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Here is the "big" set of driver core patches for 5.2-rc1 There are a number of ACPI patches in here as well, as Rafael said they should go through this tree due to the driver core changes they required. They have all been acked by the ACPI developers. There are also a number of small subsystem-specific changes in here, due to some changes to the kobject core code. Those too have all been acked by the various subsystem maintainers. As for content, it's pretty boring outside of the ACPI changes: - spdx cleanups - kobject documentation updates - default attribute groups for kobjects - other minor kobject/driver core fixes All have been in linux-next for a while with no reported issues. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> -----BEGIN PGP SIGNATURE----- iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCXNHDbw8cZ3JlZ0Brcm9h aC5jb20ACgkQMUfUDdst+ynDAgCfbb4LBR6I50wFXb8JM/R6cAS7qrsAn1unshKV 8XCYcif2RxjtdJWXbjdm =/rLh -----END PGP SIGNATURE----- Merge tag 'driver-core-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core/kobject updates from Greg KH: "Here is the "big" set of driver core patches for 5.2-rc1 There are a number of ACPI patches in here as well, as Rafael said they should go through this tree due to the driver core changes they required. They have all been acked by the ACPI developers. There are also a number of small subsystem-specific changes in here, due to some changes to the kobject core code. Those too have all been acked by the various subsystem maintainers. As for content, it's pretty boring outside of the ACPI changes: - spdx cleanups - kobject documentation updates - default attribute groups for kobjects - other minor kobject/driver core fixes All have been in linux-next for a while with no reported issues" * tag 'driver-core-5.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (47 commits) kobject: clean up the kobject add documentation a bit more kobject: Fix kernel-doc comment first line kobject: Remove docstring reference to kset firmware_loader: Fix a typo ("syfs" -> "sysfs") kobject: fix dereference before null check on kobj Revert "driver core: platform: Fix the usage of platform device name(pdev->name)" init/config: Do not select BUILD_BIN2C for IKCONFIG Provide in-kernel headers to make extending kernel easier kobject: Improve doc clarity kobject_init_and_add() kobject: Improve docs for kobject_add/del driver core: platform: Fix the usage of platform device name(pdev->name) livepatch: Replace klp_ktype_patch's default_attrs with groups cpufreq: schedutil: Replace default_attrs field with groups padata: Replace padata_attr_type default_attrs field with groups irqdesc: Replace irq_kobj_type's default_attrs field with groups net-sysfs: Replace ktype default_attrs field with groups block: Replace all ktype default_attrs with groups samples/kobject: Replace foo_ktype's default_attrs field with groups kobject: Add support for default attribute groups to kobj_type driver core: Postpone DMA tear-down until after devres release for probe failure ...
930 lines
25 KiB
C
930 lines
25 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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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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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include "sched.h"
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#include <linux/sched/cpufreq.h>
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#include <trace/events/power.h>
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#define IOWAIT_BOOST_MIN (SCHED_CAPACITY_SCALE / 8)
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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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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 = map_util_freq(util, freq, 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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unsigned long schedutil_freq_util(int cpu, unsigned long util_cfs,
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unsigned long max, enum schedutil_type type)
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{
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unsigned long dl_util, util, irq;
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struct rq *rq = cpu_rq(cpu);
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if (type == FREQUENCY_UTIL && 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 = util_cfs;
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util += cpu_util_rt(rq);
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dl_util = cpu_util_dl(rq);
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/*
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* For frequency selection we do not make cpu_util_dl() a permanent part
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* of this sum because we want to use cpu_bw_dl() later on, but we need
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* to check if the CFS+RT+DL sum is saturated (ie. no idle time) such
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* that we select 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 + dl_util >= max)
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return max;
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/*
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* OTOH, for energy computation we need the estimated running time, so
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* include util_dl and ignore dl_bw.
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*/
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if (type == ENERGY_UTIL)
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util += dl_util;
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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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if (type == FREQUENCY_UTIL)
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util += cpu_bw_dl(rq);
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return min(max, util);
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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 = cpu_util_cfs(rq);
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unsigned long max = arch_scale_cpu_capacity(NULL, sg_cpu->cpu);
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sg_cpu->max = max;
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sg_cpu->bw_dl = cpu_bw_dl(rq);
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return schedutil_freq_util(sg_cpu->cpu, util, max, FREQUENCY_UTIL);
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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 IOWAIT_BOOST_MIN, which improves energy
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* 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 ? IOWAIT_BOOST_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 IOWAIT_BOOST_MIN to the utilization
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* of the maximum OPP.
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*
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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 =
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min_t(unsigned int, sg_cpu->iowait_boost << 1, SCHED_CAPACITY_SCALE);
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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 = IOWAIT_BOOST_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 unsigned long 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 long boost;
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/* No boost currently required */
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if (!sg_cpu->iowait_boost)
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return util;
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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 util;
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if (!sg_cpu->iowait_boost_pending) {
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/*
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* No boost pending; reduce the boost value.
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*/
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sg_cpu->iowait_boost >>= 1;
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if (sg_cpu->iowait_boost < IOWAIT_BOOST_MIN) {
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sg_cpu->iowait_boost = 0;
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return util;
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}
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}
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sg_cpu->iowait_boost_pending = false;
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/*
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* @util is already in capacity scale; convert iowait_boost
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* into the same scale so we can compare.
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*/
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boost = (sg_cpu->iowait_boost * max) >> SCHED_CAPACITY_SHIFT;
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return max(boost, util);
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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);
|
|
|
|
if (!sugov_should_update_freq(sg_policy, time))
|
|
return;
|
|
|
|
busy = sugov_cpu_is_busy(sg_cpu);
|
|
|
|
util = sugov_get_util(sg_cpu);
|
|
max = sg_cpu->max;
|
|
util = 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;
|
|
|
|
j_util = sugov_get_util(j_sg_cpu);
|
|
j_max = j_sg_cpu->max;
|
|
j_util = 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_attrs[] = {
|
|
&rate_limit_us.attr,
|
|
NULL
|
|
};
|
|
ATTRIBUTE_GROUPS(sugov);
|
|
|
|
static struct kobj_type sugov_tunables_ktype = {
|
|
.default_groups = sugov_groups,
|
|
.sysfs_ops = &governor_sysfs_ops,
|
|
};
|
|
|
|
/********************** 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_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:
|
|
kobject_put(&tunables->attr_set.kobj);
|
|
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;
|
|
}
|
|
|
|
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_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->need_freq_update = true;
|
|
}
|
|
|
|
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);
|
|
|
|
#ifdef CONFIG_ENERGY_MODEL
|
|
extern bool sched_energy_update;
|
|
extern struct mutex sched_energy_mutex;
|
|
|
|
static void rebuild_sd_workfn(struct work_struct *work)
|
|
{
|
|
mutex_lock(&sched_energy_mutex);
|
|
sched_energy_update = true;
|
|
rebuild_sched_domains();
|
|
sched_energy_update = false;
|
|
mutex_unlock(&sched_energy_mutex);
|
|
}
|
|
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
|