| /* |
| * CPUFreq governor based on scheduler-provided CPU utilization data. |
| * |
| * Copyright (C) 2016, Intel Corporation |
| * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| */ |
| |
| #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| |
| #include "sched.h" |
| |
| #include <trace/events/power.h> |
| |
| 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; /* For shared policies */ |
| 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 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; |
| unsigned int iowait_boost_max; |
| u64 last_update; |
| |
| /* The fields below are only needed when sharing a policy: */ |
| unsigned long util_cfs; |
| unsigned long util_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. |
| * |
| * For the slow switching platforms, the kthread is always scheduled on |
| * the right set of CPUs and any CPU can find the next frequency and |
| * schedule the kthread. |
| */ |
| if (sg_policy->policy->fast_switch_enabled && |
| !cpufreq_this_cpu_can_update(sg_policy->policy)) |
| return false; |
| |
| if (unlikely(sg_policy->need_freq_update)) |
| 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->next_freq == next_freq) |
| return false; |
| |
| sg_policy->next_freq = next_freq; |
| sg_policy->last_freq_update_time = time; |
| |
| return true; |
| } |
| |
| static void sugov_fast_switch(struct sugov_policy *sg_policy, u64 time, |
| unsigned int next_freq) |
| { |
| struct cpufreq_policy *policy = sg_policy->policy; |
| |
| if (!sugov_update_next_freq(sg_policy, time, next_freq)) |
| return; |
| |
| next_freq = cpufreq_driver_fast_switch(policy, next_freq); |
| if (!next_freq) |
| return; |
| |
| policy->cur = next_freq; |
| trace_cpu_frequency(next_freq, smp_processor_id()); |
| } |
| |
| static void sugov_deferred_update(struct sugov_policy *sg_policy, u64 time, |
| unsigned int next_freq) |
| { |
| if (!sugov_update_next_freq(sg_policy, time, next_freq)) |
| return; |
| |
| 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; |
| |
| freq = (freq + (freq >> 2)) * util / max; |
| |
| if (freq == sg_policy->cached_raw_freq && !sg_policy->need_freq_update) |
| return sg_policy->next_freq; |
| |
| sg_policy->need_freq_update = false; |
| 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(NULL, sg_cpu->cpu); |
| sg_cpu->util_cfs = cpu_util_cfs(rq); |
| sg_cpu->util_dl = cpu_util_dl(rq); |
| } |
| |
| static unsigned long sugov_aggregate_util(struct sugov_cpu *sg_cpu) |
| { |
| struct rq *rq = cpu_rq(sg_cpu->cpu); |
| |
| if (rt_rq_is_runnable(&rq->rt)) |
| return sg_cpu->max; |
| |
| /* |
| * Utilization required by DEADLINE must always be granted while, for |
| * FAIR, we use blocked utilization of IDLE CPUs as a mechanism to |
| * gracefully reduce the frequency when no tasks show up for longer |
| * periods of time. |
| * |
| * Ideally we would like to set util_dl as min/guaranteed freq and |
| * util_cfs + util_dl as requested freq. However, cpufreq is not yet |
| * ready for such an interface. So, we only do the latter for now. |
| */ |
| return min(sg_cpu->max, (sg_cpu->util_dl + sg_cpu->util_cfs)); |
| } |
| |
| /** |
| * 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 the minimum frequency, 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 |
| ? sg_cpu->sg_policy->policy->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 the utilization of the minimum |
| * OPP 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 <<= 1; |
| if (sg_cpu->iowait_boost > sg_cpu->iowait_boost_max) |
| sg_cpu->iowait_boost = sg_cpu->iowait_boost_max; |
| return; |
| } |
| |
| /* First wakeup after IO: start with minimum boost */ |
| sg_cpu->iowait_boost = sg_cpu->sg_policy->policy->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 |
| * @util: the utilization to (eventually) boost |
| * @max: the maximum value the utilization can be boosted to |
| * |
| * 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 *util, unsigned long *max) |
| { |
| unsigned int boost_util, boost_max; |
| |
| /* 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; |
| |
| /* |
| * An IO waiting task has just woken up: |
| * allow to further double the boost value |
| */ |
| if (sg_cpu->iowait_boost_pending) { |
| sg_cpu->iowait_boost_pending = false; |
| } else { |
| /* |
| * Otherwise: reduce the boost value and disable it when we |
| * reach the minimum. |
| */ |
| sg_cpu->iowait_boost >>= 1; |
| if (sg_cpu->iowait_boost < sg_cpu->sg_policy->policy->min) { |
| sg_cpu->iowait_boost = 0; |
| return; |
| } |
| } |
| |
| /* |
| * Apply the current boost value: a CPU is boosted only if its current |
| * utilization is smaller then the current IO boost level. |
| */ |
| boost_util = sg_cpu->iowait_boost; |
| boost_max = sg_cpu->iowait_boost_max; |
| if (*util * boost_max < *max * boost_util) { |
| *util = boost_util; |
| *max = boost_max; |
| } |
| } |
| |
| #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, struct sugov_policy *sg_policy) |
| { |
| if (cpu_util_dl(cpu_rq(sg_cpu->cpu)) > sg_cpu->util_dl) |
| sg_policy->need_freq_update = true; |
| } |
| |
| static void sugov_update_single(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 long util, max; |
| unsigned int next_f; |
| bool busy; |
| |
| sugov_iowait_boost(sg_cpu, time, flags); |
| sg_cpu->last_update = time; |
| |
| ignore_dl_rate_limit(sg_cpu, sg_policy); |
| |
| if (!sugov_should_update_freq(sg_policy, time)) |
| return; |
| |
| busy = sugov_cpu_is_busy(sg_cpu); |
| |
| sugov_get_util(sg_cpu); |
| max = sg_cpu->max; |
| util = sugov_aggregate_util(sg_cpu); |
| sugov_iowait_apply(sg_cpu, time, &util, &max); |
| next_f = get_next_freq(sg_policy, util, max); |
| /* |
| * Do not reduce the frequency if the CPU has not been idle |
| * recently, as the reduction is likely to be premature then. |
| */ |
| if (busy && next_f < sg_policy->next_freq) { |
| next_f = sg_policy->next_freq; |
| |
| /* Reset cached freq as next_freq has changed */ |
| sg_policy->cached_raw_freq = 0; |
| } |
| |
| /* |
| * 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) { |
| sugov_fast_switch(sg_policy, time, next_f); |
| } else { |
| raw_spin_lock(&sg_policy->update_lock); |
| sugov_deferred_update(sg_policy, time, next_f); |
| raw_spin_unlock(&sg_policy->update_lock); |
| } |
| } |
| |
| 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); |
| j_max = j_sg_cpu->max; |
| j_util = sugov_aggregate_util(j_sg_cpu); |
| sugov_iowait_apply(j_sg_cpu, time, &j_util, &j_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, sg_policy); |
| |
| if (sugov_should_update_freq(sg_policy, time)) { |
| next_f = sugov_next_freq_shared(sg_cpu, time); |
| |
| if (sg_policy->policy->fast_switch_enabled) |
| sugov_fast_switch(sg_policy, time, next_f); |
| else |
| sugov_deferred_update(sg_policy, time, next_f); |
| } |
| |
| 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: |
| * incase 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_attributes[] = { |
| &rate_limit_us.attr, |
| NULL |
| }; |
| |
| static struct kobj_type sugov_tunables_ktype = { |
| .default_attrs = sugov_attributes, |
| .sysfs_ops = &governor_sysfs_ops, |
| }; |
| |
| /********************** cpufreq governor interface *********************/ |
| |
| static 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_tunables_free(struct sugov_tunables *tunables) |
| { |
| if (!have_governor_per_policy()) |
| global_tunables = NULL; |
| |
| kfree(tunables); |
| } |
| |
| 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: |
| policy->governor_data = NULL; |
| sugov_tunables_free(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_tunables_free(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; |
| 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->need_freq_update = false; |
| sg_policy->cached_raw_freq = 0; |
| |
| 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; |
| sg_cpu->iowait_boost_max = policy->cpuinfo.max_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, |
| policy_is_shared(policy) ? |
| sugov_update_shared : |
| sugov_update_single); |
| } |
| 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_sched(); |
| |
| 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->need_freq_update = true; |
| } |
| |
| static struct cpufreq_governor schedutil_gov = { |
| .name = "schedutil", |
| .owner = THIS_MODULE, |
| .dynamic_switching = true, |
| .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 |
| |
| static int __init sugov_register(void) |
| { |
| return cpufreq_register_governor(&schedutil_gov); |
| } |
| fs_initcall(sugov_register); |