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
);