/* * drivers/cpufreq/cpufreq_adaptive.c * * Copyright (C) 2001 Russell King * (C) 2003 Venkatesh Pallipadi . * Jun Nakajima * * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include /* * 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 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_ONDEMAND_THRESHOLD (4) /* * 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) static void (*pm_idle_old)(void); 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_ADAPTIVE static #endif struct cpufreq_governor cpufreq_gov_adaptive = { .name = "adaptive", .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_hi_jiffies; int cpu; unsigned int sample_type:1; bool ondemand; /* * 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 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 task_struct *up_task; static struct workqueue_struct *down_wq; static struct work_struct freq_scale_down_work; static cpumask_t up_cpumask; static spinlock_t up_cpumask_lock; static cpumask_t down_cpumask; static spinlock_t down_cpumask_lock; static DEFINE_PER_CPU(cputime64_t, idle_in_idle); static DEFINE_PER_CPU(cputime64_t, idle_exit_wall); static struct timer_list cpu_timer; static unsigned int target_freq; static DEFINE_MUTEX(short_timer_mutex); /* Go to max speed when CPU load at or above this value. */ #define DEFAULT_GO_MAXSPEED_LOAD 60 static unsigned long go_maxspeed_load; #define DEFAULT_KEEP_MINSPEED_LOAD 30 static unsigned long keep_minspeed_load; #define DEFAULT_STEPUP_LOAD 10 static unsigned long step_up_load; static struct dbs_tuners { unsigned int sampling_rate; unsigned int up_threshold; unsigned int down_differential; unsigned int ignore_nice; unsigned int io_is_busy; } dbs_tuners_ins = { .up_threshold = DEF_FREQUENCY_UP_THRESHOLD, .down_differential = DEF_FREQUENCY_DOWN_DIFFERENTIAL, .ignore_nice = 0, }; 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; } static void adaptive_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); } /************************** sysfs interface ************************/ static ssize_t show_sampling_rate_max(struct kobject *kobj, struct attribute *attr, char *buf) { printk_once(KERN_INFO "CPUFREQ: adaptive sampling_rate_max " "sysfs file is deprecated - used by: %s\n", current->comm); return sprintf(buf, "%u\n", -1U); } 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_max); define_one_global_ro(sampling_rate_min); /* cpufreq_adaptive 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(ignore_nice_load, ignore_nice); /*** delete after deprecation time ***/ #define DEPRECATION_MSG(file_name) \ printk_once(KERN_INFO "CPUFREQ: Per core adaptive sysfs " \ "interface is deprecated - " #file_name "\n"); #define show_one_old(file_name) \ static ssize_t show_##file_name##_old \ (struct cpufreq_policy *unused, char *buf) \ { \ printk_once(KERN_INFO "CPUFREQ: Per core adaptive sysfs " \ "interface is deprecated - " #file_name "\n"); \ return show_##file_name(NULL, NULL, buf); \ } /*** delete after deprecation time ***/ 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 = max(input, min_sampling_rate); 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; } 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; } mutex_lock(&dbs_mutex); dbs_tuners_ins.up_threshold = input; mutex_unlock(&dbs_mutex); 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; 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(od_cpu_dbs_info, j); dbs_info->prev_cpu_idle = get_cpu_idle_time_us(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; } define_one_global_rw(sampling_rate); define_one_global_rw(io_is_busy); define_one_global_rw(up_threshold); define_one_global_rw(ignore_nice_load); static struct attribute *dbs_attributes[] = { &sampling_rate_max.attr, &sampling_rate_min.attr, &sampling_rate.attr, &up_threshold.attr, &ignore_nice_load.attr, &io_is_busy.attr, NULL }; static struct attribute_group dbs_attr_group = { .attrs = dbs_attributes, .name = "adaptive", }; /*** delete after deprecation time ***/ #define write_one_old(file_name) \ static ssize_t store_##file_name##_old \ (struct cpufreq_policy *unused, const char *buf, size_t count) \ { \ printk_once(KERN_INFO "CPUFREQ: Per core adaptive sysfs " \ "interface is deprecated - " #file_name "\n"); \ return store_##file_name(NULL, NULL, buf, count); \ } static void cpufreq_adaptive_timer(unsigned long data) { cputime64_t cur_idle; cputime64_t cur_wall; unsigned int delta_idle; unsigned int delta_time; int short_load; unsigned int new_freq; unsigned long flags; struct cpu_dbs_info_s *this_dbs_info; struct cpufreq_policy *policy; unsigned int j; unsigned int index; unsigned int max_load = 0; this_dbs_info = &per_cpu(od_cpu_dbs_info, 0); policy = this_dbs_info->cur_policy; for_each_online_cpu(j) { cur_idle = get_cpu_idle_time_us(j, &cur_wall); delta_idle = (unsigned int) cputime64_sub(cur_idle, per_cpu(idle_in_idle, j)); delta_time = (unsigned int) cputime64_sub(cur_wall, per_cpu(idle_exit_wall, j)); /* * If timer ran less than 1ms after short-term sample started, retry. */ if (delta_time < 1000) goto do_nothing; if (delta_idle > delta_time) short_load = 0; else short_load = 100 * (delta_time - delta_idle) / delta_time; if (short_load > max_load) max_load = short_load; } if (this_dbs_info->ondemand) goto do_nothing; if (max_load >= go_maxspeed_load) new_freq = policy->max; else new_freq = policy->max * max_load / 100; if ((max_load <= keep_minspeed_load) && (policy->cur == policy->min)) new_freq = policy->cur; if (cpufreq_frequency_table_target(policy, this_dbs_info->freq_table, new_freq, CPUFREQ_RELATION_L, &index)) { goto do_nothing; } new_freq = this_dbs_info->freq_table[index].frequency; target_freq = new_freq; if (new_freq < this_dbs_info->cur_policy->cur) { spin_lock_irqsave(&down_cpumask_lock, flags); cpumask_set_cpu(0, &down_cpumask); spin_unlock_irqrestore(&down_cpumask_lock, flags); queue_work(down_wq, &freq_scale_down_work); } else { spin_lock_irqsave(&up_cpumask_lock, flags); cpumask_set_cpu(0, &up_cpumask); spin_unlock_irqrestore(&up_cpumask_lock, flags); wake_up_process(up_task); } return; do_nothing: for_each_online_cpu(j) { per_cpu(idle_in_idle, j) = get_cpu_idle_time_us(j, &per_cpu(idle_exit_wall, j)); } mod_timer(&cpu_timer, jiffies + 2); schedule_delayed_work_on(0, &this_dbs_info->work, 10); if (mutex_is_locked(&short_timer_mutex)) mutex_unlock(&short_timer_mutex); return; } /*** delete after deprecation time ***/ /************************** sysfs end ************************/ static void dbs_freq_increase(struct cpufreq_policy *p, unsigned int freq) { #ifndef CONFIG_ARCH_EXYNOS4 if (p->cur == p->max) return; #endif __cpufreq_driver_target(p, freq, CPUFREQ_RELATION_H); } static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info) { unsigned int max_load_freq; struct cpufreq_policy *policy; unsigned int j; unsigned int index, new_freq; unsigned int longterm_load = 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, load_freq; int freq_avg; j_dbs_info = &per_cpu(od_cpu_dbs_info, j); cur_idle_time = get_cpu_idle_time_us(j, &cur_wall_time); cur_iowait_time = get_cpu_iowait_time(j, &cur_wall_time); wall_time = (unsigned int) cputime64_sub(cur_wall_time, j_dbs_info->prev_cpu_wall); j_dbs_info->prev_cpu_wall = cur_wall_time; idle_time = (unsigned int) cputime64_sub(cur_idle_time, j_dbs_info->prev_cpu_idle); j_dbs_info->prev_cpu_idle = cur_idle_time; iowait_time = (unsigned int) cputime64_sub(cur_iowait_time, j_dbs_info->prev_cpu_iowait); j_dbs_info->prev_cpu_iowait = cur_iowait_time; if (dbs_tuners_ins.ignore_nice) { cputime64_t cur_nice; unsigned long cur_nice_jiffies; cur_nice = cputime64_sub(kstat_cpu(j).cpustat.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 = kstat_cpu(j).cpustat.nice; idle_time += jiffies_to_usecs(cur_nice_jiffies); } /* * For the purpose of adaptive, 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; load = 100 * (wall_time - idle_time) / wall_time; if (load > longterm_load) longterm_load = load; freq_avg = __cpufreq_driver_getavg(policy, j); if (freq_avg <= 0) freq_avg = policy->cur; load_freq = load * freq_avg; if (load_freq > max_load_freq) max_load_freq = load_freq; } if (longterm_load >= MIN_ONDEMAND_THRESHOLD) this_dbs_info->ondemand = true; else this_dbs_info->ondemand = false; /* Check for frequency increase */ if (max_load_freq > (dbs_tuners_ins.up_threshold * policy->cur)) { cpufreq_frequency_table_target(policy, this_dbs_info->freq_table, (policy->cur + step_up_load), CPUFREQ_RELATION_L, &index); new_freq = this_dbs_info->freq_table[index].frequency; dbs_freq_increase(policy, new_freq); return; } /* Check for frequency decrease */ /* if we cannot reduce the frequency anymore, break out early */ #ifndef CONFIG_ARCH_EXYNOS4 if (policy->cur == policy->min) return; #endif /* * 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); if (freq_next < policy->min) freq_next = policy->min; __cpufreq_driver_target(policy, freq_next, 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 delay; mutex_lock(&dbs_info->timer_mutex); /* Common NORMAL_SAMPLE setup */ dbs_info->sample_type = DBS_NORMAL_SAMPLE; dbs_check_cpu(dbs_info); /* We want all CPUs to do sampling nearly on * same jiffy */ delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate); 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); 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 cpufreq_adaptive_idle(void) { int i; struct cpu_dbs_info_s *dbs_info = &per_cpu(od_cpu_dbs_info, 0); struct cpufreq_policy *policy; policy = dbs_info->cur_policy; pm_idle_old(); if ((policy->cur == policy->min) || (policy->cur == policy->max)) { if (timer_pending(&cpu_timer)) return; if (mutex_trylock(&short_timer_mutex)) { for_each_online_cpu(i) { per_cpu(idle_in_idle, i) = get_cpu_idle_time_us(i, &per_cpu(idle_exit_wall, i)); } mod_timer(&cpu_timer, jiffies + 2); cancel_delayed_work(&dbs_info->work); } } else { if (timer_pending(&cpu_timer)) del_timer(&cpu_timer); } } 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); rc = sysfs_create_group(&policy->kobj, &dbs_attr_group); if (rc) { mutex_unlock(&dbs_mutex); return rc; } 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_us(j, &j_dbs_info->prev_cpu_wall); if (dbs_tuners_ins.ignore_nice) { j_dbs_info->prev_cpu_nice = kstat_cpu(j).cpustat.nice; } } this_dbs_info->cpu = cpu; adaptive_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(); } mutex_unlock(&dbs_mutex); mutex_init(&this_dbs_info->timer_mutex); dbs_timer_init(this_dbs_info); pm_idle_old = pm_idle; pm_idle = cpufreq_adaptive_idle; break; case CPUFREQ_GOV_STOP: dbs_timer_exit(this_dbs_info); mutex_lock(&dbs_mutex); sysfs_remove_group(&policy->kobj, &dbs_attr_group); 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); pm_idle = pm_idle_old; 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 inline void cpufreq_adaptive_update_time(void) { struct cpu_dbs_info_s *this_dbs_info; struct cpufreq_policy *policy; int j; this_dbs_info = &per_cpu(od_cpu_dbs_info, 0); policy = this_dbs_info->cur_policy; 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; j_dbs_info = &per_cpu(od_cpu_dbs_info, j); cur_idle_time = get_cpu_idle_time_us(j, &cur_wall_time); cur_iowait_time = get_cpu_iowait_time(j, &cur_wall_time); j_dbs_info->prev_cpu_wall = cur_wall_time; j_dbs_info->prev_cpu_idle = cur_idle_time; j_dbs_info->prev_cpu_iowait = cur_iowait_time; if (dbs_tuners_ins.ignore_nice) j_dbs_info->prev_cpu_nice = kstat_cpu(j).cpustat.nice; } } static int cpufreq_adaptive_up_task(void *data) { unsigned long flags; struct cpu_dbs_info_s *this_dbs_info; struct cpufreq_policy *policy; int delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate); this_dbs_info = &per_cpu(od_cpu_dbs_info, 0); policy = this_dbs_info->cur_policy; while (1) { set_current_state(TASK_INTERRUPTIBLE); spin_lock_irqsave(&up_cpumask_lock, flags); if (cpumask_empty(&up_cpumask)) { spin_unlock_irqrestore(&up_cpumask_lock, flags); schedule(); if (kthread_should_stop()) break; spin_lock_irqsave(&up_cpumask_lock, flags); } set_current_state(TASK_RUNNING); cpumask_clear(&up_cpumask); spin_unlock_irqrestore(&up_cpumask_lock, flags); __cpufreq_driver_target(this_dbs_info->cur_policy, target_freq, CPUFREQ_RELATION_H); if (policy->cur != policy->max) { mutex_lock(&this_dbs_info->timer_mutex); schedule_delayed_work_on(0, &this_dbs_info->work, delay); mutex_unlock(&this_dbs_info->timer_mutex); cpufreq_adaptive_update_time(); } if (mutex_is_locked(&short_timer_mutex)) mutex_unlock(&short_timer_mutex); } return 0; } static void cpufreq_adaptive_freq_down(struct work_struct *work) { unsigned long flags; struct cpu_dbs_info_s *this_dbs_info; struct cpufreq_policy *policy; int delay = usecs_to_jiffies(dbs_tuners_ins.sampling_rate); spin_lock_irqsave(&down_cpumask_lock, flags); cpumask_clear(&down_cpumask); spin_unlock_irqrestore(&down_cpumask_lock, flags); this_dbs_info = &per_cpu(od_cpu_dbs_info, 0); policy = this_dbs_info->cur_policy; __cpufreq_driver_target(this_dbs_info->cur_policy, target_freq, CPUFREQ_RELATION_H); if (policy->cur != policy->min) { mutex_lock(&this_dbs_info->timer_mutex); schedule_delayed_work_on(0, &this_dbs_info->work, delay); mutex_unlock(&this_dbs_info->timer_mutex); cpufreq_adaptive_update_time(); } if (mutex_is_locked(&short_timer_mutex)) mutex_unlock(&short_timer_mutex); } static int __init cpufreq_gov_dbs_init(void) { cputime64_t wall; u64 idle_time; int cpu = get_cpu(); struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 }; go_maxspeed_load = DEFAULT_GO_MAXSPEED_LOAD; keep_minspeed_load = DEFAULT_KEEP_MINSPEED_LOAD; step_up_load = DEFAULT_STEPUP_LOAD; idle_time = get_cpu_idle_time_us(cpu, &wall); 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 no_hz/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); } init_timer(&cpu_timer); cpu_timer.function = cpufreq_adaptive_timer; up_task = kthread_create(cpufreq_adaptive_up_task, NULL, "kadaptiveup"); if (IS_ERR(up_task)) return PTR_ERR(up_task); sched_setscheduler_nocheck(up_task, SCHED_FIFO, ¶m); get_task_struct(up_task); /* No rescuer thread, bind to CPU queuing the work for possibly warm cache (probably doesn't matter much). */ down_wq = alloc_workqueue("kadaptive_down", 0, 1); if (!down_wq) goto err_freeuptask; INIT_WORK(&freq_scale_down_work, cpufreq_adaptive_freq_down); return cpufreq_register_governor(&cpufreq_gov_adaptive); err_freeuptask: put_task_struct(up_task); return -ENOMEM; } static void __exit cpufreq_gov_dbs_exit(void) { cpufreq_unregister_governor(&cpufreq_gov_adaptive); } MODULE_AUTHOR("Venkatesh Pallipadi "); MODULE_AUTHOR("Alexey Starikovskiy "); MODULE_DESCRIPTION("'cpufreq_adaptive' - A dynamic cpufreq governor for " "Low Latency Frequency Transition capable processors"); MODULE_LICENSE("GPL"); #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_ADAPTIVE fs_initcall(cpufreq_gov_dbs_init); #else module_init(cpufreq_gov_dbs_init); #endif module_exit(cpufreq_gov_dbs_exit);