/* SPDX-License-Identifier: GPL-2.0 */ /* * Scheduler internal types and methods: */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef CONFIG_PARAVIRT # include #endif #include "cpupri.h" #include "cpudeadline.h" #ifdef CONFIG_SCHED_DEBUG # define SCHED_WARN_ON(x) WARN_ONCE(x, #x) #else # define SCHED_WARN_ON(x) ({ (void)(x), 0; }) #endif struct rq; struct cpuidle_state; /* task_struct::on_rq states: */ #define TASK_ON_RQ_QUEUED 1 #define TASK_ON_RQ_MIGRATING 2 extern __read_mostly int scheduler_running; extern unsigned long calc_load_update; extern atomic_long_t calc_load_tasks; extern void calc_global_load_tick(struct rq *this_rq); extern long calc_load_fold_active(struct rq *this_rq, long adjust); /* * Helpers for converting nanosecond timing to jiffy resolution */ #define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ)) /* * Increase resolution of nice-level calculations for 64-bit architectures. * The extra resolution improves shares distribution and load balancing of * low-weight task groups (eg. nice +19 on an autogroup), deeper taskgroup * hierarchies, especially on larger systems. This is not a user-visible change * and does not change the user-interface for setting shares/weights. * * We increase resolution only if we have enough bits to allow this increased * resolution (i.e. 64-bit). The costs for increasing resolution when 32-bit * are pretty high and the returns do not justify the increased costs. * * Really only required when CONFIG_FAIR_GROUP_SCHED=y is also set, but to * increase coverage and consistency always enable it on 64-bit platforms. */ #ifdef CONFIG_64BIT # define NICE_0_LOAD_SHIFT (SCHED_FIXEDPOINT_SHIFT + SCHED_FIXEDPOINT_SHIFT) # define scale_load(w) ((w) << SCHED_FIXEDPOINT_SHIFT) # define scale_load_down(w) ((w) >> SCHED_FIXEDPOINT_SHIFT) #else # define NICE_0_LOAD_SHIFT (SCHED_FIXEDPOINT_SHIFT) # define scale_load(w) (w) # define scale_load_down(w) (w) #endif /* * Task weight (visible to users) and its load (invisible to users) have * independent resolution, but they should be well calibrated. We use * scale_load() and scale_load_down(w) to convert between them. The * following must be true: * * scale_load(sched_prio_to_weight[USER_PRIO(NICE_TO_PRIO(0))]) == NICE_0_LOAD * */ #define NICE_0_LOAD (1L << NICE_0_LOAD_SHIFT) /* * Single value that decides SCHED_DEADLINE internal math precision. * 10 -> just above 1us * 9 -> just above 0.5us */ #define DL_SCALE 10 /* * Single value that denotes runtime == period, ie unlimited time. */ #define RUNTIME_INF ((u64)~0ULL) static inline int idle_policy(int policy) { return policy == SCHED_IDLE; } static inline int fair_policy(int policy) { return policy == SCHED_NORMAL || policy == SCHED_BATCH; } static inline int rt_policy(int policy) { return policy == SCHED_FIFO || policy == SCHED_RR; } static inline int dl_policy(int policy) { return policy == SCHED_DEADLINE; } static inline bool valid_policy(int policy) { return idle_policy(policy) || fair_policy(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); } static inline int task_has_dl_policy(struct task_struct *p) { return dl_policy(p->policy); } #define cap_scale(v, s) ((v)*(s) >> SCHED_CAPACITY_SHIFT) /* * !! For sched_setattr_nocheck() (kernel) only !! * * This is actually gross. :( * * It is used to make schedutil kworker(s) higher priority than SCHED_DEADLINE * tasks, but still be able to sleep. We need this on platforms that cannot * atomically change clock frequency. Remove once fast switching will be * available on such platforms. * * SUGOV stands for SchedUtil GOVernor. */ #define SCHED_FLAG_SUGOV 0x10000000 static inline bool dl_entity_is_special(struct sched_dl_entity *dl_se) { #ifdef CONFIG_CPU_FREQ_GOV_SCHEDUTIL return unlikely(dl_se->flags & SCHED_FLAG_SUGOV); #else return false; #endif } /* * Tells if entity @a should preempt entity @b. */ static inline bool dl_entity_preempt(struct sched_dl_entity *a, struct sched_dl_entity *b) { return dl_entity_is_special(a) || dl_time_before(a->deadline, b->deadline); } /* * This is the priority-queue data structure of the RT scheduling class: */ struct rt_prio_array { DECLARE_BITMAP(bitmap, MAX_RT_PRIO+1); /* include 1 bit for delimiter */ struct list_head queue[MAX_RT_PRIO]; }; struct rt_bandwidth { /* nests inside the rq lock: */ raw_spinlock_t rt_runtime_lock; ktime_t rt_period; u64 rt_runtime; struct hrtimer rt_period_timer; unsigned int rt_period_active; }; void __dl_clear_params(struct task_struct *p); /* * To keep the bandwidth of -deadline tasks and groups under control * we need some place where: * - store the maximum -deadline bandwidth of the system (the group); * - cache the fraction of that bandwidth that is currently allocated. * * This is all done in the data structure below. It is similar to the * one used for RT-throttling (rt_bandwidth), with the main difference * that, since here we are only interested in admission control, we * do not decrease any runtime while the group "executes", neither we * need a timer to replenish it. * * With respect to SMP, the bandwidth is given on a per-CPU basis, * meaning that: * - dl_bw (< 100%) is the bandwidth of the system (group) on each CPU; * - dl_total_bw array contains, in the i-eth element, the currently * allocated bandwidth on the i-eth CPU. * Moreover, groups consume bandwidth on each CPU, while tasks only * consume bandwidth on the CPU they're running on. * Finally, dl_total_bw_cpu is used to cache the index of dl_total_bw * that will be shown the next time the proc or cgroup controls will * be red. It on its turn can be changed by writing on its own * control. */ struct dl_bandwidth { raw_spinlock_t dl_runtime_lock; u64 dl_runtime; u64 dl_period; }; static inline int dl_bandwidth_enabled(void) { return sysctl_sched_rt_runtime >= 0; } struct dl_bw { raw_spinlock_t lock; u64 bw; u64 total_bw; }; static inline void __dl_update(struct dl_bw *dl_b, s64 bw); static inline void __dl_sub(struct dl_bw *dl_b, u64 tsk_bw, int cpus) { dl_b->total_bw -= tsk_bw; __dl_update(dl_b, (s32)tsk_bw / cpus); } static inline void __dl_add(struct dl_bw *dl_b, u64 tsk_bw, int cpus) { dl_b->total_bw += tsk_bw; __dl_update(dl_b, -((s32)tsk_bw / cpus)); } static inline bool __dl_overflow(struct dl_bw *dl_b, int cpus, u64 old_bw, u64 new_bw) { return dl_b->bw != -1 && dl_b->bw * cpus < dl_b->total_bw - old_bw + new_bw; } extern void dl_change_utilization(struct task_struct *p, u64 new_bw); extern void init_dl_bw(struct dl_bw *dl_b); extern int sched_dl_global_validate(void); extern void sched_dl_do_global(void); extern int sched_dl_overflow(struct task_struct *p, int policy, const struct sched_attr *attr); extern void __setparam_dl(struct task_struct *p, const struct sched_attr *attr); extern void __getparam_dl(struct task_struct *p, struct sched_attr *attr); extern bool __checkparam_dl(const struct sched_attr *attr); extern bool dl_param_changed(struct task_struct *p, const struct sched_attr *attr); extern int dl_task_can_attach(struct task_struct *p, const struct cpumask *cs_cpus_allowed); extern int dl_cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial); extern bool dl_cpu_busy(unsigned int cpu); #ifdef CONFIG_CGROUP_SCHED #include #include struct cfs_rq; struct rt_rq; extern struct list_head task_groups; struct cfs_bandwidth { #ifdef CONFIG_CFS_BANDWIDTH raw_spinlock_t lock; ktime_t period; u64 quota; u64 runtime; s64 hierarchical_quota; u8 idle; u8 period_active; u8 distribute_running; u8 slack_started; struct hrtimer period_timer; struct hrtimer slack_timer; struct list_head throttled_cfs_rq; /* Statistics: */ int nr_periods; int nr_throttled; u64 throttled_time; #endif }; /* Task group related information */ struct task_group { struct cgroup_subsys_state css; #ifdef CONFIG_FAIR_GROUP_SCHED /* schedulable entities of this group on each CPU */ struct sched_entity **se; /* runqueue "owned" by this group on each CPU */ struct cfs_rq **cfs_rq; unsigned long shares; #ifdef CONFIG_SMP /* * load_avg can be heavily contended at clock tick time, so put * it in its own cacheline separated from the fields above which * will also be accessed at each tick. */ atomic_long_t load_avg ____cacheline_aligned; #endif #endif #ifdef CONFIG_RT_GROUP_SCHED struct sched_rt_entity **rt_se; struct rt_rq **rt_rq; struct rt_bandwidth rt_bandwidth; #endif struct rcu_head rcu; struct list_head list; struct task_group *parent; struct list_head siblings; struct list_head children; #ifdef CONFIG_SCHED_AUTOGROUP struct autogroup *autogroup; #endif struct cfs_bandwidth cfs_bandwidth; #ifdef CONFIG_UCLAMP_TASK_GROUP /* The two decimal precision [%] value requested from user-space */ unsigned int uclamp_pct[UCLAMP_CNT]; /* Clamp values requested for a task group */ struct uclamp_se uclamp_req[UCLAMP_CNT]; /* Effective clamp values used for a task group */ struct uclamp_se uclamp[UCLAMP_CNT]; #endif }; #ifdef CONFIG_FAIR_GROUP_SCHED #define ROOT_TASK_GROUP_LOAD NICE_0_LOAD /* * A weight of 0 or 1 can cause arithmetics problems. * A weight of a cfs_rq is the sum of weights of which entities * are queued on this cfs_rq, so a weight of a entity should not be * too large, so as the shares value of a task group. * (The default weight is 1024 - so there's no practical * limitation from this.) */ #define MIN_SHARES (1UL << 1) #define MAX_SHARES (1UL << 18) #endif typedef int (*tg_visitor)(struct task_group *, void *); extern int walk_tg_tree_from(struct task_group *from, tg_visitor down, tg_visitor up, void *data); /* * Iterate the full tree, calling @down when first entering a node and @up when * leaving it for the final time. * * Caller must hold rcu_lock or sufficient equivalent. */ static inline int walk_tg_tree(tg_visitor down, tg_visitor up, void *data) { return walk_tg_tree_from(&root_task_group, down, up, data); } extern int tg_nop(struct task_group *tg, void *data); extern void free_fair_sched_group(struct task_group *tg); extern int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent); extern void online_fair_sched_group(struct task_group *tg); extern void unregister_fair_sched_group(struct task_group *tg); extern void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq, struct sched_entity *se, int cpu, struct sched_entity *parent); extern void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b); extern void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b); extern void start_cfs_bandwidth(struct cfs_bandwidth *cfs_b); extern void unthrottle_cfs_rq(struct cfs_rq *cfs_rq); extern void free_rt_sched_group(struct task_group *tg); extern int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent); extern void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq, struct sched_rt_entity *rt_se, int cpu, struct sched_rt_entity *parent); extern int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us); extern int sched_group_set_rt_period(struct task_group *tg, u64 rt_period_us); extern long sched_group_rt_runtime(struct task_group *tg); extern long sched_group_rt_period(struct task_group *tg); extern int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk); extern struct task_group *sched_create_group(struct task_group *parent); extern void sched_online_group(struct task_group *tg, struct task_group *parent); extern void sched_destroy_group(struct task_group *tg); extern void sched_offline_group(struct task_group *tg); extern void sched_move_task(struct task_struct *tsk); #ifdef CONFIG_FAIR_GROUP_SCHED extern int sched_group_set_shares(struct task_group *tg, unsigned long shares); #ifdef CONFIG_SMP extern void set_task_rq_fair(struct sched_entity *se, struct cfs_rq *prev, struct cfs_rq *next); #else /* !CONFIG_SMP */ static inline void set_task_rq_fair(struct sched_entity *se, struct cfs_rq *prev, struct cfs_rq *next) { } #endif /* CONFIG_SMP */ #endif /* CONFIG_FAIR_GROUP_SCHED */ #else /* CONFIG_CGROUP_SCHED */ struct cfs_bandwidth { }; #endif /* CONFIG_CGROUP_SCHED */ /* CFS-related fields in a runqueue */ struct cfs_rq { struct load_weight load; unsigned int nr_running; unsigned int h_nr_running; /* SCHED_{NORMAL,BATCH,IDLE} */ unsigned int idle_h_nr_running; /* SCHED_IDLE */ u64 exec_clock; u64 min_vruntime; #ifndef CONFIG_64BIT u64 min_vruntime_copy; #endif struct rb_root_cached tasks_timeline; /* * 'curr' points to currently running entity on this cfs_rq. * It is set to NULL otherwise (i.e when none are currently running). */ struct sched_entity *curr; struct sched_entity *next; struct sched_entity *last; struct sched_entity *skip; #ifdef CONFIG_SCHED_DEBUG unsigned int nr_spread_over; #endif #ifdef CONFIG_SMP /* * CFS load tracking */ struct sched_avg avg; #ifndef CONFIG_64BIT u64 load_last_update_time_copy; #endif struct { raw_spinlock_t lock ____cacheline_aligned; int nr; unsigned long load_avg; unsigned long util_avg; unsigned long runnable_sum; } removed; #ifdef CONFIG_FAIR_GROUP_SCHED unsigned long tg_load_avg_contrib; long propagate; long prop_runnable_sum; /* * h_load = weight * f(tg) * * Where f(tg) is the recursive weight fraction assigned to * this group. */ unsigned long h_load; u64 last_h_load_update; struct sched_entity *h_load_next; #endif /* CONFIG_FAIR_GROUP_SCHED */ #endif /* CONFIG_SMP */ #ifdef CONFIG_FAIR_GROUP_SCHED struct rq *rq; /* CPU runqueue to which this cfs_rq is attached */ /* * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in * a hierarchy). Non-leaf lrqs hold other higher schedulable entities * (like users, containers etc.) * * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a CPU. * This list is used during load balance. */ int on_list; struct list_head leaf_cfs_rq_list; struct task_group *tg; /* group that "owns" this runqueue */ #ifdef CONFIG_CFS_BANDWIDTH int runtime_enabled; s64 runtime_remaining; u64 throttled_clock; u64 throttled_clock_task; u64 throttled_clock_task_time; int throttled; int throttle_count; struct list_head throttled_list; #endif /* CONFIG_CFS_BANDWIDTH */ #endif /* CONFIG_FAIR_GROUP_SCHED */ }; static inline int rt_bandwidth_enabled(void) { return sysctl_sched_rt_runtime >= 0; } /* RT IPI pull logic requires IRQ_WORK */ #if defined(CONFIG_IRQ_WORK) && defined(CONFIG_SMP) # define HAVE_RT_PUSH_IPI #endif /* Real-Time classes' related field in a runqueue: */ struct rt_rq { struct rt_prio_array active; unsigned int rt_nr_running; unsigned int rr_nr_running; #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED struct { int curr; /* highest queued rt task prio */ #ifdef CONFIG_SMP int next; /* next highest */ #endif } highest_prio; #endif #ifdef CONFIG_SMP unsigned long rt_nr_migratory; unsigned long rt_nr_total; int overloaded; struct plist_head pushable_tasks; #endif /* CONFIG_SMP */ int rt_queued; int rt_throttled; u64 rt_time; u64 rt_runtime; /* Nests inside the rq lock: */ raw_spinlock_t rt_runtime_lock; #ifdef CONFIG_RT_GROUP_SCHED unsigned long rt_nr_boosted; struct rq *rq; struct task_group *tg; #endif }; static inline bool rt_rq_is_runnable(struct rt_rq *rt_rq) { return rt_rq->rt_queued && rt_rq->rt_nr_running; } /* Deadline class' related fields in a runqueue */ struct dl_rq { /* runqueue is an rbtree, ordered by deadline */ struct rb_root_cached root; unsigned long dl_nr_running; #ifdef CONFIG_SMP /* * Deadline values of the currently executing and the * earliest ready task on this rq. Caching these facilitates * the decision whether or not a ready but not running task * should migrate somewhere else. */ struct { u64 curr; u64 next; } earliest_dl; unsigned long dl_nr_migratory; int overloaded; /* * Tasks on this rq that can be pushed away. They are kept in * an rb-tree, ordered by tasks' deadlines, with caching * of the leftmost (earliest deadline) element. */ struct rb_root_cached pushable_dl_tasks_root; #else struct dl_bw dl_bw; #endif /* * "Active utilization" for this runqueue: increased when a * task wakes up (becomes TASK_RUNNING) and decreased when a * task blocks */ u64 running_bw; /* * Utilization of the tasks "assigned" to this runqueue (including * the tasks that are in runqueue and the tasks that executed on this * CPU and blocked). Increased when a task moves to this runqueue, and * decreased when the task moves away (migrates, changes scheduling * policy, or terminates). * This is needed to compute the "inactive utilization" for the * runqueue (inactive utilization = this_bw - running_bw). */ u64 this_bw; u64 extra_bw; /* * Inverse of the fraction of CPU utilization that can be reclaimed * by the GRUB algorithm. */ u64 bw_ratio; }; #ifdef CONFIG_FAIR_GROUP_SCHED /* An entity is a task if it doesn't "own" a runqueue */ #define entity_is_task(se) (!se->my_q) #else #define entity_is_task(se) 1 #endif #ifdef CONFIG_SMP /* * XXX we want to get rid of these helpers and use the full load resolution. */ static inline long se_weight(struct sched_entity *se) { return scale_load_down(se->load.weight); } 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 * fully partitioning the member CPUs from any other cpuset. Whenever a new * exclusive cpuset is created, we also create and attach a new root-domain * object. * */ struct root_domain { atomic_t refcount; atomic_t rto_count; struct rcu_head rcu; cpumask_var_t span; cpumask_var_t online; /* * Indicate pullable load on at least one CPU, e.g: * - More than one runnable task * - Running task is misfit */ 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). */ cpumask_var_t dlo_mask; atomic_t dlo_count; struct dl_bw dl_bw; struct cpudl cpudl; #ifdef HAVE_RT_PUSH_IPI /* * For IPI pull requests, loop across the rto_mask. */ struct irq_work rto_push_work; raw_spinlock_t rto_lock; /* These are only updated and read within rto_lock */ int rto_loop; int rto_cpu; /* These atomics are updated outside of a lock */ atomic_t rto_loop_next; atomic_t rto_loop_start; #endif /* * The "RT overload" flag: it gets set if a CPU has more than * one runnable RT task. */ cpumask_var_t rto_mask; 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 __rcu *pd; }; extern void init_defrootdomain(void); extern int sched_init_domains(const struct cpumask *cpu_map); extern void rq_attach_root(struct rq *rq, struct root_domain *rd); extern void sched_get_rd(struct root_domain *rd); extern void sched_put_rd(struct root_domain *rd); #ifdef HAVE_RT_PUSH_IPI extern void rto_push_irq_work_func(struct irq_work *work); #endif #endif /* CONFIG_SMP */ #ifdef CONFIG_UCLAMP_TASK /* * struct uclamp_bucket - Utilization clamp bucket * @value: utilization clamp value for tasks on this clamp bucket * @tasks: number of RUNNABLE tasks on this clamp bucket * * Keep track of how many tasks are RUNNABLE for a given utilization * clamp value. */ struct uclamp_bucket { unsigned long value : bits_per(SCHED_CAPACITY_SCALE); unsigned long tasks : BITS_PER_LONG - bits_per(SCHED_CAPACITY_SCALE); }; /* * struct uclamp_rq - rq's utilization clamp * @value: currently active clamp values for a rq * @bucket: utilization clamp buckets affecting a rq * * Keep track of RUNNABLE tasks on a rq to aggregate their clamp values. * A clamp value is affecting a rq when there is at least one task RUNNABLE * (or actually running) with that value. * * There are up to UCLAMP_CNT possible different clamp values, currently there * are only two: minimum utilization and maximum utilization. * * All utilization clamping values are MAX aggregated, since: * - for util_min: we want to run the CPU at least at the max of the minimum * utilization required by its currently RUNNABLE tasks. * - for util_max: we want to allow the CPU to run up to the max of the * maximum utilization allowed by its currently RUNNABLE tasks. * * Since on each system we expect only a limited number of different * utilization clamp values (UCLAMP_BUCKETS), use a simple array to track * the metrics required to compute all the per-rq utilization clamp values. */ struct uclamp_rq { unsigned int value; struct uclamp_bucket bucket[UCLAMP_BUCKETS]; }; #endif /* CONFIG_UCLAMP_TASK */ /* * This is the main, per-CPU runqueue data structure. * * Locking rule: those places that want to lock multiple runqueues * (such as the load balancing or the thread migration code), lock * acquire operations must be ordered by ascending &runqueue. */ struct rq { /* runqueue lock: */ raw_spinlock_t lock; /* * nr_running and cpu_load should be in the same cacheline because * remote CPUs use both these fields when doing load calculation. */ unsigned int nr_running; #ifdef CONFIG_NUMA_BALANCING unsigned int nr_numa_running; unsigned int nr_preferred_running; unsigned int numa_migrate_on; #endif #ifdef CONFIG_NO_HZ_COMMON #ifdef CONFIG_SMP unsigned long last_load_update_tick; unsigned long last_blocked_load_update_tick; unsigned int has_blocked_load; #endif /* CONFIG_SMP */ unsigned int nohz_tick_stopped; atomic_t nohz_flags; #endif /* CONFIG_NO_HZ_COMMON */ unsigned long nr_load_updates; u64 nr_switches; #ifdef CONFIG_UCLAMP_TASK /* Utilization clamp values based on CPU's RUNNABLE tasks */ struct uclamp_rq uclamp[UCLAMP_CNT] ____cacheline_aligned; unsigned int uclamp_flags; #define UCLAMP_FLAG_IDLE 0x01 #endif struct cfs_rq cfs; struct rt_rq rt; struct dl_rq dl; #ifdef CONFIG_FAIR_GROUP_SCHED /* list of leaf cfs_rq on this CPU: */ struct list_head leaf_cfs_rq_list; struct list_head *tmp_alone_branch; #endif /* CONFIG_FAIR_GROUP_SCHED */ /* * This is part of a global counter where only the total sum * over all CPUs matters. A task can increase this counter on * one CPU and if it got migrated afterwards it may decrease * it on another CPU. Always updated under the runqueue lock: */ unsigned long nr_uninterruptible; struct task_struct __rcu *curr; struct task_struct *idle; struct task_struct *stop; unsigned long next_balance; struct mm_struct *prev_mm; unsigned int clock_update_flags; u64 clock; /* Ensure that all clocks are in the same cache line */ u64 clock_task ____cacheline_aligned; u64 clock_pelt; unsigned long lost_idle_time; atomic_t nr_iowait; #ifdef CONFIG_MEMBARRIER int membarrier_state; #endif #ifdef CONFIG_SMP struct root_domain *rd; struct sched_domain __rcu *sd; unsigned long cpu_capacity; unsigned long cpu_capacity_orig; struct callback_head *balance_callback; unsigned char idle_balance; unsigned long misfit_task_load; /* For active balancing */ int active_balance; int push_cpu; struct cpu_stop_work active_balance_work; /* CPU of this runqueue: */ int cpu; int online; struct list_head cfs_tasks; struct sched_avg avg_rt; struct sched_avg avg_dl; #ifdef CONFIG_HAVE_SCHED_AVG_IRQ struct sched_avg avg_irq; #endif u64 idle_stamp; u64 avg_idle; /* This is used to determine avg_idle's max value */ u64 max_idle_balance_cost; #endif #ifdef CONFIG_IRQ_TIME_ACCOUNTING u64 prev_irq_time; #endif #ifdef CONFIG_PARAVIRT u64 prev_steal_time; #endif #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING u64 prev_steal_time_rq; #endif /* calc_load related fields */ unsigned long calc_load_update; long calc_load_active; #ifdef CONFIG_SCHED_HRTICK #ifdef CONFIG_SMP int hrtick_csd_pending; call_single_data_t hrtick_csd; #endif struct hrtimer hrtick_timer; #endif #ifdef CONFIG_SCHEDSTATS /* latency stats */ struct sched_info rq_sched_info; unsigned long long rq_cpu_time; /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */ /* sys_sched_yield() stats */ unsigned int yld_count; /* schedule() stats */ unsigned int sched_count; unsigned int sched_goidle; /* try_to_wake_up() stats */ unsigned int ttwu_count; unsigned int ttwu_local; #endif #ifdef CONFIG_SMP struct llist_head wake_list; #endif #ifdef CONFIG_CPU_IDLE /* Must be inspected within a rcu lock section */ struct cpuidle_state *idle_state; #endif }; #ifdef CONFIG_FAIR_GROUP_SCHED /* CPU runqueue to which this cfs_rq is attached */ static inline struct rq *rq_of(struct cfs_rq *cfs_rq) { return cfs_rq->rq; } #else static inline struct rq *rq_of(struct cfs_rq *cfs_rq) { return container_of(cfs_rq, struct rq, cfs); } #endif static inline int cpu_of(struct rq *rq) { #ifdef CONFIG_SMP return rq->cpu; #else return 0; #endif } #ifdef CONFIG_SCHED_SMT extern void __update_idle_core(struct rq *rq); static inline void update_idle_core(struct rq *rq) { if (static_branch_unlikely(&sched_smt_present)) __update_idle_core(rq); } #else static inline void update_idle_core(struct rq *rq) { } #endif DECLARE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); #define cpu_rq(cpu) (&per_cpu(runqueues, (cpu))) #define this_rq() this_cpu_ptr(&runqueues) #define task_rq(p) cpu_rq(task_cpu(p)) #define cpu_curr(cpu) (cpu_rq(cpu)->curr) #define raw_rq() raw_cpu_ptr(&runqueues) extern void update_rq_clock(struct rq *rq); static inline u64 __rq_clock_broken(struct rq *rq) { return READ_ONCE(rq->clock); } /* * rq::clock_update_flags bits * * %RQCF_REQ_SKIP - will request skipping of clock update on the next * call to __schedule(). This is an optimisation to avoid * neighbouring rq clock updates. * * %RQCF_ACT_SKIP - is set from inside of __schedule() when skipping is * in effect and calls to update_rq_clock() are being ignored. * * %RQCF_UPDATED - is a debug flag that indicates whether a call has been * made to update_rq_clock() since the last time rq::lock was pinned. * * If inside of __schedule(), clock_update_flags will have been * shifted left (a left shift is a cheap operation for the fast path * to promote %RQCF_REQ_SKIP to %RQCF_ACT_SKIP), so you must use, * * if (rq-clock_update_flags >= RQCF_UPDATED) * * to check if %RQCF_UPADTED is set. It'll never be shifted more than * one position though, because the next rq_unpin_lock() will shift it * back. */ #define RQCF_REQ_SKIP 0x01 #define RQCF_ACT_SKIP 0x02 #define RQCF_UPDATED 0x04 static inline void assert_clock_updated(struct rq *rq) { /* * The only reason for not seeing a clock update since the * last rq_pin_lock() is if we're currently skipping updates. */ SCHED_WARN_ON(rq->clock_update_flags < RQCF_ACT_SKIP); } static inline u64 rq_clock(struct rq *rq) { lockdep_assert_held(&rq->lock); assert_clock_updated(rq); return rq->clock; } static inline u64 rq_clock_task(struct rq *rq) { lockdep_assert_held(&rq->lock); assert_clock_updated(rq); return rq->clock_task; } static inline void rq_clock_skip_update(struct rq *rq) { lockdep_assert_held(&rq->lock); rq->clock_update_flags |= RQCF_REQ_SKIP; } /* * See rt task throttling, which is the only time a skip * request is cancelled. */ static inline void rq_clock_cancel_skipupdate(struct rq *rq) { lockdep_assert_held(&rq->lock); rq->clock_update_flags &= ~RQCF_REQ_SKIP; } struct rq_flags { unsigned long flags; struct pin_cookie cookie; #ifdef CONFIG_SCHED_DEBUG /* * A copy of (rq::clock_update_flags & RQCF_UPDATED) for the * current pin context is stashed here in case it needs to be * restored in rq_repin_lock(). */ unsigned int clock_update_flags; #endif }; static inline void rq_pin_lock(struct rq *rq, struct rq_flags *rf) { rf->cookie = lockdep_pin_lock(&rq->lock); #ifdef CONFIG_SCHED_DEBUG rq->clock_update_flags &= (RQCF_REQ_SKIP|RQCF_ACT_SKIP); rf->clock_update_flags = 0; #endif } static inline void rq_unpin_lock(struct rq *rq, struct rq_flags *rf) { #ifdef CONFIG_SCHED_DEBUG if (rq->clock_update_flags > RQCF_ACT_SKIP) rf->clock_update_flags = RQCF_UPDATED; #endif lockdep_unpin_lock(&rq->lock, rf->cookie); } static inline void rq_repin_lock(struct rq *rq, struct rq_flags *rf) { lockdep_repin_lock(&rq->lock, rf->cookie); #ifdef CONFIG_SCHED_DEBUG /* * Restore the value we stashed in @rf for this pin context. */ rq->clock_update_flags |= rf->clock_update_flags; #endif } struct rq *__task_rq_lock(struct task_struct *p, struct rq_flags *rf) __acquires(rq->lock); struct rq *task_rq_lock(struct task_struct *p, struct rq_flags *rf) __acquires(p->pi_lock) __acquires(rq->lock); static inline void __task_rq_unlock(struct rq *rq, struct rq_flags *rf) __releases(rq->lock) { rq_unpin_lock(rq, rf); raw_spin_unlock(&rq->lock); } static inline void task_rq_unlock(struct rq *rq, struct task_struct *p, struct rq_flags *rf) __releases(rq->lock) __releases(p->pi_lock) { rq_unpin_lock(rq, rf); raw_spin_unlock(&rq->lock); raw_spin_unlock_irqrestore(&p->pi_lock, rf->flags); } static inline void rq_lock_irqsave(struct rq *rq, struct rq_flags *rf) __acquires(rq->lock) { raw_spin_lock_irqsave(&rq->lock, rf->flags); rq_pin_lock(rq, rf); } static inline void rq_lock_irq(struct rq *rq, struct rq_flags *rf) __acquires(rq->lock) { raw_spin_lock_irq(&rq->lock); rq_pin_lock(rq, rf); } static inline void rq_lock(struct rq *rq, struct rq_flags *rf) __acquires(rq->lock) { raw_spin_lock(&rq->lock); rq_pin_lock(rq, rf); } static inline void rq_relock(struct rq *rq, struct rq_flags *rf) __acquires(rq->lock) { raw_spin_lock(&rq->lock); rq_repin_lock(rq, rf); } static inline void rq_unlock_irqrestore(struct rq *rq, struct rq_flags *rf) __releases(rq->lock) { rq_unpin_lock(rq, rf); raw_spin_unlock_irqrestore(&rq->lock, rf->flags); } static inline void rq_unlock_irq(struct rq *rq, struct rq_flags *rf) __releases(rq->lock) { rq_unpin_lock(rq, rf); raw_spin_unlock_irq(&rq->lock); } static inline void rq_unlock(struct rq *rq, struct rq_flags *rf) __releases(rq->lock) { rq_unpin_lock(rq, rf); raw_spin_unlock(&rq->lock); } static inline struct rq * this_rq_lock_irq(struct rq_flags *rf) __acquires(rq->lock) { struct rq *rq; local_irq_disable(); rq = this_rq(); rq_lock(rq, rf); return rq; } #ifdef CONFIG_NUMA enum numa_topology_type { NUMA_DIRECT, NUMA_GLUELESS_MESH, NUMA_BACKPLANE, }; extern enum numa_topology_type sched_numa_topology_type; extern int sched_max_numa_distance; extern bool find_numa_distance(int distance); extern void sched_init_numa(void); extern void sched_domains_numa_masks_set(unsigned int cpu); extern void sched_domains_numa_masks_clear(unsigned int cpu); extern int sched_numa_find_closest(const struct cpumask *cpus, int cpu); #else static inline void sched_init_numa(void) { } static inline void sched_domains_numa_masks_set(unsigned int cpu) { } static inline void sched_domains_numa_masks_clear(unsigned int cpu) { } static inline int sched_numa_find_closest(const struct cpumask *cpus, int cpu) { return nr_cpu_ids; } #endif #ifdef CONFIG_NUMA_BALANCING /* The regions in numa_faults array from task_struct */ enum numa_faults_stats { NUMA_MEM = 0, NUMA_CPU, NUMA_MEMBUF, NUMA_CPUBUF }; extern void sched_setnuma(struct task_struct *p, int node); extern int migrate_task_to(struct task_struct *p, int cpu); extern int migrate_swap(struct task_struct *p, struct task_struct *t, int cpu, int scpu); extern void init_numa_balancing(unsigned long clone_flags, struct task_struct *p); #else static inline void init_numa_balancing(unsigned long clone_flags, struct task_struct *p) { } #endif /* CONFIG_NUMA_BALANCING */ #ifdef CONFIG_SMP static inline void queue_balance_callback(struct rq *rq, struct callback_head *head, void (*func)(struct rq *rq)) { lockdep_assert_held(&rq->lock); if (unlikely(head->next)) return; head->func = (void (*)(struct callback_head *))func; head->next = rq->balance_callback; rq->balance_callback = head; } extern void sched_ttwu_pending(void); #define rcu_dereference_check_sched_domain(p) \ rcu_dereference_check((p), \ lockdep_is_held(&sched_domains_mutex)) /* * The domain tree (rq->sd) is protected by RCU's quiescent state transition. * See destroy_sched_domains: call_rcu for details. * * The domain tree of any CPU may only be accessed from within * preempt-disabled sections. */ #define for_each_domain(cpu, __sd) \ for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); \ __sd; __sd = __sd->parent) /** * highest_flag_domain - Return highest sched_domain containing flag. * @cpu: The CPU whose highest level of sched domain is to * be returned. * @flag: The flag to check for the highest sched_domain * for the given CPU. * * Returns the highest sched_domain of a CPU which contains the given flag. */ static inline struct sched_domain *highest_flag_domain(int cpu, int flag) { struct sched_domain *sd, *hsd = NULL; for_each_domain(cpu, sd) { if (!(sd->flags & flag)) break; hsd = sd; } return hsd; } static inline struct sched_domain *lowest_flag_domain(int cpu, int flag) { struct sched_domain *sd; for_each_domain(cpu, sd) { if (sd->flags & flag) break; } return sd; } DECLARE_PER_CPU(struct sched_domain __rcu *, sd_llc); DECLARE_PER_CPU(int, sd_llc_size); DECLARE_PER_CPU(int, sd_llc_id); DECLARE_PER_CPU(struct sched_domain_shared __rcu *, sd_llc_shared); DECLARE_PER_CPU(struct sched_domain __rcu *, sd_numa); DECLARE_PER_CPU(struct sched_domain __rcu *, sd_asym_packing); DECLARE_PER_CPU(struct sched_domain __rcu *, sd_asym_cpucapacity); extern struct static_key_false sched_asym_cpucapacity; struct sched_group_capacity { atomic_t ref; /* * CPU capacity of this group, SCHED_CAPACITY_SCALE being max capacity * for a single CPU. */ unsigned long capacity; unsigned long min_capacity; /* Min per-CPU capacity in group */ unsigned long max_capacity; /* Max per-CPU capacity in group */ unsigned long next_update; int imbalance; /* XXX unrelated to capacity but shared group state */ #ifdef CONFIG_SCHED_DEBUG int id; #endif unsigned long cpumask[0]; /* Balance mask */ }; struct sched_group { struct sched_group *next; /* Must be a circular list */ atomic_t ref; unsigned int group_weight; struct sched_group_capacity *sgc; int asym_prefer_cpu; /* CPU of highest priority in group */ /* * The CPUs this group covers. * * NOTE: this field is variable length. (Allocated dynamically * by attaching extra space to the end of the structure, * depending on how many CPUs the kernel has booted up with) */ unsigned long cpumask[0]; }; static inline struct cpumask *sched_group_span(struct sched_group *sg) { return to_cpumask(sg->cpumask); } /* * See build_balance_mask(). */ static inline struct cpumask *group_balance_mask(struct sched_group *sg) { return to_cpumask(sg->sgc->cpumask); } /** * group_first_cpu - Returns the first CPU in the cpumask of a sched_group. * @group: The group whose first CPU is to be returned. */ static inline unsigned int group_first_cpu(struct sched_group *group) { return cpumask_first(sched_group_span(group)); } extern int group_balance_cpu(struct sched_group *sg); #if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL) void register_sched_domain_sysctl(void); void dirty_sched_domain_sysctl(int cpu); void unregister_sched_domain_sysctl(void); #else static inline void register_sched_domain_sysctl(void) { } static inline void dirty_sched_domain_sysctl(int cpu) { } static inline void unregister_sched_domain_sysctl(void) { } #endif extern int newidle_balance(struct rq *this_rq, struct rq_flags *rf); #else static inline void sched_ttwu_pending(void) { } static inline int newidle_balance(struct rq *this_rq, struct rq_flags *rf) { return 0; } #endif /* CONFIG_SMP */ #include "stats.h" #include "autogroup.h" #ifdef CONFIG_CGROUP_SCHED /* * Return the group to which this tasks belongs. * * We cannot use task_css() and friends because the cgroup subsystem * changes that value before the cgroup_subsys::attach() method is called, * therefore we cannot pin it and might observe the wrong value. * * The same is true for autogroup's p->signal->autogroup->tg, the autogroup * core changes this before calling sched_move_task(). * * Instead we use a 'copy' which is updated from sched_move_task() while * holding both task_struct::pi_lock and rq::lock. */ static inline struct task_group *task_group(struct task_struct *p) { return p->sched_task_group; } /* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */ static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { #if defined(CONFIG_FAIR_GROUP_SCHED) || defined(CONFIG_RT_GROUP_SCHED) struct task_group *tg = task_group(p); #endif #ifdef CONFIG_FAIR_GROUP_SCHED set_task_rq_fair(&p->se, p->se.cfs_rq, tg->cfs_rq[cpu]); p->se.cfs_rq = tg->cfs_rq[cpu]; p->se.parent = tg->se[cpu]; #endif #ifdef CONFIG_RT_GROUP_SCHED p->rt.rt_rq = tg->rt_rq[cpu]; p->rt.parent = tg->rt_se[cpu]; #endif } #else /* CONFIG_CGROUP_SCHED */ static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { } static inline struct task_group *task_group(struct task_struct *p) { return NULL; } #endif /* CONFIG_CGROUP_SCHED */ static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) { set_task_rq(p, cpu); #ifdef CONFIG_SMP /* * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be * successfully executed on another CPU. We must ensure that updates of * per-task data have been completed by this moment. */ smp_wmb(); #ifdef CONFIG_THREAD_INFO_IN_TASK WRITE_ONCE(p->cpu, cpu); #else WRITE_ONCE(task_thread_info(p)->cpu, cpu); #endif p->wake_cpu = cpu; #endif } /* * Tunables that become constants when CONFIG_SCHED_DEBUG is off: */ #ifdef CONFIG_SCHED_DEBUG # include # define const_debug __read_mostly #else # define const_debug const #endif #define SCHED_FEAT(name, enabled) \ __SCHED_FEAT_##name , enum { #include "features.h" __SCHED_FEAT_NR, }; #undef SCHED_FEAT #if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_JUMP_LABEL) /* * To support run-time toggling of sched features, all the translation units * (but core.c) reference the sysctl_sched_features defined in core.c. */ extern const_debug unsigned int sysctl_sched_features; #define SCHED_FEAT(name, enabled) \ static __always_inline bool static_branch_##name(struct static_key *key) \ { \ return static_key_##enabled(key); \ } #include "features.h" #undef SCHED_FEAT extern struct static_key sched_feat_keys[__SCHED_FEAT_NR]; #define sched_feat(x) (static_branch_##x(&sched_feat_keys[__SCHED_FEAT_##x])) #else /* !(SCHED_DEBUG && CONFIG_JUMP_LABEL) */ /* * Each translation unit has its own copy of sysctl_sched_features to allow * constants propagation at compile time and compiler optimization based on * features default. */ #define SCHED_FEAT(name, enabled) \ (1UL << __SCHED_FEAT_##name) * enabled | static const_debug __maybe_unused unsigned int sysctl_sched_features = #include "features.h" 0; #undef SCHED_FEAT #define sched_feat(x) !!(sysctl_sched_features & (1UL << __SCHED_FEAT_##x)) #endif /* SCHED_DEBUG && CONFIG_JUMP_LABEL */ extern struct static_key_false sched_numa_balancing; extern struct static_key_false sched_schedstats; static inline u64 global_rt_period(void) { return (u64)sysctl_sched_rt_period * NSEC_PER_USEC; } static inline u64 global_rt_runtime(void) { if (sysctl_sched_rt_runtime < 0) return RUNTIME_INF; return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC; } static inline int task_current(struct rq *rq, struct task_struct *p) { return rq->curr == p; } static inline int task_running(struct rq *rq, struct task_struct *p) { #ifdef CONFIG_SMP return p->on_cpu; #else return task_current(rq, p); #endif } static inline int task_on_rq_queued(struct task_struct *p) { return p->on_rq == TASK_ON_RQ_QUEUED; } static inline int task_on_rq_migrating(struct task_struct *p) { return READ_ONCE(p->on_rq) == TASK_ON_RQ_MIGRATING; } /* * wake flags */ #define WF_SYNC 0x01 /* Waker goes to sleep after wakeup */ #define WF_FORK 0x02 /* Child wakeup after fork */ #define WF_MIGRATED 0x4 /* Internal use, task got migrated */ /* * To aid in avoiding the subversion of "niceness" due to uneven distribution * of tasks with abnormal "nice" values across CPUs the contribution that * each task makes to its run queue's load is weighted according to its * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a * scaled version of the new time slice allocation that they receive on time * slice expiry etc. */ #define WEIGHT_IDLEPRIO 3 #define WMULT_IDLEPRIO 1431655765 extern const int sched_prio_to_weight[40]; extern const u32 sched_prio_to_wmult[40]; /* * {de,en}queue flags: * * DEQUEUE_SLEEP - task is no longer runnable * ENQUEUE_WAKEUP - task just became runnable * * SAVE/RESTORE - an otherwise spurious dequeue/enqueue, done to ensure tasks * are in a known state which allows modification. Such pairs * should preserve as much state as possible. * * MOVE - paired with SAVE/RESTORE, explicitly does not preserve the location * in the runqueue. * * ENQUEUE_HEAD - place at front of runqueue (tail if not specified) * ENQUEUE_REPLENISH - CBS (replenish runtime and postpone deadline) * ENQUEUE_MIGRATED - the task was migrated during wakeup * */ #define DEQUEUE_SLEEP 0x01 #define DEQUEUE_SAVE 0x02 /* Matches ENQUEUE_RESTORE */ #define DEQUEUE_MOVE 0x04 /* Matches ENQUEUE_MOVE */ #define DEQUEUE_NOCLOCK 0x08 /* Matches ENQUEUE_NOCLOCK */ #define ENQUEUE_WAKEUP 0x01 #define ENQUEUE_RESTORE 0x02 #define ENQUEUE_MOVE 0x04 #define ENQUEUE_NOCLOCK 0x08 #define ENQUEUE_HEAD 0x10 #define ENQUEUE_REPLENISH 0x20 #ifdef CONFIG_SMP #define ENQUEUE_MIGRATED 0x40 #else #define ENQUEUE_MIGRATED 0x00 #endif #define RETRY_TASK ((void *)-1UL) struct sched_class { const struct sched_class *next; #ifdef CONFIG_UCLAMP_TASK int uclamp_enabled; #endif void (*enqueue_task) (struct rq *rq, struct task_struct *p, int flags); void (*dequeue_task) (struct rq *rq, struct task_struct *p, int flags); void (*yield_task) (struct rq *rq); bool (*yield_to_task)(struct rq *rq, struct task_struct *p, bool preempt); void (*check_preempt_curr)(struct rq *rq, struct task_struct *p, int flags); struct task_struct *(*pick_next_task)(struct rq *rq); void (*put_prev_task)(struct rq *rq, struct task_struct *p); void (*set_next_task)(struct rq *rq, struct task_struct *p, bool first); #ifdef CONFIG_SMP int (*balance)(struct rq *rq, struct task_struct *prev, struct rq_flags *rf); int (*select_task_rq)(struct task_struct *p, int task_cpu, int sd_flag, int flags); void (*migrate_task_rq)(struct task_struct *p, int new_cpu); void (*task_woken)(struct rq *this_rq, struct task_struct *task); void (*set_cpus_allowed)(struct task_struct *p, const struct cpumask *newmask); void (*rq_online)(struct rq *rq); void (*rq_offline)(struct rq *rq); #endif void (*task_tick)(struct rq *rq, struct task_struct *p, int queued); void (*task_fork)(struct task_struct *p); void (*task_dead)(struct task_struct *p); /* * The switched_from() call is allowed to drop rq->lock, therefore we * cannot assume the switched_from/switched_to pair is serliazed by * rq->lock. They are however serialized by p->pi_lock. */ void (*switched_from)(struct rq *this_rq, struct task_struct *task); void (*switched_to) (struct rq *this_rq, struct task_struct *task); void (*prio_changed) (struct rq *this_rq, struct task_struct *task, int oldprio); unsigned int (*get_rr_interval)(struct rq *rq, struct task_struct *task); void (*update_curr)(struct rq *rq); #define TASK_SET_GROUP 0 #define TASK_MOVE_GROUP 1 #ifdef CONFIG_FAIR_GROUP_SCHED void (*task_change_group)(struct task_struct *p, int type); #endif }; static inline void put_prev_task(struct rq *rq, struct task_struct *prev) { WARN_ON_ONCE(rq->curr != prev); prev->sched_class->put_prev_task(rq, prev); } static inline void set_next_task(struct rq *rq, struct task_struct *next) { WARN_ON_ONCE(rq->curr != next); next->sched_class->set_next_task(rq, next, false); } #ifdef CONFIG_SMP #define sched_class_highest (&stop_sched_class) #else #define sched_class_highest (&dl_sched_class) #endif #define for_class_range(class, _from, _to) \ for (class = (_from); class != (_to); class = class->next) #define for_each_class(class) \ for_class_range(class, sched_class_highest, NULL) extern const struct sched_class stop_sched_class; extern const struct sched_class dl_sched_class; extern const struct sched_class rt_sched_class; extern const struct sched_class fair_sched_class; extern const struct sched_class idle_sched_class; static inline bool sched_stop_runnable(struct rq *rq) { return rq->stop && task_on_rq_queued(rq->stop); } static inline bool sched_dl_runnable(struct rq *rq) { return rq->dl.dl_nr_running > 0; } static inline bool sched_rt_runnable(struct rq *rq) { return rq->rt.rt_queued > 0; } static inline bool sched_fair_runnable(struct rq *rq) { return rq->cfs.nr_running > 0; } extern struct task_struct *pick_next_task_fair(struct rq *rq, struct task_struct *prev, struct rq_flags *rf); extern struct task_struct *pick_next_task_idle(struct rq *rq); #ifdef CONFIG_SMP extern void update_group_capacity(struct sched_domain *sd, int cpu); extern void trigger_load_balance(struct rq *rq); extern void set_cpus_allowed_common(struct task_struct *p, const struct cpumask *new_mask); #endif #ifdef CONFIG_CPU_IDLE static inline void idle_set_state(struct rq *rq, struct cpuidle_state *idle_state) { rq->idle_state = idle_state; } static inline struct cpuidle_state *idle_get_state(struct rq *rq) { SCHED_WARN_ON(!rcu_read_lock_held()); return rq->idle_state; } #else static inline void idle_set_state(struct rq *rq, struct cpuidle_state *idle_state) { } static inline struct cpuidle_state *idle_get_state(struct rq *rq) { return NULL; } #endif extern void schedule_idle(void); extern void sysrq_sched_debug_show(void); extern void sched_init_granularity(void); extern void update_max_interval(void); extern void init_sched_dl_class(void); extern void init_sched_rt_class(void); extern void init_sched_fair_class(void); extern void reweight_task(struct task_struct *p, int prio); extern void resched_curr(struct rq *rq); extern void resched_cpu(int cpu); extern struct rt_bandwidth def_rt_bandwidth; extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime); extern struct dl_bandwidth def_dl_bandwidth; extern void init_dl_bandwidth(struct dl_bandwidth *dl_b, u64 period, u64 runtime); extern void init_dl_task_timer(struct sched_dl_entity *dl_se); extern void init_dl_inactive_task_timer(struct sched_dl_entity *dl_se); extern void init_dl_rq_bw_ratio(struct dl_rq *dl_rq); #define BW_SHIFT 20 #define BW_UNIT (1 << BW_SHIFT) #define RATIO_SHIFT 8 unsigned long to_ratio(u64 period, u64 runtime); extern void init_entity_runnable_average(struct sched_entity *se); extern void post_init_entity_util_avg(struct task_struct *p); #ifdef CONFIG_NO_HZ_FULL extern bool sched_can_stop_tick(struct rq *rq); extern int __init sched_tick_offload_init(void); /* * Tick may be needed by tasks in the runqueue depending on their policy and * requirements. If tick is needed, lets send the target an IPI to kick it out of * nohz mode if necessary. */ static inline void sched_update_tick_dependency(struct rq *rq) { int cpu; if (!tick_nohz_full_enabled()) return; cpu = cpu_of(rq); if (!tick_nohz_full_cpu(cpu)) return; if (sched_can_stop_tick(rq)) tick_nohz_dep_clear_cpu(cpu, TICK_DEP_BIT_SCHED); else tick_nohz_dep_set_cpu(cpu, TICK_DEP_BIT_SCHED); } #else static inline int sched_tick_offload_init(void) { return 0; } static inline void sched_update_tick_dependency(struct rq *rq) { } #endif static inline void add_nr_running(struct rq *rq, unsigned count) { unsigned prev_nr = rq->nr_running; rq->nr_running = prev_nr + count; #ifdef CONFIG_SMP if (prev_nr < 2 && rq->nr_running >= 2) { if (!READ_ONCE(rq->rd->overload)) WRITE_ONCE(rq->rd->overload, 1); } #endif sched_update_tick_dependency(rq); } static inline void sub_nr_running(struct rq *rq, unsigned count) { rq->nr_running -= count; /* Check if we still need preemption */ sched_update_tick_dependency(rq); } extern void activate_task(struct rq *rq, struct task_struct *p, int flags); extern void deactivate_task(struct rq *rq, struct task_struct *p, int flags); extern void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags); extern const_debug unsigned int sysctl_sched_nr_migrate; extern const_debug unsigned int sysctl_sched_migration_cost; #ifdef CONFIG_SCHED_HRTICK /* * Use hrtick when: * - enabled by features * - hrtimer is actually high res */ static inline int hrtick_enabled(struct rq *rq) { if (!sched_feat(HRTICK)) return 0; if (!cpu_active(cpu_of(rq))) return 0; return hrtimer_is_hres_active(&rq->hrtick_timer); } void hrtick_start(struct rq *rq, u64 delay); #else static inline int hrtick_enabled(struct rq *rq) { return 0; } #endif /* CONFIG_SCHED_HRTICK */ #ifndef arch_scale_freq_tick static __always_inline void arch_scale_freq_tick(void) { } #endif #ifndef arch_scale_freq_capacity static __always_inline unsigned long arch_scale_freq_capacity(int cpu) { return SCHED_CAPACITY_SCALE; } #endif #ifdef CONFIG_SMP #ifdef CONFIG_PREEMPTION static inline void double_rq_lock(struct rq *rq1, struct rq *rq2); /* * fair double_lock_balance: Safely acquires both rq->locks in a fair * way at the expense of forcing extra atomic operations in all * invocations. This assures that the double_lock is acquired using the * same underlying policy as the spinlock_t on this architecture, which * reduces latency compared to the unfair variant below. However, it * also adds more overhead and therefore may reduce throughput. */ static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) __releases(this_rq->lock) __acquires(busiest->lock) __acquires(this_rq->lock) { raw_spin_unlock(&this_rq->lock); double_rq_lock(this_rq, busiest); return 1; } #else /* * Unfair double_lock_balance: Optimizes throughput at the expense of * latency by eliminating extra atomic operations when the locks are * already in proper order on entry. This favors lower CPU-ids and will * grant the double lock to lower CPUs over higher ids under contention, * regardless of entry order into the function. */ static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) __releases(this_rq->lock) __acquires(busiest->lock) __acquires(this_rq->lock) { int ret = 0; if (unlikely(!raw_spin_trylock(&busiest->lock))) { if (busiest < this_rq) { raw_spin_unlock(&this_rq->lock); raw_spin_lock(&busiest->lock); raw_spin_lock_nested(&this_rq->lock, SINGLE_DEPTH_NESTING); ret = 1; } else raw_spin_lock_nested(&busiest->lock, SINGLE_DEPTH_NESTING); } return ret; } #endif /* CONFIG_PREEMPTION */ /* * double_lock_balance - lock the busiest runqueue, this_rq is locked already. */ static inline int double_lock_balance(struct rq *this_rq, struct rq *busiest) { if (unlikely(!irqs_disabled())) { /* printk() doesn't work well under rq->lock */ raw_spin_unlock(&this_rq->lock); BUG_ON(1); } return _double_lock_balance(this_rq, busiest); } static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest) __releases(busiest->lock) { raw_spin_unlock(&busiest->lock); lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_); } static inline void double_lock(spinlock_t *l1, spinlock_t *l2) { if (l1 > l2) swap(l1, l2); spin_lock(l1); spin_lock_nested(l2, SINGLE_DEPTH_NESTING); } static inline void double_lock_irq(spinlock_t *l1, spinlock_t *l2) { if (l1 > l2) swap(l1, l2); spin_lock_irq(l1); spin_lock_nested(l2, SINGLE_DEPTH_NESTING); } static inline void double_raw_lock(raw_spinlock_t *l1, raw_spinlock_t *l2) { if (l1 > l2) swap(l1, l2); raw_spin_lock(l1); raw_spin_lock_nested(l2, SINGLE_DEPTH_NESTING); } /* * double_rq_lock - safely lock two runqueues * * Note this does not disable interrupts like task_rq_lock, * you need to do so manually before calling. */ static inline void double_rq_lock(struct rq *rq1, struct rq *rq2) __acquires(rq1->lock) __acquires(rq2->lock) { BUG_ON(!irqs_disabled()); if (rq1 == rq2) { raw_spin_lock(&rq1->lock); __acquire(rq2->lock); /* Fake it out ;) */ } else { if (rq1 < rq2) { raw_spin_lock(&rq1->lock); raw_spin_lock_nested(&rq2->lock, SINGLE_DEPTH_NESTING); } else { raw_spin_lock(&rq2->lock); raw_spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING); } } } /* * double_rq_unlock - safely unlock two runqueues * * Note this does not restore interrupts like task_rq_unlock, * you need to do so manually after calling. */ static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2) __releases(rq1->lock) __releases(rq2->lock) { raw_spin_unlock(&rq1->lock); if (rq1 != rq2) raw_spin_unlock(&rq2->lock); else __release(rq2->lock); } extern void set_rq_online (struct rq *rq); extern void set_rq_offline(struct rq *rq); extern bool sched_smp_initialized; #else /* CONFIG_SMP */ /* * double_rq_lock - safely lock two runqueues * * Note this does not disable interrupts like task_rq_lock, * you need to do so manually before calling. */ static inline void double_rq_lock(struct rq *rq1, struct rq *rq2) __acquires(rq1->lock) __acquires(rq2->lock) { BUG_ON(!irqs_disabled()); BUG_ON(rq1 != rq2); raw_spin_lock(&rq1->lock); __acquire(rq2->lock); /* Fake it out ;) */ } /* * double_rq_unlock - safely unlock two runqueues * * Note this does not restore interrupts like task_rq_unlock, * you need to do so manually after calling. */ static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2) __releases(rq1->lock) __releases(rq2->lock) { BUG_ON(rq1 != rq2); raw_spin_unlock(&rq1->lock); __release(rq2->lock); } #endif extern struct sched_entity *__pick_first_entity(struct cfs_rq *cfs_rq); extern struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq); #ifdef CONFIG_SCHED_DEBUG extern bool sched_debug_enabled; extern void print_cfs_stats(struct seq_file *m, int cpu); extern void print_rt_stats(struct seq_file *m, int cpu); extern void print_dl_stats(struct seq_file *m, int cpu); extern void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq); extern void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq); extern void print_dl_rq(struct seq_file *m, int cpu, struct dl_rq *dl_rq); #ifdef CONFIG_NUMA_BALANCING extern void show_numa_stats(struct task_struct *p, struct seq_file *m); extern void print_numa_stats(struct seq_file *m, int node, unsigned long tsf, unsigned long tpf, unsigned long gsf, unsigned long gpf); #endif /* CONFIG_NUMA_BALANCING */ #endif /* CONFIG_SCHED_DEBUG */ extern void init_cfs_rq(struct cfs_rq *cfs_rq); extern void init_rt_rq(struct rt_rq *rt_rq); extern void init_dl_rq(struct dl_rq *dl_rq); extern void cfs_bandwidth_usage_inc(void); extern void cfs_bandwidth_usage_dec(void); #ifdef CONFIG_NO_HZ_COMMON #define NOHZ_BALANCE_KICK_BIT 0 #define NOHZ_STATS_KICK_BIT 1 #define NOHZ_BALANCE_KICK BIT(NOHZ_BALANCE_KICK_BIT) #define NOHZ_STATS_KICK BIT(NOHZ_STATS_KICK_BIT) #define NOHZ_KICK_MASK (NOHZ_BALANCE_KICK | NOHZ_STATS_KICK) #define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags) extern void nohz_balance_exit_idle(struct rq *rq); #else static inline void nohz_balance_exit_idle(struct rq *rq) { } #endif #ifdef CONFIG_SMP static inline void __dl_update(struct dl_bw *dl_b, s64 bw) { struct root_domain *rd = container_of(dl_b, struct root_domain, dl_bw); int i; RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held(), "sched RCU must be held"); for_each_cpu_and(i, rd->span, cpu_active_mask) { struct rq *rq = cpu_rq(i); rq->dl.extra_bw += bw; } } #else static inline void __dl_update(struct dl_bw *dl_b, s64 bw) { struct dl_rq *dl = container_of(dl_b, struct dl_rq, dl_bw); dl->extra_bw += bw; } #endif #ifdef CONFIG_IRQ_TIME_ACCOUNTING struct irqtime { u64 total; u64 tick_delta; u64 irq_start_time; struct u64_stats_sync sync; }; DECLARE_PER_CPU(struct irqtime, cpu_irqtime); /* * Returns the irqtime minus the softirq time computed by ksoftirqd. * Otherwise ksoftirqd's sum_exec_runtime is substracted its own runtime * and never move forward. */ static inline u64 irq_time_read(int cpu) { struct irqtime *irqtime = &per_cpu(cpu_irqtime, cpu); unsigned int seq; u64 total; do { seq = __u64_stats_fetch_begin(&irqtime->sync); total = irqtime->total; } while (__u64_stats_fetch_retry(&irqtime->sync, seq)); return total; } #endif /* CONFIG_IRQ_TIME_ACCOUNTING */ #ifdef CONFIG_CPU_FREQ DECLARE_PER_CPU(struct update_util_data __rcu *, cpufreq_update_util_data); /** * cpufreq_update_util - Take a note about CPU utilization changes. * @rq: Runqueue to carry out the update for. * @flags: Update reason flags. * * This function is called by the scheduler on the CPU whose utilization is * being updated. * * It can only be called from RCU-sched read-side critical sections. * * The way cpufreq is currently arranged requires it to evaluate the CPU * performance state (frequency/voltage) on a regular basis to prevent it from * being stuck in a completely inadequate performance level for too long. * That is not guaranteed to happen if the updates are only triggered from CFS * and DL, though, because they may not be coming in if only RT tasks are * active all the time (or there are RT tasks only). * * As a workaround for that issue, this function is called periodically by the * RT sched class to trigger extra cpufreq updates to prevent it from stalling, * but that really is a band-aid. Going forward it should be replaced with * solutions targeted more specifically at RT tasks. */ static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) { struct update_util_data *data; data = rcu_dereference_sched(*per_cpu_ptr(&cpufreq_update_util_data, cpu_of(rq))); if (data) data->func(data, rq_clock(rq), flags); } #else static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) {} #endif /* CONFIG_CPU_FREQ */ #ifdef CONFIG_UCLAMP_TASK unsigned long uclamp_eff_value(struct task_struct *p, enum uclamp_id clamp_id); static __always_inline unsigned long uclamp_rq_util_with(struct rq *rq, unsigned long util, struct task_struct *p) { unsigned long min_util = READ_ONCE(rq->uclamp[UCLAMP_MIN].value); unsigned long max_util = READ_ONCE(rq->uclamp[UCLAMP_MAX].value); if (p) { min_util = max(min_util, uclamp_eff_value(p, UCLAMP_MIN)); max_util = max(max_util, uclamp_eff_value(p, UCLAMP_MAX)); } /* * Since CPU's {min,max}_util clamps are MAX aggregated considering * RUNNABLE tasks with _different_ clamps, we can end up with an * inversion. Fix it now when the clamps are applied. */ if (unlikely(min_util >= max_util)) return min_util; return clamp(util, min_util, max_util); } #else /* CONFIG_UCLAMP_TASK */ static inline unsigned long uclamp_rq_util_with(struct rq *rq, unsigned long util, struct task_struct *p) { return util; } #endif /* CONFIG_UCLAMP_TASK */ #ifdef arch_scale_freq_capacity # ifndef arch_scale_freq_invariant # define arch_scale_freq_invariant() true # endif #else # define arch_scale_freq_invariant() false #endif #ifdef CONFIG_SMP static inline unsigned long capacity_orig_of(int cpu) { return cpu_rq(cpu)->cpu_capacity_orig; } #endif /** * 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, }; #ifdef CONFIG_CPU_FREQ_GOV_SCHEDUTIL unsigned long schedutil_cpu_util(int cpu, unsigned long util_cfs, unsigned long max, enum schedutil_type type, struct task_struct *p); static inline unsigned long cpu_bw_dl(struct rq *rq) { return (rq->dl.running_bw * SCHED_CAPACITY_SCALE) >> BW_SHIFT; } static inline unsigned long cpu_util_dl(struct rq *rq) { return READ_ONCE(rq->avg_dl.util_avg); } static inline unsigned long cpu_util_cfs(struct rq *rq) { unsigned long util = READ_ONCE(rq->cfs.avg.util_avg); if (sched_feat(UTIL_EST)) { util = max_t(unsigned long, util, READ_ONCE(rq->cfs.avg.util_est.enqueued)); } return util; } 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_cpu_util(int cpu, unsigned long util_cfs, unsigned long max, enum schedutil_type type, struct task_struct *p) { return 0; } #endif /* CONFIG_CPU_FREQ_GOV_SCHEDUTIL */ #ifdef CONFIG_HAVE_SCHED_AVG_IRQ static inline unsigned long cpu_util_irq(struct rq *rq) { return rq->avg_irq.util_avg; } static inline unsigned long scale_irq_capacity(unsigned long util, unsigned long irq, unsigned long max) { util *= (max - irq); util /= max; return util; } #else static inline unsigned long cpu_util_irq(struct rq *rq) { return 0; } static inline unsigned long scale_irq_capacity(unsigned long util, unsigned long irq, unsigned long max) { 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))) DECLARE_STATIC_KEY_FALSE(sched_energy_present); static inline bool sched_energy_enabled(void) { return static_branch_unlikely(&sched_energy_present); } #else /* ! (CONFIG_ENERGY_MODEL && CONFIG_CPU_FREQ_GOV_SCHEDUTIL) */ #define perf_domain_span(pd) NULL static inline bool sched_energy_enabled(void) { return false; } #endif /* CONFIG_ENERGY_MODEL && CONFIG_CPU_FREQ_GOV_SCHEDUTIL */ #ifdef CONFIG_MEMBARRIER /* * The scheduler provides memory barriers required by membarrier between: * - prior user-space memory accesses and store to rq->membarrier_state, * - store to rq->membarrier_state and following user-space memory accesses. * In the same way it provides those guarantees around store to rq->curr. */ static inline void membarrier_switch_mm(struct rq *rq, struct mm_struct *prev_mm, struct mm_struct *next_mm) { int membarrier_state; if (prev_mm == next_mm) return; membarrier_state = atomic_read(&next_mm->membarrier_state); if (READ_ONCE(rq->membarrier_state) == membarrier_state) return; WRITE_ONCE(rq->membarrier_state, membarrier_state); } #else static inline void membarrier_switch_mm(struct rq *rq, struct mm_struct *prev_mm, struct mm_struct *next_mm) { } #endif #ifdef CONFIG_SMP static inline bool is_per_cpu_kthread(struct task_struct *p) { if (!(p->flags & PF_KTHREAD)) return false; if (p->nr_cpus_allowed != 1) return false; return true; } #endif