |
| jiffies_hi += ((freq_hi - freq_lo) / 2); |
| jiffies_hi /= (freq_hi - freq_lo); |
| jiffies_lo = jiffies_total - jiffies_hi; |
| dbs_info->freq_lo = freq_lo; |
| dbs_info->freq_lo_jiffies = jiffies_lo; |
| dbs_info->freq_hi_jiffies = jiffies_hi; |
| return freq_hi; |
| } |
| |
| static int ondemand_powersave_bias_setspeed(struct cpufreq_policy *policy, |
| struct cpufreq_policy *altpolicy, |
| int level) |
| { |
| if (level == POWERSAVE_BIAS_MAXLEVEL) { |
| /* maximum powersave; set to lowest frequency */ |
| __cpufreq_driver_target(policy, |
| (altpolicy) ? altpolicy->min : policy->min, |
| CPUFREQ_RELATION_L); |
| return 1; |
| } else if (level == POWERSAVE_BIAS_MINLEVEL) { |
| /* minimum powersave; set to highest frequency */ |
| __cpufreq_driver_target(policy, |
| (altpolicy) ? altpolicy->max : policy->max, |
| CPUFREQ_RELATION_H); |
| return 1; |
| } |
| return 0; |
| } |
| |
| static void ondemand_powersave_bias_init_cpu(int cpu) |
| { |
| struct cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info, cpu); |
| dbs_info->freq_table = cpufreq_frequency_get_table(cpu); |
| dbs_info->freq_lo = 0; |
| } |
| |
| static void ondemand_powersave_bias_init(void) |
| { |
| int i; |
| for_each_online_cpu(i) { |
| ondemand_powersave_bias_init_cpu(i); |
| } |
| } |
| |
| /************************** sysfs interface ************************/ |
| |
| static ssize_t show_sampling_rate_min(struct kobject *kobj, |
| struct attribute *attr, char *buf) |
| { |
| return sprintf(buf, "%u\n", min_sampling_rate); |
| } |
| |
| define_one_global_ro(sampling_rate_min); |
| |
| /* cpufreq_ondemand 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(io_is_busy, io_is_busy); |
| show_one(up_threshold, up_threshold); |
| show_one(up_threshold_multi_core, up_threshold_multi_core); |
| show_one(down_differential, down_differential); |
| show_one(sampling_down_factor, sampling_down_factor); |
| show_one(ignore_nice_load, ignore_nice); |
| show_one(optimal_freq, optimal_freq); |
| show_one(up_threshold_any_cpu_load, up_threshold_any_cpu_load); |
| show_one(sync_freq, sync_freq); |
| |
| static ssize_t show_powersave_bias |
| (struct kobject *kobj, struct attribute *attr, char *buf) |
| { |
| return snprintf(buf, PAGE_SIZE, "%d\n", dbs_tuners_ins.powersave_bias); |
| } |
| |
| /** |
| * update_sampling_rate - update sampling rate effective immediately if needed. |
| * @new_rate: new sampling rate |
| * |
| * If new rate is smaller than the old, simply updaing |
| * dbs_tuners_int.sampling_rate might not be appropriate. For example, |
| * if the original sampling_rate was 1 second and the requested new sampling |
| * rate is 10 ms because the user needs immediate reaction from ondemand |
| * governor, but not sure if higher frequency will be required or not, |
| * then, the governor may change the sampling rate too late; up to 1 second |
| * later. Thus, if we are reducing the sampling rate, we need to make the |
| * new value effective immediately. |
| */ |
| static void update_sampling_rate(unsigned int new_rate) |
| { |
| int cpu; |
| |
| dbs_tuners_ins.sampling_rate = new_rate |
| = max(new_rate, min_sampling_rate); |
| |
| for_each_online_cpu(cpu) { |
| struct cpufreq_policy *policy; |
| struct cpu_dbs_info_s *dbs_info; |
| unsigned long next_sampling, appointed_at; |
| |
| policy = cpufreq_cpu_get(cpu); |
| if (!policy) |
| continue; |
| dbs_info = &per_cpu(od_cpu_dbs_info, policy->cpu); |
| cpufreq_cpu_put(policy); |
| |
| mutex_lock(&dbs_info->timer_mutex); |
| |
| if (!delayed_work_pending(&dbs_info->work)) { |
| mutex_unlock(&dbs_info->timer_mutex); |
| continue; |
| } |
| |
| next_sampling = jiffies + usecs_to_jiffies(new_rate); |
| appointed_at = dbs_info->work.timer.expires; |
| |
| |
| if (time_before(next_sampling, appointed_at)) { |
| |
| mutex_unlock(&dbs_info->timer_mutex); |
| cancel_delayed_work_sync(&dbs_info->work); |
| mutex_lock(&dbs_info->timer_mutex); |
| |
| schedule_delayed_work_on(dbs_info->cpu, &dbs_info->work, |
| usecs_to_jiffies(new_rate)); |
| |
| } |
| mutex_unlock(&dbs_info->timer_mutex); |
| } |
| } |
| |
| 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; |
| update_sampling_rate(input); |
| return count; |
| } |
| |
| static ssize_t store_sync_freq(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; |
| dbs_tuners_ins.sync_freq = input; |
| 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; |
| dbs_tuners_ins.io_is_busy = !!input; |
| return count; |
| } |
| |
| static ssize_t store_optimal_freq(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; |
| dbs_tuners_ins.optimal_freq = input; |
| 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 > MAX_FREQUENCY_UP_THRESHOLD || |
| input < MIN_FREQUENCY_UP_THRESHOLD) { |
| return -EINVAL; |
| } |
| dbs_tuners_ins.up_threshold = input; |
| return count; |
| } |
| |
| static ssize_t store_up_threshold_multi_core(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 > MAX_FREQUENCY_UP_THRESHOLD || |
| input < MIN_FREQUENCY_UP_THRESHOLD) { |
| return -EINVAL; |
| } |
| dbs_tuners_ins.up_threshold_multi_core = input; |
| return count; |
| } |
| |
| static ssize_t store_up_threshold_any_cpu_load(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 > MAX_FREQUENCY_UP_THRESHOLD || |
| input < MIN_FREQUENCY_UP_THRESHOLD) { |
| return -EINVAL; |
| } |
| dbs_tuners_ins.up_threshold_any_cpu_load = input; |
| 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 || |
| input < MIN_FREQUENCY_DOWN_DIFFERENTIAL) { |
| return -EINVAL; |
| } |
| |
| dbs_tuners_ins.down_differential = input; |
| |
| return count; |
| } |
| |
| static ssize_t store_sampling_down_factor(struct kobject *a, |
| struct attribute *b, const char *buf, size_t count) |
| { |
| unsigned int input, j; |
| int ret; |
| ret = sscanf(buf, "%u", &input); |
| |
| if (ret != 1 || input > MAX_SAMPLING_DOWN_FACTOR || input < 1) |
| return -EINVAL; |
| dbs_tuners_ins.sampling_down_factor = input; |
| |
| /* Reset down sampling multiplier in case it was active */ |
| for_each_online_cpu(j) { |
| struct cpu_dbs_info_s *dbs_info; |
| dbs_info = &per_cpu(od_cpu_dbs_info, j); |
| dbs_info->rate_mult = 1; |
| } |
| return count; |
| } |
| |
| 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; |
| |
| if (input == dbs_tuners_ins.ignore_nice) { /* nothing to do */ |
| 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(od_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 = kcpustat_cpu(j).cpustat[CPUTIME_NICE]; |
| |
| } |
| return count; |
| } |
| |
| static ssize_t store_powersave_bias(struct kobject *a, struct attribute *b, |
| const char *buf, size_t count) |
| { |
| int input = 0; |
| int bypass = 0; |
| int ret, cpu, reenable_timer, j; |
| struct cpu_dbs_info_s *dbs_info; |
| |
| struct cpumask cpus_timer_done; |
| cpumask_clear(&cpus_timer_done); |
| |
| ret = sscanf(buf, "%d", &input); |
| |
| if (ret != 1) |
| return -EINVAL; |
| |
| if (input >= POWERSAVE_BIAS_MAXLEVEL) { |
| input = POWERSAVE_BIAS_MAXLEVEL; |
| bypass = 1; |
| } else if (input <= POWERSAVE_BIAS_MINLEVEL) { |
| input = POWERSAVE_BIAS_MINLEVEL; |
| bypass = 1; |
| } |
| |
| if (input == dbs_tuners_ins.powersave_bias) { |
| /* no change */ |
| return count; |
| } |
| |
| reenable_timer = ((dbs_tuners_ins.powersave_bias == |
| POWERSAVE_BIAS_MAXLEVEL) || |
| (dbs_tuners_ins.powersave_bias == |
| POWERSAVE_BIAS_MINLEVEL)); |
| |
| dbs_tuners_ins.powersave_bias = input; |
| if (!bypass) { |
| if (reenable_timer) { |
| /* reinstate dbs timer */ |
| for_each_online_cpu(cpu) { |
| if (lock_policy_rwsem_write(cpu) < 0) |
| continue; |
| |
| dbs_info = &per_cpu(od_cpu_dbs_info, cpu); |
| |
| for_each_cpu(j, &cpus_timer_done) { |
| if (!dbs_info->cur_policy) { |
| pr_err("Dbs policy is NULL\n"); |
| goto skip_this_cpu; |
| } |
| if (cpumask_test_cpu(j, dbs_info-> |
| cur_policy->cpus)) |
| goto skip_this_cpu; |
| } |
| |
| cpumask_set_cpu(cpu, &cpus_timer_done); |
| if (dbs_info->cur_policy) { |
| /* restart dbs timer */ |
| dbs_timer_init(dbs_info); |
| } |
| skip_this_cpu: |
| unlock_policy_rwsem_write(cpu); |
| } |
| } |
| ondemand_powersave_bias_init(); |
| } else { |
| /* running at maximum or minimum frequencies; cancel |
| dbs timer as periodic load sampling is not necessary */ |
| for_each_online_cpu(cpu) { |
| if (lock_policy_rwsem_write(cpu) < 0) |
| continue; |
| |
| dbs_info = &per_cpu(od_cpu_dbs_info, cpu); |
| |
| for_each_cpu(j, &cpus_timer_done) { |
| if (!dbs_info->cur_policy) { |
| pr_err("Dbs policy is NULL\n"); |
| goto skip_this_cpu_bypass; |
| } |
| if (cpumask_test_cpu(j, dbs_info-> |
| cur_policy->cpus)) |
| goto skip_this_cpu_bypass; |
| } |
| |
| cpumask_set_cpu(cpu, &cpus_timer_done); |
| |
| if (dbs_info->cur_policy) { |
| /* cpu using ondemand, cancel dbs timer */ |
| mutex_lock(&dbs_info->timer_mutex); |
| dbs_timer_exit(dbs_info); |
| |
| ondemand_powersave_bias_setspeed( |
| dbs_info->cur_policy, |
| NULL, |
| input); |
| |
| mutex_unlock(&dbs_info->timer_mutex); |
| } |
| skip_this_cpu_bypass: |
| unlock_policy_rwsem_write(cpu); |
| } |
| } |
| |
| return count; |
| } |
| |
| define_one_global_rw(sampling_rate); |
| define_one_global_rw(io_is_busy); |
| define_one_global_rw(up_threshold); |
| define_one_global_rw(down_differential); |
| define_one_global_rw(sampling_down_factor); |
| define_one_global_rw(ignore_nice_load); |
| define_one_global_rw(powersave_bias); |
| define_one_global_rw(up_threshold_multi_core); |
| define_one_global_rw(optimal_freq); |
| define_one_global_rw(up_threshold_any_cpu_load); |
| define_one_global_rw(sync_freq); |
| |
| static struct attribute *dbs_attributes[] = { |
| &sampling_rate_min.attr, |
| &sampling_rate.attr, |
| &up_threshold.attr, |
| &down_differential.attr, |
| &sampling_down_factor.attr, |
| &ignore_nice_load.attr, |
| &powersave_bias.attr, |
| &io_is_busy.attr, |
| &up_threshold_multi_core.attr, |
| &optimal_freq.attr, |
| &up_threshold_any_cpu_load.attr, |
| &sync_freq.attr, |
| NULL |
| }; |
| |
| static struct attribute_group dbs_attr_group = { |
| .attrs = dbs_attributes, |
| .name = "ondemand", |
| }; |
| |
| /************************** sysfs end ************************/ |
| |
| static void dbs_freq_increase(struct cpufreq_policy *p, unsigned int freq) |
| { |
| if (dbs_tuners_ins.powersave_bias) |
| freq = powersave_bias_target(p, freq, CPUFREQ_RELATION_H); |
| else if (p->cur == p->max) |
| return; |
| |
| __cpufreq_driver_target(p, freq, dbs_tuners_ins.powersave_bias ? |
| CPUFREQ_RELATION_L : CPUFREQ_RELATION_H); |
| } |
| |
| static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info) |
| { |
| /* Extrapolated load of this CPU */ |
| unsigned int load_at_max_freq = 0; |
| unsigned int max_load_freq; |
| /* Current load across this CPU */ |
| unsigned int cur_load = 0; |
| unsigned int max_load_other_cpu = 0; |
| struct cpufreq_policy *policy; |
| unsigned int j; |
| |
| this_dbs_info->freq_lo = 0; |
| policy = this_dbs_info->cur_policy; |
| |
| /* |
| * Every sampling_rate, we check, if current idle time is less |
| * than 20% (default), then we try to increase frequency |
| * Every sampling_rate, we look for a the lowest |
| * frequency which can sustain the load while keeping idle time over |
| * 30%. If such a frequency exist, we try to decrease to this frequency. |
| * |
| * Any frequency increase takes it to the maximum frequency. |
| * Frequency reduction happens at minimum steps of |
| * 5% (default) of current frequency |
| */ |
| |
| /* Get Absolute Load - in terms of freq */ |
| max_load_freq = 0; |
| |
| for_each_cpu(j, policy->cpus) { |
| struct cpu_dbs_info_s *j_dbs_info; |
| cputime64_t cur_wall_time, cur_idle_time, cur_iowait_time; |
| unsigned int idle_time, wall_time, iowait_time; |
| unsigned int load_freq; |
| int freq_avg; |
| |
| j_dbs_info = &per_cpu(od_cpu_dbs_info, j); |
| |
| cur_idle_time = get_cpu_idle_time(j, &cur_wall_time); |
| cur_iowait_time = get_cpu_iowait_time(j, &cur_wall_time); |
| |
| wall_time = (unsigned int) |
| (cur_wall_time - j_dbs_info->prev_cpu_wall); |
| j_dbs_info->prev_cpu_wall = cur_wall_time; |
| |
| idle_time = (unsigned int) |
| (cur_idle_time - j_dbs_info->prev_cpu_idle); |
| j_dbs_info->prev_cpu_idle = cur_idle_time; |
| |
| iowait_time = (unsigned int) |
| (cur_iowait_time - j_dbs_info->prev_cpu_iowait); |
| j_dbs_info->prev_cpu_iowait = cur_iowait_time; |
| |
| if (dbs_tuners_ins.ignore_nice) { |
| u64 cur_nice; |
| unsigned long cur_nice_jiffies; |
| |
| cur_nice = kcpustat_cpu(j).cpustat[CPUTIME_NICE] - |
| j_dbs_info->prev_cpu_nice; |
| /* |
| * Assumption: nice time between sampling periods will |
| * be less than 2^32 jiffies for 32 bit sys |
| */ |
| cur_nice_jiffies = (unsigned long) |
| cputime64_to_jiffies64(cur_nice); |
| |
| j_dbs_info->prev_cpu_nice = kcpustat_cpu(j).cpustat[CPUTIME_NICE]; |
| idle_time += jiffies_to_usecs(cur_nice_jiffies); |
| } |
| |
| /* |
| * For the purpose of ondemand, waiting for disk IO is an |
| * indication that you're performance critical, and not that |
| * the system is actually idle. So subtract the iowait time |
| * from the cpu idle time. |
| */ |
| |
| if (dbs_tuners_ins.io_is_busy && idle_time >= iowait_time) |
| idle_time -= iowait_time; |
| |
| if (unlikely(!wall_time || wall_time < idle_time)) |
| continue; |
| |
| cur_load = 100 * (wall_time - idle_time) / wall_time; |
| j_dbs_info->max_load = max(cur_load, j_dbs_info->prev_load); |
| j_dbs_info->prev_load = cur_load; |
| freq_avg = __cpufreq_driver_getavg(policy, j); |
| if (freq_avg <= 0) |
| freq_avg = policy->cur; |
| |
| load_freq = cur_load * freq_avg; |
| if (load_freq > max_load_freq) |
| max_load_freq = load_freq; |
| } |
| |
| for_each_online_cpu(j) { |
| struct cpu_dbs_info_s *j_dbs_info; |
| j_dbs_info = &per_cpu(od_cpu_dbs_info, j); |
| |
| if (j == policy->cpu) |
| continue; |
| |
| if (max_load_other_cpu < j_dbs_info->max_load) |
| max_load_other_cpu = j_dbs_info->max_load; |
| /* |
| * The other cpu could be running at higher frequency |
| * but may not have completed it's sampling_down_factor. |
| * For that case consider other cpu is loaded so that |
| * frequency imbalance does not occur. |
| */ |
| |
| if ((j_dbs_info->cur_policy != NULL) |
| && (j_dbs_info->cur_policy->cur == |
| j_dbs_info->cur_policy->max)) { |
| |
| if (policy->cur >= dbs_tuners_ins.optimal_freq) |
| max_load_other_cpu = |
| dbs_tuners_ins.up_threshold_any_cpu_load; |
| } |
| } |
| |
| /* calculate the scaled load across CPU */ |
| load_at_max_freq = (cur_load * policy->cur)/policy->cpuinfo.max_freq; |
| |
| cpufreq_notify_utilization(policy, load_at_max_freq); |
| /* Check for frequency increase */ |
| if (max_load_freq > dbs_tuners_ins.up_threshold * policy->cur) { |
| /* If switching to max speed, apply sampling_down_factor */ |
| if (policy->cur < policy->max) |
| this_dbs_info->rate_mult = |
| dbs_tuners_ins.sampling_down_factor; |
| dbs_freq_increase(policy, policy->max); |
| return; |
| } |
| |
| if (num_online_cpus() > 1) { |
| |
| if (max_load_other_cpu > |
| dbs_tuners_ins.up_threshold_any_cpu_load) { |
| if (policy->cur < dbs_tuners_ins.sync_freq) |
| dbs_freq_increase(policy, |
| dbs_tuners_ins.sync_freq); |
| return; |
| } |
| |
| if (max_load_freq > dbs_tuners_ins.up_threshold_multi_core * |
| policy->cur) { |
| if (policy->cur < dbs_tuners_ins.optimal_freq) |
| dbs_freq_increase(policy, |
| dbs_tuners_ins.optimal_freq); |
| return; |
| } |
| } |
| |
| /* Check for frequency decrease */ |
| /* if we cannot reduce the frequency anymore, break out early */ |
| if (policy->cur == policy->min) |
| return; |
| |
| /* |
| * The optimal frequency is the frequency that is the lowest that |
| * can support the current CPU usage without triggering the up |
| * policy. To be safe, we focus 10 points under the threshold. |
| */ |
| if (max_load_freq < |
| (dbs_tuners_ins.up_threshold - dbs_tuners_ins.down_differential) * |
| policy->cur) { |
| unsigned int freq_next; |
| freq_next = max_load_freq / |
| (dbs_tuners_ins.up_threshold - |
| dbs_tuners_ins.down_differential); |
| |
| /* No longer fully busy, reset rate_mult */ |
| this_dbs_info->rate_mult = 1; |
| |
| if (freq_next < policy->min) |
| freq_next = policy->min; |
| |
| if (num_online_cpus() > 1) { |
| if (max_load_other_cpu > |
| (dbs_tuners_ins.up_threshold_multi_core - |
| dbs_tuners_ins.down_differential) && |
| freq_next < dbs_tuners_ins.sync_freq) |
| freq_next = dbs_tuners_ins.sync_freq; |
| |
| if (max_load_freq > |
| ((dbs_tuners_ins.up_threshold_multi_core - |
| dbs_tuners_ins.down_differential_multi_core) * |
| policy->cur) && |
| freq_next < dbs_tuners_ins.optimal_freq) |
| freq_next = dbs_tuners_ins.optimal_freq; |
| |
| } |
| if (!dbs_tuners_ins.powersave_bias) { |
| __cpufreq_driver_target(policy, freq_next, |
| CPUFREQ_RELATION_L); |
| } else { |
| int freq = powersave_bias_target(policy, freq_next, |
| CPUFREQ_RELATION_L); |
| __cpufreq_driver_target(policy, freq, |
| CPUFREQ_RELATION_L); |
| } |
| } |
| } |
| |
| 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; |
| int sample_type = dbs_info->sample_type; |
| |
| int delay; |
| |
| mutex_lock(&dbs_info->timer_mutex); |
| |
| /* Common NORMAL_SAMPLE setup */ |
| dbs_info->sample_type = DBS_NORMAL_SAMPLE; |
| if (!dbs_tuners_ins.powersave_bias || |
| sample_type == DBS_NORMAL_SAMPLE) { |
| dbs_check_cpu(dbs_info); |
| if (dbs_info->freq_lo) { |
| /* Setup timer for SUB_SAMPLE */ |
| dbs_info->sample_type = DBS_SUB_SAMPLE; |
| delay = dbs_info->freq_hi_jiffies; |
| } else { |
| /* We want all CPUs to do sampling nearly on |
| * same jiffy |
| */ |
| delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate |
| * dbs_info->rate_mult); |
| |
| if (num_online_cpus() > 1) |
| delay -= jiffies % delay; |
| } |
| } else { |
| __cpufreq_driver_target(dbs_info->cur_policy, |
| dbs_info->freq_lo, CPUFREQ_RELATION_H); |
| delay = dbs_info->freq_lo_jiffies; |
| } |
| schedule_delayed_work_on(cpu, &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 CPUs to do sampling nearly on same jiffy */ |
| int delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate); |
| |
| if (num_online_cpus() > 1) |
| delay -= jiffies % delay; |
| |
| dbs_info->sample_type = DBS_NORMAL_SAMPLE; |
| INIT_DELAYED_WORK_DEFERRABLE(&dbs_info->work, do_dbs_timer); |
| schedule_delayed_work_on(dbs_info->cpu, &dbs_info->work, delay); |
| } |
| |
| static inline void dbs_timer_exit(struct cpu_dbs_info_s *dbs_info) |
| { |
| cancel_delayed_work_sync(&dbs_info->work); |
| } |
| |
| /* |
| * Not all CPUs want IO time to be accounted as busy; this dependson how |
| * efficient idling at a higher frequency/voltage is. |
| * Pavel Machek says this is not so for various generations of AMD and old |
| * Intel systems. |
| * Mike Chan (androidlcom) calis this is also not true for ARM. |
| * Because of this, whitelist specific known (series) of CPUs by default, and |
| * leave all others up to the user. |
| */ |
| static int should_io_be_busy(void) |
| { |
| #if defined(CONFIG_X86) |
| /* |
| * For Intel, Core 2 (model 15) andl later have an efficient idle. |
| */ |
| if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL && |
| boot_cpu_data.x86 == 6 && |
| boot_cpu_data.x86_model >= 15) |
| return 1; |
| #endif |
| return 0; |
| } |
| |
| static void dbs_refresh_callback(struct work_struct *work) |
| { |
| struct cpufreq_policy *policy; |
| struct cpu_dbs_info_s *this_dbs_info; |
| struct dbs_work_struct *dbs_work; |
| unsigned int cpu; |
| |
| dbs_work = container_of(work, struct dbs_work_struct, work); |
| cpu = dbs_work->cpu; |
| |
| get_online_cpus(); |
| |
| if (lock_policy_rwsem_write(cpu) < 0) |
| goto bail_acq_sema_failed; |
| |
| this_dbs_info = &per_cpu(od_cpu_dbs_info, cpu); |
| policy = this_dbs_info->cur_policy; |
| if (!policy) { |
| /* CPU not using ondemand governor */ |
| goto bail_incorrect_governor; |
| } |
| |
| if (policy->cur < policy->max) { |
| /* |
| * Arch specific cpufreq driver may fail. |
| * Don't update governor frequency upon failure. |
| */ |
| if (__cpufreq_driver_target(policy, policy->max, |
| CPUFREQ_RELATION_L) >= 0) |
| policy->cur = policy->max; |
| |
| this_dbs_info->prev_cpu_idle = get_cpu_idle_time(cpu, |
| &this_dbs_info->prev_cpu_wall); |
| } |
| |
| bail_incorrect_governor: |
| unlock_policy_rwsem_write(cpu); |
| |
| bail_acq_sema_failed: |
| put_online_cpus(); |
| return; |
| } |
| |
| static void dbs_input_event(struct input_handle *handle, unsigned int type, |
| unsigned int code, int value) |
| { |
| int i; |
| |
| if ((dbs_tuners_ins.powersave_bias == POWERSAVE_BIAS_MAXLEVEL) || |
| (dbs_tuners_ins.powersave_bias == POWERSAVE_BIAS_MINLEVEL)) { |
| /* nothing to do */ |
| return; |
| } |
| |
| for_each_online_cpu(i) |
| queue_work_on(i, input_wq, &per_cpu(dbs_refresh_work, i).work); |
| } |
| |
| static int dbs_input_connect(struct input_handler *handler, |
| struct input_dev *dev, const struct input_device_id *id) |
| { |
| struct input_handle *handle; |
| int error; |
| |
| handle = kzalloc(sizeof(struct input_handle), GFP_KERNEL); |
| if (!handle) |
| return -ENOMEM; |
| |
| handle->dev = dev; |
| handle->handler = handler; |
| handle->name = "cpufreq"; |
| |
| error = input_register_handle(handle); |
| if (error) |
| goto err2; |
| |
| error = input_open_device(handle); |
| if (error) |
| goto err1; |
| |
| return 0; |
| err1: |
| input_unregister_handle(handle); |
| err2: |
| kfree(handle); |
| return error; |
| } |
| |
| static void dbs_input_disconnect(struct input_handle *handle) |
| { |
| input_close_device(handle); |
| input_unregister_handle(handle); |
| kfree(handle); |
| } |
| |
| static const struct input_device_id dbs_ids[] = { |
| { .driver_info = 1 }, |
| { }, |
| }; |
| |
| static struct input_handler dbs_input_handler = { |
| .event = dbs_input_event, |
| .connect = dbs_input_connect, |
| .disconnect = dbs_input_disconnect, |
| .name = "cpufreq_ond", |
| .id_table = dbs_ids, |
| }; |
| |
| 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 j; |
| int rc; |
| |
| this_dbs_info = &per_cpu(od_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(od_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 = |
| kcpustat_cpu(j).cpustat[CPUTIME_NICE]; |
| } |
| this_dbs_info->cpu = cpu; |
| this_dbs_info->rate_mult = 1; |
| ondemand_powersave_bias_init_cpu(cpu); |
| /* |
| * Start the timerschedule work, when this governor |
| * is used for first time |
| */ |
| if (dbs_enable == 1) { |
| unsigned int latency; |
| |
| rc = sysfs_create_group(cpufreq_global_kobject, |
| &dbs_attr_group); |
| if (rc) { |
| mutex_unlock(&dbs_mutex); |
| return rc; |
| } |
| |
| /* policy latency is in nS. Convert it to uS first */ |
| latency = policy->cpuinfo.transition_latency / 1000; |
| if (latency == 0) |
| latency = 1; |
| /* Bring kernel and HW constraints together */ |
| min_sampling_rate = max(min_sampling_rate, |
| MIN_LATENCY_MULTIPLIER * latency); |
| dbs_tuners_ins.sampling_rate = |
| max(min_sampling_rate, |
| latency * LATENCY_MULTIPLIER); |
| dbs_tuners_ins.io_is_busy = should_io_be_busy(); |
| |
| if (dbs_tuners_ins.optimal_freq == 0) |
| dbs_tuners_ins.optimal_freq = policy->min; |
| |
| if (dbs_tuners_ins.sync_freq == 0) |
| dbs_tuners_ins.sync_freq = policy->min; |
| } |
| if (!cpu) |
| rc = input_register_handler(&dbs_input_handler); |
| mutex_unlock(&dbs_mutex); |
| |
| |
| if (!ondemand_powersave_bias_setspeed( |
| this_dbs_info->cur_policy, |
| NULL, |
| dbs_tuners_ins.powersave_bias)) |
| dbs_timer_init(this_dbs_info); |
| break; |
| |
| case CPUFREQ_GOV_STOP: |
| dbs_timer_exit(this_dbs_info); |
| |
| mutex_lock(&dbs_mutex); |
| dbs_enable--; |
| /* If device is being removed, policy is no longer |
| * valid. */ |
| this_dbs_info->cur_policy = NULL; |
| if (!cpu) |
| input_unregister_handler(&dbs_input_handler); |
| if (!dbs_enable) |
| sysfs_remove_group(cpufreq_global_kobject, |
| &dbs_attr_group); |
| mutex_unlock(&dbs_mutex); |
| |
| 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); |
| else if (dbs_tuners_ins.powersave_bias != 0) |
| ondemand_powersave_bias_setspeed( |
| this_dbs_info->cur_policy, |
| policy, |
| dbs_tuners_ins.powersave_bias); |
| mutex_unlock(&this_dbs_info->timer_mutex); |
| break; |
| } |
| return 0; |
| } |
| |
| static int __init cpufreq_gov_dbs_init(void) |
| { |
| u64 idle_time; |
| unsigned int i; |
| int cpu = get_cpu(); |
| |
| idle_time = get_cpu_idle_time_us(cpu, NULL); |
| put_cpu(); |
| if (idle_time != -1ULL) { |
| /* Idle micro accounting is supported. Use finer thresholds */ |
| dbs_tuners_ins.up_threshold = MICRO_FREQUENCY_UP_THRESHOLD; |
| dbs_tuners_ins.down_differential = |
| MICRO_FREQUENCY_DOWN_DIFFERENTIAL; |
| /* |
| * In nohz/micro accounting case we set the minimum frequency |
| * not depending on HZ, but fixed (very low). The deferred |
| * timer might skip some samples if idle/sleeping as needed. |
| */ |
| min_sampling_rate = MICRO_FREQUENCY_MIN_SAMPLE_RATE; |
| } else { |
| /* For correct statistics, we need 10 ticks for each measure */ |
| min_sampling_rate = |
| MIN_SAMPLING_RATE_RATIO * jiffies_to_usecs(10); |
| } |
| |
| input_wq = create_workqueue("iewq"); |
| if (!input_wq) { |
| printk(KERN_ERR "Failed to create iewq workqueue\n"); |
| return -EFAULT; |
| } |
| for_each_possible_cpu(i) { |
| struct cpu_dbs_info_s *this_dbs_info = |
| &per_cpu(od_cpu_dbs_info, i); |
| struct dbs_work_struct *dbs_work = |
| &per_cpu(dbs_refresh_work, i); |
| |
| mutex_init(&this_dbs_info->timer_mutex); |
| INIT_WORK(&dbs_work->work, dbs_refresh_callback); |
| dbs_work->cpu = i; |
| } |
| |
| return cpufreq_register_governor(&cpufreq_gov_ondemand); |
| } |
| |
| static void __exit cpufreq_gov_dbs_exit(void) |
| { |
| unsigned int i; |
| |
| cpufreq_unregister_governor(&cpufreq_gov_ondemand); |
| for_each_possible_cpu(i) { |
| struct cpu_dbs_info_s *this_dbs_info = |
| &per_cpu(od_cpu_dbs_info, i); |
| mutex_destroy(&this_dbs_info->timer_mutex); |
| } |
| destroy_workqueue(input_wq); |
| } |
| |
| |
| MODULE_AUTHOR("Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>"); |
| MODULE_AUTHOR("Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>"); |
| MODULE_DESCRIPTION("'cpufreq_ondemand' - A dynamic cpufreq governor for " |
| "Low Latency Frequency Transition capable processors"); |
| MODULE_LICENSE("GPL"); |
| |
| #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND |
| fs_initcall(cpufreq_gov_dbs_init); |
| #else |
| module_init(cpufreq_gov_dbs_init); |
| #endif |
| module_exit(cpufreq_gov_dbs_exit); |