2 * drivers/cpufreq/cpufreq_interactive.c
4 * Copyright (C) 2010 Google, Inc.
6 * This software is licensed under the terms of the GNU General Public
7 * License version 2, as published by the Free Software Foundation, and
8 * may be copied, distributed, and modified under those terms.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * Author: Mike Chan (mike@android.com)
19 #include <linux/cpu.h>
20 #include <linux/cpumask.h>
21 #include <linux/cpufreq.h>
22 #include <linux/module.h>
23 #include <linux/moduleparam.h>
24 #include <linux/rwsem.h>
25 #include <linux/sched.h>
26 #include <linux/sched/rt.h>
27 #include <linux/tick.h>
28 #include <linux/time.h>
29 #include <linux/timer.h>
30 #include <linux/workqueue.h>
31 #include <linux/kthread.h>
32 #include <linux/slab.h>
33 #include <linux/kernel_stat.h>
34 #include <asm/cputime.h>
36 #define CREATE_TRACE_POINTS
37 #include <trace/events/cpufreq_interactive.h>
39 static int active_count;
41 struct cpufreq_interactive_cpuinfo {
42 struct timer_list cpu_timer;
43 struct timer_list cpu_slack_timer;
44 spinlock_t load_lock; /* protects the next 4 fields */
46 u64 time_in_idle_timestamp;
48 u64 cputime_speedadj_timestamp;
49 struct cpufreq_policy *policy;
50 struct cpufreq_frequency_table *freq_table;
51 unsigned int target_freq;
52 unsigned int floor_freq;
53 u64 floor_validate_time;
54 u64 hispeed_validate_time;
55 struct rw_semaphore enable_sem;
59 static DEFINE_PER_CPU(struct cpufreq_interactive_cpuinfo, cpuinfo);
61 /* realtime thread handles frequency scaling */
62 static struct task_struct *speedchange_task;
63 static cpumask_t speedchange_cpumask;
64 static spinlock_t speedchange_cpumask_lock;
65 static struct mutex gov_lock;
67 /* Hi speed to bump to from lo speed when load burst (default max) */
68 static unsigned int hispeed_freq;
70 /* Go to hi speed when CPU load at or above this value. */
71 #define DEFAULT_GO_HISPEED_LOAD 99
72 static unsigned long go_hispeed_load = DEFAULT_GO_HISPEED_LOAD;
74 /* Target load. Lower values result in higher CPU speeds. */
75 #define DEFAULT_TARGET_LOAD 90
76 static unsigned int default_target_loads[] = {DEFAULT_TARGET_LOAD};
77 static spinlock_t target_loads_lock;
78 static unsigned int *target_loads = default_target_loads;
79 static int ntarget_loads = ARRAY_SIZE(default_target_loads);
82 * The minimum amount of time to spend at a frequency before we can ramp down.
84 #define DEFAULT_MIN_SAMPLE_TIME (80 * USEC_PER_MSEC)
85 static unsigned long min_sample_time = DEFAULT_MIN_SAMPLE_TIME;
88 * The sample rate of the timer used to increase frequency
90 #define DEFAULT_TIMER_RATE (20 * USEC_PER_MSEC)
91 static unsigned long timer_rate = DEFAULT_TIMER_RATE;
94 * Wait this long before raising speed above hispeed, by default a single
97 #define DEFAULT_ABOVE_HISPEED_DELAY DEFAULT_TIMER_RATE
98 static unsigned int default_above_hispeed_delay[] = {
99 DEFAULT_ABOVE_HISPEED_DELAY };
100 static spinlock_t above_hispeed_delay_lock;
101 static unsigned int *above_hispeed_delay = default_above_hispeed_delay;
102 static int nabove_hispeed_delay = ARRAY_SIZE(default_above_hispeed_delay);
104 /* Non-zero means indefinite speed boost active */
105 static int boost_val;
106 /* Duration of a boot pulse in usecs */
107 static int boostpulse_duration_val = DEFAULT_MIN_SAMPLE_TIME;
108 /* End time of boost pulse in ktime converted to usecs */
109 static u64 boostpulse_endtime;
112 * Max additional time to wait in idle, beyond timer_rate, at speeds above
113 * minimum before wakeup to reduce speed, or -1 if unnecessary.
115 #define DEFAULT_TIMER_SLACK (4 * DEFAULT_TIMER_RATE)
116 static int timer_slack_val = DEFAULT_TIMER_SLACK;
118 static bool io_is_busy;
120 static int cpufreq_governor_interactive(struct cpufreq_policy *policy,
123 #ifndef CONFIG_CPU_FREQ_DEFAULT_GOV_INTERACTIVE
126 struct cpufreq_governor cpufreq_gov_interactive = {
127 .name = "interactive",
128 .governor = cpufreq_governor_interactive,
129 .max_transition_latency = 10000000,
130 .owner = THIS_MODULE,
133 static inline cputime64_t get_cpu_idle_time_jiffy(unsigned int cpu,
140 cur_wall_time = jiffies64_to_cputime64(get_jiffies_64());
142 busy_time = kcpustat_cpu(cpu).cpustat[CPUTIME_USER];
143 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SYSTEM];
144 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_IRQ];
145 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SOFTIRQ];
146 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL];
147 busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE];
149 idle_time = cur_wall_time - busy_time;
151 *wall = jiffies_to_usecs(cur_wall_time);
153 return jiffies_to_usecs(idle_time);
156 static inline cputime64_t get_cpu_idle_time(unsigned int cpu,
159 u64 idle_time = get_cpu_idle_time_us(cpu, wall);
161 if (idle_time == -1ULL)
162 idle_time = get_cpu_idle_time_jiffy(cpu, wall);
163 else if (!io_is_busy)
164 idle_time += get_cpu_iowait_time_us(cpu, wall);
169 static void cpufreq_interactive_timer_resched(
170 struct cpufreq_interactive_cpuinfo *pcpu)
172 unsigned long expires;
175 spin_lock_irqsave(&pcpu->load_lock, flags);
177 get_cpu_idle_time(smp_processor_id(),
178 &pcpu->time_in_idle_timestamp);
179 pcpu->cputime_speedadj = 0;
180 pcpu->cputime_speedadj_timestamp = pcpu->time_in_idle_timestamp;
181 expires = jiffies + usecs_to_jiffies(timer_rate);
182 mod_timer_pinned(&pcpu->cpu_timer, expires);
184 if (timer_slack_val >= 0 && pcpu->target_freq > pcpu->policy->min) {
185 expires += usecs_to_jiffies(timer_slack_val);
186 mod_timer_pinned(&pcpu->cpu_slack_timer, expires);
189 spin_unlock_irqrestore(&pcpu->load_lock, flags);
192 static unsigned int freq_to_above_hispeed_delay(unsigned int freq)
198 spin_lock_irqsave(&above_hispeed_delay_lock, flags);
200 for (i = 0; i < nabove_hispeed_delay - 1 &&
201 freq >= above_hispeed_delay[i+1]; i += 2)
204 ret = above_hispeed_delay[i];
205 spin_unlock_irqrestore(&above_hispeed_delay_lock, flags);
209 static unsigned int freq_to_targetload(unsigned int freq)
215 spin_lock_irqsave(&target_loads_lock, flags);
217 for (i = 0; i < ntarget_loads - 1 && freq >= target_loads[i+1]; i += 2)
220 ret = target_loads[i];
221 spin_unlock_irqrestore(&target_loads_lock, flags);
226 * If increasing frequencies never map to a lower target load then
227 * choose_freq() will find the minimum frequency that does not exceed its
228 * target load given the current load.
231 static unsigned int choose_freq(
232 struct cpufreq_interactive_cpuinfo *pcpu, unsigned int loadadjfreq)
234 unsigned int freq = pcpu->policy->cur;
235 unsigned int prevfreq, freqmin, freqmax;
244 tl = freq_to_targetload(freq);
247 * Find the lowest frequency where the computed load is less
248 * than or equal to the target load.
251 if (cpufreq_frequency_table_target(
252 pcpu->policy, pcpu->freq_table, loadadjfreq / tl,
253 CPUFREQ_RELATION_L, &index))
255 freq = pcpu->freq_table[index].frequency;
257 if (freq > prevfreq) {
258 /* The previous frequency is too low. */
261 if (freq >= freqmax) {
263 * Find the highest frequency that is less
266 if (cpufreq_frequency_table_target(
267 pcpu->policy, pcpu->freq_table,
268 freqmax - 1, CPUFREQ_RELATION_H,
271 freq = pcpu->freq_table[index].frequency;
273 if (freq == freqmin) {
275 * The first frequency below freqmax
276 * has already been found to be too
277 * low. freqmax is the lowest speed
278 * we found that is fast enough.
284 } else if (freq < prevfreq) {
285 /* The previous frequency is high enough. */
288 if (freq <= freqmin) {
290 * Find the lowest frequency that is higher
293 if (cpufreq_frequency_table_target(
294 pcpu->policy, pcpu->freq_table,
295 freqmin + 1, CPUFREQ_RELATION_L,
298 freq = pcpu->freq_table[index].frequency;
301 * If freqmax is the first frequency above
302 * freqmin then we have already found that
303 * this speed is fast enough.
310 /* If same frequency chosen as previous then done. */
311 } while (freq != prevfreq);
316 static u64 update_load(int cpu)
318 struct cpufreq_interactive_cpuinfo *pcpu = &per_cpu(cpuinfo, cpu);
321 unsigned int delta_idle;
322 unsigned int delta_time;
325 now_idle = get_cpu_idle_time(cpu, &now);
326 delta_idle = (unsigned int)(now_idle - pcpu->time_in_idle);
327 delta_time = (unsigned int)(now - pcpu->time_in_idle_timestamp);
328 active_time = delta_time - delta_idle;
329 pcpu->cputime_speedadj += active_time * pcpu->policy->cur;
331 pcpu->time_in_idle = now_idle;
332 pcpu->time_in_idle_timestamp = now;
336 static void cpufreq_interactive_timer(unsigned long data)
339 unsigned int delta_time;
340 u64 cputime_speedadj;
342 struct cpufreq_interactive_cpuinfo *pcpu =
343 &per_cpu(cpuinfo, data);
344 unsigned int new_freq;
345 unsigned int loadadjfreq;
350 if (!down_read_trylock(&pcpu->enable_sem))
352 if (!pcpu->governor_enabled)
355 spin_lock_irqsave(&pcpu->load_lock, flags);
356 now = update_load(data);
357 delta_time = (unsigned int)(now - pcpu->cputime_speedadj_timestamp);
358 cputime_speedadj = pcpu->cputime_speedadj;
359 spin_unlock_irqrestore(&pcpu->load_lock, flags);
361 if (WARN_ON_ONCE(!delta_time))
364 do_div(cputime_speedadj, delta_time);
365 loadadjfreq = (unsigned int)cputime_speedadj * 100;
366 cpu_load = loadadjfreq / pcpu->target_freq;
367 boosted = boost_val || now < boostpulse_endtime;
369 if (cpu_load >= go_hispeed_load || boosted) {
370 if (pcpu->target_freq < hispeed_freq) {
371 new_freq = hispeed_freq;
373 new_freq = choose_freq(pcpu, loadadjfreq);
375 if (new_freq < hispeed_freq)
376 new_freq = hispeed_freq;
379 new_freq = choose_freq(pcpu, loadadjfreq);
382 if (pcpu->target_freq >= hispeed_freq &&
383 new_freq > pcpu->target_freq &&
384 now - pcpu->hispeed_validate_time <
385 freq_to_above_hispeed_delay(pcpu->target_freq)) {
386 trace_cpufreq_interactive_notyet(
387 data, cpu_load, pcpu->target_freq,
388 pcpu->policy->cur, new_freq);
392 pcpu->hispeed_validate_time = now;
394 if (cpufreq_frequency_table_target(pcpu->policy, pcpu->freq_table,
395 new_freq, CPUFREQ_RELATION_L,
399 new_freq = pcpu->freq_table[index].frequency;
402 * Do not scale below floor_freq unless we have been at or above the
403 * floor frequency for the minimum sample time since last validated.
405 if (new_freq < pcpu->floor_freq) {
406 if (now - pcpu->floor_validate_time < min_sample_time) {
407 trace_cpufreq_interactive_notyet(
408 data, cpu_load, pcpu->target_freq,
409 pcpu->policy->cur, new_freq);
415 * Update the timestamp for checking whether speed has been held at
416 * or above the selected frequency for a minimum of min_sample_time,
417 * if not boosted to hispeed_freq. If boosted to hispeed_freq then we
418 * allow the speed to drop as soon as the boostpulse duration expires
419 * (or the indefinite boost is turned off).
422 if (!boosted || new_freq > hispeed_freq) {
423 pcpu->floor_freq = new_freq;
424 pcpu->floor_validate_time = now;
427 if (pcpu->target_freq == new_freq) {
428 trace_cpufreq_interactive_already(
429 data, cpu_load, pcpu->target_freq,
430 pcpu->policy->cur, new_freq);
431 goto rearm_if_notmax;
434 trace_cpufreq_interactive_target(data, cpu_load, pcpu->target_freq,
435 pcpu->policy->cur, new_freq);
437 pcpu->target_freq = new_freq;
438 spin_lock_irqsave(&speedchange_cpumask_lock, flags);
439 cpumask_set_cpu(data, &speedchange_cpumask);
440 spin_unlock_irqrestore(&speedchange_cpumask_lock, flags);
441 wake_up_process(speedchange_task);
445 * Already set max speed and don't see a need to change that,
446 * wait until next idle to re-evaluate, don't need timer.
448 if (pcpu->target_freq == pcpu->policy->max)
452 if (!timer_pending(&pcpu->cpu_timer))
453 cpufreq_interactive_timer_resched(pcpu);
456 up_read(&pcpu->enable_sem);
460 static void cpufreq_interactive_idle_start(void)
462 struct cpufreq_interactive_cpuinfo *pcpu =
463 &per_cpu(cpuinfo, smp_processor_id());
466 if (!down_read_trylock(&pcpu->enable_sem))
468 if (!pcpu->governor_enabled) {
469 up_read(&pcpu->enable_sem);
473 pending = timer_pending(&pcpu->cpu_timer);
475 if (pcpu->target_freq != pcpu->policy->min) {
477 * Entering idle while not at lowest speed. On some
478 * platforms this can hold the other CPU(s) at that speed
479 * even though the CPU is idle. Set a timer to re-evaluate
480 * speed so this idle CPU doesn't hold the other CPUs above
481 * min indefinitely. This should probably be a quirk of
482 * the CPUFreq driver.
485 cpufreq_interactive_timer_resched(pcpu);
488 up_read(&pcpu->enable_sem);
491 static void cpufreq_interactive_idle_end(void)
493 struct cpufreq_interactive_cpuinfo *pcpu =
494 &per_cpu(cpuinfo, smp_processor_id());
496 if (!down_read_trylock(&pcpu->enable_sem))
498 if (!pcpu->governor_enabled) {
499 up_read(&pcpu->enable_sem);
503 /* Arm the timer for 1-2 ticks later if not already. */
504 if (!timer_pending(&pcpu->cpu_timer)) {
505 cpufreq_interactive_timer_resched(pcpu);
506 } else if (time_after_eq(jiffies, pcpu->cpu_timer.expires)) {
507 del_timer(&pcpu->cpu_timer);
508 del_timer(&pcpu->cpu_slack_timer);
509 cpufreq_interactive_timer(smp_processor_id());
512 up_read(&pcpu->enable_sem);
515 static int cpufreq_interactive_speedchange_task(void *data)
520 struct cpufreq_interactive_cpuinfo *pcpu;
523 set_current_state(TASK_INTERRUPTIBLE);
524 spin_lock_irqsave(&speedchange_cpumask_lock, flags);
526 if (cpumask_empty(&speedchange_cpumask)) {
527 spin_unlock_irqrestore(&speedchange_cpumask_lock,
531 if (kthread_should_stop())
534 spin_lock_irqsave(&speedchange_cpumask_lock, flags);
537 set_current_state(TASK_RUNNING);
538 tmp_mask = speedchange_cpumask;
539 cpumask_clear(&speedchange_cpumask);
540 spin_unlock_irqrestore(&speedchange_cpumask_lock, flags);
542 for_each_cpu(cpu, &tmp_mask) {
544 unsigned int max_freq = 0;
546 pcpu = &per_cpu(cpuinfo, cpu);
547 if (!down_read_trylock(&pcpu->enable_sem))
549 if (!pcpu->governor_enabled) {
550 up_read(&pcpu->enable_sem);
554 for_each_cpu(j, pcpu->policy->cpus) {
555 struct cpufreq_interactive_cpuinfo *pjcpu =
556 &per_cpu(cpuinfo, j);
558 if (pjcpu->target_freq > max_freq)
559 max_freq = pjcpu->target_freq;
562 if (max_freq != pcpu->policy->cur)
563 __cpufreq_driver_target(pcpu->policy,
566 trace_cpufreq_interactive_setspeed(cpu,
570 up_read(&pcpu->enable_sem);
577 static void cpufreq_interactive_boost(void)
582 struct cpufreq_interactive_cpuinfo *pcpu;
584 spin_lock_irqsave(&speedchange_cpumask_lock, flags);
586 for_each_online_cpu(i) {
587 pcpu = &per_cpu(cpuinfo, i);
589 if (pcpu->target_freq < hispeed_freq) {
590 pcpu->target_freq = hispeed_freq;
591 cpumask_set_cpu(i, &speedchange_cpumask);
592 pcpu->hispeed_validate_time =
593 ktime_to_us(ktime_get());
598 * Set floor freq and (re)start timer for when last
602 pcpu->floor_freq = hispeed_freq;
603 pcpu->floor_validate_time = ktime_to_us(ktime_get());
606 spin_unlock_irqrestore(&speedchange_cpumask_lock, flags);
609 wake_up_process(speedchange_task);
612 static int cpufreq_interactive_notifier(
613 struct notifier_block *nb, unsigned long val, void *data)
615 struct cpufreq_freqs *freq = data;
616 struct cpufreq_interactive_cpuinfo *pcpu;
620 if (val == CPUFREQ_POSTCHANGE) {
621 pcpu = &per_cpu(cpuinfo, freq->cpu);
622 if (!down_read_trylock(&pcpu->enable_sem))
624 if (!pcpu->governor_enabled) {
625 up_read(&pcpu->enable_sem);
629 for_each_cpu(cpu, pcpu->policy->cpus) {
630 struct cpufreq_interactive_cpuinfo *pjcpu =
631 &per_cpu(cpuinfo, cpu);
632 spin_lock_irqsave(&pjcpu->load_lock, flags);
634 spin_unlock_irqrestore(&pjcpu->load_lock, flags);
637 up_read(&pcpu->enable_sem);
642 static struct notifier_block cpufreq_notifier_block = {
643 .notifier_call = cpufreq_interactive_notifier,
646 static unsigned int *get_tokenized_data(const char *buf, int *num_tokens)
651 unsigned int *tokenized_data;
655 while ((cp = strpbrk(cp + 1, " :")))
658 if (!(ntokens & 0x1))
661 tokenized_data = kmalloc(ntokens * sizeof(unsigned int), GFP_KERNEL);
662 if (!tokenized_data) {
669 while (i < ntokens) {
670 if (sscanf(cp, "%u", &tokenized_data[i++]) != 1)
673 cp = strpbrk(cp, " :");
682 *num_tokens = ntokens;
683 return tokenized_data;
686 kfree(tokenized_data);
691 static ssize_t show_target_loads(
692 struct kobject *kobj, struct attribute *attr, char *buf)
698 spin_lock_irqsave(&target_loads_lock, flags);
700 for (i = 0; i < ntarget_loads; i++)
701 ret += sprintf(buf + ret, "%u%s", target_loads[i],
702 i & 0x1 ? ":" : " ");
704 ret += sprintf(buf + ret, "\n");
705 spin_unlock_irqrestore(&target_loads_lock, flags);
709 static ssize_t store_target_loads(
710 struct kobject *kobj, struct attribute *attr, const char *buf,
714 unsigned int *new_target_loads = NULL;
717 new_target_loads = get_tokenized_data(buf, &ntokens);
718 if (IS_ERR(new_target_loads))
719 return PTR_RET(new_target_loads);
721 spin_lock_irqsave(&target_loads_lock, flags);
722 if (target_loads != default_target_loads)
724 target_loads = new_target_loads;
725 ntarget_loads = ntokens;
726 spin_unlock_irqrestore(&target_loads_lock, flags);
730 static struct global_attr target_loads_attr =
731 __ATTR(target_loads, S_IRUGO | S_IWUSR,
732 show_target_loads, store_target_loads);
734 static ssize_t show_above_hispeed_delay(
735 struct kobject *kobj, struct attribute *attr, char *buf)
741 spin_lock_irqsave(&above_hispeed_delay_lock, flags);
743 for (i = 0; i < nabove_hispeed_delay; i++)
744 ret += sprintf(buf + ret, "%u%s", above_hispeed_delay[i],
745 i & 0x1 ? ":" : " ");
747 ret += sprintf(buf + ret, "\n");
748 spin_unlock_irqrestore(&above_hispeed_delay_lock, flags);
752 static ssize_t store_above_hispeed_delay(
753 struct kobject *kobj, struct attribute *attr, const char *buf,
757 unsigned int *new_above_hispeed_delay = NULL;
760 new_above_hispeed_delay = get_tokenized_data(buf, &ntokens);
761 if (IS_ERR(new_above_hispeed_delay))
762 return PTR_RET(new_above_hispeed_delay);
764 spin_lock_irqsave(&above_hispeed_delay_lock, flags);
765 if (above_hispeed_delay != default_above_hispeed_delay)
766 kfree(above_hispeed_delay);
767 above_hispeed_delay = new_above_hispeed_delay;
768 nabove_hispeed_delay = ntokens;
769 spin_unlock_irqrestore(&above_hispeed_delay_lock, flags);
774 static struct global_attr above_hispeed_delay_attr =
775 __ATTR(above_hispeed_delay, S_IRUGO | S_IWUSR,
776 show_above_hispeed_delay, store_above_hispeed_delay);
778 static ssize_t show_hispeed_freq(struct kobject *kobj,
779 struct attribute *attr, char *buf)
781 return sprintf(buf, "%u\n", hispeed_freq);
784 static ssize_t store_hispeed_freq(struct kobject *kobj,
785 struct attribute *attr, const char *buf,
789 long unsigned int val;
791 ret = strict_strtoul(buf, 0, &val);
798 static struct global_attr hispeed_freq_attr = __ATTR(hispeed_freq, 0644,
799 show_hispeed_freq, store_hispeed_freq);
802 static ssize_t show_go_hispeed_load(struct kobject *kobj,
803 struct attribute *attr, char *buf)
805 return sprintf(buf, "%lu\n", go_hispeed_load);
808 static ssize_t store_go_hispeed_load(struct kobject *kobj,
809 struct attribute *attr, const char *buf, size_t count)
814 ret = strict_strtoul(buf, 0, &val);
817 go_hispeed_load = val;
821 static struct global_attr go_hispeed_load_attr = __ATTR(go_hispeed_load, 0644,
822 show_go_hispeed_load, store_go_hispeed_load);
824 static ssize_t show_min_sample_time(struct kobject *kobj,
825 struct attribute *attr, char *buf)
827 return sprintf(buf, "%lu\n", min_sample_time);
830 static ssize_t store_min_sample_time(struct kobject *kobj,
831 struct attribute *attr, const char *buf, size_t count)
836 ret = strict_strtoul(buf, 0, &val);
839 min_sample_time = val;
843 static struct global_attr min_sample_time_attr = __ATTR(min_sample_time, 0644,
844 show_min_sample_time, store_min_sample_time);
846 static ssize_t show_timer_rate(struct kobject *kobj,
847 struct attribute *attr, char *buf)
849 return sprintf(buf, "%lu\n", timer_rate);
852 static ssize_t store_timer_rate(struct kobject *kobj,
853 struct attribute *attr, const char *buf, size_t count)
858 ret = strict_strtoul(buf, 0, &val);
865 static struct global_attr timer_rate_attr = __ATTR(timer_rate, 0644,
866 show_timer_rate, store_timer_rate);
868 static ssize_t show_timer_slack(
869 struct kobject *kobj, struct attribute *attr, char *buf)
871 return sprintf(buf, "%d\n", timer_slack_val);
874 static ssize_t store_timer_slack(
875 struct kobject *kobj, struct attribute *attr, const char *buf,
881 ret = kstrtol(buf, 10, &val);
885 timer_slack_val = val;
889 define_one_global_rw(timer_slack);
891 static ssize_t show_boost(struct kobject *kobj, struct attribute *attr,
894 return sprintf(buf, "%d\n", boost_val);
897 static ssize_t store_boost(struct kobject *kobj, struct attribute *attr,
898 const char *buf, size_t count)
903 ret = kstrtoul(buf, 0, &val);
910 trace_cpufreq_interactive_boost("on");
911 cpufreq_interactive_boost();
913 trace_cpufreq_interactive_unboost("off");
919 define_one_global_rw(boost);
921 static ssize_t store_boostpulse(struct kobject *kobj, struct attribute *attr,
922 const char *buf, size_t count)
927 ret = kstrtoul(buf, 0, &val);
931 boostpulse_endtime = ktime_to_us(ktime_get()) + boostpulse_duration_val;
932 trace_cpufreq_interactive_boost("pulse");
933 cpufreq_interactive_boost();
937 static struct global_attr boostpulse =
938 __ATTR(boostpulse, 0200, NULL, store_boostpulse);
940 static ssize_t show_boostpulse_duration(
941 struct kobject *kobj, struct attribute *attr, char *buf)
943 return sprintf(buf, "%d\n", boostpulse_duration_val);
946 static ssize_t store_boostpulse_duration(
947 struct kobject *kobj, struct attribute *attr, const char *buf,
953 ret = kstrtoul(buf, 0, &val);
957 boostpulse_duration_val = val;
961 define_one_global_rw(boostpulse_duration);
963 static ssize_t show_io_is_busy(struct kobject *kobj,
964 struct attribute *attr, char *buf)
966 return sprintf(buf, "%u\n", io_is_busy);
969 static ssize_t store_io_is_busy(struct kobject *kobj,
970 struct attribute *attr, const char *buf, size_t count)
975 ret = kstrtoul(buf, 0, &val);
982 static struct global_attr io_is_busy_attr = __ATTR(io_is_busy, 0644,
983 show_io_is_busy, store_io_is_busy);
985 static struct attribute *interactive_attributes[] = {
986 &target_loads_attr.attr,
987 &above_hispeed_delay_attr.attr,
988 &hispeed_freq_attr.attr,
989 &go_hispeed_load_attr.attr,
990 &min_sample_time_attr.attr,
991 &timer_rate_attr.attr,
995 &boostpulse_duration.attr,
996 &io_is_busy_attr.attr,
1000 static struct attribute_group interactive_attr_group = {
1001 .attrs = interactive_attributes,
1002 .name = "interactive",
1005 static int cpufreq_interactive_idle_notifier(struct notifier_block *nb,
1011 cpufreq_interactive_idle_start();
1014 cpufreq_interactive_idle_end();
1021 static struct notifier_block cpufreq_interactive_idle_nb = {
1022 .notifier_call = cpufreq_interactive_idle_notifier,
1025 static int cpufreq_governor_interactive(struct cpufreq_policy *policy,
1030 struct cpufreq_interactive_cpuinfo *pcpu;
1031 struct cpufreq_frequency_table *freq_table;
1034 case CPUFREQ_GOV_START:
1035 if (!cpu_online(policy->cpu))
1038 mutex_lock(&gov_lock);
1041 cpufreq_frequency_get_table(policy->cpu);
1043 hispeed_freq = policy->max;
1045 for_each_cpu(j, policy->cpus) {
1046 unsigned long expires;
1048 pcpu = &per_cpu(cpuinfo, j);
1049 pcpu->policy = policy;
1050 pcpu->target_freq = policy->cur;
1051 pcpu->freq_table = freq_table;
1052 pcpu->floor_freq = pcpu->target_freq;
1053 pcpu->floor_validate_time =
1054 ktime_to_us(ktime_get());
1055 pcpu->hispeed_validate_time =
1056 pcpu->floor_validate_time;
1057 down_write(&pcpu->enable_sem);
1058 expires = jiffies + usecs_to_jiffies(timer_rate);
1059 pcpu->cpu_timer.expires = expires;
1060 add_timer_on(&pcpu->cpu_timer, j);
1061 if (timer_slack_val >= 0) {
1062 expires += usecs_to_jiffies(timer_slack_val);
1063 pcpu->cpu_slack_timer.expires = expires;
1064 add_timer_on(&pcpu->cpu_slack_timer, j);
1066 pcpu->governor_enabled = 1;
1067 up_write(&pcpu->enable_sem);
1071 * Do not register the idle hook and create sysfs
1072 * entries if we have already done so.
1074 if (++active_count > 1) {
1075 mutex_unlock(&gov_lock);
1079 rc = sysfs_create_group(cpufreq_global_kobject,
1080 &interactive_attr_group);
1082 mutex_unlock(&gov_lock);
1086 idle_notifier_register(&cpufreq_interactive_idle_nb);
1087 cpufreq_register_notifier(
1088 &cpufreq_notifier_block, CPUFREQ_TRANSITION_NOTIFIER);
1089 mutex_unlock(&gov_lock);
1092 case CPUFREQ_GOV_STOP:
1093 mutex_lock(&gov_lock);
1094 for_each_cpu(j, policy->cpus) {
1095 pcpu = &per_cpu(cpuinfo, j);
1096 down_write(&pcpu->enable_sem);
1097 pcpu->governor_enabled = 0;
1098 del_timer_sync(&pcpu->cpu_timer);
1099 del_timer_sync(&pcpu->cpu_slack_timer);
1100 up_write(&pcpu->enable_sem);
1103 if (--active_count > 0) {
1104 mutex_unlock(&gov_lock);
1108 cpufreq_unregister_notifier(
1109 &cpufreq_notifier_block, CPUFREQ_TRANSITION_NOTIFIER);
1110 idle_notifier_unregister(&cpufreq_interactive_idle_nb);
1111 sysfs_remove_group(cpufreq_global_kobject,
1112 &interactive_attr_group);
1113 mutex_unlock(&gov_lock);
1117 case CPUFREQ_GOV_LIMITS:
1118 if (policy->max < policy->cur)
1119 __cpufreq_driver_target(policy,
1120 policy->max, CPUFREQ_RELATION_H);
1121 else if (policy->min > policy->cur)
1122 __cpufreq_driver_target(policy,
1123 policy->min, CPUFREQ_RELATION_L);
1129 static void cpufreq_interactive_nop_timer(unsigned long data)
1133 static int __init cpufreq_interactive_init(void)
1136 struct cpufreq_interactive_cpuinfo *pcpu;
1137 struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };
1139 /* Initalize per-cpu timers */
1140 for_each_possible_cpu(i) {
1141 pcpu = &per_cpu(cpuinfo, i);
1142 init_timer_deferrable(&pcpu->cpu_timer);
1143 pcpu->cpu_timer.function = cpufreq_interactive_timer;
1144 pcpu->cpu_timer.data = i;
1145 init_timer(&pcpu->cpu_slack_timer);
1146 pcpu->cpu_slack_timer.function = cpufreq_interactive_nop_timer;
1147 spin_lock_init(&pcpu->load_lock);
1148 init_rwsem(&pcpu->enable_sem);
1151 spin_lock_init(&target_loads_lock);
1152 spin_lock_init(&speedchange_cpumask_lock);
1153 spin_lock_init(&above_hispeed_delay_lock);
1154 mutex_init(&gov_lock);
1156 kthread_create(cpufreq_interactive_speedchange_task, NULL,
1158 if (IS_ERR(speedchange_task))
1159 return PTR_ERR(speedchange_task);
1161 sched_setscheduler_nocheck(speedchange_task, SCHED_FIFO, ¶m);
1162 get_task_struct(speedchange_task);
1164 /* NB: wake up so the thread does not look hung to the freezer */
1165 wake_up_process(speedchange_task);
1167 return cpufreq_register_governor(&cpufreq_gov_interactive);
1170 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_INTERACTIVE
1171 fs_initcall(cpufreq_interactive_init);
1173 module_init(cpufreq_interactive_init);
1176 static void __exit cpufreq_interactive_exit(void)
1178 cpufreq_unregister_governor(&cpufreq_gov_interactive);
1179 kthread_stop(speedchange_task);
1180 put_task_struct(speedchange_task);
1183 module_exit(cpufreq_interactive_exit);
1185 MODULE_AUTHOR("Mike Chan <mike@android.com>");
1186 MODULE_DESCRIPTION("'cpufreq_interactive' - A cpufreq governor for "
1187 "Latency sensitive workloads");
1188 MODULE_LICENSE("GPL");