/* * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #define CREATE_TRACE_POINTS #include 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; /* 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 long above_hispeed_delay_val = 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 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 void cpufreq_interactive_timer_resched( struct cpufreq_interactive_cpuinfo *pcpu) { unsigned long expires = jiffies + usecs_to_jiffies(timer_rate); unsigned long flags; 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_lock_irqsave(&pcpu->load_lock, flags); pcpu->time_in_idle = get_cpu_idle_time_us(smp_processor_id(), &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_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. */ cpufreq_frequency_table_target( pcpu->policy, pcpu->freq_table, loadadjfreq / tl, CPUFREQ_RELATION_L, &index); 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. */ cpufreq_frequency_table_target( pcpu->policy, pcpu->freq_table, freqmax - 1, CPUFREQ_RELATION_H, &index); 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. */ cpufreq_frequency_table_target( pcpu->policy, pcpu->freq_table, freqmin + 1, CPUFREQ_RELATION_L, &index); 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_us(cpu, &now); delta_idle = (unsigned int)(now_idle - pcpu->time_in_idle); delta_time = (unsigned int)(now - pcpu->time_in_idle_timestamp); 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; 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 < above_hispeed_delay_val) { 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)) { pr_warn_once("timer %d: cpufreq_frequency_table_target error\n", (int) data); 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 (new_freq < pcpu->floor_freq) { if (now - pcpu->floor_validate_time < 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); spin_lock_irqsave(&pjcpu->load_lock, flags); update_load(cpu); spin_unlock_irqrestore(&pjcpu->load_lock, flags); } up_read(&pcpu->enable_sem); } return 0; } static struct notifier_block cpufreq_notifier_block = { .notifier_call = cpufreq_interactive_notifier, }; 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 ret; const char *cp; unsigned int *new_target_loads = NULL; int ntokens = 1; int i; unsigned long flags; cp = buf; while ((cp = strpbrk(cp + 1, " :"))) ntokens++; if (!(ntokens & 0x1)) goto err_inval; new_target_loads = kmalloc(ntokens * sizeof(unsigned int), GFP_KERNEL); if (!new_target_loads) { ret = -ENOMEM; goto err; } cp = buf; i = 0; while (i < ntokens) { if (sscanf(cp, "%u", &new_target_loads[i++]) != 1) goto err_inval; cp = strpbrk(cp, " :"); if (!cp) break; cp++; } if (i != ntokens) goto err_inval; 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; err_inval: ret = -EINVAL; err: kfree(new_target_loads); return ret; } static struct global_attr target_loads_attr = __ATTR(target_loads, S_IRUGO | S_IWUSR, show_target_loads, store_target_loads); 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_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_above_hispeed_delay(struct kobject *kobj, struct attribute *attr, char *buf) { return sprintf(buf, "%lu\n", above_hispeed_delay_val); } static ssize_t store_above_hispeed_delay(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; above_hispeed_delay_val = val; return count; } define_one_global_rw(above_hispeed_delay); 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 struct attribute *interactive_attributes[] = { &target_loads_attr.attr, &hispeed_freq_attr.attr, &go_hispeed_load_attr.attr, &above_hispeed_delay.attr, &min_sample_time_attr.attr, &timer_rate_attr.attr, &timer_slack.attr, &boost.attr, &boostpulse.attr, &boostpulse_duration.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) { unsigned long expires; 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); expires = jiffies + usecs_to_jiffies(timer_rate); pcpu->cpu_timer.expires = expires; add_timer_on(&pcpu->cpu_timer, j); if (timer_slack_val >= 0) { expires += usecs_to_jiffies(timer_slack_val); pcpu->cpu_slack_timer.expires = expires; add_timer_on(&pcpu->cpu_slack_timer, 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); 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); 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, ¶m); 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 "); MODULE_DESCRIPTION("'cpufreq_interactive' - A cpufreq governor for " "Latency sensitive workloads"); MODULE_LICENSE("GPL");