diff --git a/Documentation/scheduler/sched-capacity.rst b/Documentation/scheduler/sched-capacity.rst index e2c1cf7431588..de414b33dd2ab 100644 --- a/Documentation/scheduler/sched-capacity.rst +++ b/Documentation/scheduler/sched-capacity.rst @@ -39,14 +39,15 @@ per Hz, leading to:: ------------------- Two different capacity values are used within the scheduler. A CPU's -``capacity_orig`` is its maximum attainable capacity, i.e. its maximum -attainable performance level. A CPU's ``capacity`` is its ``capacity_orig`` to -which some loss of available performance (e.g. time spent handling IRQs) is -subtracted. +``original capacity`` is its maximum attainable capacity, i.e. its maximum +attainable performance level. This original capacity is returned by +the function arch_scale_cpu_capacity(). A CPU's ``capacity`` is its ``original +capacity`` to which some loss of available performance (e.g. time spent +handling IRQs) is subtracted. Note that a CPU's ``capacity`` is solely intended to be used by the CFS class, -while ``capacity_orig`` is class-agnostic. The rest of this document will use -the term ``capacity`` interchangeably with ``capacity_orig`` for the sake of +while ``original capacity`` is class-agnostic. The rest of this document will use +the term ``capacity`` interchangeably with ``original capacity`` for the sake of brevity. 1.3 Platform examples diff --git a/Documentation/scheduler/schedutil.rst b/Documentation/scheduler/schedutil.rst index 32c7d69fc86c1..803fba8fc7142 100644 --- a/Documentation/scheduler/schedutil.rst +++ b/Documentation/scheduler/schedutil.rst @@ -90,8 +90,8 @@ For more detail see: - Documentation/scheduler/sched-capacity.rst:"1. CPU Capacity + 2. Task utilization" -UTIL_EST / UTIL_EST_FASTUP -========================== +UTIL_EST +======== Because periodic tasks have their averages decayed while they sleep, even though when running their expected utilization will be the same, they suffer a @@ -99,8 +99,7 @@ though when running their expected utilization will be the same, they suffer a To alleviate this (a default enabled option) UTIL_EST drives an Infinite Impulse Response (IIR) EWMA with the 'running' value on dequeue -- when it is -highest. A further default enabled option UTIL_EST_FASTUP modifies the IIR -filter to instantly increase and only decay on decrease. +highest. UTIL_EST filters to instantly increase and only decay on decrease. A further runqueue wide sum (of runnable tasks) is maintained of: diff --git a/Documentation/translations/zh_CN/scheduler/schedutil.rst b/Documentation/translations/zh_CN/scheduler/schedutil.rst index d1ea680075201..7c8d87f21c422 100644 --- a/Documentation/translations/zh_CN/scheduler/schedutil.rst +++ b/Documentation/translations/zh_CN/scheduler/schedutil.rst @@ -89,16 +89,15 @@ r_cpu被定义为当前CPU的最高性能水平与系统中任何其它CPU的最 - Documentation/translations/zh_CN/scheduler/sched-capacity.rst:"1. CPU Capacity + 2. Task utilization" -UTIL_EST / UTIL_EST_FASTUP -========================== +UTIL_EST +======== 由于周期性任务的平均数在睡眠时会衰减，而在运行时其预期利用率会和睡眠前相同， 因此它们在再次运行后会面临（DVFS）的上涨。 为了缓解这个问题，（一个默认使能的编译选项）UTIL_EST驱动一个无限脉冲响应 （Infinite Impulse Response，IIR）的EWMA，“运行”值在出队时是最高的。 -另一个默认使能的编译选项UTIL_EST_FASTUP修改了IIR滤波器，使其允许立即增加， -仅在利用率下降时衰减。 +UTIL_EST滤波使其在遇到更高值时立刻增加，而遇到低值时会缓慢衰减。 进一步，运行队列的（可运行任务的）利用率之和由下式计算： diff --git a/arch/arm/include/asm/topology.h b/arch/arm/include/asm/topology.h index c7d2510e5a786..853c4f81ba4a5 100644 --- a/arch/arm/include/asm/topology.h +++ b/arch/arm/include/asm/topology.h @@ -13,6 +13,7 @@ #define arch_set_freq_scale topology_set_freq_scale #define arch_scale_freq_capacity topology_get_freq_scale #define arch_scale_freq_invariant topology_scale_freq_invariant +#define arch_scale_freq_ref topology_get_freq_ref #endif /* Replace task scheduler's default cpu-invariant accounting */ diff --git a/arch/arm64/include/asm/topology.h b/arch/arm64/include/asm/topology.h index 9fab663dd2de9..a323b109b9c44 100644 --- a/arch/arm64/include/asm/topology.h +++ b/arch/arm64/include/asm/topology.h @@ -23,6 +23,7 @@ void update_freq_counters_refs(void); #define arch_set_freq_scale topology_set_freq_scale #define arch_scale_freq_capacity topology_get_freq_scale #define arch_scale_freq_invariant topology_scale_freq_invariant +#define arch_scale_freq_ref topology_get_freq_ref #ifdef CONFIG_ACPI_CPPC_LIB #define arch_init_invariance_cppc topology_init_cpu_capacity_cppc diff --git a/arch/riscv/include/asm/topology.h b/arch/riscv/include/asm/topology.h index e316ab3b77f34..61183688bdd54 100644 --- a/arch/riscv/include/asm/topology.h +++ b/arch/riscv/include/asm/topology.h @@ -9,6 +9,7 @@ #define arch_set_freq_scale topology_set_freq_scale #define arch_scale_freq_capacity topology_get_freq_scale #define arch_scale_freq_invariant topology_scale_freq_invariant +#define arch_scale_freq_ref topology_get_freq_ref /* Replace task scheduler's default cpu-invariant accounting */ #define arch_scale_cpu_capacity topology_get_cpu_scale diff --git a/arch/x86/kernel/cpu/aperfmperf.c b/arch/x86/kernel/cpu/aperfmperf.c index fdbb5f07448fa..c508b4205d70b 100644 --- a/arch/x86/kernel/cpu/aperfmperf.c +++ b/arch/x86/kernel/cpu/aperfmperf.c @@ -346,6 +346,7 @@ static DECLARE_WORK(disable_freq_invariance_work, disable_freq_invariance_workfn); DEFINE_PER_CPU(unsigned long, arch_freq_scale) = SCHED_CAPACITY_SCALE; +EXPORT_PER_CPU_SYMBOL_GPL(arch_freq_scale); static void scale_freq_tick(u64 acnt, u64 mcnt) { diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c index b741b5ba82bd6..73e409be37ea1 100644 --- a/drivers/base/arch_topology.c +++ b/drivers/base/arch_topology.c @@ -19,6 +19,7 @@ #include #include #include +#include #define CREATE_TRACE_POINTS #include @@ -26,7 +27,8 @@ static DEFINE_PER_CPU(struct scale_freq_data __rcu *, sft_data); static struct cpumask scale_freq_counters_mask; static bool scale_freq_invariant; -static DEFINE_PER_CPU(u32, freq_factor) = 1; +DEFINE_PER_CPU(unsigned long, capacity_freq_ref) = 1; +EXPORT_PER_CPU_SYMBOL_GPL(capacity_freq_ref); static bool supports_scale_freq_counters(const struct cpumask *cpus) { @@ -170,9 +172,9 @@ DEFINE_PER_CPU(unsigned long, thermal_pressure); * operating on stale data when hot-plug is used for some CPUs. The * @capped_freq reflects the currently allowed max CPUs frequency due to * thermal capping. It might be also a boost frequency value, which is bigger - * than the internal 'freq_factor' max frequency. In such case the pressure - * value should simply be removed, since this is an indication that there is - * no thermal throttling. The @capped_freq must be provided in kHz. + * than the internal 'capacity_freq_ref' max frequency. In such case the + * pressure value should simply be removed, since this is an indication that + * there is no thermal throttling. The @capped_freq must be provided in kHz. */ void topology_update_thermal_pressure(const struct cpumask *cpus, unsigned long capped_freq) @@ -183,10 +185,7 @@ void topology_update_thermal_pressure(const struct cpumask *cpus, cpu = cpumask_first(cpus); max_capacity = arch_scale_cpu_capacity(cpu); - max_freq = per_cpu(freq_factor, cpu); - - /* Convert to MHz scale which is used in 'freq_factor' */ - capped_freq /= 1000; + max_freq = arch_scale_freq_ref(cpu); /* * Handle properly the boost frequencies, which should simply clean @@ -279,13 +278,13 @@ void topology_normalize_cpu_scale(void) capacity_scale = 1; for_each_possible_cpu(cpu) { - capacity = raw_capacity[cpu] * per_cpu(freq_factor, cpu); + capacity = raw_capacity[cpu] * per_cpu(capacity_freq_ref, cpu); capacity_scale = max(capacity, capacity_scale); } pr_debug("cpu_capacity: capacity_scale=%llu\n", capacity_scale); for_each_possible_cpu(cpu) { - capacity = raw_capacity[cpu] * per_cpu(freq_factor, cpu); + capacity = raw_capacity[cpu] * per_cpu(capacity_freq_ref, cpu); capacity = div64_u64(capacity << SCHED_CAPACITY_SHIFT, capacity_scale); topology_set_cpu_scale(cpu, capacity); @@ -321,15 +320,15 @@ bool __init topology_parse_cpu_capacity(struct device_node *cpu_node, int cpu) cpu_node, raw_capacity[cpu]); /* - * Update freq_factor for calculating early boot cpu capacities. + * Update capacity_freq_ref for calculating early boot CPU capacities. * For non-clk CPU DVFS mechanism, there's no way to get the * frequency value now, assuming they are running at the same - * frequency (by keeping the initial freq_factor value). + * frequency (by keeping the initial capacity_freq_ref value). */ cpu_clk = of_clk_get(cpu_node, 0); if (!PTR_ERR_OR_ZERO(cpu_clk)) { - per_cpu(freq_factor, cpu) = - clk_get_rate(cpu_clk) / 1000; + per_cpu(capacity_freq_ref, cpu) = + clk_get_rate(cpu_clk) / HZ_PER_KHZ; clk_put(cpu_clk); } } else { @@ -398,9 +397,6 @@ init_cpu_capacity_callback(struct notifier_block *nb, struct cpufreq_policy *policy = data; int cpu; - if (!raw_capacity) - return 0; - if (val != CPUFREQ_CREATE_POLICY) return 0; @@ -411,12 +407,14 @@ init_cpu_capacity_callback(struct notifier_block *nb, cpumask_andnot(cpus_to_visit, cpus_to_visit, policy->related_cpus); for_each_cpu(cpu, policy->related_cpus) - per_cpu(freq_factor, cpu) = policy->cpuinfo.max_freq / 1000; + per_cpu(capacity_freq_ref, cpu) = policy->cpuinfo.max_freq; if (cpumask_empty(cpus_to_visit)) { - topology_normalize_cpu_scale(); - schedule_work(&update_topology_flags_work); - free_raw_capacity(); + if (raw_capacity) { + topology_normalize_cpu_scale(); + schedule_work(&update_topology_flags_work); + free_raw_capacity(); + } pr_debug("cpu_capacity: parsing done\n"); schedule_work(&parsing_done_work); } @@ -436,7 +434,7 @@ static int __init register_cpufreq_notifier(void) * On ACPI-based systems skip registering cpufreq notifier as cpufreq * information is not needed for cpu capacity initialization. */ - if (!acpi_disabled || !raw_capacity) + if (!acpi_disabled) return -EINVAL; if (!alloc_cpumask_var(&cpus_to_visit, GFP_KERNEL)) diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index df445b44e9ec0..1ab5a1884af4b 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -454,7 +454,7 @@ void cpufreq_freq_transition_end(struct cpufreq_policy *policy, arch_set_freq_scale(policy->related_cpus, policy->cur, - policy->cpuinfo.max_freq); + arch_scale_freq_ref(policy->cpu)); spin_lock(&policy->transition_lock); policy->transition_ongoing = false; @@ -2188,7 +2188,7 @@ unsigned int cpufreq_driver_fast_switch(struct cpufreq_policy *policy, policy->cur = freq; arch_set_freq_scale(policy->related_cpus, freq, - policy->cpuinfo.max_freq); + arch_scale_freq_ref(policy->cpu)); cpufreq_stats_record_transition(policy, freq); if (trace_cpu_frequency_enabled()) { diff --git a/include/linux/arch_topology.h b/include/linux/arch_topology.h index a07b510e7dc55..32c24ff4f2a80 100644 --- a/include/linux/arch_topology.h +++ b/include/linux/arch_topology.h @@ -27,6 +27,13 @@ static inline unsigned long topology_get_cpu_scale(int cpu) void topology_set_cpu_scale(unsigned int cpu, unsigned long capacity); +DECLARE_PER_CPU(unsigned long, capacity_freq_ref); + +static inline unsigned long topology_get_freq_ref(int cpu) +{ + return per_cpu(capacity_freq_ref, cpu); +} + DECLARE_PER_CPU(unsigned long, arch_freq_scale); static inline unsigned long topology_get_freq_scale(int cpu) diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index 9ca4211c063f3..d3aed5818f075 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -1220,6 +1220,7 @@ void arch_set_freq_scale(const struct cpumask *cpus, { } #endif + /* the following are really really optional */ extern struct freq_attr cpufreq_freq_attr_scaling_available_freqs; extern struct freq_attr cpufreq_freq_attr_scaling_boost_freqs; diff --git a/include/linux/energy_model.h b/include/linux/energy_model.h index b9caa01dfac48..c19e7effe7643 100644 --- a/include/linux/energy_model.h +++ b/include/linux/energy_model.h @@ -224,7 +224,7 @@ static inline unsigned long em_cpu_energy(struct em_perf_domain *pd, unsigned long max_util, unsigned long sum_util, unsigned long allowed_cpu_cap) { - unsigned long freq, scale_cpu; + unsigned long freq, ref_freq, scale_cpu; struct em_perf_state *ps; int cpu; @@ -241,11 +241,11 @@ static inline unsigned long em_cpu_energy(struct em_perf_domain *pd, */ cpu = cpumask_first(to_cpumask(pd->cpus)); scale_cpu = arch_scale_cpu_capacity(cpu); - ps = &pd->table[pd->nr_perf_states - 1]; + ref_freq = arch_scale_freq_ref(cpu); max_util = map_util_perf(max_util); max_util = min(max_util, allowed_cpu_cap); - freq = map_util_freq(max_util, ps->frequency, scale_cpu); + freq = map_util_freq(max_util, ref_freq, scale_cpu); /* * Find the lowest performance state of the Energy Model above the diff --git a/include/linux/sched.h b/include/linux/sched.h index 323b5c0ad431c..77978d0130761 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -416,42 +416,6 @@ struct load_weight { u32 inv_weight; }; -/** - * struct util_est - Estimation utilization of FAIR tasks - * @enqueued: instantaneous estimated utilization of a task/cpu - * @ewma: the Exponential Weighted Moving Average (EWMA) - * utilization of a task - * - * Support data structure to track an Exponential Weighted Moving Average - * (EWMA) of a FAIR task's utilization. New samples are added to the moving - * average each time a task completes an activation. Sample's weight is chosen - * so that the EWMA will be relatively insensitive to transient changes to the - * task's workload. - * - * The enqueued attribute has a slightly different meaning for tasks and cpus: - * - task: the task's util_avg at last task dequeue time - * - cfs_rq: the sum of util_est.enqueued for each RUNNABLE task on that CPU - * Thus, the util_est.enqueued of a task represents the contribution on the - * estimated utilization of the CPU where that task is currently enqueued. - * - * Only for tasks we track a moving average of the past instantaneous - * estimated utilization. This allows to absorb sporadic drops in utilization - * of an otherwise almost periodic task. - * - * The UTIL_AVG_UNCHANGED flag is used to synchronize util_est with util_avg - * updates. When a task is dequeued, its util_est should not be updated if its - * util_avg has not been updated in the meantime. - * This information is mapped into the MSB bit of util_est.enqueued at dequeue - * time. Since max value of util_est.enqueued for a task is 1024 (PELT util_avg - * for a task) it is safe to use MSB. - */ -struct util_est { - unsigned int enqueued; - unsigned int ewma; -#define UTIL_EST_WEIGHT_SHIFT 2 -#define UTIL_AVG_UNCHANGED 0x80000000 -} __attribute__((__aligned__(sizeof(u64)))); - /* * The load/runnable/util_avg accumulates an infinite geometric series * (see __update_load_avg_cfs_rq() in kernel/sched/pelt.c). @@ -506,11 +470,22 @@ struct sched_avg { unsigned long load_avg; unsigned long runnable_avg; unsigned long util_avg; - struct util_est util_est; + unsigned int util_est; DEEPIN_KABI_RESERVE(1) DEEPIN_KABI_RESERVE(2) } ____cacheline_aligned; +/* + * The UTIL_AVG_UNCHANGED flag is used to synchronize util_est with util_avg + * updates. When a task is dequeued, its util_est should not be updated if its + * util_avg has not been updated in the meantime. + * This information is mapped into the MSB bit of util_est at dequeue time. + * Since max value of util_est for a task is 1024 (PELT util_avg for a task) + * it is safe to use MSB. + */ +#define UTIL_EST_WEIGHT_SHIFT 2 +#define UTIL_AVG_UNCHANGED 0x80000000 + struct sched_statistics { #ifdef CONFIG_SCHEDSTATS u64 wait_start; diff --git a/include/linux/sched/topology.h b/include/linux/sched/topology.h index 67b573d5bf28f..9671b7234684a 100644 --- a/include/linux/sched/topology.h +++ b/include/linux/sched/topology.h @@ -275,6 +275,14 @@ void arch_update_thermal_pressure(const struct cpumask *cpus, { } #endif +#ifndef arch_scale_freq_ref +static __always_inline +unsigned int arch_scale_freq_ref(int cpu) +{ + return 0; +} +#endif + static inline int task_node(const struct task_struct *p) { return cpu_to_node(task_cpu(p)); diff --git a/kernel/sched/core.c b/kernel/sched/core.c index d5e3262a5dd48..890abd79f404e 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -10047,7 +10047,7 @@ void __init sched_init(void) #ifdef CONFIG_SMP rq->sd = NULL; rq->rd = NULL; - rq->cpu_capacity = rq->cpu_capacity_orig = SCHED_CAPACITY_SCALE; + rq->cpu_capacity = SCHED_CAPACITY_SCALE; rq->balance_callback = &balance_push_callback; rq->active_balance = 0; rq->next_balance = jiffies; diff --git a/kernel/sched/cpudeadline.c b/kernel/sched/cpudeadline.c index 57c92d751bcd7..95baa12a10293 100644 --- a/kernel/sched/cpudeadline.c +++ b/kernel/sched/cpudeadline.c @@ -131,7 +131,7 @@ int cpudl_find(struct cpudl *cp, struct task_struct *p, if (!dl_task_fits_capacity(p, cpu)) { cpumask_clear_cpu(cpu, later_mask); - cap = capacity_orig_of(cpu); + cap = arch_scale_cpu_capacity(cpu); if (cap > max_cap || (cpu == task_cpu(p) && cap == max_cap)) { diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c index 458d359f5991c..f3a87fa163327 100644 --- a/kernel/sched/cpufreq_schedutil.c +++ b/kernel/sched/cpufreq_schedutil.c @@ -114,6 +114,28 @@ static void sugov_deferred_update(struct sugov_policy *sg_policy) } } +/** + * get_capacity_ref_freq - get the reference frequency that has been used to + * correlate frequency and compute capacity for a given cpufreq policy. We use + * the CPU managing it for the arch_scale_freq_ref() call in the function. + * @policy: the cpufreq policy of the CPU in question. + * + * Return: the reference CPU frequency to compute a capacity. + */ +static __always_inline +unsigned long get_capacity_ref_freq(struct cpufreq_policy *policy) +{ + unsigned int freq = arch_scale_freq_ref(policy->cpu); + + if (freq) + return freq; + + if (arch_scale_freq_invariant()) + return policy->cpuinfo.max_freq; + + return policy->cur; +} + /** * get_next_freq - Compute a new frequency for a given cpufreq policy. * @sg_policy: schedutil policy object to compute the new frequency for. @@ -140,10 +162,10 @@ static unsigned int get_next_freq(struct sugov_policy *sg_policy, unsigned long util, unsigned long max) { struct cpufreq_policy *policy = sg_policy->policy; - unsigned int freq = arch_scale_freq_invariant() ? - policy->cpuinfo.max_freq : policy->cur; + unsigned int freq; util = map_util_perf(util); + freq = get_capacity_ref_freq(policy); freq = map_util_freq(util, freq, max); if (freq == sg_policy->cached_raw_freq && !sg_policy->need_freq_update) diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index b9e99bc3b1cf2..af8acebcd72cf 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -132,7 +132,7 @@ static inline unsigned long __dl_bw_capacity(const struct cpumask *mask) int i; for_each_cpu_and(i, mask, cpu_active_mask) - cap += capacity_orig_of(i); + cap += arch_scale_cpu_capacity(i); return cap; } @@ -144,7 +144,7 @@ static inline unsigned long __dl_bw_capacity(const struct cpumask *mask) static inline unsigned long dl_bw_capacity(int i) { if (!sched_asym_cpucap_active() && - capacity_orig_of(i) == SCHED_CAPACITY_SCALE) { + arch_scale_cpu_capacity(i) == SCHED_CAPACITY_SCALE) { return dl_bw_cpus(i) << SCHED_CAPACITY_SHIFT; } else { RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held(), diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c index 4c3d0d9f3db63..bcdd6c6a27c6f 100644 --- a/kernel/sched/debug.c +++ b/kernel/sched/debug.c @@ -679,8 +679,8 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq) cfs_rq->avg.runnable_avg); SEQ_printf(m, " .%-30s: %lu\n", "util_avg", cfs_rq->avg.util_avg); - SEQ_printf(m, " .%-30s: %u\n", "util_est_enqueued", - cfs_rq->avg.util_est.enqueued); + SEQ_printf(m, " .%-30s: %u\n", "util_est", + cfs_rq->avg.util_est); SEQ_printf(m, " .%-30s: %ld\n", "removed.load_avg", cfs_rq->removed.load_avg); SEQ_printf(m, " .%-30s: %ld\n", "removed.util_avg", @@ -1075,8 +1075,7 @@ void proc_sched_show_task(struct task_struct *p, struct pid_namespace *ns, P(se.avg.runnable_avg); P(se.avg.util_avg); P(se.avg.last_update_time); - P(se.avg.util_est.ewma); - PM(se.avg.util_est.enqueued, ~UTIL_AVG_UNCHANGED); + PM(se.avg.util_est, ~UTIL_AVG_UNCHANGED); #endif #ifdef CONFIG_UCLAMP_TASK __PS("uclamp.min", p->uclamp_req[UCLAMP_MIN].value); diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 3b2cfdb8d788d..f74023f2920fa 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -4834,11 +4834,14 @@ static inline unsigned long task_util(struct task_struct *p) return READ_ONCE(p->se.avg.util_avg); } -static inline unsigned long _task_util_est(struct task_struct *p) +static inline unsigned long task_runnable(struct task_struct *p) { - struct util_est ue = READ_ONCE(p->se.avg.util_est); + return READ_ONCE(p->se.avg.runnable_avg); +} - return max(ue.ewma, (ue.enqueued & ~UTIL_AVG_UNCHANGED)); +static inline unsigned long _task_util_est(struct task_struct *p) +{ + return READ_ONCE(p->se.avg.util_est) & ~UTIL_AVG_UNCHANGED; } static inline unsigned long task_util_est(struct task_struct *p) @@ -4855,9 +4858,9 @@ static inline void util_est_enqueue(struct cfs_rq *cfs_rq, return; /* Update root cfs_rq's estimated utilization */ - enqueued = cfs_rq->avg.util_est.enqueued; + enqueued = cfs_rq->avg.util_est; enqueued += _task_util_est(p); - WRITE_ONCE(cfs_rq->avg.util_est.enqueued, enqueued); + WRITE_ONCE(cfs_rq->avg.util_est, enqueued); trace_sched_util_est_cfs_tp(cfs_rq); } @@ -4871,34 +4874,20 @@ static inline void util_est_dequeue(struct cfs_rq *cfs_rq, return; /* Update root cfs_rq's estimated utilization */ - enqueued = cfs_rq->avg.util_est.enqueued; + enqueued = cfs_rq->avg.util_est; enqueued -= min_t(unsigned int, enqueued, _task_util_est(p)); - WRITE_ONCE(cfs_rq->avg.util_est.enqueued, enqueued); + WRITE_ONCE(cfs_rq->avg.util_est, enqueued); trace_sched_util_est_cfs_tp(cfs_rq); } #define UTIL_EST_MARGIN (SCHED_CAPACITY_SCALE / 100) -/* - * Check if a (signed) value is within a specified (unsigned) margin, - * based on the observation that: - * - * abs(x) < y := (unsigned)(x + y - 1) < (2 * y - 1) - * - * NOTE: this only works when value + margin < INT_MAX. - */ -static inline bool within_margin(int value, int margin) -{ - return ((unsigned int)(value + margin - 1) < (2 * margin - 1)); -} - static inline void util_est_update(struct cfs_rq *cfs_rq, struct task_struct *p, bool task_sleep) { - long last_ewma_diff, last_enqueued_diff; - struct util_est ue; + unsigned int ewma, dequeued, last_ewma_diff; if (!sched_feat(UTIL_EST)) return; @@ -4910,71 +4899,73 @@ static inline void util_est_update(struct cfs_rq *cfs_rq, if (!task_sleep) return; + /* Get current estimate of utilization */ + ewma = READ_ONCE(p->se.avg.util_est); + /* * If the PELT values haven't changed since enqueue time, * skip the util_est update. */ - ue = p->se.avg.util_est; - if (ue.enqueued & UTIL_AVG_UNCHANGED) + if (ewma & UTIL_AVG_UNCHANGED) return; - last_enqueued_diff = ue.enqueued; + /* Get utilization at dequeue */ + dequeued = task_util(p); /* * Reset EWMA on utilization increases, the moving average is used only * to smooth utilization decreases. */ - ue.enqueued = task_util(p); - if (sched_feat(UTIL_EST_FASTUP)) { - if (ue.ewma < ue.enqueued) { - ue.ewma = ue.enqueued; - goto done; - } + if (ewma <= dequeued) { + ewma = dequeued; + goto done; } /* * Skip update of task's estimated utilization when its members are * already ~1% close to its last activation value. */ - last_ewma_diff = ue.enqueued - ue.ewma; - last_enqueued_diff -= ue.enqueued; - if (within_margin(last_ewma_diff, UTIL_EST_MARGIN)) { - if (!within_margin(last_enqueued_diff, UTIL_EST_MARGIN)) - goto done; - - return; - } + last_ewma_diff = ewma - dequeued; + if (last_ewma_diff < UTIL_EST_MARGIN) + goto done; /* * To avoid overestimation of actual task utilization, skip updates if * we cannot grant there is idle time in this CPU. */ - if (task_util(p) > capacity_orig_of(cpu_of(rq_of(cfs_rq)))) + if (dequeued > arch_scale_cpu_capacity(cpu_of(rq_of(cfs_rq)))) return; + /* + * To avoid underestimate of task utilization, skip updates of EWMA if + * we cannot grant that thread got all CPU time it wanted. + */ + if ((dequeued + UTIL_EST_MARGIN) < task_runnable(p)) + goto done; + + /* * Update Task's estimated utilization * * When *p completes an activation we can consolidate another sample - * of the task size. This is done by storing the current PELT value - * as ue.enqueued and by using this value to update the Exponential - * Weighted Moving Average (EWMA): + * of the task size. This is done by using this value to update the + * Exponential Weighted Moving Average (EWMA): * * ewma(t) = w * task_util(p) + (1-w) * ewma(t-1) * = w * task_util(p) + ewma(t-1) - w * ewma(t-1) * = w * (task_util(p) - ewma(t-1)) + ewma(t-1) - * = w * ( last_ewma_diff ) + ewma(t-1) - * = w * (last_ewma_diff + ewma(t-1) / w) + * = w * ( -last_ewma_diff ) + ewma(t-1) + * = w * (-last_ewma_diff + ewma(t-1) / w) * * Where 'w' is the weight of new samples, which is configured to be * 0.25, thus making w=1/4 ( >>= UTIL_EST_WEIGHT_SHIFT) */ - ue.ewma <<= UTIL_EST_WEIGHT_SHIFT; - ue.ewma += last_ewma_diff; - ue.ewma >>= UTIL_EST_WEIGHT_SHIFT; + ewma <<= UTIL_EST_WEIGHT_SHIFT; + ewma -= last_ewma_diff; + ewma >>= UTIL_EST_WEIGHT_SHIFT; done: - ue.enqueued |= UTIL_AVG_UNCHANGED; - WRITE_ONCE(p->se.avg.util_est, ue); + ewma |= UTIL_AVG_UNCHANGED; + WRITE_ONCE(p->se.avg.util_est, ewma); trace_sched_util_est_se_tp(&p->se); } @@ -4997,14 +4988,14 @@ static inline int util_fits_cpu(unsigned long util, return fits; /* - * We must use capacity_orig_of() for comparing against uclamp_min and + * We must use arch_scale_cpu_capacity() for comparing against uclamp_min and * uclamp_max. We only care about capacity pressure (by using * capacity_of()) for comparing against the real util. * * If a task is boosted to 1024 for example, we don't want a tiny * pressure to skew the check whether it fits a CPU or not. * - * Similarly if a task is capped to capacity_orig_of(little_cpu), it + * Similarly if a task is capped to arch_scale_cpu_capacity(little_cpu), it * should fit a little cpu even if there's some pressure. * * Only exception is for thermal pressure since it has a direct impact @@ -5016,7 +5007,7 @@ static inline int util_fits_cpu(unsigned long util, * For uclamp_max, we can tolerate a drop in performance level as the * goal is to cap the task. So it's okay if it's getting less. */ - capacity_orig = capacity_orig_of(cpu); + capacity_orig = arch_scale_cpu_capacity(cpu); capacity_orig_thermal = capacity_orig - arch_scale_thermal_pressure(cpu); /* @@ -7513,7 +7504,7 @@ select_idle_capacity(struct task_struct *p, struct sched_domain *sd, int target) * Look for the CPU with best capacity. */ else if (fits < 0) - cpu_cap = capacity_orig_of(cpu) - thermal_load_avg(cpu_rq(cpu)); + cpu_cap = arch_scale_cpu_capacity(cpu) - thermal_load_avg(cpu_rq(cpu)); /* * First, select CPU which fits better (-1 being better than 0). @@ -7719,16 +7710,16 @@ cpu_util(int cpu, struct task_struct *p, int dst_cpu, int boost) if (sched_feat(UTIL_EST)) { unsigned long util_est; - util_est = READ_ONCE(cfs_rq->avg.util_est.enqueued); + util_est = READ_ONCE(cfs_rq->avg.util_est); /* * During wake-up @p isn't enqueued yet and doesn't contribute - * to any cpu_rq(cpu)->cfs.avg.util_est.enqueued. + * to any cpu_rq(cpu)->cfs.avg.util_est. * If @dst_cpu == @cpu add it to "simulate" cpu_util after @p * has been enqueued. * * During exec (@dst_cpu = -1) @p is enqueued and does - * contribute to cpu_rq(cpu)->cfs.util_est.enqueued. + * contribute to cpu_rq(cpu)->cfs.util_est. * Remove it to "simulate" cpu_util without @p's contribution. * * Despite the task_on_rq_queued(@p) check there is still a @@ -7755,7 +7746,7 @@ cpu_util(int cpu, struct task_struct *p, int dst_cpu, int boost) util = max(util, util_est); } - return min(util, capacity_orig_of(cpu)); + return min(util, arch_scale_cpu_capacity(cpu)); } unsigned long cpu_util_cfs(int cpu) @@ -9533,8 +9524,6 @@ static void update_cpu_capacity(struct sched_domain *sd, int cpu) unsigned long capacity = scale_rt_capacity(cpu); struct sched_group *sdg = sd->groups; - cpu_rq(cpu)->cpu_capacity_orig = arch_scale_cpu_capacity(cpu); - if (!capacity) capacity = 1; @@ -9610,7 +9599,7 @@ static inline int check_cpu_capacity(struct rq *rq, struct sched_domain *sd) { return ((rq->cpu_capacity * sd->imbalance_pct) < - (rq->cpu_capacity_orig * 100)); + (arch_scale_cpu_capacity(cpu_of(rq)) * 100)); } /* @@ -9621,7 +9610,7 @@ check_cpu_capacity(struct rq *rq, struct sched_domain *sd) static inline int check_misfit_status(struct rq *rq, struct sched_domain *sd) { return rq->misfit_task_load && - (rq->cpu_capacity_orig < rq->rd->max_cpu_capacity || + (arch_scale_cpu_capacity(rq->cpu) < rq->rd->max_cpu_capacity || check_cpu_capacity(rq, sd)); } diff --git a/kernel/sched/features.h b/kernel/sched/features.h index f770168230ae4..eb315c739dce8 100644 --- a/kernel/sched/features.h +++ b/kernel/sched/features.h @@ -84,7 +84,6 @@ SCHED_FEAT(WA_BIAS, true) * UtilEstimation. Use estimated CPU utilization. */ SCHED_FEAT(UTIL_EST, true) -SCHED_FEAT(UTIL_EST_FASTUP, true) SCHED_FEAT(LATENCY_WARN, false) diff --git a/kernel/sched/pelt.h b/kernel/sched/pelt.h index 3a0e0dc287219..9e1083465fbc3 100644 --- a/kernel/sched/pelt.h +++ b/kernel/sched/pelt.h @@ -52,13 +52,13 @@ static inline void cfs_se_util_change(struct sched_avg *avg) return; /* Avoid store if the flag has been already reset */ - enqueued = avg->util_est.enqueued; + enqueued = avg->util_est; if (!(enqueued & UTIL_AVG_UNCHANGED)) return; /* Reset flag to report util_avg has been updated */ enqueued &= ~UTIL_AVG_UNCHANGED; - WRITE_ONCE(avg->util_est.enqueued, enqueued); + WRITE_ONCE(avg->util_est, enqueued); } static inline u64 rq_clock_pelt(struct rq *rq) diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index b89223a973168..91b1ee0d81fce 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -519,7 +519,7 @@ static inline bool rt_task_fits_capacity(struct task_struct *p, int cpu) min_cap = uclamp_eff_value(p, UCLAMP_MIN); max_cap = uclamp_eff_value(p, UCLAMP_MAX); - cpu_cap = capacity_orig_of(cpu); + cpu_cap = arch_scale_cpu_capacity(cpu); return cpu_cap >= min(min_cap, max_cap); } diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 1beaaaf6d2338..3751993c70557 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -1070,7 +1070,6 @@ struct rq { struct sched_domain __rcu *sd; unsigned long cpu_capacity; - unsigned long cpu_capacity_orig; struct balance_callback *balance_callback; @@ -3019,11 +3018,6 @@ static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) {} #endif #ifdef CONFIG_SMP -static inline unsigned long capacity_orig_of(int cpu) -{ - return cpu_rq(cpu)->cpu_capacity_orig; -} - /** * enum cpu_util_type - CPU utilization type * @FREQUENCY_UTIL: Utilization used to select frequency diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c index 36cfbfc86952e..61e6c076c1a26 100644 --- a/kernel/sched/topology.c +++ b/kernel/sched/topology.c @@ -2497,12 +2497,15 @@ build_sched_domains(const struct cpumask *cpu_map, struct sched_domain_attr *att /* Attach the domains */ rcu_read_lock(); for_each_cpu(i, cpu_map) { + unsigned long capacity; + rq = cpu_rq(i); sd = *per_cpu_ptr(d.sd, i); + capacity = arch_scale_cpu_capacity(i); /* Use READ_ONCE()/WRITE_ONCE() to avoid load/store tearing: */ - if (rq->cpu_capacity_orig > READ_ONCE(d.rd->max_cpu_capacity)) - WRITE_ONCE(d.rd->max_cpu_capacity, rq->cpu_capacity_orig); + if (capacity > READ_ONCE(d.rd->max_cpu_capacity)) + WRITE_ONCE(d.rd->max_cpu_capacity, capacity); cpu_attach_domain(sd, d.rd, i); }