diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2018-12-26 23:56:10 +0100 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-12-26 23:56:10 +0100 |
commit | 17bf423a1f2d134187191f0ceb4b395173cc98a7 (patch) | |
tree | df27481f3149103f01ef027aed1bc76e699d6470 | |
parent | Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kern... (diff) | |
parent | sched/fair: Select an energy-efficient CPU on task wake-up (diff) | |
download | linux-17bf423a1f2d134187191f0ceb4b395173cc98a7.tar.xz linux-17bf423a1f2d134187191f0ceb4b395173cc98a7.zip |
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
"The main changes in this cycle were:
- Introduce "Energy Aware Scheduling" - by Quentin Perret.
This is a coherent topology description of CPUs in cooperation with
the PM subsystem, with the goal to schedule more energy-efficiently
on asymetric SMP platform - such as waking up tasks to the more
energy-efficient CPUs first, as long as the system isn't
oversubscribed.
For details of the design, see:
https://lore.kernel.org/lkml/20180724122521.22109-1-quentin.perret@arm.com/
- Misc cleanups and smaller enhancements"
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
sched/fair: Select an energy-efficient CPU on task wake-up
sched/fair: Introduce an energy estimation helper function
sched/fair: Add over-utilization/tipping point indicator
sched/fair: Clean-up update_sg_lb_stats parameters
sched/toplogy: Introduce the 'sched_energy_present' static key
sched/topology: Make Energy Aware Scheduling depend on schedutil
sched/topology: Disable EAS on inappropriate platforms
sched/topology: Add lowest CPU asymmetry sched_domain level pointer
sched/topology: Reference the Energy Model of CPUs when available
PM: Introduce an Energy Model management framework
sched/cpufreq: Prepare schedutil for Energy Aware Scheduling
sched/topology: Relocate arch_scale_cpu_capacity() to the internal header
sched/core: Remove unnecessary unlikely() in push_*_task()
sched/topology: Remove the ::smt_gain field from 'struct sched_domain'
sched: Fix various typos in comments
sched/core: Clean up the #ifdef block in add_nr_running()
sched/fair: Make some variables static
sched/core: Create task_has_idle_policy() helper
sched/fair: Add lsub_positive() and use it consistently
sched/fair: Mask UTIL_AVG_UNCHANGED usages
...
-rw-r--r-- | drivers/cpufreq/cpufreq.c | 1 | ||||
-rw-r--r-- | include/linux/cpufreq.h | 8 | ||||
-rw-r--r-- | include/linux/energy_model.h | 187 | ||||
-rw-r--r-- | include/linux/sched.h | 4 | ||||
-rw-r--r-- | include/linux/sched/cpufreq.h | 6 | ||||
-rw-r--r-- | include/linux/sched/isolation.h | 4 | ||||
-rw-r--r-- | include/linux/sched/mm.h | 2 | ||||
-rw-r--r-- | include/linux/sched/stat.h | 2 | ||||
-rw-r--r-- | include/linux/sched/topology.h | 17 | ||||
-rw-r--r-- | kernel/power/Kconfig | 15 | ||||
-rw-r--r-- | kernel/power/Makefile | 2 | ||||
-rw-r--r-- | kernel/power/energy_model.c | 201 | ||||
-rw-r--r-- | kernel/sched/core.c | 6 | ||||
-rw-r--r-- | kernel/sched/cpufreq_schedutil.c | 90 | ||||
-rw-r--r-- | kernel/sched/cputime.c | 2 | ||||
-rw-r--r-- | kernel/sched/deadline.c | 25 | ||||
-rw-r--r-- | kernel/sched/debug.c | 2 | ||||
-rw-r--r-- | kernel/sched/fair.c | 385 | ||||
-rw-r--r-- | kernel/sched/isolation.c | 14 | ||||
-rw-r--r-- | kernel/sched/rt.c | 28 | ||||
-rw-r--r-- | kernel/sched/sched.h | 97 | ||||
-rw-r--r-- | kernel/sched/topology.c | 231 |
22 files changed, 1179 insertions, 150 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 7aa3dcad2175..6f23ebb395f1 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -2277,6 +2277,7 @@ static int cpufreq_set_policy(struct cpufreq_policy *policy, ret = cpufreq_start_governor(policy); if (!ret) { pr_debug("cpufreq: governor change\n"); + sched_cpufreq_governor_change(policy, old_gov); return 0; } cpufreq_exit_governor(policy); diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index 882a9b9e34bc..c86d6d8bdfed 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -950,6 +950,14 @@ static inline bool policy_has_boost_freq(struct cpufreq_policy *policy) } #endif +#if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_CPU_FREQ_GOV_SCHEDUTIL) +void sched_cpufreq_governor_change(struct cpufreq_policy *policy, + struct cpufreq_governor *old_gov); +#else +static inline void sched_cpufreq_governor_change(struct cpufreq_policy *policy, + struct cpufreq_governor *old_gov) { } +#endif + extern void arch_freq_prepare_all(void); extern unsigned int arch_freq_get_on_cpu(int cpu); diff --git a/include/linux/energy_model.h b/include/linux/energy_model.h new file mode 100644 index 000000000000..aa027f7bcb3e --- /dev/null +++ b/include/linux/energy_model.h @@ -0,0 +1,187 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_ENERGY_MODEL_H +#define _LINUX_ENERGY_MODEL_H +#include <linux/cpumask.h> +#include <linux/jump_label.h> +#include <linux/kobject.h> +#include <linux/rcupdate.h> +#include <linux/sched/cpufreq.h> +#include <linux/sched/topology.h> +#include <linux/types.h> + +#ifdef CONFIG_ENERGY_MODEL +/** + * em_cap_state - Capacity state of a performance domain + * @frequency: The CPU frequency in KHz, for consistency with CPUFreq + * @power: The power consumed by 1 CPU at this level, in milli-watts + * @cost: The cost coefficient associated with this level, used during + * energy calculation. Equal to: power * max_frequency / frequency + */ +struct em_cap_state { + unsigned long frequency; + unsigned long power; + unsigned long cost; +}; + +/** + * em_perf_domain - Performance domain + * @table: List of capacity states, in ascending order + * @nr_cap_states: Number of capacity states + * @cpus: Cpumask covering the CPUs of the domain + * + * A "performance domain" represents a group of CPUs whose performance is + * scaled together. All CPUs of a performance domain must have the same + * micro-architecture. Performance domains often have a 1-to-1 mapping with + * CPUFreq policies. + */ +struct em_perf_domain { + struct em_cap_state *table; + int nr_cap_states; + unsigned long cpus[0]; +}; + +#define EM_CPU_MAX_POWER 0xFFFF + +struct em_data_callback { + /** + * active_power() - Provide power at the next capacity state of a CPU + * @power : Active power at the capacity state in mW (modified) + * @freq : Frequency at the capacity state in kHz (modified) + * @cpu : CPU for which we do this operation + * + * active_power() must find the lowest capacity state of 'cpu' above + * 'freq' and update 'power' and 'freq' to the matching active power + * and frequency. + * + * The power is the one of a single CPU in the domain, expressed in + * milli-watts. It is expected to fit in the [0, EM_CPU_MAX_POWER] + * range. + * + * Return 0 on success. + */ + int (*active_power)(unsigned long *power, unsigned long *freq, int cpu); +}; +#define EM_DATA_CB(_active_power_cb) { .active_power = &_active_power_cb } + +struct em_perf_domain *em_cpu_get(int cpu); +int em_register_perf_domain(cpumask_t *span, unsigned int nr_states, + struct em_data_callback *cb); + +/** + * em_pd_energy() - Estimates the energy consumed by the CPUs of a perf. domain + * @pd : performance domain for which energy has to be estimated + * @max_util : highest utilization among CPUs of the domain + * @sum_util : sum of the utilization of all CPUs in the domain + * + * Return: the sum of the energy consumed by the CPUs of the domain assuming + * a capacity state satisfying the max utilization of the domain. + */ +static inline unsigned long em_pd_energy(struct em_perf_domain *pd, + unsigned long max_util, unsigned long sum_util) +{ + unsigned long freq, scale_cpu; + struct em_cap_state *cs; + int i, cpu; + + /* + * In order to predict the capacity state, map the utilization of the + * most utilized CPU of the performance domain to a requested frequency, + * like schedutil. + */ + cpu = cpumask_first(to_cpumask(pd->cpus)); + scale_cpu = arch_scale_cpu_capacity(NULL, cpu); + cs = &pd->table[pd->nr_cap_states - 1]; + freq = map_util_freq(max_util, cs->frequency, scale_cpu); + + /* + * Find the lowest capacity state of the Energy Model above the + * requested frequency. + */ + for (i = 0; i < pd->nr_cap_states; i++) { + cs = &pd->table[i]; + if (cs->frequency >= freq) + break; + } + + /* + * The capacity of a CPU in the domain at that capacity state (cs) + * can be computed as: + * + * cs->freq * scale_cpu + * cs->cap = -------------------- (1) + * cpu_max_freq + * + * So, ignoring the costs of idle states (which are not available in + * the EM), the energy consumed by this CPU at that capacity state is + * estimated as: + * + * cs->power * cpu_util + * cpu_nrg = -------------------- (2) + * cs->cap + * + * since 'cpu_util / cs->cap' represents its percentage of busy time. + * + * NOTE: Although the result of this computation actually is in + * units of power, it can be manipulated as an energy value + * over a scheduling period, since it is assumed to be + * constant during that interval. + * + * By injecting (1) in (2), 'cpu_nrg' can be re-expressed as a product + * of two terms: + * + * cs->power * cpu_max_freq cpu_util + * cpu_nrg = ------------------------ * --------- (3) + * cs->freq scale_cpu + * + * The first term is static, and is stored in the em_cap_state struct + * as 'cs->cost'. + * + * Since all CPUs of the domain have the same micro-architecture, they + * share the same 'cs->cost', and the same CPU capacity. Hence, the + * total energy of the domain (which is the simple sum of the energy of + * all of its CPUs) can be factorized as: + * + * cs->cost * \Sum cpu_util + * pd_nrg = ------------------------ (4) + * scale_cpu + */ + return cs->cost * sum_util / scale_cpu; +} + +/** + * em_pd_nr_cap_states() - Get the number of capacity states of a perf. domain + * @pd : performance domain for which this must be done + * + * Return: the number of capacity states in the performance domain table + */ +static inline int em_pd_nr_cap_states(struct em_perf_domain *pd) +{ + return pd->nr_cap_states; +} + +#else +struct em_perf_domain {}; +struct em_data_callback {}; +#define EM_DATA_CB(_active_power_cb) { } + +static inline int em_register_perf_domain(cpumask_t *span, + unsigned int nr_states, struct em_data_callback *cb) +{ + return -EINVAL; +} +static inline struct em_perf_domain *em_cpu_get(int cpu) +{ + return NULL; +} +static inline unsigned long em_pd_energy(struct em_perf_domain *pd, + unsigned long max_util, unsigned long sum_util) +{ + return 0; +} +static inline int em_pd_nr_cap_states(struct em_perf_domain *pd) +{ + return 0; +} +#endif + +#endif diff --git a/include/linux/sched.h b/include/linux/sched.h index 4f1db3ef62a9..89541d248893 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -176,7 +176,7 @@ struct task_group; * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING). * * However, with slightly different timing the wakeup TASK_RUNNING store can - * also collide with the TASK_UNINTERRUPTIBLE store. Loosing that store is not + * also collide with the TASK_UNINTERRUPTIBLE store. Losing that store is not * a problem either because that will result in one extra go around the loop * and our @cond test will save the day. * @@ -515,7 +515,7 @@ struct sched_dl_entity { /* * Actual scheduling parameters. Initialized with the values above, - * they are continously updated during task execution. Note that + * they are continuously updated during task execution. Note that * the remaining runtime could be < 0 in case we are in overrun. */ s64 runtime; /* Remaining runtime for this instance */ diff --git a/include/linux/sched/cpufreq.h b/include/linux/sched/cpufreq.h index 59667444669f..afa940cd50dc 100644 --- a/include/linux/sched/cpufreq.h +++ b/include/linux/sched/cpufreq.h @@ -20,6 +20,12 @@ void cpufreq_add_update_util_hook(int cpu, struct update_util_data *data, void (*func)(struct update_util_data *data, u64 time, unsigned int flags)); void cpufreq_remove_update_util_hook(int cpu); + +static inline unsigned long map_util_freq(unsigned long util, + unsigned long freq, unsigned long cap) +{ + return (freq + (freq >> 2)) * util / cap; +} #endif /* CONFIG_CPU_FREQ */ #endif /* _LINUX_SCHED_CPUFREQ_H */ diff --git a/include/linux/sched/isolation.h b/include/linux/sched/isolation.h index 4a6582c27dea..b0fb1446fe04 100644 --- a/include/linux/sched/isolation.h +++ b/include/linux/sched/isolation.h @@ -16,7 +16,7 @@ enum hk_flags { }; #ifdef CONFIG_CPU_ISOLATION -DECLARE_STATIC_KEY_FALSE(housekeeping_overriden); +DECLARE_STATIC_KEY_FALSE(housekeeping_overridden); extern int housekeeping_any_cpu(enum hk_flags flags); extern const struct cpumask *housekeeping_cpumask(enum hk_flags flags); extern void housekeeping_affine(struct task_struct *t, enum hk_flags flags); @@ -43,7 +43,7 @@ static inline void housekeeping_init(void) { } static inline bool housekeeping_cpu(int cpu, enum hk_flags flags) { #ifdef CONFIG_CPU_ISOLATION - if (static_branch_unlikely(&housekeeping_overriden)) + if (static_branch_unlikely(&housekeeping_overridden)) return housekeeping_test_cpu(cpu, flags); #endif return true; diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h index aebb370a0006..3bfa6a0cbba4 100644 --- a/include/linux/sched/mm.h +++ b/include/linux/sched/mm.h @@ -153,7 +153,7 @@ static inline gfp_t current_gfp_context(gfp_t flags) { /* * NOIO implies both NOIO and NOFS and it is a weaker context - * so always make sure it makes precendence + * so always make sure it makes precedence */ if (unlikely(current->flags & PF_MEMALLOC_NOIO)) flags &= ~(__GFP_IO | __GFP_FS); diff --git a/include/linux/sched/stat.h b/include/linux/sched/stat.h index f30954cc059d..568286411b43 100644 --- a/include/linux/sched/stat.h +++ b/include/linux/sched/stat.h @@ -8,7 +8,7 @@ * Various counters maintained by the scheduler and fork(), * exposed via /proc, sys.c or used by drivers via these APIs. * - * ( Note that all these values are aquired without locking, + * ( Note that all these values are acquired without locking, * so they can only be relied on in narrow circumstances. ) */ diff --git a/include/linux/sched/topology.h b/include/linux/sched/topology.h index 6b9976180c1e..c31d3a47a47c 100644 --- a/include/linux/sched/topology.h +++ b/include/linux/sched/topology.h @@ -89,7 +89,6 @@ struct sched_domain { unsigned int newidle_idx; unsigned int wake_idx; unsigned int forkexec_idx; - unsigned int smt_gain; int nohz_idle; /* NOHZ IDLE status */ int flags; /* See SD_* */ @@ -202,6 +201,14 @@ extern void set_sched_topology(struct sched_domain_topology_level *tl); # define SD_INIT_NAME(type) #endif +#ifndef arch_scale_cpu_capacity +static __always_inline +unsigned long arch_scale_cpu_capacity(struct sched_domain *sd, int cpu) +{ + return SCHED_CAPACITY_SCALE; +} +#endif + #else /* CONFIG_SMP */ struct sched_domain_attr; @@ -217,6 +224,14 @@ static inline bool cpus_share_cache(int this_cpu, int that_cpu) return true; } +#ifndef arch_scale_cpu_capacity +static __always_inline +unsigned long arch_scale_cpu_capacity(void __always_unused *sd, int cpu) +{ + return SCHED_CAPACITY_SCALE; +} +#endif + #endif /* !CONFIG_SMP */ static inline int task_node(const struct task_struct *p) diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig index 3a6c2f87699e..f8fe57d1022e 100644 --- a/kernel/power/Kconfig +++ b/kernel/power/Kconfig @@ -298,3 +298,18 @@ config PM_GENERIC_DOMAINS_OF config CPU_PM bool + +config ENERGY_MODEL + bool "Energy Model for CPUs" + depends on SMP + depends on CPU_FREQ + default n + help + Several subsystems (thermal and/or the task scheduler for example) + can leverage information about the energy consumed by CPUs to make + smarter decisions. This config option enables the framework from + which subsystems can access the energy models. + + The exact usage of the energy model is subsystem-dependent. + + If in doubt, say N. diff --git a/kernel/power/Makefile b/kernel/power/Makefile index a3f79f0eef36..e7e47d9be1e5 100644 --- a/kernel/power/Makefile +++ b/kernel/power/Makefile @@ -15,3 +15,5 @@ obj-$(CONFIG_PM_AUTOSLEEP) += autosleep.o obj-$(CONFIG_PM_WAKELOCKS) += wakelock.o obj-$(CONFIG_MAGIC_SYSRQ) += poweroff.o + +obj-$(CONFIG_ENERGY_MODEL) += energy_model.o diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c new file mode 100644 index 000000000000..d9dc2c38764a --- /dev/null +++ b/kernel/power/energy_model.c @@ -0,0 +1,201 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Energy Model of CPUs + * + * Copyright (c) 2018, Arm ltd. + * Written by: Quentin Perret, Arm ltd. + */ + +#define pr_fmt(fmt) "energy_model: " fmt + +#include <linux/cpu.h> +#include <linux/cpumask.h> +#include <linux/energy_model.h> +#include <linux/sched/topology.h> +#include <linux/slab.h> + +/* Mapping of each CPU to the performance domain to which it belongs. */ +static DEFINE_PER_CPU(struct em_perf_domain *, em_data); + +/* + * Mutex serializing the registrations of performance domains and letting + * callbacks defined by drivers sleep. + */ +static DEFINE_MUTEX(em_pd_mutex); + +static struct em_perf_domain *em_create_pd(cpumask_t *span, int nr_states, + struct em_data_callback *cb) +{ + unsigned long opp_eff, prev_opp_eff = ULONG_MAX; + unsigned long power, freq, prev_freq = 0; + int i, ret, cpu = cpumask_first(span); + struct em_cap_state *table; + struct em_perf_domain *pd; + u64 fmax; + + if (!cb->active_power) + return NULL; + + pd = kzalloc(sizeof(*pd) + cpumask_size(), GFP_KERNEL); + if (!pd) + return NULL; + + table = kcalloc(nr_states, sizeof(*table), GFP_KERNEL); + if (!table) + goto free_pd; + + /* Build the list of capacity states for this performance domain */ + for (i = 0, freq = 0; i < nr_states; i++, freq++) { + /* + * active_power() is a driver callback which ceils 'freq' to + * lowest capacity state of 'cpu' above 'freq' and updates + * 'power' and 'freq' accordingly. + */ + ret = cb->active_power(&power, &freq, cpu); + if (ret) { + pr_err("pd%d: invalid cap. state: %d\n", cpu, ret); + goto free_cs_table; + } + + /* + * We expect the driver callback to increase the frequency for + * higher capacity states. + */ + if (freq <= prev_freq) { + pr_err("pd%d: non-increasing freq: %lu\n", cpu, freq); + goto free_cs_table; + } + + /* + * The power returned by active_state() is expected to be + * positive, in milli-watts and to fit into 16 bits. + */ + if (!power || power > EM_CPU_MAX_POWER) { + pr_err("pd%d: invalid power: %lu\n", cpu, power); + goto free_cs_table; + } + + table[i].power = power; + table[i].frequency = prev_freq = freq; + + /* + * The hertz/watts efficiency ratio should decrease as the + * frequency grows on sane platforms. But this isn't always + * true in practice so warn the user if a higher OPP is more + * power efficient than a lower one. + */ + opp_eff = freq / power; + if (opp_eff >= prev_opp_eff) + pr_warn("pd%d: hertz/watts ratio non-monotonically decreasing: em_cap_state %d >= em_cap_state%d\n", + cpu, i, i - 1); + prev_opp_eff = opp_eff; + } + + /* Compute the cost of each capacity_state. */ + fmax = (u64) table[nr_states - 1].frequency; + for (i = 0; i < nr_states; i++) { + table[i].cost = div64_u64(fmax * table[i].power, + table[i].frequency); + } + + pd->table = table; + pd->nr_cap_states = nr_states; + cpumask_copy(to_cpumask(pd->cpus), span); + + return pd; + +free_cs_table: + kfree(table); +free_pd: + kfree(pd); + + return NULL; +} + +/** + * em_cpu_get() - Return the performance domain for a CPU + * @cpu : CPU to find the performance domain for + * + * Return: the performance domain to which 'cpu' belongs, or NULL if it doesn't + * exist. + */ +struct em_perf_domain *em_cpu_get(int cpu) +{ + return READ_ONCE(per_cpu(em_data, cpu)); +} +EXPORT_SYMBOL_GPL(em_cpu_get); + +/** + * em_register_perf_domain() - Register the Energy Model of a performance domain + * @span : Mask of CPUs in the performance domain + * @nr_states : Number of capacity states to register + * @cb : Callback functions providing the data of the Energy Model + * + * Create Energy Model tables for a performance domain using the callbacks + * defined in cb. + * + * If multiple clients register the same performance domain, all but the first + * registration will be ignored. + * + * Return 0 on success + */ +int em_register_perf_domain(cpumask_t *span, unsigned int nr_states, + struct em_data_callback *cb) +{ + unsigned long cap, prev_cap = 0; + struct em_perf_domain *pd; + int cpu, ret = 0; + + if (!span || !nr_states || !cb) + return -EINVAL; + + /* + * Use a mutex to serialize the registration of performance domains and + * let the driver-defined callback functions sleep. + */ + mutex_lock(&em_pd_mutex); + + for_each_cpu(cpu, span) { + /* Make sure we don't register again an existing domain. */ + if (READ_ONCE(per_cpu(em_data, cpu))) { + ret = -EEXIST; + goto unlock; + } + + /* + * All CPUs of a domain must have the same micro-architecture + * since they all share the same table. + */ + cap = arch_scale_cpu_capacity(NULL, cpu); + if (prev_cap && prev_cap != cap) { + pr_err("CPUs of %*pbl must have the same capacity\n", + cpumask_pr_args(span)); + ret = -EINVAL; + goto unlock; + } + prev_cap = cap; + } + + /* Create the performance domain and add it to the Energy Model. */ + pd = em_create_pd(span, nr_states, cb); + if (!pd) { + ret = -EINVAL; + goto unlock; + } + + for_each_cpu(cpu, span) { + /* + * The per-cpu array can be read concurrently from em_cpu_get(). + * The barrier enforces the ordering needed to make sure readers + * can only access well formed em_perf_domain structs. + */ + smp_store_release(per_cpu_ptr(&em_data, cpu), pd); + } + + pr_debug("Created perf domain %*pbl\n", cpumask_pr_args(span)); +unlock: + mutex_unlock(&em_pd_mutex); + + return ret; +} +EXPORT_SYMBOL_GPL(em_register_perf_domain); diff --git a/kernel/sched/core.c b/kernel/sched/core.c index a5b7f1c9f24f..f66920173370 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -697,7 +697,7 @@ static void set_load_weight(struct task_struct *p, bool update_load) /* * SCHED_IDLE tasks get minimal weight: */ - if (idle_policy(p->policy)) { + if (task_has_idle_policy(p)) { load->weight = scale_load(WEIGHT_IDLEPRIO); load->inv_weight = WMULT_IDLEPRIO; p->se.runnable_weight = load->weight; @@ -2857,7 +2857,7 @@ unsigned long nr_running(void) * preemption, thus the result might have a time-of-check-to-time-of-use * race. The caller is responsible to use it correctly, for example: * - * - from a non-preemptable section (of course) + * - from a non-preemptible section (of course) * * - from a thread that is bound to a single CPU * @@ -4191,7 +4191,7 @@ recheck: * Treat SCHED_IDLE as nice 20. Only allow a switch to * SCHED_NORMAL if the RLIMIT_NICE would normally permit it. */ - if (idle_policy(p->policy) && !idle_policy(policy)) { + if (task_has_idle_policy(p) && !idle_policy(policy)) { if (!can_nice(p, task_nice(p))) return -EPERM; } diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c index 626ddd4ffa43..033ec7c45f13 100644 --- a/kernel/sched/cpufreq_schedutil.c +++ b/kernel/sched/cpufreq_schedutil.c @@ -10,6 +10,7 @@ #include "sched.h" +#include <linux/sched/cpufreq.h> #include <trace/events/power.h> struct sugov_tunables { @@ -164,7 +165,7 @@ static unsigned int get_next_freq(struct sugov_policy *sg_policy, unsigned int freq = arch_scale_freq_invariant() ? policy->cpuinfo.max_freq : policy->cur; - freq = (freq + (freq >> 2)) * util / max; + freq = map_util_freq(util, freq, max); if (freq == sg_policy->cached_raw_freq && !sg_policy->need_freq_update) return sg_policy->next_freq; @@ -194,15 +195,13 @@ static unsigned int get_next_freq(struct sugov_policy *sg_policy, * based on the task model parameters and gives the minimal utilization * required to meet deadlines. */ -static unsigned long sugov_get_util(struct sugov_cpu *sg_cpu) +unsigned long schedutil_freq_util(int cpu, unsigned long util_cfs, + unsigned long max, enum schedutil_type type) { - struct rq *rq = cpu_rq(sg_cpu->cpu); - unsigned long util, irq, max; - - sg_cpu->max = max = arch_scale_cpu_capacity(NULL, sg_cpu->cpu); - sg_cpu->bw_dl = cpu_bw_dl(rq); + unsigned long dl_util, util, irq; + struct rq *rq = cpu_rq(cpu); - if (rt_rq_is_runnable(&rq->rt)) + if (type == FREQUENCY_UTIL && rt_rq_is_runnable(&rq->rt)) return max; /* @@ -220,22 +219,31 @@ static unsigned long sugov_get_util(struct sugov_cpu *sg_cpu) * utilization (PELT windows are synchronized) we can directly add them * to obtain the CPU's actual utilization. */ - util = cpu_util_cfs(rq); + util = util_cfs; util += cpu_util_rt(rq); + dl_util = cpu_util_dl(rq); + /* - * We do not make cpu_util_dl() a permanent part of this sum because we - * want to use cpu_bw_dl() later on, but we need to check if the - * CFS+RT+DL sum is saturated (ie. no idle time) such that we select - * f_max when there is no idle time. + * For frequency selection we do not make cpu_util_dl() a permanent part + * of this sum because we want to use cpu_bw_dl() later on, but we need + * to check if the CFS+RT+DL sum is saturated (ie. no idle time) such + * that we select f_max when there is no idle time. * * NOTE: numerical errors or stop class might cause us to not quite hit * saturation when we should -- something for later. */ - if ((util + cpu_util_dl(rq)) >= max) + if (util + dl_util >= max) return max; /* + * OTOH, for energy computation we need the estimated running time, so + * include util_dl and ignore dl_bw. + */ + if (type == ENERGY_UTIL) + util += dl_util; + + /* * There is still idle time; further improve the number by using the * irq metric. Because IRQ/steal time is hidden from the task clock we * need to scale the task numbers: @@ -257,7 +265,22 @@ static unsigned long sugov_get_util(struct sugov_cpu *sg_cpu) * bw_dl as requested freq. However, cpufreq is not yet ready for such * an interface. So, we only do the latter for now. */ - return min(max, util + sg_cpu->bw_dl); + if (type == FREQUENCY_UTIL) + util += cpu_bw_dl(rq); + + return min(max, util); +} + +static unsigned long sugov_get_util(struct sugov_cpu *sg_cpu) +{ + struct rq *rq = cpu_rq(sg_cpu->cpu); + unsigned long util = cpu_util_cfs(rq); + unsigned long max = arch_scale_cpu_capacity(NULL, sg_cpu->cpu); + + sg_cpu->max = max; + sg_cpu->bw_dl = cpu_bw_dl(rq); + + return schedutil_freq_util(sg_cpu->cpu, util, max, FREQUENCY_UTIL); } /** @@ -598,7 +621,7 @@ static struct kobj_type sugov_tunables_ktype = { /********************** cpufreq governor interface *********************/ -static struct cpufreq_governor schedutil_gov; +struct cpufreq_governor schedutil_gov; static struct sugov_policy *sugov_policy_alloc(struct cpufreq_policy *policy) { @@ -857,7 +880,7 @@ static void sugov_limits(struct cpufreq_policy *policy) sg_policy->need_freq_update = true; } -static struct cpufreq_governor schedutil_gov = { +struct cpufreq_governor schedutil_gov = { .name = "schedutil", .owner = THIS_MODULE, .dynamic_switching = true, @@ -880,3 +903,36 @@ 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 diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c index 0796f938c4f0..ba4a143bdcf3 100644 --- a/kernel/sched/cputime.c +++ b/kernel/sched/cputime.c @@ -525,7 +525,7 @@ void account_idle_ticks(unsigned long ticks) /* * Perform (stime * rtime) / total, but avoid multiplication overflow by - * loosing precision when the numbers are big. + * losing precision when the numbers are big. */ static u64 scale_stime(u64 stime, u64 rtime, u64 total) { diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 91e4202b0634..fb8b7b5d745d 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -727,7 +727,7 @@ static void replenish_dl_entity(struct sched_dl_entity *dl_se, * refill the runtime and set the deadline a period in the future, * because keeping the current (absolute) deadline of the task would * result in breaking guarantees promised to other tasks (refer to - * Documentation/scheduler/sched-deadline.txt for more informations). + * Documentation/scheduler/sched-deadline.txt for more information). * * This function returns true if: * @@ -1695,6 +1695,14 @@ static void start_hrtick_dl(struct rq *rq, struct task_struct *p) } #endif +static inline void set_next_task(struct rq *rq, struct task_struct *p) +{ + p->se.exec_start = rq_clock_task(rq); + + /* You can't push away the running task */ + dequeue_pushable_dl_task(rq, p); +} + static struct sched_dl_entity *pick_next_dl_entity(struct rq *rq, struct dl_rq *dl_rq) { @@ -1750,10 +1758,8 @@ pick_next_task_dl(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) BUG_ON(!dl_se); p = dl_task_of(dl_se); - p->se.exec_start = rq_clock_task(rq); - /* Running task will never be pushed. */ - dequeue_pushable_dl_task(rq, p); + set_next_task(rq, p); if (hrtick_enabled(rq)) start_hrtick_dl(rq, p); @@ -1808,12 +1814,7 @@ static void task_fork_dl(struct task_struct *p) static void set_curr_task_dl(struct rq *rq) { - struct task_struct *p = rq->curr; - - p->se.exec_start = rq_clock_task(rq); - - /* You can't push away the running task */ - dequeue_pushable_dl_task(rq, p); + set_next_task(rq, rq->curr); } #ifdef CONFIG_SMP @@ -2041,10 +2042,8 @@ static int push_dl_task(struct rq *rq) return 0; retry: - if (unlikely(next_task == rq->curr)) { - WARN_ON(1); + if (WARN_ON(next_task == rq->curr)) return 0; - } /* * If next_task preempts rq->curr, and rq->curr diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c index 6383aa6a60ca..02bd5f969b21 100644 --- a/kernel/sched/debug.c +++ b/kernel/sched/debug.c @@ -974,7 +974,7 @@ void proc_sched_show_task(struct task_struct *p, struct pid_namespace *ns, #endif P(policy); P(prio); - if (p->policy == SCHED_DEADLINE) { + if (task_has_dl_policy(p)) { P(dl.runtime); P(dl.deadline); } diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index db514993565b..1c1cfbf6ba0c 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -38,7 +38,7 @@ * (default: 6ms * (1 + ilog(ncpus)), units: nanoseconds) */ unsigned int sysctl_sched_latency = 6000000ULL; -unsigned int normalized_sysctl_sched_latency = 6000000ULL; +static unsigned int normalized_sysctl_sched_latency = 6000000ULL; /* * The initial- and re-scaling of tunables is configurable @@ -58,8 +58,8 @@ enum sched_tunable_scaling sysctl_sched_tunable_scaling = SCHED_TUNABLESCALING_L * * (default: 0.75 msec * (1 + ilog(ncpus)), units: nanoseconds) */ -unsigned int sysctl_sched_min_granularity = 750000ULL; -unsigned int normalized_sysctl_sched_min_granularity = 750000ULL; +unsigned int sysctl_sched_min_granularity = 750000ULL; +static unsigned int normalized_sysctl_sched_min_granularity = 750000ULL; /* * This value is kept at sysctl_sched_latency/sysctl_sched_min_granularity @@ -81,8 +81,8 @@ unsigned int sysctl_sched_child_runs_first __read_mostly; * * (default: 1 msec * (1 + ilog(ncpus)), units: nanoseconds) */ -unsigned int sysctl_sched_wakeup_granularity = 1000000UL; -unsigned int normalized_sysctl_sched_wakeup_granularity = 1000000UL; +unsigned int sysctl_sched_wakeup_granularity = 1000000UL; +static unsigned int normalized_sysctl_sched_wakeup_granularity = 1000000UL; const_debug unsigned int sysctl_sched_migration_cost = 500000UL; @@ -116,7 +116,7 @@ unsigned int sysctl_sched_cfs_bandwidth_slice = 5000UL; * * (default: ~20%) */ -unsigned int capacity_margin = 1280; +static unsigned int capacity_margin = 1280; static inline void update_load_add(struct load_weight *lw, unsigned long inc) { @@ -703,9 +703,9 @@ void init_entity_runnable_average(struct sched_entity *se) memset(sa, 0, sizeof(*sa)); /* - * Tasks are intialized with full load to be seen as heavy tasks until + * Tasks are initialized with full load to be seen as heavy tasks until * they get a chance to stabilize to their real load level. - * Group entities are intialized with zero load to reflect the fact that + * Group entities are initialized with zero load to reflect the fact that * nothing has been attached to the task group yet. */ if (entity_is_task(se)) @@ -2734,6 +2734,17 @@ account_entity_dequeue(struct cfs_rq *cfs_rq, struct sched_entity *se) WRITE_ONCE(*ptr, res); \ } while (0) +/* + * Remove and clamp on negative, from a local variable. + * + * A variant of sub_positive(), which does not use explicit load-store + * and is thus optimized for local variable updates. + */ +#define lsub_positive(_ptr, _val) do { \ + typeof(_ptr) ptr = (_ptr); \ + *ptr -= min_t(typeof(*ptr), *ptr, _val); \ +} while (0) + #ifdef CONFIG_SMP static inline void enqueue_runnable_load_avg(struct cfs_rq *cfs_rq, struct sched_entity *se) @@ -3604,7 +3615,7 @@ static inline unsigned long _task_util_est(struct task_struct *p) { struct util_est ue = READ_ONCE(p->se.avg.util_est); - return max(ue.ewma, ue.enqueued); + return (max(ue.ewma, ue.enqueued) | UTIL_AVG_UNCHANGED); } static inline unsigned long task_util_est(struct task_struct *p) @@ -3622,7 +3633,7 @@ static inline void util_est_enqueue(struct cfs_rq *cfs_rq, /* Update root cfs_rq's estimated utilization */ enqueued = cfs_rq->avg.util_est.enqueued; - enqueued += (_task_util_est(p) | UTIL_AVG_UNCHANGED); + enqueued += _task_util_est(p); WRITE_ONCE(cfs_rq->avg.util_est.enqueued, enqueued); } @@ -3650,8 +3661,7 @@ util_est_dequeue(struct cfs_rq *cfs_rq, struct task_struct *p, bool task_sleep) /* Update root cfs_rq's estimated utilization */ ue.enqueued = cfs_rq->avg.util_est.enqueued; - ue.enqueued -= min_t(unsigned int, ue.enqueued, - (_task_util_est(p) | UTIL_AVG_UNCHANGED)); + ue.enqueued -= min_t(unsigned int, ue.enqueued, _task_util_est(p)); WRITE_ONCE(cfs_rq->avg.util_est.enqueued, ue.enqueued); /* @@ -3966,8 +3976,8 @@ dequeue_entity(struct cfs_rq *cfs_rq, struct sched_entity *se, int flags) /* * When dequeuing a sched_entity, we must: * - Update loads to have both entity and cfs_rq synced with now. - * - Substract its load from the cfs_rq->runnable_avg. - * - Substract its previous weight from cfs_rq->load.weight. + * - Subtract its load from the cfs_rq->runnable_avg. + * - Subtract its previous weight from cfs_rq->load.weight. * - For group entity, update its weight to reflect the new share * of its group cfs_rq. */ @@ -4640,7 +4650,7 @@ static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun) cfs_b->distribute_running = 0; throttled = !list_empty(&cfs_b->throttled_cfs_rq); - cfs_b->runtime -= min(runtime, cfs_b->runtime); + lsub_positive(&cfs_b->runtime, runtime); } /* @@ -4774,7 +4784,7 @@ static void do_sched_cfs_slack_timer(struct cfs_bandwidth *cfs_b) raw_spin_lock(&cfs_b->lock); if (expires == cfs_b->runtime_expires) - cfs_b->runtime -= min(runtime, cfs_b->runtime); + lsub_positive(&cfs_b->runtime, runtime); cfs_b->distribute_running = 0; raw_spin_unlock(&cfs_b->lock); } @@ -5072,6 +5082,24 @@ static inline void hrtick_update(struct rq *rq) } #endif +#ifdef CONFIG_SMP +static inline unsigned long cpu_util(int cpu); +static unsigned long capacity_of(int cpu); + +static inline bool cpu_overutilized(int cpu) +{ + return (capacity_of(cpu) * 1024) < (cpu_util(cpu) * capacity_margin); +} + +static inline void update_overutilized_status(struct rq *rq) +{ + if (!READ_ONCE(rq->rd->overutilized) && cpu_overutilized(rq->cpu)) + WRITE_ONCE(rq->rd->overutilized, SG_OVERUTILIZED); +} +#else +static inline void update_overutilized_status(struct rq *rq) { } +#endif + /* * The enqueue_task method is called before nr_running is * increased. Here we update the fair scheduling stats and @@ -5129,8 +5157,26 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags) update_cfs_group(se); } - if (!se) + if (!se) { add_nr_running(rq, 1); + /* + * Since new tasks are assigned an initial util_avg equal to + * half of the spare capacity of their CPU, tiny tasks have the + * ability to cross the overutilized threshold, which will + * result in the load balancer ruining all the task placement + * done by EAS. As a way to mitigate that effect, do not account + * for the first enqueue operation of new tasks during the + * overutilized flag detection. + * + * A better way of solving this problem would be to wait for + * the PELT signals of tasks to converge before taking them + * into account, but that is not straightforward to implement, + * and the following generally works well enough in practice. + */ + if (flags & ENQUEUE_WAKEUP) + update_overutilized_status(rq); + + } hrtick_update(rq); } @@ -6241,7 +6287,7 @@ static unsigned long cpu_util_without(int cpu, struct task_struct *p) util = READ_ONCE(cfs_rq->avg.util_avg); /* Discount task's util from CPU's util */ - util -= min_t(unsigned int, util, task_util(p)); + lsub_positive(&util, task_util(p)); /* * Covered cases: @@ -6290,10 +6336,9 @@ static unsigned long cpu_util_without(int cpu, struct task_struct *p) * properly fix the execl regression and it helps in further * reducing the chances for the above race. */ - if (unlikely(task_on_rq_queued(p) || current == p)) { - estimated -= min_t(unsigned int, estimated, - (_task_util_est(p) | UTIL_AVG_UNCHANGED)); - } + if (unlikely(task_on_rq_queued(p) || current == p)) + lsub_positive(&estimated, _task_util_est(p)); + util = max(util, estimated); } @@ -6333,6 +6378,213 @@ static int wake_cap(struct task_struct *p, int cpu, int prev_cpu) } /* + * Predicts what cpu_util(@cpu) would return if @p was migrated (and enqueued) + * to @dst_cpu. + */ +static unsigned long cpu_util_next(int cpu, struct task_struct *p, int dst_cpu) +{ + struct cfs_rq *cfs_rq = &cpu_rq(cpu)->cfs; + unsigned long util_est, util = READ_ONCE(cfs_rq->avg.util_avg); + + /* + * If @p migrates from @cpu to another, remove its contribution. Or, + * if @p migrates from another CPU to @cpu, add its contribution. In + * the other cases, @cpu is not impacted by the migration, so the + * util_avg should already be correct. + */ + if (task_cpu(p) == cpu && dst_cpu != cpu) + sub_positive(&util, task_util(p)); + else if (task_cpu(p) != cpu && dst_cpu == cpu) + util += task_util(p); + + if (sched_feat(UTIL_EST)) { + util_est = READ_ONCE(cfs_rq->avg.util_est.enqueued); + + /* + * During wake-up, the task isn't enqueued yet and doesn't + * appear in the cfs_rq->avg.util_est.enqueued of any rq, + * so just add it (if needed) to "simulate" what will be + * cpu_util() after the task has been enqueued. + */ + if (dst_cpu == cpu) + util_est += _task_util_est(p); + + util = max(util, util_est); + } + + return min(util, capacity_orig_of(cpu)); +} + +/* + * compute_energy(): Estimates the energy that would be consumed if @p was + * migrated to @dst_cpu. compute_energy() predicts what will be the utilization + * landscape of the * CPUs after the task migration, and uses the Energy Model + * to compute what would be the energy if we decided to actually migrate that + * task. + */ +static long +compute_energy(struct task_struct *p, int dst_cpu, struct perf_domain *pd) +{ + long util, max_util, sum_util, energy = 0; + int cpu; + + for (; pd; pd = pd->next) { + max_util = sum_util = 0; + /* + * The capacity state of CPUs of the current rd can be driven by + * CPUs of another rd if they belong to the same performance + * domain. So, account for the utilization of these CPUs too + * by masking pd with cpu_online_mask instead of the rd span. + * + * If an entire performance domain is outside of the current rd, + * it will not appear in its pd list and will not be accounted + * by compute_energy(). + */ + for_each_cpu_and(cpu, perf_domain_span(pd), cpu_online_mask) { + util = cpu_util_next(cpu, p, dst_cpu); + util = schedutil_energy_util(cpu, util); + max_util = max(util, max_util); + sum_util += util; + } + + energy += em_pd_energy(pd->em_pd, max_util, sum_util); + } + + return energy; +} + +/* + * find_energy_efficient_cpu(): Find most energy-efficient target CPU for the + * waking task. find_energy_efficient_cpu() looks for the CPU with maximum + * spare capacity in each performance domain and uses it as a potential + * candidate to execute the task. Then, it uses the Energy Model to figure + * out which of the CPU candidates is the most energy-efficient. + * + * The rationale for this heuristic is as follows. In a performance domain, + * all the most energy efficient CPU candidates (according to the Energy + * Model) are those for which we'll request a low frequency. When there are + * several CPUs for which the frequency request will be the same, we don't + * have enough data to break the tie between them, because the Energy Model + * only includes active power costs. With this model, if we assume that + * frequency requests follow utilization (e.g. using schedutil), the CPU with + * the maximum spare capacity in a performance domain is guaranteed to be among + * the best candidates of the performance domain. + * + * In practice, it could be preferable from an energy standpoint to pack + * small tasks on a CPU in order to let other CPUs go in deeper idle states, + * but that could also hurt our chances to go cluster idle, and we have no + * ways to tell with the current Energy Model if this is actually a good + * idea or not. So, find_energy_efficient_cpu() basically favors + * cluster-packing, and spreading inside a cluster. That should at least be + * a good thing for latency, and this is consistent with the idea that most + * of the energy savings of EAS come from the asymmetry of the system, and + * not so much from breaking the tie between identical CPUs. That's also the + * reason why EAS is enabled in the topology code only for systems where + * SD_ASYM_CPUCAPACITY is set. + * + * NOTE: Forkees are not accepted in the energy-aware wake-up path because + * they don't have any useful utilization data yet and it's not possible to + * forecast their impact on energy consumption. Consequently, they will be + * placed by find_idlest_cpu() on the least loaded CPU, which might turn out + * to be energy-inefficient in some use-cases. The alternative would be to + * bias new tasks towards specific types of CPUs first, or to try to infer + * their util_avg from the parent task, but those heuristics could hurt + * other use-cases too. So, until someone finds a better way to solve this, + * let's keep things simple by re-using the existing slow path. + */ + +static int find_energy_efficient_cpu(struct task_struct *p, int prev_cpu) +{ + unsigned long prev_energy = ULONG_MAX, best_energy = ULONG_MAX; + struct root_domain *rd = cpu_rq(smp_processor_id())->rd; + int cpu, best_energy_cpu = prev_cpu; + struct perf_domain *head, *pd; + unsigned long cpu_cap, util; + struct sched_domain *sd; + + rcu_read_lock(); + pd = rcu_dereference(rd->pd); + if (!pd || READ_ONCE(rd->overutilized)) + goto fail; + head = pd; + + /* + * Energy-aware wake-up happens on the lowest sched_domain starting + * from sd_asym_cpucapacity spanning over this_cpu and prev_cpu. + */ + sd = rcu_dereference(*this_cpu_ptr(&sd_asym_cpucapacity)); + while (sd && !cpumask_test_cpu(prev_cpu, sched_domain_span(sd))) + sd = sd->parent; + if (!sd) + goto fail; + + sync_entity_load_avg(&p->se); + if (!task_util_est(p)) + goto unlock; + + for (; pd; pd = pd->next) { + unsigned long cur_energy, spare_cap, max_spare_cap = 0; + int max_spare_cap_cpu = -1; + + for_each_cpu_and(cpu, perf_domain_span(pd), sched_domain_span(sd)) { + if (!cpumask_test_cpu(cpu, &p->cpus_allowed)) + continue; + + /* Skip CPUs that will be overutilized. */ + util = cpu_util_next(cpu, p, cpu); + cpu_cap = capacity_of(cpu); + if (cpu_cap * 1024 < util * capacity_margin) + continue; + + /* Always use prev_cpu as a candidate. */ + if (cpu == prev_cpu) { + prev_energy = compute_energy(p, prev_cpu, head); + best_energy = min(best_energy, prev_energy); + continue; + } + + /* + * Find the CPU with the maximum spare capacity in + * the performance domain + */ + spare_cap = cpu_cap - util; + if (spare_cap > max_spare_cap) { + max_spare_cap = spare_cap; + max_spare_cap_cpu = cpu; + } + } + + /* Evaluate the energy impact of using this CPU. */ + if (max_spare_cap_cpu >= 0) { + cur_energy = compute_energy(p, max_spare_cap_cpu, head); + if (cur_energy < best_energy) { + best_energy = cur_energy; + best_energy_cpu = max_spare_cap_cpu; + } + } + } +unlock: + rcu_read_unlock(); + + /* + * Pick the best CPU if prev_cpu cannot be used, or if it saves at + * least 6% of the energy used by prev_cpu. + */ + if (prev_energy == ULONG_MAX) + return best_energy_cpu; + + if ((prev_energy - best_energy) > (prev_energy >> 4)) + return best_energy_cpu; + + return prev_cpu; + +fail: + rcu_read_unlock(); + + return -1; +} + +/* * select_task_rq_fair: Select target runqueue for the waking task in domains * that have the 'sd_flag' flag set. In practice, this is SD_BALANCE_WAKE, * SD_BALANCE_FORK, or SD_BALANCE_EXEC. @@ -6355,8 +6607,16 @@ select_task_rq_fair(struct task_struct *p, int prev_cpu, int sd_flag, int wake_f if (sd_flag & SD_BALANCE_WAKE) { record_wakee(p); - want_affine = !wake_wide(p) && !wake_cap(p, cpu, prev_cpu) - && cpumask_test_cpu(cpu, &p->cpus_allowed); + + if (static_branch_unlikely(&sched_energy_present)) { + new_cpu = find_energy_efficient_cpu(p, prev_cpu); + if (new_cpu >= 0) + return new_cpu; + new_cpu = prev_cpu; + } + + want_affine = !wake_wide(p) && !wake_cap(p, cpu, prev_cpu) && + cpumask_test_cpu(cpu, &p->cpus_allowed); } rcu_read_lock(); @@ -6520,7 +6780,7 @@ wakeup_preempt_entity(struct sched_entity *curr, struct sched_entity *se) static void set_last_buddy(struct sched_entity *se) { - if (entity_is_task(se) && unlikely(task_of(se)->policy == SCHED_IDLE)) + if (entity_is_task(se) && unlikely(task_has_idle_policy(task_of(se)))) return; for_each_sched_entity(se) { @@ -6532,7 +6792,7 @@ static void set_last_buddy(struct sched_entity *se) static void set_next_buddy(struct sched_entity *se) { - if (entity_is_task(se) && unlikely(task_of(se)->policy == SCHED_IDLE)) + if (entity_is_task(se) && unlikely(task_has_idle_policy(task_of(se)))) return; for_each_sched_entity(se) { @@ -6590,8 +6850,8 @@ static void check_preempt_wakeup(struct rq *rq, struct task_struct *p, int wake_ return; /* Idle tasks are by definition preempted by non-idle tasks. */ - if (unlikely(curr->policy == SCHED_IDLE) && - likely(p->policy != SCHED_IDLE)) + if (unlikely(task_has_idle_policy(curr)) && + likely(!task_has_idle_policy(p))) goto preempt; /* @@ -7012,7 +7272,7 @@ static int task_hot(struct task_struct *p, struct lb_env *env) if (p->sched_class != &fair_sched_class) return 0; - if (unlikely(p->policy == SCHED_IDLE)) + if (unlikely(task_has_idle_policy(p))) return 0; /* @@ -7896,16 +8156,16 @@ static bool update_nohz_stats(struct rq *rq, bool force) * update_sg_lb_stats - Update sched_group's statistics for load balancing. * @env: The load balancing environment. * @group: sched_group whose statistics are to be updated. - * @load_idx: Load index of sched_domain of this_cpu for load calc. - * @local_group: Does group contain this_cpu. * @sgs: variable to hold the statistics for this group. - * @overload: Indicate pullable load (e.g. >1 runnable task). + * @sg_status: Holds flag indicating the status of the sched_group */ static inline void update_sg_lb_stats(struct lb_env *env, - struct sched_group *group, int load_idx, - int local_group, struct sg_lb_stats *sgs, - bool *overload) + struct sched_group *group, + struct sg_lb_stats *sgs, + int *sg_status) { + int local_group = cpumask_test_cpu(env->dst_cpu, sched_group_span(group)); + int load_idx = get_sd_load_idx(env->sd, env->idle); unsigned long load; int i, nr_running; @@ -7929,7 +8189,10 @@ static inline void update_sg_lb_stats(struct lb_env *env, nr_running = rq->nr_running; if (nr_running > 1) - *overload = true; + *sg_status |= SG_OVERLOAD; + + if (cpu_overutilized(i)) + *sg_status |= SG_OVERUTILIZED; #ifdef CONFIG_NUMA_BALANCING sgs->nr_numa_running += rq->nr_numa_running; @@ -7945,7 +8208,7 @@ static inline void update_sg_lb_stats(struct lb_env *env, if (env->sd->flags & SD_ASYM_CPUCAPACITY && sgs->group_misfit_task_load < rq->misfit_task_load) { sgs->group_misfit_task_load = rq->misfit_task_load; - *overload = 1; + *sg_status |= SG_OVERLOAD; } } @@ -8090,17 +8353,14 @@ static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sd struct sched_group *sg = env->sd->groups; struct sg_lb_stats *local = &sds->local_stat; struct sg_lb_stats tmp_sgs; - int load_idx; - bool overload = false; bool prefer_sibling = child && child->flags & SD_PREFER_SIBLING; + int sg_status = 0; #ifdef CONFIG_NO_HZ_COMMON if (env->idle == CPU_NEWLY_IDLE && READ_ONCE(nohz.has_blocked)) env->flags |= LBF_NOHZ_STATS; #endif - load_idx = get_sd_load_idx(env->sd, env->idle); - do { struct sg_lb_stats *sgs = &tmp_sgs; int local_group; @@ -8115,8 +8375,7 @@ static inline void update_sd_lb_stats(struct lb_env *env, struct sd_lb_stats *sd update_group_capacity(env->sd, env->dst_cpu); } - update_sg_lb_stats(env, sg, load_idx, local_group, sgs, - &overload); + update_sg_lb_stats(env, sg, sgs, &sg_status); if (local_group) goto next_group; @@ -8165,9 +8424,15 @@ next_group: env->fbq_type = fbq_classify_group(&sds->busiest_stat); if (!env->sd->parent) { + struct root_domain *rd = env->dst_rq->rd; + /* update overload indicator if we are at root domain */ - if (READ_ONCE(env->dst_rq->rd->overload) != overload) - WRITE_ONCE(env->dst_rq->rd->overload, overload); + WRITE_ONCE(rd->overload, sg_status & SG_OVERLOAD); + + /* Update over-utilization (tipping point, U >= 0) indicator */ + WRITE_ONCE(rd->overutilized, sg_status & SG_OVERUTILIZED); + } else if (sg_status & SG_OVERUTILIZED) { + WRITE_ONCE(env->dst_rq->rd->overutilized, SG_OVERUTILIZED); } } @@ -8394,6 +8659,14 @@ static struct sched_group *find_busiest_group(struct lb_env *env) * this level. */ update_sd_lb_stats(env, &sds); + + if (static_branch_unlikely(&sched_energy_present)) { + struct root_domain *rd = env->dst_rq->rd; + + if (rcu_dereference(rd->pd) && !READ_ONCE(rd->overutilized)) + goto out_balanced; + } + local = &sds.local_stat; busiest = &sds.busiest_stat; @@ -8910,13 +9183,22 @@ out_all_pinned: sd->nr_balance_failed = 0; out_one_pinned: + ld_moved = 0; + + /* + * idle_balance() disregards balance intervals, so we could repeatedly + * reach this code, which would lead to balance_interval skyrocketting + * in a short amount of time. Skip the balance_interval increase logic + * to avoid that. + */ + if (env.idle == CPU_NEWLY_IDLE) + goto out; + /* tune up the balancing interval */ - if (((env.flags & LBF_ALL_PINNED) && - sd->balance_interval < MAX_PINNED_INTERVAL) || - (sd->balance_interval < sd->max_interval)) + if ((env.flags & LBF_ALL_PINNED && + sd->balance_interval < MAX_PINNED_INTERVAL) || + sd->balance_interval < sd->max_interval) sd->balance_interval *= 2; - - ld_moved = 0; out: return ld_moved; } @@ -9281,7 +9563,7 @@ static void nohz_balancer_kick(struct rq *rq) } } - sd = rcu_dereference(per_cpu(sd_asym, cpu)); + sd = rcu_dereference(per_cpu(sd_asym_packing, cpu)); if (sd) { for_each_cpu(i, sched_domain_span(sd)) { if (i == cpu || @@ -9783,6 +10065,7 @@ static void task_tick_fair(struct rq *rq, struct task_struct *curr, int queued) task_tick_numa(rq, curr); update_misfit_status(curr, rq); + update_overutilized_status(task_rq(curr)); } /* diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c index e6802181900f..81faddba9e20 100644 --- a/kernel/sched/isolation.c +++ b/kernel/sched/isolation.c @@ -8,14 +8,14 @@ */ #include "sched.h" -DEFINE_STATIC_KEY_FALSE(housekeeping_overriden); -EXPORT_SYMBOL_GPL(housekeeping_overriden); +DEFINE_STATIC_KEY_FALSE(housekeeping_overridden); +EXPORT_SYMBOL_GPL(housekeeping_overridden); static cpumask_var_t housekeeping_mask; static unsigned int housekeeping_flags; int housekeeping_any_cpu(enum hk_flags flags) { - if (static_branch_unlikely(&housekeeping_overriden)) + if (static_branch_unlikely(&housekeeping_overridden)) if (housekeeping_flags & flags) return cpumask_any_and(housekeeping_mask, cpu_online_mask); return smp_processor_id(); @@ -24,7 +24,7 @@ EXPORT_SYMBOL_GPL(housekeeping_any_cpu); const struct cpumask *housekeeping_cpumask(enum hk_flags flags) { - if (static_branch_unlikely(&housekeeping_overriden)) + if (static_branch_unlikely(&housekeeping_overridden)) if (housekeeping_flags & flags) return housekeeping_mask; return cpu_possible_mask; @@ -33,7 +33,7 @@ EXPORT_SYMBOL_GPL(housekeeping_cpumask); void housekeeping_affine(struct task_struct *t, enum hk_flags flags) { - if (static_branch_unlikely(&housekeeping_overriden)) + if (static_branch_unlikely(&housekeeping_overridden)) if (housekeeping_flags & flags) set_cpus_allowed_ptr(t, housekeeping_mask); } @@ -41,7 +41,7 @@ EXPORT_SYMBOL_GPL(housekeeping_affine); bool housekeeping_test_cpu(int cpu, enum hk_flags flags) { - if (static_branch_unlikely(&housekeeping_overriden)) + if (static_branch_unlikely(&housekeeping_overridden)) if (housekeeping_flags & flags) return cpumask_test_cpu(cpu, housekeeping_mask); return true; @@ -53,7 +53,7 @@ void __init housekeeping_init(void) if (!housekeeping_flags) return; - static_branch_enable(&housekeeping_overriden); + static_branch_enable(&housekeeping_overridden); if (housekeeping_flags & HK_FLAG_TICK) sched_tick_offload_init(); diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index a21ea6021929..e4f398ad9e73 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -1498,6 +1498,14 @@ static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p, int flag #endif } +static inline void set_next_task(struct rq *rq, struct task_struct *p) +{ + p->se.exec_start = rq_clock_task(rq); + + /* The running task is never eligible for pushing */ + dequeue_pushable_task(rq, p); +} + static struct sched_rt_entity *pick_next_rt_entity(struct rq *rq, struct rt_rq *rt_rq) { @@ -1518,7 +1526,6 @@ static struct sched_rt_entity *pick_next_rt_entity(struct rq *rq, static struct task_struct *_pick_next_task_rt(struct rq *rq) { struct sched_rt_entity *rt_se; - struct task_struct *p; struct rt_rq *rt_rq = &rq->rt; do { @@ -1527,10 +1534,7 @@ static struct task_struct *_pick_next_task_rt(struct rq *rq) rt_rq = group_rt_rq(rt_se); } while (rt_rq); - p = rt_task_of(rt_se); - p->se.exec_start = rq_clock_task(rq); - - return p; + return rt_task_of(rt_se); } static struct task_struct * @@ -1573,8 +1577,7 @@ pick_next_task_rt(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) p = _pick_next_task_rt(rq); - /* The running task is never eligible for pushing */ - dequeue_pushable_task(rq, p); + set_next_task(rq, p); rt_queue_push_tasks(rq); @@ -1810,10 +1813,8 @@ static int push_rt_task(struct rq *rq) return 0; retry: - if (unlikely(next_task == rq->curr)) { - WARN_ON(1); + if (WARN_ON(next_task == rq->curr)) return 0; - } /* * It's possible that the next_task slipped in of @@ -2355,12 +2356,7 @@ static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued) static void set_curr_task_rt(struct rq *rq) { - struct task_struct *p = rq->curr; - - p->se.exec_start = rq_clock_task(rq); - - /* The running task is never eligible for pushing */ - dequeue_pushable_task(rq, p); + set_next_task(rq, rq->curr); } static unsigned int get_rr_interval_rt(struct rq *rq, struct task_struct *task) diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 4e524ab589c9..0ba08924e017 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -45,6 +45,7 @@ #include <linux/ctype.h> #include <linux/debugfs.h> #include <linux/delayacct.h> +#include <linux/energy_model.h> #include <linux/init_task.h> #include <linux/kprobes.h> #include <linux/kthread.h> @@ -177,6 +178,11 @@ static inline bool valid_policy(int policy) rt_policy(policy) || dl_policy(policy); } +static inline int task_has_idle_policy(struct task_struct *p) +{ + return idle_policy(p->policy); +} + static inline int task_has_rt_policy(struct task_struct *p) { return rt_policy(p->policy); @@ -632,7 +638,7 @@ struct dl_rq { /* * Deadline values of the currently executing and the * earliest ready task on this rq. Caching these facilitates - * the decision wether or not a ready but not running task + * the decision whether or not a ready but not running task * should migrate somewhere else. */ struct { @@ -704,6 +710,16 @@ static inline bool sched_asym_prefer(int a, int b) return arch_asym_cpu_priority(a) > arch_asym_cpu_priority(b); } +struct perf_domain { + struct em_perf_domain *em_pd; + struct perf_domain *next; + struct rcu_head rcu; +}; + +/* Scheduling group status flags */ +#define SG_OVERLOAD 0x1 /* More than one runnable task on a CPU. */ +#define SG_OVERUTILIZED 0x2 /* One or more CPUs are over-utilized. */ + /* * We add the notion of a root-domain which will be used to define per-domain * variables. Each exclusive cpuset essentially defines an island domain by @@ -726,6 +742,9 @@ struct root_domain { */ int overload; + /* Indicate one or more cpus over-utilized (tipping point) */ + int overutilized; + /* * The bit corresponding to a CPU gets set here if such CPU has more * than one runnable -deadline task (as it is below for RT tasks). @@ -756,6 +775,12 @@ struct root_domain { struct cpupri cpupri; unsigned long max_cpu_capacity; + + /* + * NULL-terminated list of performance domains intersecting with the + * CPUs of the rd. Protected by RCU. + */ + struct perf_domain *pd; }; extern struct root_domain def_root_domain; @@ -1285,7 +1310,8 @@ DECLARE_PER_CPU(int, sd_llc_size); DECLARE_PER_CPU(int, sd_llc_id); DECLARE_PER_CPU(struct sched_domain_shared *, sd_llc_shared); DECLARE_PER_CPU(struct sched_domain *, sd_numa); -DECLARE_PER_CPU(struct sched_domain *, sd_asym); +DECLARE_PER_CPU(struct sched_domain *, sd_asym_packing); +DECLARE_PER_CPU(struct sched_domain *, sd_asym_cpucapacity); extern struct static_key_false sched_asym_cpucapacity; struct sched_group_capacity { @@ -1429,7 +1455,7 @@ static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) #ifdef CONFIG_SMP /* * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be - * successfuly executed on another CPU. We must ensure that updates of + * successfully executed on another CPU. We must ensure that updates of * per-task data have been completed by this moment. */ smp_wmb(); @@ -1794,12 +1820,12 @@ static inline void add_nr_running(struct rq *rq, unsigned count) rq->nr_running = prev_nr + count; - if (prev_nr < 2 && rq->nr_running >= 2) { #ifdef CONFIG_SMP + if (prev_nr < 2 && rq->nr_running >= 2) { if (!READ_ONCE(rq->rd->overload)) WRITE_ONCE(rq->rd->overload, 1); -#endif } +#endif sched_update_tick_dependency(rq); } @@ -1855,27 +1881,6 @@ unsigned long arch_scale_freq_capacity(int cpu) #endif #ifdef CONFIG_SMP -#ifndef arch_scale_cpu_capacity -static __always_inline -unsigned long arch_scale_cpu_capacity(struct sched_domain *sd, int cpu) -{ - if (sd && (sd->flags & SD_SHARE_CPUCAPACITY) && (sd->span_weight > 1)) - return sd->smt_gain / sd->span_weight; - - return SCHED_CAPACITY_SCALE; -} -#endif -#else -#ifndef arch_scale_cpu_capacity -static __always_inline -unsigned long arch_scale_cpu_capacity(void __always_unused *sd, int cpu) -{ - return SCHED_CAPACITY_SCALE; -} -#endif -#endif - -#ifdef CONFIG_SMP #ifdef CONFIG_PREEMPT static inline void double_rq_lock(struct rq *rq1, struct rq *rq2); @@ -2207,6 +2212,31 @@ static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) {} #endif #ifdef CONFIG_CPU_FREQ_GOV_SCHEDUTIL +/** + * enum schedutil_type - CPU utilization type + * @FREQUENCY_UTIL: Utilization used to select frequency + * @ENERGY_UTIL: Utilization used during energy calculation + * + * The utilization signals of all scheduling classes (CFS/RT/DL) and IRQ time + * need to be aggregated differently depending on the usage made of them. This + * enum is used within schedutil_freq_util() to differentiate the types of + * utilization expected by the callers, and adjust the aggregation accordingly. + */ +enum schedutil_type { + FREQUENCY_UTIL, + ENERGY_UTIL, +}; + +unsigned long schedutil_freq_util(int cpu, unsigned long util_cfs, + unsigned long max, enum schedutil_type type); + +static inline unsigned long schedutil_energy_util(int cpu, unsigned long cfs) +{ + unsigned long max = arch_scale_cpu_capacity(NULL, cpu); + + return schedutil_freq_util(cpu, cfs, max, ENERGY_UTIL); +} + static inline unsigned long cpu_bw_dl(struct rq *rq) { return (rq->dl.running_bw * SCHED_CAPACITY_SCALE) >> BW_SHIFT; @@ -2233,6 +2263,11 @@ static inline unsigned long cpu_util_rt(struct rq *rq) { return READ_ONCE(rq->avg_rt.util_avg); } +#else /* CONFIG_CPU_FREQ_GOV_SCHEDUTIL */ +static inline unsigned long schedutil_energy_util(int cpu, unsigned long cfs) +{ + return cfs; +} #endif #ifdef CONFIG_HAVE_SCHED_AVG_IRQ @@ -2262,3 +2297,13 @@ unsigned long scale_irq_capacity(unsigned long util, unsigned long irq, unsigned return util; } #endif + +#if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_CPU_FREQ_GOV_SCHEDUTIL) +#define perf_domain_span(pd) (to_cpumask(((pd)->em_pd->cpus))) +#else +#define perf_domain_span(pd) NULL +#endif + +#ifdef CONFIG_SMP +extern struct static_key_false sched_energy_present; +#endif diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c index 8d7f15ba5916..3f35ba1d8fde 100644 --- a/kernel/sched/topology.c +++ b/kernel/sched/topology.c @@ -201,6 +201,199 @@ sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent) return 1; } +DEFINE_STATIC_KEY_FALSE(sched_energy_present); +#if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_CPU_FREQ_GOV_SCHEDUTIL) +DEFINE_MUTEX(sched_energy_mutex); +bool sched_energy_update; + +static void free_pd(struct perf_domain *pd) +{ + struct perf_domain *tmp; + + while (pd) { + tmp = pd->next; + kfree(pd); + pd = tmp; + } +} + +static struct perf_domain *find_pd(struct perf_domain *pd, int cpu) +{ + while (pd) { + if (cpumask_test_cpu(cpu, perf_domain_span(pd))) + return pd; + pd = pd->next; + } + + return NULL; +} + +static struct perf_domain *pd_init(int cpu) +{ + struct em_perf_domain *obj = em_cpu_get(cpu); + struct perf_domain *pd; + + if (!obj) { + if (sched_debug()) + pr_info("%s: no EM found for CPU%d\n", __func__, cpu); + return NULL; + } + + pd = kzalloc(sizeof(*pd), GFP_KERNEL); + if (!pd) + return NULL; + pd->em_pd = obj; + + return pd; +} + +static void perf_domain_debug(const struct cpumask *cpu_map, + struct perf_domain *pd) +{ + if (!sched_debug() || !pd) + return; + + printk(KERN_DEBUG "root_domain %*pbl:", cpumask_pr_args(cpu_map)); + + while (pd) { + printk(KERN_CONT " pd%d:{ cpus=%*pbl nr_cstate=%d }", + cpumask_first(perf_domain_span(pd)), + cpumask_pr_args(perf_domain_span(pd)), + em_pd_nr_cap_states(pd->em_pd)); + pd = pd->next; + } + + printk(KERN_CONT "\n"); +} + +static void destroy_perf_domain_rcu(struct rcu_head *rp) +{ + struct perf_domain *pd; + + pd = container_of(rp, struct perf_domain, rcu); + free_pd(pd); +} + +static void sched_energy_set(bool has_eas) +{ + if (!has_eas && static_branch_unlikely(&sched_energy_present)) { + if (sched_debug()) + pr_info("%s: stopping EAS\n", __func__); + static_branch_disable_cpuslocked(&sched_energy_present); + } else if (has_eas && !static_branch_unlikely(&sched_energy_present)) { + if (sched_debug()) + pr_info("%s: starting EAS\n", __func__); + static_branch_enable_cpuslocked(&sched_energy_present); + } +} + +/* + * EAS can be used on a root domain if it meets all the following conditions: + * 1. an Energy Model (EM) is available; + * 2. the SD_ASYM_CPUCAPACITY flag is set in the sched_domain hierarchy. + * 3. the EM complexity is low enough to keep scheduling overheads low; + * 4. schedutil is driving the frequency of all CPUs of the rd; + * + * The complexity of the Energy Model is defined as: + * + * C = nr_pd * (nr_cpus + nr_cs) + * + * with parameters defined as: + * - nr_pd: the number of performance domains + * - nr_cpus: the number of CPUs + * - nr_cs: the sum of the number of capacity states of all performance + * domains (for example, on a system with 2 performance domains, + * with 10 capacity states each, nr_cs = 2 * 10 = 20). + * + * It is generally not a good idea to use such a model in the wake-up path on + * very complex platforms because of the associated scheduling overheads. The + * arbitrary constraint below prevents that. It makes EAS usable up to 16 CPUs + * with per-CPU DVFS and less than 8 capacity states each, for example. + */ +#define EM_MAX_COMPLEXITY 2048 + +extern struct cpufreq_governor schedutil_gov; +static bool build_perf_domains(const struct cpumask *cpu_map) +{ + int i, nr_pd = 0, nr_cs = 0, nr_cpus = cpumask_weight(cpu_map); + struct perf_domain *pd = NULL, *tmp; + int cpu = cpumask_first(cpu_map); + struct root_domain *rd = cpu_rq(cpu)->rd; + struct cpufreq_policy *policy; + struct cpufreq_governor *gov; + + /* EAS is enabled for asymmetric CPU capacity topologies. */ + if (!per_cpu(sd_asym_cpucapacity, cpu)) { + if (sched_debug()) { + pr_info("rd %*pbl: CPUs do not have asymmetric capacities\n", + cpumask_pr_args(cpu_map)); + } + goto free; + } + + for_each_cpu(i, cpu_map) { + /* Skip already covered CPUs. */ + if (find_pd(pd, i)) + continue; + + /* Do not attempt EAS if schedutil is not being used. */ + policy = cpufreq_cpu_get(i); + if (!policy) + goto free; + gov = policy->governor; + cpufreq_cpu_put(policy); + if (gov != &schedutil_gov) { + if (rd->pd) + pr_warn("rd %*pbl: Disabling EAS, schedutil is mandatory\n", + cpumask_pr_args(cpu_map)); + goto free; + } + + /* Create the new pd and add it to the local list. */ + tmp = pd_init(i); + if (!tmp) + goto free; + tmp->next = pd; + pd = tmp; + + /* + * Count performance domains and capacity states for the + * complexity check. + */ + nr_pd++; + nr_cs += em_pd_nr_cap_states(pd->em_pd); + } + + /* Bail out if the Energy Model complexity is too high. */ + if (nr_pd * (nr_cs + nr_cpus) > EM_MAX_COMPLEXITY) { + WARN(1, "rd %*pbl: Failed to start EAS, EM complexity is too high\n", + cpumask_pr_args(cpu_map)); + goto free; + } + + perf_domain_debug(cpu_map, pd); + + /* Attach the new list of performance domains to the root domain. */ + tmp = rd->pd; + rcu_assign_pointer(rd->pd, pd); + if (tmp) + call_rcu(&tmp->rcu, destroy_perf_domain_rcu); + + return !!pd; + +free: + free_pd(pd); + tmp = rd->pd; + rcu_assign_pointer(rd->pd, NULL); + if (tmp) + call_rcu(&tmp->rcu, destroy_perf_domain_rcu); + + return false; +} +#else +static void free_pd(struct perf_domain *pd) { } +#endif /* CONFIG_ENERGY_MODEL && CONFIG_CPU_FREQ_GOV_SCHEDUTIL*/ + static void free_rootdomain(struct rcu_head *rcu) { struct root_domain *rd = container_of(rcu, struct root_domain, rcu); @@ -211,6 +404,7 @@ static void free_rootdomain(struct rcu_head *rcu) free_cpumask_var(rd->rto_mask); free_cpumask_var(rd->online); free_cpumask_var(rd->span); + free_pd(rd->pd); kfree(rd); } @@ -397,7 +591,8 @@ DEFINE_PER_CPU(int, sd_llc_size); DEFINE_PER_CPU(int, sd_llc_id); DEFINE_PER_CPU(struct sched_domain_shared *, sd_llc_shared); DEFINE_PER_CPU(struct sched_domain *, sd_numa); -DEFINE_PER_CPU(struct sched_domain *, sd_asym); +DEFINE_PER_CPU(struct sched_domain *, sd_asym_packing); +DEFINE_PER_CPU(struct sched_domain *, sd_asym_cpucapacity); DEFINE_STATIC_KEY_FALSE(sched_asym_cpucapacity); static void update_top_cache_domain(int cpu) @@ -423,7 +618,10 @@ static void update_top_cache_domain(int cpu) rcu_assign_pointer(per_cpu(sd_numa, cpu), sd); sd = highest_flag_domain(cpu, SD_ASYM_PACKING); - rcu_assign_pointer(per_cpu(sd_asym, cpu), sd); + rcu_assign_pointer(per_cpu(sd_asym_packing, cpu), sd); + + sd = lowest_flag_domain(cpu, SD_ASYM_CPUCAPACITY); + rcu_assign_pointer(per_cpu(sd_asym_cpucapacity, cpu), sd); } /* @@ -1133,7 +1331,6 @@ sd_init(struct sched_domain_topology_level *tl, .last_balance = jiffies, .balance_interval = sd_weight, - .smt_gain = 0, .max_newidle_lb_cost = 0, .next_decay_max_lb_cost = jiffies, .child = child, @@ -1164,7 +1361,6 @@ sd_init(struct sched_domain_topology_level *tl, if (sd->flags & SD_SHARE_CPUCAPACITY) { sd->imbalance_pct = 110; - sd->smt_gain = 1178; /* ~15% */ } else if (sd->flags & SD_SHARE_PKG_RESOURCES) { sd->imbalance_pct = 117; @@ -1934,6 +2130,7 @@ static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur, void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], struct sched_domain_attr *dattr_new) { + bool __maybe_unused has_eas = false; int i, j, n; int new_topology; @@ -1961,8 +2158,8 @@ void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], /* Destroy deleted domains: */ for (i = 0; i < ndoms_cur; i++) { for (j = 0; j < n && !new_topology; j++) { - if (cpumask_equal(doms_cur[i], doms_new[j]) - && dattrs_equal(dattr_cur, i, dattr_new, j)) + if (cpumask_equal(doms_cur[i], doms_new[j]) && + dattrs_equal(dattr_cur, i, dattr_new, j)) goto match1; } /* No match - a current sched domain not in new doms_new[] */ @@ -1982,8 +2179,8 @@ match1: /* Build new domains: */ for (i = 0; i < ndoms_new; i++) { for (j = 0; j < n && !new_topology; j++) { - if (cpumask_equal(doms_new[i], doms_cur[j]) - && dattrs_equal(dattr_new, i, dattr_cur, j)) + if (cpumask_equal(doms_new[i], doms_cur[j]) && + dattrs_equal(dattr_new, i, dattr_cur, j)) goto match2; } /* No match - add a new doms_new */ @@ -1992,6 +2189,24 @@ match2: ; } +#if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_CPU_FREQ_GOV_SCHEDUTIL) + /* Build perf. domains: */ + for (i = 0; i < ndoms_new; i++) { + for (j = 0; j < n && !sched_energy_update; j++) { + if (cpumask_equal(doms_new[i], doms_cur[j]) && + cpu_rq(cpumask_first(doms_cur[j]))->rd->pd) { + has_eas = true; + goto match3; + } + } + /* No match - add perf. domains for a new rd */ + has_eas |= build_perf_domains(doms_new[i]); +match3: + ; + } + sched_energy_set(has_eas); +#endif + /* Remember the new sched domains: */ if (doms_cur != &fallback_doms) free_sched_domains(doms_cur, ndoms_cur); |