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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0
 /*
  * CPUFreq governor based on scheduler-provided CPU utilization data.
  *
  * Copyright (C) 2016, Intel Corporation
  * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
  */
 
 #define IOWAIT_BOOST_MIN    (SCHED_CAPACITY_SCALE / 8)
 
 struct sugov_tunables {
     struct gov_attr_set attr_set;
     unsigned int        rate_limit_us;
 };
 
 struct sugov_policy {
     struct cpufreq_policy   *policy;
 
     struct sugov_tunables   *tunables;
     struct list_head    tunables_hook;
 
     raw_spinlock_t      update_lock;
     u64         last_freq_update_time;
     s64         freq_update_delay_ns;
     unsigned int        next_freq;
     unsigned int        cached_raw_freq;
 
     /* The next fields are only needed if fast switch cannot be used: */
     struct          irq_work irq_work;
     struct          kthread_work work;
     struct          mutex work_lock;
     struct          kthread_worker worker;
     struct task_struct  *thread;
     bool            work_in_progress;
 
     bool            limits_changed;
     bool            need_freq_update;
 };
 
 struct sugov_cpu {
     struct update_util_data update_util;
     struct sugov_policy *sg_policy;
     unsigned int        cpu;
 
     bool            iowait_boost_pending;
     unsigned int        iowait_boost;
     u64         last_update;
 
     unsigned long       util;
     unsigned long       bw_dl;
     unsigned long       max;
 
     /* The field below is for single-CPU policies only: */
 #ifdef CONFIG_NO_HZ_COMMON
     unsigned long       saved_idle_calls;
 #endif
 };
 
 static DEFINE_PER_CPU(struct sugov_cpu, sugov_cpu);
 
 /************************ Governor internals ***********************/
 
 static bool sugov_should_update_freq(struct sugov_policy *sg_policy, u64 time)
 {
     s64 delta_ns;
 
     /*
      * Since cpufreq_update_util() is called with rq->lock held for
      * the @target_cpu, our per-CPU data is fully serialized.
      *
      * However, drivers cannot in general deal with cross-CPU
      * requests, so while get_next_freq() will work, our
      * sugov_update_commit() call may not for the fast switching platforms.
      *
      * Hence stop here for remote requests if they aren't supported
      * by the hardware, as calculating the frequency is pointless if
      * we cannot in fact act on it.
      *
      * This is needed on the slow switching platforms too to prevent CPUs
      * going offline from leaving stale IRQ work items behind.
      */
     if (!cpufreq_this_cpu_can_update(sg_policy->policy))
         return false;
 
     if (unlikely(sg_policy->limits_changed)) {
         sg_policy->limits_changed = false;
         sg_policy->need_freq_update = true;
         return true;
     }
 
     delta_ns = time - sg_policy->last_freq_update_time;
 
     return delta_ns >= sg_policy->freq_update_delay_ns;
 }
 
 static bool sugov_update_next_freq(struct sugov_policy *sg_policy, u64 time,
                    unsigned int next_freq)
 {
     if (sg_policy->need_freq_update)
         sg_policy->need_freq_update = cpufreq_driver_test_flags(CPUFREQ_NEED_UPDATE_LIMITS);
     else if (sg_policy->next_freq == next_freq)
         return false;
 
     sg_policy->next_freq = next_freq;
     sg_policy->last_freq_update_time = time;
 
     return true;
 }
 
 static void sugov_deferred_update(struct sugov_policy *sg_policy)
 {
     if (!sg_policy->work_in_progress) {
         sg_policy->work_in_progress = true;
         irq_work_queue(&sg_policy->irq_work);
     }
 }
 
 /**
  * get_next_freq - Compute a new frequency for a given cpufreq policy.
  * @sg_policy: schedutil policy object to compute the new frequency for.
  * @util: Current CPU utilization.
  * @max: CPU capacity.
  *
  * If the utilization is frequency-invariant, choose the new frequency to be
  * proportional to it, that is
  *
  * next_freq = C * max_freq * util / max
  *
  * Otherwise, approximate the would-be frequency-invariant utilization by
  * util_raw * (curr_freq / max_freq) which leads to
  *
  * next_freq = C * curr_freq * util_raw / max
  *
  * Take C = 1.25 for the frequency tipping point at (util / max) = 0.8.
  *
  * The lowest driver-supported frequency which is equal or greater than the raw
  * next_freq (as calculated above) is returned, subject to policy min/max and
  * cpufreq driver limitations.
  */
 static unsigned int get_next_freq(struct sugov_policy *sg_policy,
                   unsigned long util, unsigned long max)
 {
     struct cpufreq_policy *policy = sg_policy->policy;
     unsigned int freq = arch_scale_freq_invariant() ?
                 policy->cpuinfo.max_freq : policy->cur;
 
     util = map_util_perf(util);
     freq = map_util_freq(util, freq, max);
 
     if (freq == sg_policy->cached_raw_freq && !sg_policy->need_freq_update)
         return sg_policy->next_freq;
 
     sg_policy->cached_raw_freq = freq;
     return cpufreq_driver_resolve_freq(policy, freq);
 }
 
 static void sugov_get_util(struct sugov_cpu *sg_cpu)
 {
     struct rq *rq = cpu_rq(sg_cpu->cpu);
 
     sg_cpu->max = arch_scale_cpu_capacity(sg_cpu->cpu);
     sg_cpu->bw_dl = cpu_bw_dl(rq);
     sg_cpu->util = effective_cpu_util(sg_cpu->cpu, cpu_util_cfs(sg_cpu->cpu),
                       FREQUENCY_UTIL, NULL);
 }
 
 /**
  * sugov_iowait_reset() - Reset the IO boost status of a CPU.
  * @sg_cpu: the sugov data for the CPU to boost
  * @time: the update time from the caller
  * @set_iowait_boost: true if an IO boost has been requested
  *
  * The IO wait boost of a task is disabled after a tick since the last update
  * of a CPU. If a new IO wait boost is requested after more then a tick, then
  * we enable the boost starting from IOWAIT_BOOST_MIN, which improves energy
  * efficiency by ignoring sporadic wakeups from IO.
  */
 static bool sugov_iowait_reset(struct sugov_cpu *sg_cpu, u64 time,
                    bool set_iowait_boost)
 {
     s64 delta_ns = time - sg_cpu->last_update;
 
     /* Reset boost only if a tick has elapsed since last request */
     if (delta_ns <= TICK_NSEC)
         return false;
 
     sg_cpu->iowait_boost = set_iowait_boost ? IOWAIT_BOOST_MIN : 0;
     sg_cpu->iowait_boost_pending = set_iowait_boost;
 
     return true;
 }
 
 /**
  * sugov_iowait_boost() - Updates the IO boost status of a CPU.
  * @sg_cpu: the sugov data for the CPU to boost
  * @time: the update time from the caller
  * @flags: SCHED_CPUFREQ_IOWAIT if the task is waking up after an IO wait
  *
  * Each time a task wakes up after an IO operation, the CPU utilization can be
  * boosted to a certain utilization which doubles at each "frequent and
  * successive" wakeup from IO, ranging from IOWAIT_BOOST_MIN to the utilization
  * of the maximum OPP.
  *
  * To keep doubling, an IO boost has to be requested at least once per tick,
  * otherwise we restart from the utilization of the minimum OPP.
  */
 static void sugov_iowait_boost(struct sugov_cpu *sg_cpu, u64 time,
                    unsigned int flags)
 {
     bool set_iowait_boost = flags & SCHED_CPUFREQ_IOWAIT;
 
     /* Reset boost if the CPU appears to have been idle enough */
     if (sg_cpu->iowait_boost &&
         sugov_iowait_reset(sg_cpu, time, set_iowait_boost))
         return;
 
     /* Boost only tasks waking up after IO */
     if (!set_iowait_boost)
         return;
 
     /* Ensure boost doubles only one time at each request */
     if (sg_cpu->iowait_boost_pending)
         return;
     sg_cpu->iowait_boost_pending = true;
 
     /* Double the boost at each request */
     if (sg_cpu->iowait_boost) {
         sg_cpu->iowait_boost =
             min_t(unsigned int, sg_cpu->iowait_boost << 1, SCHED_CAPACITY_SCALE);
         return;
     }
 
     /* First wakeup after IO: start with minimum boost */
     sg_cpu->iowait_boost = IOWAIT_BOOST_MIN;
 }
 
 /**
  * sugov_iowait_apply() - Apply the IO boost to a CPU.
  * @sg_cpu: the sugov data for the cpu to boost
  * @time: the update time from the caller
  *
  * A CPU running a task which woken up after an IO operation can have its
  * utilization boosted to speed up the completion of those IO operations.
  * The IO boost value is increased each time a task wakes up from IO, in
  * sugov_iowait_apply(), and it's instead decreased by this function,
  * each time an increase has not been requested (!iowait_boost_pending).
  *
  * A CPU which also appears to have been idle for at least one tick has also
  * its IO boost utilization reset.
  *
  * This mechanism is designed to boost high frequently IO waiting tasks, while
  * being more conservative on tasks which does sporadic IO operations.
  */
 static void sugov_iowait_apply(struct sugov_cpu *sg_cpu, u64 time)
 {
     unsigned long boost;
 
     /* No boost currently required */
     if (!sg_cpu->iowait_boost)
         return;
 
     /* Reset boost if the CPU appears to have been idle enough */
     if (sugov_iowait_reset(sg_cpu, time, false))
         return;
 
     if (!sg_cpu->iowait_boost_pending) {
         /*
          * No boost pending; reduce the boost value.
          */
         sg_cpu->iowait_boost >>= 1;
         if (sg_cpu->iowait_boost < IOWAIT_BOOST_MIN) {
             sg_cpu->iowait_boost = 0;
             return;
         }
     }
 
     sg_cpu->iowait_boost_pending = false;
 
     /*
      * sg_cpu->util is already in capacity scale; convert iowait_boost
      * into the same scale so we can compare.
      */
     boost = (sg_cpu->iowait_boost * sg_cpu->max) >> SCHED_CAPACITY_SHIFT;
     boost = uclamp_rq_util_with(cpu_rq(sg_cpu->cpu), boost, NULL);
     if (sg_cpu->util < boost)
         sg_cpu->util = boost;
 }
 
 #ifdef CONFIG_NO_HZ_COMMON
 static bool sugov_cpu_is_busy(struct sugov_cpu *sg_cpu)
 {
     unsigned long idle_calls = tick_nohz_get_idle_calls_cpu(sg_cpu->cpu);
     bool ret = idle_calls == sg_cpu->saved_idle_calls;
 
     sg_cpu->saved_idle_calls = idle_calls;
     return ret;
 }
 #else
 static inline bool sugov_cpu_is_busy(struct sugov_cpu *sg_cpu) { return false; }
 #endif /* CONFIG_NO_HZ_COMMON */
 
 /*
  * Make sugov_should_update_freq() ignore the rate limit when DL
  * has increased the utilization.
  */
 static inline void ignore_dl_rate_limit(struct sugov_cpu *sg_cpu)
 {
     if (cpu_bw_dl(cpu_rq(sg_cpu->cpu)) > sg_cpu->bw_dl)
         sg_cpu->sg_policy->limits_changed = true;
 }
 
 static inline bool sugov_update_single_common(struct sugov_cpu *sg_cpu,
                           u64 time, unsigned int flags)
 {
     sugov_iowait_boost(sg_cpu, time, flags);
     sg_cpu->last_update = time;
 
     ignore_dl_rate_limit(sg_cpu);
 
     if (!sugov_should_update_freq(sg_cpu->sg_policy, time))
         return false;
 
     sugov_get_util(sg_cpu);
     sugov_iowait_apply(sg_cpu, time);
 
     return true;
 }
 
 static void sugov_update_single_freq(struct update_util_data *hook, u64 time,
                      unsigned int flags)
 {
     struct sugov_cpu *sg_cpu = container_of(hook, struct sugov_cpu, update_util);
     struct sugov_policy *sg_policy = sg_cpu->sg_policy;
     unsigned int cached_freq = sg_policy->cached_raw_freq;
     unsigned int next_f;
 
     if (!sugov_update_single_common(sg_cpu, time, flags))
         return;
 
     next_f = get_next_freq(sg_policy, sg_cpu->util, sg_cpu->max);
     /*
      * Do not reduce the frequency if the CPU has not been idle
      * recently, as the reduction is likely to be premature then.
      *
      * Except when the rq is capped by uclamp_max.
      */
     if (!uclamp_rq_is_capped(cpu_rq(sg_cpu->cpu)) &&
         sugov_cpu_is_busy(sg_cpu) && next_f < sg_policy->next_freq) {
         next_f = sg_policy->next_freq;
 
         /* Restore cached freq as next_freq has changed */
         sg_policy->cached_raw_freq = cached_freq;
     }
 
     if (!sugov_update_next_freq(sg_policy, time, next_f))
         return;
 
     /*
      * This code runs under rq->lock for the target CPU, so it won't run
      * concurrently on two different CPUs for the same target and it is not
      * necessary to acquire the lock in the fast switch case.
      */
     if (sg_policy->policy->fast_switch_enabled) {
         cpufreq_driver_fast_switch(sg_policy->policy, next_f);
     } else {
         raw_spin_lock(&sg_policy->update_lock);
         sugov_deferred_update(sg_policy);
         raw_spin_unlock(&sg_policy->update_lock);
     }
 }
 
 static void sugov_update_single_perf(struct update_util_data *hook, u64 time,
                      unsigned int flags)
 {
     struct sugov_cpu *sg_cpu = container_of(hook, struct sugov_cpu, update_util);
     unsigned long prev_util = sg_cpu->util;
 
     /*
      * Fall back to the "frequency" path if frequency invariance is not
      * supported, because the direct mapping between the utilization and
      * the performance levels depends on the frequency invariance.
      */
     if (!arch_scale_freq_invariant()) {
         sugov_update_single_freq(hook, time, flags);
         return;
     }
 
     if (!sugov_update_single_common(sg_cpu, time, flags))
         return;
 
     /*
      * Do not reduce the target performance level if the CPU has not been
      * idle recently, as the reduction is likely to be premature then.
      *
      * Except when the rq is capped by uclamp_max.
      */
     if (!uclamp_rq_is_capped(cpu_rq(sg_cpu->cpu)) &&
         sugov_cpu_is_busy(sg_cpu) && sg_cpu->util < prev_util)
         sg_cpu->util = prev_util;
 
     cpufreq_driver_adjust_perf(sg_cpu->cpu, map_util_perf(sg_cpu->bw_dl),
                    map_util_perf(sg_cpu->util), sg_cpu->max);
 
     sg_cpu->sg_policy->last_freq_update_time = time;
 }
 
 static unsigned int sugov_next_freq_shared(struct sugov_cpu *sg_cpu, u64 time)
 {
     struct sugov_policy *sg_policy = sg_cpu->sg_policy;
     struct cpufreq_policy *policy = sg_policy->policy;
     unsigned long util = 0, max = 1;
     unsigned int j;
 
     for_each_cpu(j, policy->cpus) {
         struct sugov_cpu *j_sg_cpu = &per_cpu(sugov_cpu, j);
         unsigned long j_util, j_max;
 
         sugov_get_util(j_sg_cpu);
         sugov_iowait_apply(j_sg_cpu, time);
         j_util = j_sg_cpu->util;
         j_max = j_sg_cpu->max;
 
         if (j_util * max > j_max * util) {
             util = j_util;
             max = j_max;
         }
     }
 
     return get_next_freq(sg_policy, util, max);
 }
 
 static void
 sugov_update_shared(struct update_util_data *hook, u64 time, unsigned int flags)
 {
     struct sugov_cpu *sg_cpu = container_of(hook, struct sugov_cpu, update_util);
     struct sugov_policy *sg_policy = sg_cpu->sg_policy;
     unsigned int next_f;
 
     raw_spin_lock(&sg_policy->update_lock);
 
     sugov_iowait_boost(sg_cpu, time, flags);
     sg_cpu->last_update = time;
 
     ignore_dl_rate_limit(sg_cpu);
 
     if (sugov_should_update_freq(sg_policy, time)) {
         next_f = sugov_next_freq_shared(sg_cpu, time);
 
         if (!sugov_update_next_freq(sg_policy, time, next_f))
             goto unlock;
 
         if (sg_policy->policy->fast_switch_enabled)
             cpufreq_driver_fast_switch(sg_policy->policy, next_f);
         else
             sugov_deferred_update(sg_policy);
     }
 unlock:
     raw_spin_unlock(&sg_policy->update_lock);
 }
 
 static void sugov_work(struct kthread_work *work)
 {
     struct sugov_policy *sg_policy = container_of(work, struct sugov_policy, work);
     unsigned int freq;
     unsigned long flags;
 
     /*
      * Hold sg_policy->update_lock shortly to handle the case where:
      * in case sg_policy->next_freq is read here, and then updated by
      * sugov_deferred_update() just before work_in_progress is set to false
      * here, we may miss queueing the new update.
      *
      * Note: If a work was queued after the update_lock is released,
      * sugov_work() will just be called again by kthread_work code; and the
      * request will be proceed before the sugov thread sleeps.
      */
     raw_spin_lock_irqsave(&sg_policy->update_lock, flags);
     freq = sg_policy->next_freq;
     sg_policy->work_in_progress = false;
     raw_spin_unlock_irqrestore(&sg_policy->update_lock, flags);
 
     mutex_lock(&sg_policy->work_lock);
     __cpufreq_driver_target(sg_policy->policy, freq, CPUFREQ_RELATION_L);
     mutex_unlock(&sg_policy->work_lock);
 }
 
 static void sugov_irq_work(struct irq_work *irq_work)
 {
     struct sugov_policy *sg_policy;
 
     sg_policy = container_of(irq_work, struct sugov_policy, irq_work);
 
     kthread_queue_work(&sg_policy->worker, &sg_policy->work);
 }
 
 /************************** sysfs interface ************************/
 
 static struct sugov_tunables *global_tunables;
 static DEFINE_MUTEX(global_tunables_lock);
 
 static inline struct sugov_tunables *to_sugov_tunables(struct gov_attr_set *attr_set)
 {
     return container_of(attr_set, struct sugov_tunables, attr_set);
 }
 
 static ssize_t rate_limit_us_show(struct gov_attr_set *attr_set, char *buf)
 {
     struct sugov_tunables *tunables = to_sugov_tunables(attr_set);
 
     return sprintf(buf, "%u\n", tunables->rate_limit_us);
 }
 
 static ssize_t
 rate_limit_us_store(struct gov_attr_set *attr_set, const char *buf, size_t count)
 {
     struct sugov_tunables *tunables = to_sugov_tunables(attr_set);
     struct sugov_policy *sg_policy;
     unsigned int rate_limit_us;
 
     if (kstrtouint(buf, 10, &rate_limit_us))
         return -EINVAL;
 
     tunables->rate_limit_us = rate_limit_us;
 
     list_for_each_entry(sg_policy, &attr_set->policy_list, tunables_hook)
         sg_policy->freq_update_delay_ns = rate_limit_us * NSEC_PER_USEC;
 
     return count;
 }
 
 static struct governor_attr rate_limit_us = __ATTR_RW(rate_limit_us);
 
 static struct attribute *sugov_attrs[] = {
     &rate_limit_us.attr,
     NULL
 };
 ATTRIBUTE_GROUPS(sugov);
 
 static void sugov_tunables_free(struct kobject *kobj)
 {
     struct gov_attr_set *attr_set = to_gov_attr_set(kobj);
 
     kfree(to_sugov_tunables(attr_set));
 }
 
 static struct kobj_type sugov_tunables_ktype = {
     .default_groups = sugov_groups,
     .sysfs_ops = &governor_sysfs_ops,
     .release = &sugov_tunables_free,
 };
 
 /********************** cpufreq governor interface *********************/
 
 struct cpufreq_governor schedutil_gov;
 
 static struct sugov_policy *sugov_policy_alloc(struct cpufreq_policy *policy)
 {
     struct sugov_policy *sg_policy;
 
     sg_policy = kzalloc(sizeof(*sg_policy), GFP_KERNEL);
     if (!sg_policy)
         return NULL;
 
     sg_policy->policy = policy;
     raw_spin_lock_init(&sg_policy->update_lock);
     return sg_policy;
 }
 
 static void sugov_policy_free(struct sugov_policy *sg_policy)
 {
     kfree(sg_policy);
 }
 
 static int sugov_kthread_create(struct sugov_policy *sg_policy)
 {
     struct task_struct *thread;
     struct sched_attr attr = {
         .size       = sizeof(struct sched_attr),
         .sched_policy   = SCHED_DEADLINE,
         .sched_flags    = SCHED_FLAG_SUGOV,
         .sched_nice = 0,
         .sched_priority = 0,
         /*
          * Fake (unused) bandwidth; workaround to "fix"
          * priority inheritance.
          */
         .sched_runtime  =  1000000,
         .sched_deadline = 10000000,
         .sched_period   = 10000000,
     };
     struct cpufreq_policy *policy = sg_policy->policy;
     int ret;
 
     /* kthread only required for slow path */
     if (policy->fast_switch_enabled)
         return 0;
 
     kthread_init_work(&sg_policy->work, sugov_work);
     kthread_init_worker(&sg_policy->worker);
     thread = kthread_create(kthread_worker_fn, &sg_policy->worker,
                 "sugov:%d",
                 cpumask_first(policy->related_cpus));
     if (IS_ERR(thread)) {
         pr_err("failed to create sugov thread: %ld\n", PTR_ERR(thread));
         return PTR_ERR(thread);
     }
 
     ret = sched_setattr_nocheck(thread, &attr);
     if (ret) {
         kthread_stop(thread);
         pr_warn("%s: failed to set SCHED_DEADLINE\n", __func__);
         return ret;
     }
 
     sg_policy->thread = thread;
     kthread_bind_mask(thread, policy->related_cpus);
     init_irq_work(&sg_policy->irq_work, sugov_irq_work);
     mutex_init(&sg_policy->work_lock);
 
     wake_up_process(thread);
 
     return 0;
 }
 
 static void sugov_kthread_stop(struct sugov_policy *sg_policy)
 {
     /* kthread only required for slow path */
     if (sg_policy->policy->fast_switch_enabled)
         return;
 
     kthread_flush_worker(&sg_policy->worker);
     kthread_stop(sg_policy->thread);
     mutex_destroy(&sg_policy->work_lock);
 }
 
 static struct sugov_tunables *sugov_tunables_alloc(struct sugov_policy *sg_policy)
 {
     struct sugov_tunables *tunables;
 
     tunables = kzalloc(sizeof(*tunables), GFP_KERNEL);
     if (tunables) {
         gov_attr_set_init(&tunables->attr_set, &sg_policy->tunables_hook);
         if (!have_governor_per_policy())
             global_tunables = tunables;
     }
     return tunables;
 }
 
 static void sugov_clear_global_tunables(void)
 {
     if (!have_governor_per_policy())
         global_tunables = NULL;
 }
 
 static int sugov_init(struct cpufreq_policy *policy)
 {
     struct sugov_policy *sg_policy;
     struct sugov_tunables *tunables;
     int ret = 0;
 
     /* State should be equivalent to EXIT */
     if (policy->governor_data)
         return -EBUSY;
 
     cpufreq_enable_fast_switch(policy);
 
     sg_policy = sugov_policy_alloc(policy);
     if (!sg_policy) {
         ret = -ENOMEM;
         goto disable_fast_switch;
     }
 
     ret = sugov_kthread_create(sg_policy);
     if (ret)
         goto free_sg_policy;
 
     mutex_lock(&global_tunables_lock);
 
     if (global_tunables) {
         if (WARN_ON(have_governor_per_policy())) {
             ret = -EINVAL;
             goto stop_kthread;
         }
         policy->governor_data = sg_policy;
         sg_policy->tunables = global_tunables;
 
         gov_attr_set_get(&global_tunables->attr_set, &sg_policy->tunables_hook);
         goto out;
     }
 
     tunables = sugov_tunables_alloc(sg_policy);
     if (!tunables) {
         ret = -ENOMEM;
         goto stop_kthread;
     }
 
     tunables->rate_limit_us = cpufreq_policy_transition_delay_us(policy);
 
     policy->governor_data = sg_policy;
     sg_policy->tunables = tunables;
 
     ret = kobject_init_and_add(&tunables->attr_set.kobj, &sugov_tunables_ktype,
                    get_governor_parent_kobj(policy), "%s",
                    schedutil_gov.name);
     if (ret)
         goto fail;
 
 out:
     mutex_unlock(&global_tunables_lock);
     return 0;
 
 fail:
     kobject_put(&tunables->attr_set.kobj);
     policy->governor_data = NULL;
     sugov_clear_global_tunables();
 
 stop_kthread:
     sugov_kthread_stop(sg_policy);
     mutex_unlock(&global_tunables_lock);
 
 free_sg_policy:
     sugov_policy_free(sg_policy);
 
 disable_fast_switch:
     cpufreq_disable_fast_switch(policy);
 
     pr_err("initialization failed (error %d)\n", ret);
     return ret;
 }
 
 static void sugov_exit(struct cpufreq_policy *policy)
 {
     struct sugov_policy *sg_policy = policy->governor_data;
     struct sugov_tunables *tunables = sg_policy->tunables;
     unsigned int count;
 
     mutex_lock(&global_tunables_lock);
 
     count = gov_attr_set_put(&tunables->attr_set, &sg_policy->tunables_hook);
     policy->governor_data = NULL;
     if (!count)
         sugov_clear_global_tunables();
 
     mutex_unlock(&global_tunables_lock);
 
     sugov_kthread_stop(sg_policy);
     sugov_policy_free(sg_policy);
     cpufreq_disable_fast_switch(policy);
 }
 
 static int sugov_start(struct cpufreq_policy *policy)
 {
     struct sugov_policy *sg_policy = policy->governor_data;
     void (*uu)(struct update_util_data *data, u64 time, unsigned int flags);
     unsigned int cpu;
 
     sg_policy->freq_update_delay_ns = sg_policy->tunables->rate_limit_us * NSEC_PER_USEC;
     sg_policy->last_freq_update_time    = 0;
     sg_policy->next_freq            = 0;
     sg_policy->work_in_progress     = false;
     sg_policy->limits_changed       = false;
     sg_policy->cached_raw_freq      = 0;
 
     sg_policy->need_freq_update = cpufreq_driver_test_flags(CPUFREQ_NEED_UPDATE_LIMITS);
 
     for_each_cpu(cpu, policy->cpus) {
         struct sugov_cpu *sg_cpu = &per_cpu(sugov_cpu, cpu);
 
         memset(sg_cpu, 0, sizeof(*sg_cpu));
         sg_cpu->cpu         = cpu;
         sg_cpu->sg_policy       = sg_policy;
     }
 
     if (policy_is_shared(policy))
         uu = sugov_update_shared;
     else if (policy->fast_switch_enabled && cpufreq_driver_has_adjust_perf())
         uu = sugov_update_single_perf;
     else
         uu = sugov_update_single_freq;
 
     for_each_cpu(cpu, policy->cpus) {
         struct sugov_cpu *sg_cpu = &per_cpu(sugov_cpu, cpu);
 
         cpufreq_add_update_util_hook(cpu, &sg_cpu->update_util, uu);
     }
     return 0;
 }
 
 static void sugov_stop(struct cpufreq_policy *policy)
 {
     struct sugov_policy *sg_policy = policy->governor_data;
     unsigned int cpu;
 
     for_each_cpu(cpu, policy->cpus)
         cpufreq_remove_update_util_hook(cpu);
 
     synchronize_rcu();
 
     if (!policy->fast_switch_enabled) {
         irq_work_sync(&sg_policy->irq_work);
         kthread_cancel_work_sync(&sg_policy->work);
     }
 }
 
 static void sugov_limits(struct cpufreq_policy *policy)
 {
     struct sugov_policy *sg_policy = policy->governor_data;
 
     if (!policy->fast_switch_enabled) {
         mutex_lock(&sg_policy->work_lock);
         cpufreq_policy_apply_limits(policy);
         mutex_unlock(&sg_policy->work_lock);
     }
 
     sg_policy->limits_changed = true;
 }
 
 struct cpufreq_governor schedutil_gov = {
     .name           = "schedutil",
     .owner          = THIS_MODULE,
     .flags          = CPUFREQ_GOV_DYNAMIC_SWITCHING,
     .init           = sugov_init,
     .exit           = sugov_exit,
     .start          = sugov_start,
     .stop           = sugov_stop,
     .limits         = sugov_limits,
 };
 
 #ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_SCHEDUTIL
 struct cpufreq_governor *cpufreq_default_governor(void)
 {
     return &schedutil_gov;
 }
 #endif
 
 cpufreq_governor_init(schedutil_gov);
 
 #ifdef CONFIG_ENERGY_MODEL
 static void rebuild_sd_workfn(struct work_struct *work)
 {
     rebuild_sched_domains_energy();
 }
 static DECLARE_WORK(rebuild_sd_work, rebuild_sd_workfn);
 
 /*
  * EAS shouldn't be attempted without sugov, so rebuild the sched_domains
  * on governor changes to make sure the scheduler knows about it.
  */
 void sched_cpufreq_governor_change(struct cpufreq_policy *policy,
                   struct cpufreq_governor *old_gov)
 {
     if (old_gov == &schedutil_gov || policy->governor == &schedutil_gov) {
         /*
          * When called from the cpufreq_register_driver() path, the
          * cpu_hotplug_lock is already held, so use a work item to
          * avoid nested locking in rebuild_sched_domains().
          */
         schedule_work(&rebuild_sd_work);
     }
 
 }
 #endif

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