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![Vincent Guittot](/assets/img/avatar_default.png)
Reuse cpu_util_irq() that has been defined for schedutil and set irq util to 0 when !CONFIG_IRQ_TIME_ACCOUNTING. But the compiler is not able to optimize the sequence (at least with aarch64 GCC 7.2.1): free *= (max - irq); free /= max; when irq is fixed to 0 Add a new inline function scale_irq_capacity() that will scale utilization when irq is accounted. Reuse this funciton in schedutil which applies similar formula. Suggested-by: Ingo Molnar <mingo@redhat.com> Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: rjw@rjwysocki.net Link: http://lkml.kernel.org/r/1532001606-6689-1-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
885 lines
24 KiB
C
885 lines
24 KiB
C
/*
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* CPUFreq governor based on scheduler-provided CPU utilization data.
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*
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* Copyright (C) 2016, Intel Corporation
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* Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include "sched.h"
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#include <trace/events/power.h>
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struct sugov_tunables {
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struct gov_attr_set attr_set;
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unsigned int rate_limit_us;
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};
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struct sugov_policy {
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struct cpufreq_policy *policy;
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struct sugov_tunables *tunables;
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struct list_head tunables_hook;
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raw_spinlock_t update_lock; /* For shared policies */
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u64 last_freq_update_time;
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s64 freq_update_delay_ns;
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unsigned int next_freq;
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unsigned int cached_raw_freq;
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/* The next fields are only needed if fast switch cannot be used: */
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struct irq_work irq_work;
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struct kthread_work work;
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struct mutex work_lock;
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struct kthread_worker worker;
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struct task_struct *thread;
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bool work_in_progress;
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bool need_freq_update;
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};
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struct sugov_cpu {
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struct update_util_data update_util;
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struct sugov_policy *sg_policy;
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unsigned int cpu;
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bool iowait_boost_pending;
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unsigned int iowait_boost;
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unsigned int iowait_boost_max;
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u64 last_update;
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unsigned long bw_dl;
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unsigned long max;
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/* The field below is for single-CPU policies only: */
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#ifdef CONFIG_NO_HZ_COMMON
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unsigned long saved_idle_calls;
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#endif
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};
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static DEFINE_PER_CPU(struct sugov_cpu, sugov_cpu);
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/************************ Governor internals ***********************/
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static bool sugov_should_update_freq(struct sugov_policy *sg_policy, u64 time)
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{
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s64 delta_ns;
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/*
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* Since cpufreq_update_util() is called with rq->lock held for
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* the @target_cpu, our per-CPU data is fully serialized.
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*
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* However, drivers cannot in general deal with cross-CPU
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* requests, so while get_next_freq() will work, our
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* sugov_update_commit() call may not for the fast switching platforms.
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*
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* Hence stop here for remote requests if they aren't supported
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* by the hardware, as calculating the frequency is pointless if
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* we cannot in fact act on it.
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*
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* For the slow switching platforms, the kthread is always scheduled on
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* the right set of CPUs and any CPU can find the next frequency and
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* schedule the kthread.
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*/
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if (sg_policy->policy->fast_switch_enabled &&
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!cpufreq_this_cpu_can_update(sg_policy->policy))
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return false;
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if (unlikely(sg_policy->need_freq_update))
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return true;
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delta_ns = time - sg_policy->last_freq_update_time;
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return delta_ns >= sg_policy->freq_update_delay_ns;
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}
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static bool sugov_update_next_freq(struct sugov_policy *sg_policy, u64 time,
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unsigned int next_freq)
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{
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if (sg_policy->next_freq == next_freq)
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return false;
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sg_policy->next_freq = next_freq;
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sg_policy->last_freq_update_time = time;
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return true;
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}
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static void sugov_fast_switch(struct sugov_policy *sg_policy, u64 time,
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unsigned int next_freq)
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{
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struct cpufreq_policy *policy = sg_policy->policy;
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if (!sugov_update_next_freq(sg_policy, time, next_freq))
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return;
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next_freq = cpufreq_driver_fast_switch(policy, next_freq);
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if (!next_freq)
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return;
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policy->cur = next_freq;
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trace_cpu_frequency(next_freq, smp_processor_id());
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}
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static void sugov_deferred_update(struct sugov_policy *sg_policy, u64 time,
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unsigned int next_freq)
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{
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if (!sugov_update_next_freq(sg_policy, time, next_freq))
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return;
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if (!sg_policy->work_in_progress) {
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sg_policy->work_in_progress = true;
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irq_work_queue(&sg_policy->irq_work);
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}
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}
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/**
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* get_next_freq - Compute a new frequency for a given cpufreq policy.
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* @sg_policy: schedutil policy object to compute the new frequency for.
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* @util: Current CPU utilization.
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* @max: CPU capacity.
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*
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* If the utilization is frequency-invariant, choose the new frequency to be
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* proportional to it, that is
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*
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* next_freq = C * max_freq * util / max
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*
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* Otherwise, approximate the would-be frequency-invariant utilization by
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* util_raw * (curr_freq / max_freq) which leads to
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*
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* next_freq = C * curr_freq * util_raw / max
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*
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* Take C = 1.25 for the frequency tipping point at (util / max) = 0.8.
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*
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* The lowest driver-supported frequency which is equal or greater than the raw
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* next_freq (as calculated above) is returned, subject to policy min/max and
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* cpufreq driver limitations.
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*/
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static unsigned int get_next_freq(struct sugov_policy *sg_policy,
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unsigned long util, unsigned long max)
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{
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struct cpufreq_policy *policy = sg_policy->policy;
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unsigned int freq = arch_scale_freq_invariant() ?
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policy->cpuinfo.max_freq : policy->cur;
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freq = (freq + (freq >> 2)) * util / max;
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if (freq == sg_policy->cached_raw_freq && !sg_policy->need_freq_update)
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return sg_policy->next_freq;
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sg_policy->need_freq_update = false;
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sg_policy->cached_raw_freq = freq;
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return cpufreq_driver_resolve_freq(policy, freq);
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}
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/*
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* This function computes an effective utilization for the given CPU, to be
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* used for frequency selection given the linear relation: f = u * f_max.
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*
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* The scheduler tracks the following metrics:
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*
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* cpu_util_{cfs,rt,dl,irq}()
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* cpu_bw_dl()
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*
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* Where the cfs,rt and dl util numbers are tracked with the same metric and
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* synchronized windows and are thus directly comparable.
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*
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* The cfs,rt,dl utilization are the running times measured with rq->clock_task
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* which excludes things like IRQ and steal-time. These latter are then accrued
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* in the irq utilization.
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*
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* The DL bandwidth number otoh is not a measured metric but a value computed
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* based on the task model parameters and gives the minimal utilization
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* required to meet deadlines.
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*/
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static unsigned long sugov_get_util(struct sugov_cpu *sg_cpu)
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{
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struct rq *rq = cpu_rq(sg_cpu->cpu);
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unsigned long util, irq, max;
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sg_cpu->max = max = arch_scale_cpu_capacity(NULL, sg_cpu->cpu);
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sg_cpu->bw_dl = cpu_bw_dl(rq);
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if (rt_rq_is_runnable(&rq->rt))
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return max;
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/*
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* Early check to see if IRQ/steal time saturates the CPU, can be
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* because of inaccuracies in how we track these -- see
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* update_irq_load_avg().
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*/
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irq = cpu_util_irq(rq);
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if (unlikely(irq >= max))
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return max;
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/*
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* Because the time spend on RT/DL tasks is visible as 'lost' time to
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* CFS tasks and we use the same metric to track the effective
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* utilization (PELT windows are synchronized) we can directly add them
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* to obtain the CPU's actual utilization.
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*/
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util = cpu_util_cfs(rq);
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util += cpu_util_rt(rq);
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/*
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* We do not make cpu_util_dl() a permanent part of this sum because we
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* want to use cpu_bw_dl() later on, but we need to check if the
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* CFS+RT+DL sum is saturated (ie. no idle time) such that we select
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* f_max when there is no idle time.
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*
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* NOTE: numerical errors or stop class might cause us to not quite hit
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* saturation when we should -- something for later.
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*/
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if ((util + cpu_util_dl(rq)) >= max)
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return max;
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/*
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* There is still idle time; further improve the number by using the
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* irq metric. Because IRQ/steal time is hidden from the task clock we
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* need to scale the task numbers:
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*
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* 1 - irq
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* U' = irq + ------- * U
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* max
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*/
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util = scale_irq_capacity(util, irq, max);
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util += irq;
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/*
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* Bandwidth required by DEADLINE must always be granted while, for
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* FAIR and RT, we use blocked utilization of IDLE CPUs as a mechanism
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* to gracefully reduce the frequency when no tasks show up for longer
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* periods of time.
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*
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* Ideally we would like to set bw_dl as min/guaranteed freq and util +
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* bw_dl as requested freq. However, cpufreq is not yet ready for such
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* an interface. So, we only do the latter for now.
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*/
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return min(max, util + sg_cpu->bw_dl);
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}
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/**
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* sugov_iowait_reset() - Reset the IO boost status of a CPU.
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* @sg_cpu: the sugov data for the CPU to boost
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* @time: the update time from the caller
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* @set_iowait_boost: true if an IO boost has been requested
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*
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* The IO wait boost of a task is disabled after a tick since the last update
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* of a CPU. If a new IO wait boost is requested after more then a tick, then
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* we enable the boost starting from the minimum frequency, which improves
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* energy efficiency by ignoring sporadic wakeups from IO.
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*/
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static bool sugov_iowait_reset(struct sugov_cpu *sg_cpu, u64 time,
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bool set_iowait_boost)
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{
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s64 delta_ns = time - sg_cpu->last_update;
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/* Reset boost only if a tick has elapsed since last request */
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if (delta_ns <= TICK_NSEC)
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return false;
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sg_cpu->iowait_boost = set_iowait_boost
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? sg_cpu->sg_policy->policy->min : 0;
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sg_cpu->iowait_boost_pending = set_iowait_boost;
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return true;
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}
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/**
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* sugov_iowait_boost() - Updates the IO boost status of a CPU.
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* @sg_cpu: the sugov data for the CPU to boost
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* @time: the update time from the caller
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* @flags: SCHED_CPUFREQ_IOWAIT if the task is waking up after an IO wait
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*
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* Each time a task wakes up after an IO operation, the CPU utilization can be
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* boosted to a certain utilization which doubles at each "frequent and
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* successive" wakeup from IO, ranging from the utilization of the minimum
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* OPP to the utilization of the maximum OPP.
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* To keep doubling, an IO boost has to be requested at least once per tick,
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* otherwise we restart from the utilization of the minimum OPP.
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*/
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static void sugov_iowait_boost(struct sugov_cpu *sg_cpu, u64 time,
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unsigned int flags)
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{
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bool set_iowait_boost = flags & SCHED_CPUFREQ_IOWAIT;
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/* Reset boost if the CPU appears to have been idle enough */
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if (sg_cpu->iowait_boost &&
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sugov_iowait_reset(sg_cpu, time, set_iowait_boost))
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return;
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/* Boost only tasks waking up after IO */
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if (!set_iowait_boost)
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return;
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/* Ensure boost doubles only one time at each request */
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if (sg_cpu->iowait_boost_pending)
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return;
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sg_cpu->iowait_boost_pending = true;
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/* Double the boost at each request */
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if (sg_cpu->iowait_boost) {
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sg_cpu->iowait_boost <<= 1;
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if (sg_cpu->iowait_boost > sg_cpu->iowait_boost_max)
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sg_cpu->iowait_boost = sg_cpu->iowait_boost_max;
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return;
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}
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/* First wakeup after IO: start with minimum boost */
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sg_cpu->iowait_boost = sg_cpu->sg_policy->policy->min;
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}
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/**
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* sugov_iowait_apply() - Apply the IO boost to a CPU.
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* @sg_cpu: the sugov data for the cpu to boost
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* @time: the update time from the caller
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* @util: the utilization to (eventually) boost
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* @max: the maximum value the utilization can be boosted to
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*
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* A CPU running a task which woken up after an IO operation can have its
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* utilization boosted to speed up the completion of those IO operations.
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* The IO boost value is increased each time a task wakes up from IO, in
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* sugov_iowait_apply(), and it's instead decreased by this function,
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* each time an increase has not been requested (!iowait_boost_pending).
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*
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* A CPU which also appears to have been idle for at least one tick has also
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* its IO boost utilization reset.
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*
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* This mechanism is designed to boost high frequently IO waiting tasks, while
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* being more conservative on tasks which does sporadic IO operations.
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*/
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static void sugov_iowait_apply(struct sugov_cpu *sg_cpu, u64 time,
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unsigned long *util, unsigned long *max)
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{
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unsigned int boost_util, boost_max;
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/* No boost currently required */
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if (!sg_cpu->iowait_boost)
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return;
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/* Reset boost if the CPU appears to have been idle enough */
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if (sugov_iowait_reset(sg_cpu, time, false))
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return;
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/*
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* An IO waiting task has just woken up:
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* allow to further double the boost value
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*/
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if (sg_cpu->iowait_boost_pending) {
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sg_cpu->iowait_boost_pending = false;
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} else {
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/*
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* Otherwise: reduce the boost value and disable it when we
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* reach the minimum.
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*/
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sg_cpu->iowait_boost >>= 1;
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if (sg_cpu->iowait_boost < sg_cpu->sg_policy->policy->min) {
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sg_cpu->iowait_boost = 0;
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return;
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}
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}
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/*
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* Apply the current boost value: a CPU is boosted only if its current
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* utilization is smaller then the current IO boost level.
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*/
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boost_util = sg_cpu->iowait_boost;
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boost_max = sg_cpu->iowait_boost_max;
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if (*util * boost_max < *max * boost_util) {
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*util = boost_util;
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*max = boost_max;
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}
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}
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#ifdef CONFIG_NO_HZ_COMMON
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static bool sugov_cpu_is_busy(struct sugov_cpu *sg_cpu)
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{
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unsigned long idle_calls = tick_nohz_get_idle_calls_cpu(sg_cpu->cpu);
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bool ret = idle_calls == sg_cpu->saved_idle_calls;
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sg_cpu->saved_idle_calls = idle_calls;
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return ret;
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}
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#else
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static inline bool sugov_cpu_is_busy(struct sugov_cpu *sg_cpu) { return false; }
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#endif /* CONFIG_NO_HZ_COMMON */
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/*
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* Make sugov_should_update_freq() ignore the rate limit when DL
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* has increased the utilization.
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*/
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static inline void ignore_dl_rate_limit(struct sugov_cpu *sg_cpu, struct sugov_policy *sg_policy)
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{
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if (cpu_bw_dl(cpu_rq(sg_cpu->cpu)) > sg_cpu->bw_dl)
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sg_policy->need_freq_update = true;
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}
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static void sugov_update_single(struct update_util_data *hook, u64 time,
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unsigned int flags)
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{
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struct sugov_cpu *sg_cpu = container_of(hook, struct sugov_cpu, update_util);
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struct sugov_policy *sg_policy = sg_cpu->sg_policy;
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unsigned long util, max;
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unsigned int next_f;
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bool busy;
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sugov_iowait_boost(sg_cpu, time, flags);
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sg_cpu->last_update = time;
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ignore_dl_rate_limit(sg_cpu, sg_policy);
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if (!sugov_should_update_freq(sg_policy, time))
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return;
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busy = sugov_cpu_is_busy(sg_cpu);
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util = sugov_get_util(sg_cpu);
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max = sg_cpu->max;
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sugov_iowait_apply(sg_cpu, time, &util, &max);
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next_f = get_next_freq(sg_policy, util, max);
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/*
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* Do not reduce the frequency if the CPU has not been idle
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* recently, as the reduction is likely to be premature then.
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*/
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if (busy && next_f < sg_policy->next_freq) {
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next_f = sg_policy->next_freq;
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/* Reset cached freq as next_freq has changed */
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sg_policy->cached_raw_freq = 0;
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}
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/*
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* This code runs under rq->lock for the target CPU, so it won't run
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* concurrently on two different CPUs for the same target and it is not
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* necessary to acquire the lock in the fast switch case.
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*/
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if (sg_policy->policy->fast_switch_enabled) {
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sugov_fast_switch(sg_policy, time, next_f);
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} else {
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raw_spin_lock(&sg_policy->update_lock);
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sugov_deferred_update(sg_policy, time, next_f);
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raw_spin_unlock(&sg_policy->update_lock);
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}
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}
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static unsigned int sugov_next_freq_shared(struct sugov_cpu *sg_cpu, u64 time)
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{
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struct sugov_policy *sg_policy = sg_cpu->sg_policy;
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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;
|
|
|
|
j_util = sugov_get_util(j_sg_cpu);
|
|
j_max = j_sg_cpu->max;
|
|
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);
|