sched/fair: Add snapshot of load-balancing changes (2febb53a) · Commits · e / devices / android_kernel_xiaomi_nabu

include/trace/events/sched.h

+182 −0

Original line number	Diff line number	Diff line
		@@ -8,6 +8,7 @@
		#include <linux/sched/numa_balancing.h>
		#include <linux/tracepoint.h>
		#include <linux/binfmts.h>
		#include <linux/sched/idle.h>

		/*
		* Tracepoint for calling kthread_stop, performed to end a kthread:
		@@ -208,6 +209,187 @@ TRACE_EVENT(sched_migrate_task,
		__entry->orig_cpu, __entry->dest_cpu)
		);

		/*
		* Tracepoint for load balancing:
		*/
		#ifdef CONFIG_SMP
		#if NR_CPUS > 32
		#error "Unsupported NR_CPUS for lb tracepoint."
		#endif
		TRACE_EVENT(sched_load_balance,

		TP_PROTO(int cpu, enum cpu_idle_type idle, int balance,
		unsigned long group_mask, int busiest_nr_running,
		unsigned long imbalance, unsigned int env_flags, int ld_moved,
		unsigned int balance_interval, int active_balance),

		TP_ARGS(cpu, idle, balance, group_mask, busiest_nr_running,
		imbalance, env_flags, ld_moved, balance_interval,
		active_balance),

		TP_STRUCT__entry(
		__field(int, cpu)
		__field(enum cpu_idle_type, idle)
		__field(int, balance)
		__field(unsigned long, group_mask)
		__field(int, busiest_nr_running)
		__field(unsigned long, imbalance)
		__field(unsigned int, env_flags)
		__field(int, ld_moved)
		__field(unsigned int, balance_interval)
		__field(int, active_balance)
		),

		TP_fast_assign(
		__entry->cpu = cpu;
		__entry->idle = idle;
		__entry->balance = balance;
		__entry->group_mask = group_mask;
		__entry->busiest_nr_running = busiest_nr_running;
		__entry->imbalance = imbalance;
		__entry->env_flags = env_flags;
		__entry->ld_moved = ld_moved;
		__entry->balance_interval = balance_interval;
		__entry->active_balance = active_balance;
		),

		TP_printk("cpu=%d state=%s balance=%d group=%#lx busy_nr=%d imbalance=%ld flags=%#x ld_moved=%d bal_int=%d active_balance=%d",
		__entry->cpu,
		__entry->idle == CPU_IDLE ? "idle" :
		(__entry->idle == CPU_NEWLY_IDLE ? "newly_idle" : "busy"),
		__entry->balance,
		__entry->group_mask, __entry->busiest_nr_running,
		__entry->imbalance, __entry->env_flags, __entry->ld_moved,
		__entry->balance_interval, __entry->active_balance)
		);

		TRACE_EVENT(sched_load_balance_nohz_kick,

		TP_PROTO(int cpu, int kick_cpu),

		TP_ARGS(cpu, kick_cpu),

		TP_STRUCT__entry(
		__field(int, cpu)
		__field(unsigned int, cpu_nr)
		__field(unsigned long, misfit_task_load)
		__field(int, cpu_overutil)
		__field(int, kick_cpu)
		__field(unsigned long, nohz_flags)
		),

		TP_fast_assign(
		__entry->cpu = cpu;
		__entry->cpu_nr = cpu_rq(cpu)->nr_running;
		__entry->misfit_task_load = cpu_rq(cpu)->misfit_task_load;
		__entry->cpu_overutil = cpu_overutilized(cpu);
		__entry->kick_cpu = kick_cpu;
		__entry->nohz_flags = atomic_read(nohz_flags(kick_cpu));
		),

		TP_printk("cpu=%d nr_run=%u misfit_task_load=%lu overutilized=%d kick_cpu=%d nohz_flags=0x%lx",
		__entry->cpu, __entry->cpu_nr,
		__entry->misfit_task_load, __entry->cpu_overutil,
		__entry->kick_cpu, __entry->nohz_flags)

		);

		TRACE_EVENT(sched_load_balance_sg_stats,

		TP_PROTO(unsigned long sg_cpus, int group_type, unsigned int idle_cpus,
		unsigned int sum_nr_running, unsigned long group_load,
		unsigned long group_capacity, unsigned long group_util,
		int group_no_capacity, unsigned long load_per_task,
		unsigned long misfit_load, unsigned long busiest),

		TP_ARGS(sg_cpus, group_type, idle_cpus, sum_nr_running, group_load,
		group_capacity, group_util, group_no_capacity, load_per_task,
		misfit_load, busiest),

		TP_STRUCT__entry(
		__field(unsigned long, group_mask)
		__field(int, group_type)
		__field(unsigned int, group_idle_cpus)
		__field(unsigned int, sum_nr_running)
		__field(unsigned long, group_load)
		__field(unsigned long, group_capacity)
		__field(unsigned long, group_util)
		__field(int, group_no_capacity)
		__field(unsigned long, load_per_task)
		__field(unsigned long, misfit_task_load)
		__field(unsigned long, busiest)
		),

		TP_fast_assign(
		__entry->group_mask = sg_cpus;
		__entry->group_type = group_type;
		__entry->group_idle_cpus = idle_cpus;
		__entry->sum_nr_running = sum_nr_running;
		__entry->group_load = group_load;
		__entry->group_capacity = group_capacity;
		__entry->group_util = group_util;
		__entry->group_no_capacity = group_no_capacity;
		__entry->load_per_task = load_per_task;
		__entry->misfit_task_load = misfit_load;
		__entry->busiest = busiest;
		),

		TP_printk("sched_group=%#lx type=%d idle_cpus=%u sum_nr_run=%u group_load=%lu capacity=%lu util=%lu no_capacity=%d lpt=%lu misfit_tload=%lu busiest_group=%#lx",
		__entry->group_mask, __entry->group_type,
		__entry->group_idle_cpus, __entry->sum_nr_running,
		__entry->group_load, __entry->group_capacity,
		__entry->group_util, __entry->group_no_capacity,
		__entry->load_per_task, __entry->misfit_task_load,
		__entry->busiest)
		);

		TRACE_EVENT(sched_load_balance_stats,

		TP_PROTO(unsigned long busiest, int bgroup_type,
		unsigned long bavg_load, unsigned long bload_per_task,
		unsigned long local, int lgroup_type, unsigned long lavg_load,
		unsigned long lload_per_task, unsigned long sds_avg_load,
		unsigned long imbalance),

		TP_ARGS(busiest, bgroup_type, bavg_load, bload_per_task, local,
		lgroup_type, lavg_load, lload_per_task, sds_avg_load,
		imbalance),

		TP_STRUCT__entry(
		__field(unsigned long, busiest)
		__field(int, bgp_type)
		__field(unsigned long, bavg_load)
		__field(unsigned long, blpt)
		__field(unsigned long, local)
		__field(int, lgp_type)
		__field(unsigned long, lavg_load)
		__field(unsigned long, llpt)
		__field(unsigned long, sds_avg)
		__field(unsigned long, imbalance)
		),

		TP_fast_assign(
		__entry->busiest = busiest;
		__entry->bgp_type = bgroup_type;
		__entry->bavg_load = bavg_load;
		__entry->blpt = bload_per_task;
		__entry->bgp_type = bgroup_type;
		__entry->local = local;
		__entry->lgp_type = lgroup_type;
		__entry->lavg_load = lavg_load;
		__entry->llpt = lload_per_task;
		__entry->sds_avg = sds_avg_load;
		__entry->imbalance = imbalance;
		),

		TP_printk("busiest_group=%#lx busiest_type=%d busiest_avg_load=%ld busiest_lpt=%ld local_group=%#lx local_type=%d local_avg_load=%ld local_lpt=%ld domain_avg_load=%ld imbalance=%ld",
		__entry->busiest, __entry->bgp_type, __entry->bavg_load,
		__entry->blpt, __entry->local, __entry->lgp_type,
		__entry->lavg_load, __entry->llpt, __entry->sds_avg,
		__entry->imbalance)
		);
		#endif

		DECLARE_EVENT_CLASS(sched_process_template,

		TP_PROTO(struct task_struct *p),

kernel/sched/fair.c

+253 −23

Original line number	Diff line number	Diff line
		@@ -5203,9 +5203,15 @@ static inline void hrtick_update(struct rq *rq)
		#ifdef CONFIG_SMP
		static unsigned long capacity_of(int cpu);

		static inline bool cpu_overutilized(int cpu)
		bool __cpu_overutilized(int cpu, int delta)
		{
		return (capacity_of(cpu) * 1024) < (cpu_util(cpu) * capacity_margin);
		return (capacity_orig_of(cpu) * 1024) <
		((cpu_util(cpu) + delta) * sched_capacity_margin_up[cpu]);
		}

		bool cpu_overutilized(int cpu)
		{
		return __cpu_overutilized(cpu, 0);
		}

		static inline void update_overutilized_status(struct rq *rq)
		@@ -7817,6 +7823,8 @@ enum group_type {
		#define LBF_SOME_PINNED 0x08
		#define LBF_NOHZ_STATS 0x10
		#define LBF_NOHZ_AGAIN 0x20
		#define LBF_IGNORE_BIG_TASKS 0x100
		#define LBF_IGNORE_PREFERRED_CLUSTER_TASKS 0x200

		struct lb_env {
		struct sched_domain *sd;
		@@ -7992,6 +8000,38 @@ int can_migrate_task(struct task_struct p, struct lb_env env)
		/* Record that we found atleast one task that could run on dst_cpu */
		env->flags &= ~LBF_ALL_PINNED;

		if (static_branch_unlikely(&sched_energy_present)) {
		struct root_domain *rd = env->dst_rq->rd;

		if (rcu_dereference(rd->pd) && !READ_ONCE(rd->overutilized) &&
		env->idle == CPU_NEWLY_IDLE) {
		long util_cum_dst, util_cum_src;
		unsigned long demand;

		demand = task_util(p);
		util_cum_dst = cpu_util_cum(env->dst_cpu, 0) + demand;
		util_cum_src = cpu_util_cum(env->src_cpu, 0) - demand;

		if (util_cum_dst > util_cum_src)
		return 0;
		}
		}

		#ifdef CONFIG_SCHED_WALT
		if (env->flags & LBF_IGNORE_PREFERRED_CLUSTER_TASKS &&
		!preferred_cluster(cpu_rq(env->dst_cpu)->cluster, p))
		return 0;

		/* Don't detach task if it doesn't fit on the destination */
		if (env->flags & LBF_IGNORE_BIG_TASKS &&
		!task_fits_max(p, env->dst_cpu))
		return 0;
		#endif

		/* Don't detach task if it is under active migration */
		if (env->src_rq->push_task == p)
		return 0;

		if (task_running(env->src_rq, p)) {
		schedstat_inc(p->se.statistics.nr_failed_migrations_running);
		return 0;
		@@ -7999,15 +8039,16 @@ int can_migrate_task(struct task_struct p, struct lb_env env)

		/*
		* Aggressive migration if:
		* 1) destination numa is preferred
		* 2) task is cache cold, or
		* 3) too many balance attempts have failed.
		* 1) IDLE or NEWLY_IDLE balance.
		* 2) destination numa is preferred
		* 3) task is cache cold, or
		* 4) too many balance attempts have failed.
		*/
		tsk_cache_hot = migrate_degrades_locality(p, env);
		if (tsk_cache_hot == -1)
		tsk_cache_hot = task_hot(p, env);

		if (tsk_cache_hot <= 0 \|\|
		if (env->idle != CPU_NOT_IDLE \|\| tsk_cache_hot <= 0 \|\|
		env->sd->nr_balance_failed > env->sd->cache_nice_tries) {
		if (tsk_cache_hot == 1) {
		schedstat_inc(env->sd->lb_hot_gained[env->idle]);
		@@ -8079,14 +8120,22 @@ static int detach_tasks(struct lb_env *env)
		{
		struct list_head *tasks = &env->src_rq->cfs_tasks;
		struct task_struct *p;
		unsigned long load;
		unsigned long load = 0;
		int detached = 0;
		int orig_loop = env->loop;

		lockdep_assert_held(&env->src_rq->lock);

		if (env->imbalance <= 0)
		return 0;

		if (!same_cluster(env->dst_cpu, env->src_cpu))
		env->flags \|= LBF_IGNORE_PREFERRED_CLUSTER_TASKS;

		if (cpu_capacity(env->dst_cpu) < cpu_capacity(env->src_cpu))
		env->flags \|= LBF_IGNORE_BIG_TASKS;

		redo:
		while (!list_empty(tasks)) {
		/*
		* We don't want to steal all, otherwise we may be treated likewise,
		@@ -8145,9 +8194,23 @@ static int detach_tasks(struct lb_env *env)

		continue;
		next:
		#ifdef CONFIG_SCHED_WALT
		trace_sched_load_balance_skip_tasks(env->src_cpu, env->dst_cpu,
		env->src_grp_type, p->pid, load, task_util(p),
		cpumask_bits(&p->cpus_allowed)[0]);
		#endif
		list_move(&p->se.group_node, tasks);
		}

		if (env->flags & (LBF_IGNORE_BIG_TASKS \|
		LBF_IGNORE_PREFERRED_CLUSTER_TASKS) && !detached) {
		tasks = &env->src_rq->cfs_tasks;
		env->flags &= ~(LBF_IGNORE_BIG_TASKS \|
		LBF_IGNORE_PREFERRED_CLUSTER_TASKS);
		env->loop = orig_loop;
		goto redo;
		}

		/*
		* Right now, this is one of only two places we collect this stat
		* so we can safely collect detach_one_task() stats here rather
		@@ -8515,11 +8578,12 @@ static void update_cpu_capacity(struct sched_domain *sd, int cpu)
		int max_cap_cpu;
		unsigned long flags;

		cpu_rq(cpu)->cpu_capacity_orig = capacity;

		capacity *= arch_scale_max_freq_capacity(sd, cpu);
		capacity >>= SCHED_CAPACITY_SHIFT;

		capacity = min(capacity, thermal_cap(cpu));
		cpu_rq(cpu)->cpu_capacity_orig = capacity;

		mcc = &cpu_rq(cpu)->rd->max_cpu_capacity;

		raw_spin_lock_irqsave(&mcc->lock, flags);
		@@ -8532,7 +8596,8 @@ static void update_cpu_capacity(struct sched_domain *sd, int cpu)
		mcc->cpu = cpu;
		#ifdef CONFIG_SCHED_DEBUG
		raw_spin_unlock_irqrestore(&mcc->lock, flags);
		pr_info("CPU%d: update max cpu_capacity %lu\n", cpu, capacity);
		printk_deferred("CPU%d: update max cpu_capacity %lu\n",
		cpu, capacity);
		goto skip_unlock;
		#endif
		}
		@@ -9052,6 +9117,14 @@ static inline void update_sd_lb_stats(struct lb_env env, struct sd_lb_stats sd
		sds->total_load += sgs->group_load;
		sds->total_capacity += sgs->group_capacity;

		trace_sched_load_balance_sg_stats(sg->cpumask[0],
		sgs->group_type, sgs->idle_cpus,
		sgs->sum_nr_running, sgs->group_load,
		sgs->group_capacity, sgs->group_util,
		sgs->group_no_capacity, sgs->load_per_task,
		sgs->group_misfit_task_load,
		sds->busiest ? sds->busiest->cpumask[0] : 0);

		sg = sg->next;
		} while (sg != env->sd->groups);

		@@ -9250,6 +9323,11 @@ static inline void calculate_imbalance(struct lb_env env, struct sd_lb_stats s
		(busiest->avg_load <= sds->avg_load \|\|
		local->avg_load >= sds->avg_load)) {
		env->imbalance = 0;
		if (busiest->group_type == group_overloaded &&
		local->group_type <= group_misfit_task) {
		env->imbalance = busiest->load_per_task;
		return;
		}
		return fix_small_imbalance(env, sds);
		}

		@@ -9304,9 +9382,24 @@ static inline void calculate_imbalance(struct lb_env env, struct sd_lb_stats s
		* a think about bumping its value to force at least one task to be
		* moved
		*/
		if (env->imbalance < busiest->load_per_task)
		if (env->imbalance < busiest->load_per_task) {
		/*
		* The busiest group is overloaded so it could use help
		* from the other groups. If the local group has idle CPUs
		* and it is not overloaded and has no imbalance with in
		* the group, allow the load balance by bumping the
		* imbalance.
		*/
		if (busiest->group_type == group_overloaded &&
		local->group_type <= group_misfit_task &&
		env->idle != CPU_NOT_IDLE) {
		env->imbalance = busiest->load_per_task;
		return;
		}

		return fix_small_imbalance(env, sds);
		}
		}

		/***** find_busiest_group() helpers end here *******************/

		@@ -9337,9 +9430,35 @@ static struct sched_group find_busiest_group(struct lb_env env)
		if (static_branch_unlikely(&sched_energy_present)) {
		struct root_domain *rd = env->dst_rq->rd;

		if (rcu_dereference(rd->pd) && !READ_ONCE(rd->overutilized))
		if (rcu_dereference(rd->pd) && !READ_ONCE(rd->overutilized)) {
		int cpu_local, cpu_busiest;
		long util_cum;
		unsigned long capacity_local, capacity_busiest;

		if (env->idle != CPU_NEWLY_IDLE)
		goto out_balanced;

		if (!sds.local \|\| !sds.busiest)
		goto out_balanced;

		cpu_local = group_first_cpu(sds.local);
		cpu_busiest = group_first_cpu(sds.busiest);

		/* TODO:don't assume same cap cpus are in same domain */
		capacity_local = capacity_orig_of(cpu_local);
		capacity_busiest = capacity_orig_of(cpu_busiest);
		if (capacity_local > capacity_busiest) {
		goto out_balanced;
		} else if (capacity_local == capacity_busiest) {
		if (cpu_rq(cpu_busiest)->nr_running < 2)
		goto out_balanced;

		util_cum = cpu_util_cum(cpu_busiest, 0);
		if (util_cum < cpu_util_cum(cpu_local, 0))
		goto out_balanced;
		}
		}
		}

		local = &sds.local_stat;
		busiest = &sds.busiest_stat;
		@@ -9415,6 +9534,12 @@ static struct sched_group find_busiest_group(struct lb_env env)
		/* Looks like there is an imbalance. Compute it */
		env->src_grp_type = busiest->group_type;
		calculate_imbalance(env, &sds);
		trace_sched_load_balance_stats(sds.busiest->cpumask[0],
		busiest->group_type, busiest->avg_load,
		busiest->load_per_task, sds.local->cpumask[0],
		local->group_type, local->avg_load,
		local->load_per_task,
		sds.avg_load, env->imbalance);
		return env->imbalance ? sds.busiest : NULL;

		out_balanced:
		@@ -9524,6 +9649,7 @@ static struct rq find_busiest_queue(struct lb_env env,
		* so long as it is large enough.
		*/
		#define MAX_PINNED_INTERVAL 512
		#define NEED_ACTIVE_BALANCE_THRESHOLD 10

		static int need_active_balance(struct lb_env *env)
		{
		@@ -9554,10 +9680,14 @@ static int need_active_balance(struct lb_env *env)
		return 1;
		}

		if (env->src_grp_type == group_misfit_task)
		if (env->idle != CPU_NOT_IDLE &&
		env->src_grp_type == group_misfit_task)
		return 1;

		if ((capacity_of(env->src_cpu) < capacity_of(env->dst_cpu)) &&
		if ((env->idle != CPU_NOT_IDLE) &&
		(capacity_of(env->src_cpu) < capacity_of(env->dst_cpu)) &&
		((capacity_orig_of(env->src_cpu) <
		capacity_orig_of(env->dst_cpu))) &&
		env->src_rq->cfs.h_nr_running == 1 &&
		cpu_overutilized(env->src_cpu) &&
		!cpu_overutilized(env->dst_cpu)) {
		@@ -9628,10 +9758,10 @@ static int load_balance(int this_cpu, struct rq *this_rq,
		struct sched_domain *sd, enum cpu_idle_type idle,
		int *continue_balancing)
		{
		int ld_moved, cur_ld_moved, active_balance = 0;
		int ld_moved = 0, cur_ld_moved, active_balance = 0;
		struct sched_domain *sd_parent = sd->parent;
		struct sched_group *group;
		struct rq *busiest;
		struct sched_group *group = NULL;
		struct rq *busiest = NULL;
		struct rq_flags rf;
		struct cpumask *cpus = this_cpu_cpumask_var_ptr(load_balance_mask);

		@@ -9645,6 +9775,9 @@ static int load_balance(int this_cpu, struct rq *this_rq,
		.cpus = cpus,
		.fbq_type = all,
		.tasks = LIST_HEAD_INIT(env.tasks),
		.imbalance = 0,
		.flags = 0,
		.loop = 0,
		};

		cpumask_and(cpus, sched_domain_span(sd), cpu_active_mask);
		@@ -9689,6 +9822,14 @@ static int load_balance(int this_cpu, struct rq *this_rq,

		more_balance:
		rq_lock_irqsave(busiest, &rf);

		/* The world might have changed. Validate assumptions */
		if (busiest->nr_running <= 1) {
		rq_unlock_irqrestore(busiest, &rf);
		env.flags &= ~LBF_ALL_PINNED;
		goto no_move;
		}

		update_rq_clock(busiest);

		/*
		@@ -9786,23 +9927,37 @@ static int load_balance(int this_cpu, struct rq *this_rq,
		}
		}

		no_move:
		if (!ld_moved) {
		schedstat_inc(sd->lb_failed[idle]);
		/*
		* Increment the failure counter only on periodic balance.
		* We do not want newidle balance, which can be very
		* frequent, pollute the failure counter causing
		* excessive cache_hot migrations and active balances.
		*/
		if (idle != CPU_NEWLY_IDLE)
		if (idle != CPU_NEWLY_IDLE) {
		if (env.src_grp_nr_running > 1)
		sd->nr_balance_failed++;
		}

		if (need_active_balance(&env)) {
		unsigned long flags;

		raw_spin_lock_irqsave(&busiest->lock, flags);

		/*
		* The CPUs are marked as reserved if tasks
		* are pushed/pulled from other CPUs. In that case,
		* bail out from the load balancer.
		*/
		if (is_reserved(this_cpu) \|\|
		is_reserved(cpu_of(busiest))) {
		raw_spin_unlock_irqrestore(&busiest->lock,
		flags);
		*continue_balancing = 0;
		goto out;
		}

		/*
		* Don't kick the active_load_balance_cpu_stop,
		* if the curr task on busiest CPU can't be
		@@ -9832,10 +9987,12 @@ static int load_balance(int this_cpu, struct rq *this_rq,
		stop_one_cpu_nowait(cpu_of(busiest),
		active_load_balance_cpu_stop, busiest,
		&busiest->active_balance_work);
		*continue_balancing = 0;
		}

		/* We've kicked active balancing, force task migration. */
		sd->nr_balance_failed = sd->cache_nice_tries+1;
		sd->nr_balance_failed = sd->cache_nice_tries +
		NEED_ACTIVE_BALANCE_THRESHOLD - 1;
		}
		} else
		sd->nr_balance_failed = 0;
		@@ -9887,6 +10044,11 @@ static int load_balance(int this_cpu, struct rq *this_rq,

		ld_moved = 0;
		out:
		trace_sched_load_balance(this_cpu, idle, *continue_balancing,
		group ? group->cpumask[0] : 0,
		busiest ? busiest->nr_running : 0,
		env.imbalance, env.flags, ld_moved,
		sd->balance_interval, active_balance);
		return ld_moved;
		}

		@@ -9930,9 +10092,22 @@ static int active_load_balance_cpu_stop(void *data)
		int busiest_cpu = cpu_of(busiest_rq);
		int target_cpu = busiest_rq->push_cpu;
		struct rq *target_rq = cpu_rq(target_cpu);
		struct sched_domain *sd;
		struct sched_domain *sd = NULL;
		struct task_struct *p = NULL;
		struct rq_flags rf;
		struct task_struct *push_task;
		int push_task_detached = 0;
		struct lb_env env = {
		.sd = sd,
		.dst_cpu = target_cpu,
		.dst_rq = target_rq,
		.src_cpu = busiest_rq->cpu,
		.src_rq = busiest_rq,
		.idle = CPU_IDLE,
		.flags = 0,
		.loop = 0,
		};
		bool moved = false;

		rq_lock_irq(busiest_rq, &rf);
		/*
		@@ -9959,6 +10134,20 @@ static int active_load_balance_cpu_stop(void *data)
		*/
		BUG_ON(busiest_rq == target_rq);

		push_task = busiest_rq->push_task;
		target_cpu = busiest_rq->push_cpu;
		if (push_task) {
		if (task_on_rq_queued(push_task) &&
		push_task->state == TASK_RUNNING &&
		task_cpu(push_task) == busiest_cpu &&
		cpu_online(target_cpu)) {
		detach_task(push_task, &env);
		push_task_detached = 1;
		moved = true;
		}
		goto out_unlock;
		}

		/* Search for an sd spanning us and the target CPU. */
		rcu_read_lock();
		for_each_domain(target_cpu, sd) {
		@@ -9992,6 +10181,7 @@ static int active_load_balance_cpu_stop(void *data)
		schedstat_inc(sd->alb_pushed);
		/* Active balancing done, reset the failure counter. */
		sd->nr_balance_failed = 0;
		moved = true;
		} else {
		schedstat_inc(sd->alb_failed);
		}
		@@ -9999,8 +10189,21 @@ static int active_load_balance_cpu_stop(void *data)
		rcu_read_unlock();
		out_unlock:
		busiest_rq->active_balance = 0;
		push_task = busiest_rq->push_task;
		target_cpu = busiest_rq->push_cpu;

		if (push_task)
		busiest_rq->push_task = NULL;

		rq_unlock(busiest_rq, &rf);

		if (push_task) {
		if (push_task_detached)
		attach_one_task(target_rq, push_task);
		put_task_struct(push_task);
		clear_reserved(target_cpu);
		}

		if (p)
		attach_one_task(target_rq, p);

		@@ -10148,7 +10351,33 @@ static inline int on_null_domain(struct rq *rq)

		static inline int find_new_ilb(void)
		{
		int ilb = cpumask_first(nohz.idle_cpus_mask);
		int ilb = nr_cpu_ids;
		struct sched_domain *sd;
		int cpu = raw_smp_processor_id();
		struct rq *rq = cpu_rq(cpu);
		cpumask_t cpumask;

		rcu_read_lock();
		sd = rcu_dereference_check_sched_domain(rq->sd);
		if (sd) {
		cpumask_and(&cpumask, nohz.idle_cpus_mask,
		sched_domain_span(sd));
		cpumask_andnot(&cpumask, &cpumask,
		cpu_isolated_mask);
		ilb = cpumask_first(&cpumask);
		}
		rcu_read_unlock();

		if (sd && (ilb >= nr_cpu_ids \|\| !idle_cpu(ilb))) {
		if (!energy_aware() \|\|
		(capacity_orig_of(cpu) ==
		cpu_rq(cpu)->rd->max_cpu_capacity.val \|\|
		cpu_overutilized(cpu))) {
		cpumask_andnot(&cpumask, nohz.idle_cpus_mask,
		cpu_isolated_mask);
		ilb = cpumask_first(&cpumask);
		}
		}

		if (ilb < nr_cpu_ids && idle_cpu(ilb))
		return ilb;
		@@ -10182,6 +10411,7 @@ static void kick_ilb(unsigned int flags)
		* is idle. And the softirq performing nohz idle load balance
		* will be run before returning from the IPI.
		*/
		trace_sched_load_balance_nohz_kick(smp_processor_id(), ilb_cpu);
		smp_send_reschedule(ilb_cpu);
		}

kernel/sched/sched.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -1755,6 +1755,9 @@ extern void trigger_load_balance(struct rq *rq);

		extern void set_cpus_allowed_common(struct task_struct p, const struct cpumask new_mask);

		bool __cpu_overutilized(int cpu, int delta);
		bool cpu_overutilized(int cpu);

		#endif

		#ifdef CONFIG_CPU_IDLE