1 // SPDX-License-Identifier: GPL-2.0
3 * CPUFreq governor based on scheduler-provided CPU utilization data.
5 * Copyright (C) 2016, Intel Corporation
6 * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13 #include <linux/sched/cpufreq.h>
14 #include <trace/events/power.h>
16 #define IOWAIT_BOOST_MIN (SCHED_CAPACITY_SCALE / 8)
18 struct sugov_tunables {
19 struct gov_attr_set attr_set;
20 unsigned int rate_limit_us;
24 struct cpufreq_policy *policy;
26 struct sugov_tunables *tunables;
27 struct list_head tunables_hook;
29 raw_spinlock_t update_lock; /* For shared policies */
30 u64 last_freq_update_time;
31 s64 freq_update_delay_ns;
32 unsigned int next_freq;
33 unsigned int cached_raw_freq;
35 /* The next fields are only needed if fast switch cannot be used: */
36 struct irq_work irq_work;
37 struct kthread_work work;
38 struct mutex work_lock;
39 struct kthread_worker worker;
40 struct task_struct *thread;
41 bool work_in_progress;
43 bool need_freq_update;
47 struct update_util_data update_util;
48 struct sugov_policy *sg_policy;
51 bool iowait_boost_pending;
52 unsigned int iowait_boost;
58 /* The field below is for single-CPU policies only: */
59 #ifdef CONFIG_NO_HZ_COMMON
60 unsigned long saved_idle_calls;
64 static DEFINE_PER_CPU(struct sugov_cpu, sugov_cpu);
66 /************************ Governor internals ***********************/
68 static bool sugov_should_update_freq(struct sugov_policy *sg_policy, u64 time)
73 * Since cpufreq_update_util() is called with rq->lock held for
74 * the @target_cpu, our per-CPU data is fully serialized.
76 * However, drivers cannot in general deal with cross-CPU
77 * requests, so while get_next_freq() will work, our
78 * sugov_update_commit() call may not for the fast switching platforms.
80 * Hence stop here for remote requests if they aren't supported
81 * by the hardware, as calculating the frequency is pointless if
82 * we cannot in fact act on it.
84 * For the slow switching platforms, the kthread is always scheduled on
85 * the right set of CPUs and any CPU can find the next frequency and
86 * schedule the kthread.
88 if (sg_policy->policy->fast_switch_enabled &&
89 !cpufreq_this_cpu_can_update(sg_policy->policy))
92 if (unlikely(sg_policy->need_freq_update))
95 delta_ns = time - sg_policy->last_freq_update_time;
97 return delta_ns >= sg_policy->freq_update_delay_ns;
100 static bool sugov_update_next_freq(struct sugov_policy *sg_policy, u64 time,
101 unsigned int next_freq)
103 if (sg_policy->next_freq == next_freq)
106 sg_policy->next_freq = next_freq;
107 sg_policy->last_freq_update_time = time;
112 static void sugov_fast_switch(struct sugov_policy *sg_policy, u64 time,
113 unsigned int next_freq)
115 struct cpufreq_policy *policy = sg_policy->policy;
117 if (!sugov_update_next_freq(sg_policy, time, next_freq))
120 next_freq = cpufreq_driver_fast_switch(policy, next_freq);
124 policy->cur = next_freq;
125 trace_cpu_frequency(next_freq, smp_processor_id());
128 static void sugov_deferred_update(struct sugov_policy *sg_policy, u64 time,
129 unsigned int next_freq)
131 if (!sugov_update_next_freq(sg_policy, time, next_freq))
134 if (!sg_policy->work_in_progress) {
135 sg_policy->work_in_progress = true;
136 irq_work_queue(&sg_policy->irq_work);
141 * get_next_freq - Compute a new frequency for a given cpufreq policy.
142 * @sg_policy: schedutil policy object to compute the new frequency for.
143 * @util: Current CPU utilization.
144 * @max: CPU capacity.
146 * If the utilization is frequency-invariant, choose the new frequency to be
147 * proportional to it, that is
149 * next_freq = C * max_freq * util / max
151 * Otherwise, approximate the would-be frequency-invariant utilization by
152 * util_raw * (curr_freq / max_freq) which leads to
154 * next_freq = C * curr_freq * util_raw / max
156 * Take C = 1.25 for the frequency tipping point at (util / max) = 0.8.
158 * The lowest driver-supported frequency which is equal or greater than the raw
159 * next_freq (as calculated above) is returned, subject to policy min/max and
160 * cpufreq driver limitations.
162 static unsigned int get_next_freq(struct sugov_policy *sg_policy,
163 unsigned long util, unsigned long max)
165 struct cpufreq_policy *policy = sg_policy->policy;
166 unsigned int freq = arch_scale_freq_invariant() ?
167 policy->cpuinfo.max_freq : policy->cur;
169 freq = map_util_freq(util, freq, max);
171 if (freq == sg_policy->cached_raw_freq && !sg_policy->need_freq_update)
172 return sg_policy->next_freq;
174 sg_policy->need_freq_update = false;
175 sg_policy->cached_raw_freq = freq;
176 return cpufreq_driver_resolve_freq(policy, freq);
180 * This function computes an effective utilization for the given CPU, to be
181 * used for frequency selection given the linear relation: f = u * f_max.
183 * The scheduler tracks the following metrics:
185 * cpu_util_{cfs,rt,dl,irq}()
188 * Where the cfs,rt and dl util numbers are tracked with the same metric and
189 * synchronized windows and are thus directly comparable.
191 * The cfs,rt,dl utilization are the running times measured with rq->clock_task
192 * which excludes things like IRQ and steal-time. These latter are then accrued
193 * in the irq utilization.
195 * The DL bandwidth number otoh is not a measured metric but a value computed
196 * based on the task model parameters and gives the minimal utilization
197 * required to meet deadlines.
199 unsigned long schedutil_cpu_util(int cpu, unsigned long util_cfs,
200 unsigned long max, enum schedutil_type type,
201 struct task_struct *p)
203 unsigned long dl_util, util, irq;
204 struct rq *rq = cpu_rq(cpu);
206 if (!IS_BUILTIN(CONFIG_UCLAMP_TASK) &&
207 type == FREQUENCY_UTIL && rt_rq_is_runnable(&rq->rt)) {
212 * Early check to see if IRQ/steal time saturates the CPU, can be
213 * because of inaccuracies in how we track these -- see
214 * update_irq_load_avg().
216 irq = cpu_util_irq(rq);
217 if (unlikely(irq >= max))
221 * Because the time spend on RT/DL tasks is visible as 'lost' time to
222 * CFS tasks and we use the same metric to track the effective
223 * utilization (PELT windows are synchronized) we can directly add them
224 * to obtain the CPU's actual utilization.
226 * CFS and RT utilization can be boosted or capped, depending on
227 * utilization clamp constraints requested by currently RUNNABLE
229 * When there are no CFS RUNNABLE tasks, clamps are released and
230 * frequency will be gracefully reduced with the utilization decay.
232 util = util_cfs + cpu_util_rt(rq);
233 if (type == FREQUENCY_UTIL)
234 util = uclamp_util_with(rq, util, p);
236 dl_util = cpu_util_dl(rq);
239 * For frequency selection we do not make cpu_util_dl() a permanent part
240 * of this sum because we want to use cpu_bw_dl() later on, but we need
241 * to check if the CFS+RT+DL sum is saturated (ie. no idle time) such
242 * that we select f_max when there is no idle time.
244 * NOTE: numerical errors or stop class might cause us to not quite hit
245 * saturation when we should -- something for later.
247 if (util + dl_util >= max)
251 * OTOH, for energy computation we need the estimated running time, so
252 * include util_dl and ignore dl_bw.
254 if (type == ENERGY_UTIL)
258 * There is still idle time; further improve the number by using the
259 * irq metric. Because IRQ/steal time is hidden from the task clock we
260 * need to scale the task numbers:
263 * U' = irq + ------- * U
266 util = scale_irq_capacity(util, irq, max);
270 * Bandwidth required by DEADLINE must always be granted while, for
271 * FAIR and RT, we use blocked utilization of IDLE CPUs as a mechanism
272 * to gracefully reduce the frequency when no tasks show up for longer
275 * Ideally we would like to set bw_dl as min/guaranteed freq and util +
276 * bw_dl as requested freq. However, cpufreq is not yet ready for such
277 * an interface. So, we only do the latter for now.
279 if (type == FREQUENCY_UTIL)
280 util += cpu_bw_dl(rq);
282 return min(max, util);
285 static unsigned long sugov_get_util(struct sugov_cpu *sg_cpu)
287 struct rq *rq = cpu_rq(sg_cpu->cpu);
288 unsigned long util = cpu_util_cfs(rq);
289 unsigned long max = arch_scale_cpu_capacity(sg_cpu->cpu);
292 sg_cpu->bw_dl = cpu_bw_dl(rq);
294 return schedutil_cpu_util(sg_cpu->cpu, util, max, FREQUENCY_UTIL, NULL);
298 * sugov_iowait_reset() - Reset the IO boost status of a CPU.
299 * @sg_cpu: the sugov data for the CPU to boost
300 * @time: the update time from the caller
301 * @set_iowait_boost: true if an IO boost has been requested
303 * The IO wait boost of a task is disabled after a tick since the last update
304 * of a CPU. If a new IO wait boost is requested after more then a tick, then
305 * we enable the boost starting from IOWAIT_BOOST_MIN, which improves energy
306 * efficiency by ignoring sporadic wakeups from IO.
308 static bool sugov_iowait_reset(struct sugov_cpu *sg_cpu, u64 time,
309 bool set_iowait_boost)
311 s64 delta_ns = time - sg_cpu->last_update;
313 /* Reset boost only if a tick has elapsed since last request */
314 if (delta_ns <= TICK_NSEC)
317 sg_cpu->iowait_boost = set_iowait_boost ? IOWAIT_BOOST_MIN : 0;
318 sg_cpu->iowait_boost_pending = set_iowait_boost;
324 * sugov_iowait_boost() - Updates the IO boost status of a CPU.
325 * @sg_cpu: the sugov data for the CPU to boost
326 * @time: the update time from the caller
327 * @flags: SCHED_CPUFREQ_IOWAIT if the task is waking up after an IO wait
329 * Each time a task wakes up after an IO operation, the CPU utilization can be
330 * boosted to a certain utilization which doubles at each "frequent and
331 * successive" wakeup from IO, ranging from IOWAIT_BOOST_MIN to the utilization
332 * of the maximum OPP.
334 * To keep doubling, an IO boost has to be requested at least once per tick,
335 * otherwise we restart from the utilization of the minimum OPP.
337 static void sugov_iowait_boost(struct sugov_cpu *sg_cpu, u64 time,
340 bool set_iowait_boost = flags & SCHED_CPUFREQ_IOWAIT;
342 /* Reset boost if the CPU appears to have been idle enough */
343 if (sg_cpu->iowait_boost &&
344 sugov_iowait_reset(sg_cpu, time, set_iowait_boost))
347 /* Boost only tasks waking up after IO */
348 if (!set_iowait_boost)
351 /* Ensure boost doubles only one time at each request */
352 if (sg_cpu->iowait_boost_pending)
354 sg_cpu->iowait_boost_pending = true;
356 /* Double the boost at each request */
357 if (sg_cpu->iowait_boost) {
358 sg_cpu->iowait_boost =
359 min_t(unsigned int, sg_cpu->iowait_boost << 1, SCHED_CAPACITY_SCALE);
363 /* First wakeup after IO: start with minimum boost */
364 sg_cpu->iowait_boost = IOWAIT_BOOST_MIN;
368 * sugov_iowait_apply() - Apply the IO boost to a CPU.
369 * @sg_cpu: the sugov data for the cpu to boost
370 * @time: the update time from the caller
371 * @util: the utilization to (eventually) boost
372 * @max: the maximum value the utilization can be boosted to
374 * A CPU running a task which woken up after an IO operation can have its
375 * utilization boosted to speed up the completion of those IO operations.
376 * The IO boost value is increased each time a task wakes up from IO, in
377 * sugov_iowait_apply(), and it's instead decreased by this function,
378 * each time an increase has not been requested (!iowait_boost_pending).
380 * A CPU which also appears to have been idle for at least one tick has also
381 * its IO boost utilization reset.
383 * This mechanism is designed to boost high frequently IO waiting tasks, while
384 * being more conservative on tasks which does sporadic IO operations.
386 static unsigned long sugov_iowait_apply(struct sugov_cpu *sg_cpu, u64 time,
387 unsigned long util, unsigned long max)
391 /* No boost currently required */
392 if (!sg_cpu->iowait_boost)
395 /* Reset boost if the CPU appears to have been idle enough */
396 if (sugov_iowait_reset(sg_cpu, time, false))
399 if (!sg_cpu->iowait_boost_pending) {
401 * No boost pending; reduce the boost value.
403 sg_cpu->iowait_boost >>= 1;
404 if (sg_cpu->iowait_boost < IOWAIT_BOOST_MIN) {
405 sg_cpu->iowait_boost = 0;
410 sg_cpu->iowait_boost_pending = false;
413 * @util is already in capacity scale; convert iowait_boost
414 * into the same scale so we can compare.
416 boost = (sg_cpu->iowait_boost * max) >> SCHED_CAPACITY_SHIFT;
417 return max(boost, util);
420 #ifdef CONFIG_NO_HZ_COMMON
421 static bool sugov_cpu_is_busy(struct sugov_cpu *sg_cpu)
423 unsigned long idle_calls = tick_nohz_get_idle_calls_cpu(sg_cpu->cpu);
424 bool ret = idle_calls == sg_cpu->saved_idle_calls;
426 sg_cpu->saved_idle_calls = idle_calls;
430 static inline bool sugov_cpu_is_busy(struct sugov_cpu *sg_cpu) { return false; }
431 #endif /* CONFIG_NO_HZ_COMMON */
434 * Make sugov_should_update_freq() ignore the rate limit when DL
435 * has increased the utilization.
437 static inline void ignore_dl_rate_limit(struct sugov_cpu *sg_cpu, struct sugov_policy *sg_policy)
439 if (cpu_bw_dl(cpu_rq(sg_cpu->cpu)) > sg_cpu->bw_dl)
440 sg_policy->need_freq_update = true;
443 static void sugov_update_single(struct update_util_data *hook, u64 time,
446 struct sugov_cpu *sg_cpu = container_of(hook, struct sugov_cpu, update_util);
447 struct sugov_policy *sg_policy = sg_cpu->sg_policy;
448 unsigned long util, max;
452 sugov_iowait_boost(sg_cpu, time, flags);
453 sg_cpu->last_update = time;
455 ignore_dl_rate_limit(sg_cpu, sg_policy);
457 if (!sugov_should_update_freq(sg_policy, time))
460 busy = sugov_cpu_is_busy(sg_cpu);
462 util = sugov_get_util(sg_cpu);
464 util = sugov_iowait_apply(sg_cpu, time, util, max);
465 next_f = get_next_freq(sg_policy, util, max);
467 * Do not reduce the frequency if the CPU has not been idle
468 * recently, as the reduction is likely to be premature then.
470 if (busy && next_f < sg_policy->next_freq) {
471 next_f = sg_policy->next_freq;
473 /* Reset cached freq as next_freq has changed */
474 sg_policy->cached_raw_freq = 0;
478 * This code runs under rq->lock for the target CPU, so it won't run
479 * concurrently on two different CPUs for the same target and it is not
480 * necessary to acquire the lock in the fast switch case.
482 if (sg_policy->policy->fast_switch_enabled) {
483 sugov_fast_switch(sg_policy, time, next_f);
485 raw_spin_lock(&sg_policy->update_lock);
486 sugov_deferred_update(sg_policy, time, next_f);
487 raw_spin_unlock(&sg_policy->update_lock);
491 static unsigned int sugov_next_freq_shared(struct sugov_cpu *sg_cpu, u64 time)
493 struct sugov_policy *sg_policy = sg_cpu->sg_policy;
494 struct cpufreq_policy *policy = sg_policy->policy;
495 unsigned long util = 0, max = 1;
498 for_each_cpu(j, policy->cpus) {
499 struct sugov_cpu *j_sg_cpu = &per_cpu(sugov_cpu, j);
500 unsigned long j_util, j_max;
502 j_util = sugov_get_util(j_sg_cpu);
503 j_max = j_sg_cpu->max;
504 j_util = sugov_iowait_apply(j_sg_cpu, time, j_util, j_max);
506 if (j_util * max > j_max * util) {
512 return get_next_freq(sg_policy, util, max);
516 sugov_update_shared(struct update_util_data *hook, u64 time, unsigned int flags)
518 struct sugov_cpu *sg_cpu = container_of(hook, struct sugov_cpu, update_util);
519 struct sugov_policy *sg_policy = sg_cpu->sg_policy;
522 raw_spin_lock(&sg_policy->update_lock);
524 sugov_iowait_boost(sg_cpu, time, flags);
525 sg_cpu->last_update = time;
527 ignore_dl_rate_limit(sg_cpu, sg_policy);
529 if (sugov_should_update_freq(sg_policy, time)) {
530 next_f = sugov_next_freq_shared(sg_cpu, time);
532 if (sg_policy->policy->fast_switch_enabled)
533 sugov_fast_switch(sg_policy, time, next_f);
535 sugov_deferred_update(sg_policy, time, next_f);
538 raw_spin_unlock(&sg_policy->update_lock);
541 static void sugov_work(struct kthread_work *work)
543 struct sugov_policy *sg_policy = container_of(work, struct sugov_policy, work);
548 * Hold sg_policy->update_lock shortly to handle the case where:
549 * incase sg_policy->next_freq is read here, and then updated by
550 * sugov_deferred_update() just before work_in_progress is set to false
551 * here, we may miss queueing the new update.
553 * Note: If a work was queued after the update_lock is released,
554 * sugov_work() will just be called again by kthread_work code; and the
555 * request will be proceed before the sugov thread sleeps.
557 raw_spin_lock_irqsave(&sg_policy->update_lock, flags);
558 freq = sg_policy->next_freq;
559 sg_policy->work_in_progress = false;
560 raw_spin_unlock_irqrestore(&sg_policy->update_lock, flags);
562 mutex_lock(&sg_policy->work_lock);
563 __cpufreq_driver_target(sg_policy->policy, freq, CPUFREQ_RELATION_L);
564 mutex_unlock(&sg_policy->work_lock);
567 static void sugov_irq_work(struct irq_work *irq_work)
569 struct sugov_policy *sg_policy;
571 sg_policy = container_of(irq_work, struct sugov_policy, irq_work);
573 kthread_queue_work(&sg_policy->worker, &sg_policy->work);
576 /************************** sysfs interface ************************/
578 static struct sugov_tunables *global_tunables;
579 static DEFINE_MUTEX(global_tunables_lock);
581 static inline struct sugov_tunables *to_sugov_tunables(struct gov_attr_set *attr_set)
583 return container_of(attr_set, struct sugov_tunables, attr_set);
586 static ssize_t rate_limit_us_show(struct gov_attr_set *attr_set, char *buf)
588 struct sugov_tunables *tunables = to_sugov_tunables(attr_set);
590 return sprintf(buf, "%u\n", tunables->rate_limit_us);
594 rate_limit_us_store(struct gov_attr_set *attr_set, const char *buf, size_t count)
596 struct sugov_tunables *tunables = to_sugov_tunables(attr_set);
597 struct sugov_policy *sg_policy;
598 unsigned int rate_limit_us;
600 if (kstrtouint(buf, 10, &rate_limit_us))
603 tunables->rate_limit_us = rate_limit_us;
605 list_for_each_entry(sg_policy, &attr_set->policy_list, tunables_hook)
606 sg_policy->freq_update_delay_ns = rate_limit_us * NSEC_PER_USEC;
611 static struct governor_attr rate_limit_us = __ATTR_RW(rate_limit_us);
613 static struct attribute *sugov_attrs[] = {
617 ATTRIBUTE_GROUPS(sugov);
619 static struct kobj_type sugov_tunables_ktype = {
620 .default_groups = sugov_groups,
621 .sysfs_ops = &governor_sysfs_ops,
624 /********************** cpufreq governor interface *********************/
626 struct cpufreq_governor schedutil_gov;
628 static struct sugov_policy *sugov_policy_alloc(struct cpufreq_policy *policy)
630 struct sugov_policy *sg_policy;
632 sg_policy = kzalloc(sizeof(*sg_policy), GFP_KERNEL);
636 sg_policy->policy = policy;
637 raw_spin_lock_init(&sg_policy->update_lock);
641 static void sugov_policy_free(struct sugov_policy *sg_policy)
646 static int sugov_kthread_create(struct sugov_policy *sg_policy)
648 struct task_struct *thread;
649 struct sched_attr attr = {
650 .size = sizeof(struct sched_attr),
651 .sched_policy = SCHED_DEADLINE,
652 .sched_flags = SCHED_FLAG_SUGOV,
656 * Fake (unused) bandwidth; workaround to "fix"
657 * priority inheritance.
659 .sched_runtime = 1000000,
660 .sched_deadline = 10000000,
661 .sched_period = 10000000,
663 struct cpufreq_policy *policy = sg_policy->policy;
666 /* kthread only required for slow path */
667 if (policy->fast_switch_enabled)
670 kthread_init_work(&sg_policy->work, sugov_work);
671 kthread_init_worker(&sg_policy->worker);
672 thread = kthread_create(kthread_worker_fn, &sg_policy->worker,
674 cpumask_first(policy->related_cpus));
675 if (IS_ERR(thread)) {
676 pr_err("failed to create sugov thread: %ld\n", PTR_ERR(thread));
677 return PTR_ERR(thread);
680 ret = sched_setattr_nocheck(thread, &attr);
682 kthread_stop(thread);
683 pr_warn("%s: failed to set SCHED_DEADLINE\n", __func__);
687 sg_policy->thread = thread;
688 kthread_bind_mask(thread, policy->related_cpus);
689 init_irq_work(&sg_policy->irq_work, sugov_irq_work);
690 mutex_init(&sg_policy->work_lock);
692 wake_up_process(thread);
697 static void sugov_kthread_stop(struct sugov_policy *sg_policy)
699 /* kthread only required for slow path */
700 if (sg_policy->policy->fast_switch_enabled)
703 kthread_flush_worker(&sg_policy->worker);
704 kthread_stop(sg_policy->thread);
705 mutex_destroy(&sg_policy->work_lock);
708 static struct sugov_tunables *sugov_tunables_alloc(struct sugov_policy *sg_policy)
710 struct sugov_tunables *tunables;
712 tunables = kzalloc(sizeof(*tunables), GFP_KERNEL);
714 gov_attr_set_init(&tunables->attr_set, &sg_policy->tunables_hook);
715 if (!have_governor_per_policy())
716 global_tunables = tunables;
721 static void sugov_tunables_free(struct sugov_tunables *tunables)
723 if (!have_governor_per_policy())
724 global_tunables = NULL;
729 static int sugov_init(struct cpufreq_policy *policy)
731 struct sugov_policy *sg_policy;
732 struct sugov_tunables *tunables;
735 /* State should be equivalent to EXIT */
736 if (policy->governor_data)
739 cpufreq_enable_fast_switch(policy);
741 sg_policy = sugov_policy_alloc(policy);
744 goto disable_fast_switch;
747 ret = sugov_kthread_create(sg_policy);
751 mutex_lock(&global_tunables_lock);
753 if (global_tunables) {
754 if (WARN_ON(have_governor_per_policy())) {
758 policy->governor_data = sg_policy;
759 sg_policy->tunables = global_tunables;
761 gov_attr_set_get(&global_tunables->attr_set, &sg_policy->tunables_hook);
765 tunables = sugov_tunables_alloc(sg_policy);
771 tunables->rate_limit_us = cpufreq_policy_transition_delay_us(policy);
773 policy->governor_data = sg_policy;
774 sg_policy->tunables = tunables;
776 ret = kobject_init_and_add(&tunables->attr_set.kobj, &sugov_tunables_ktype,
777 get_governor_parent_kobj(policy), "%s",
783 mutex_unlock(&global_tunables_lock);
787 kobject_put(&tunables->attr_set.kobj);
788 policy->governor_data = NULL;
789 sugov_tunables_free(tunables);
792 sugov_kthread_stop(sg_policy);
793 mutex_unlock(&global_tunables_lock);
796 sugov_policy_free(sg_policy);
799 cpufreq_disable_fast_switch(policy);
801 pr_err("initialization failed (error %d)\n", ret);
805 static void sugov_exit(struct cpufreq_policy *policy)
807 struct sugov_policy *sg_policy = policy->governor_data;
808 struct sugov_tunables *tunables = sg_policy->tunables;
811 mutex_lock(&global_tunables_lock);
813 count = gov_attr_set_put(&tunables->attr_set, &sg_policy->tunables_hook);
814 policy->governor_data = NULL;
816 sugov_tunables_free(tunables);
818 mutex_unlock(&global_tunables_lock);
820 sugov_kthread_stop(sg_policy);
821 sugov_policy_free(sg_policy);
822 cpufreq_disable_fast_switch(policy);
825 static int sugov_start(struct cpufreq_policy *policy)
827 struct sugov_policy *sg_policy = policy->governor_data;
830 sg_policy->freq_update_delay_ns = sg_policy->tunables->rate_limit_us * NSEC_PER_USEC;
831 sg_policy->last_freq_update_time = 0;
832 sg_policy->next_freq = 0;
833 sg_policy->work_in_progress = false;
834 sg_policy->need_freq_update = false;
835 sg_policy->cached_raw_freq = 0;
837 for_each_cpu(cpu, policy->cpus) {
838 struct sugov_cpu *sg_cpu = &per_cpu(sugov_cpu, cpu);
840 memset(sg_cpu, 0, sizeof(*sg_cpu));
842 sg_cpu->sg_policy = sg_policy;
845 for_each_cpu(cpu, policy->cpus) {
846 struct sugov_cpu *sg_cpu = &per_cpu(sugov_cpu, cpu);
848 cpufreq_add_update_util_hook(cpu, &sg_cpu->update_util,
849 policy_is_shared(policy) ?
850 sugov_update_shared :
851 sugov_update_single);
856 static void sugov_stop(struct cpufreq_policy *policy)
858 struct sugov_policy *sg_policy = policy->governor_data;
861 for_each_cpu(cpu, policy->cpus)
862 cpufreq_remove_update_util_hook(cpu);
866 if (!policy->fast_switch_enabled) {
867 irq_work_sync(&sg_policy->irq_work);
868 kthread_cancel_work_sync(&sg_policy->work);
872 static void sugov_limits(struct cpufreq_policy *policy)
874 struct sugov_policy *sg_policy = policy->governor_data;
876 if (!policy->fast_switch_enabled) {
877 mutex_lock(&sg_policy->work_lock);
878 cpufreq_policy_apply_limits(policy);
879 mutex_unlock(&sg_policy->work_lock);
882 sg_policy->need_freq_update = true;
885 struct cpufreq_governor schedutil_gov = {
887 .owner = THIS_MODULE,
888 .dynamic_switching = true,
891 .start = sugov_start,
893 .limits = sugov_limits,
896 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_SCHEDUTIL
897 struct cpufreq_governor *cpufreq_default_governor(void)
899 return &schedutil_gov;
903 static int __init sugov_register(void)
905 return cpufreq_register_governor(&schedutil_gov);
907 fs_initcall(sugov_register);
909 #ifdef CONFIG_ENERGY_MODEL
910 extern bool sched_energy_update;
911 extern struct mutex sched_energy_mutex;
913 static void rebuild_sd_workfn(struct work_struct *work)
915 mutex_lock(&sched_energy_mutex);
916 sched_energy_update = true;
917 rebuild_sched_domains();
918 sched_energy_update = false;
919 mutex_unlock(&sched_energy_mutex);
921 static DECLARE_WORK(rebuild_sd_work, rebuild_sd_workfn);
924 * EAS shouldn't be attempted without sugov, so rebuild the sched_domains
925 * on governor changes to make sure the scheduler knows about it.
927 void sched_cpufreq_governor_change(struct cpufreq_policy *policy,
928 struct cpufreq_governor *old_gov)
930 if (old_gov == &schedutil_gov || policy->governor == &schedutil_gov) {
932 * When called from the cpufreq_register_driver() path, the
933 * cpu_hotplug_lock is already held, so use a work item to
934 * avoid nested locking in rebuild_sched_domains().
936 schedule_work(&rebuild_sd_work);