#include #include #include #include #include #include #include #include #include #include "cpupri.h" #include "cpudeadline.h" #include "cpuacct.h" 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 long calc_load_fold_active(struct rq *this_rq); extern void update_cpu_load_active(struct rq *this_rq); /* * 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. BITS_PER_LONG > 32). The costs for increasing resolution * when BITS_PER_LONG <= 32 are pretty high and the returns do not justify the * increased costs. */ #if 0 /* BITS_PER_LONG > 32 -- currently broken: it increases power usage under light load */ # define SCHED_LOAD_RESOLUTION 10 # define scale_load(w) ((w) << SCHED_LOAD_RESOLUTION) # define scale_load_down(w) ((w) >> SCHED_LOAD_RESOLUTION) #else # define SCHED_LOAD_RESOLUTION 0 # define scale_load(w) (w) # define scale_load_down(w) (w) #endif #define SCHED_LOAD_SHIFT (10 + SCHED_LOAD_RESOLUTION) #define SCHED_LOAD_SCALE (1L << SCHED_LOAD_SHIFT) #define NICE_0_LOAD SCHED_LOAD_SCALE #define NICE_0_SHIFT SCHED_LOAD_SHIFT /* * Single value that decides SCHED_DEADLINE internal math precision. * 10 -> just above 1us * 9 -> just above 0.5us */ #define DL_SCALE (10) /* * These are the 'tuning knobs' of the scheduler: */ /* * single value that denotes runtime == period, ie unlimited time. */ #define RUNTIME_INF ((u64)~0ULL) 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 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); } static inline bool dl_time_before(u64 a, u64 b) { return (s64)(a - b) < 0; } /* * 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_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; }; 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; } extern struct dl_bw *dl_bw_of(int i); struct dl_bw { raw_spinlock_t lock; u64 bw, total_bw; }; static inline void __dl_clear(struct dl_bw *dl_b, u64 tsk_bw) { dl_b->total_bw -= tsk_bw; } static inline void __dl_add(struct dl_bw *dl_b, u64 tsk_bw) { dl_b->total_bw += tsk_bw; } 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 struct mutex sched_domains_mutex; #ifdef CONFIG_CGROUP_SCHED #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, runtime; s64 hierarchical_quota; u64 runtime_expires; int idle, timer_active; struct hrtimer period_timer, slack_timer; struct list_head throttled_cfs_rq; /* statistics */ int nr_periods, 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 atomic_long_t load_avg; atomic_t runnable_avg; #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_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 unregister_fair_sched_group(struct task_group *tg, int cpu); 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 int sched_group_set_shares(struct task_group *tg, unsigned long shares); extern void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b); extern void __start_cfs_bandwidth(struct cfs_bandwidth *cfs_b, bool force); 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 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); #endif #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, h_nr_running; u64 exec_clock; u64 min_vruntime; #ifndef CONFIG_64BIT u64 min_vruntime_copy; #endif struct rb_root tasks_timeline; struct rb_node *rb_leftmost; /* * '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, *next, *last, *skip; #ifdef CONFIG_SCHED_DEBUG unsigned int nr_spread_over; #endif #ifdef CONFIG_SMP /* * CFS Load tracking * Under CFS, load is tracked on a per-entity basis and aggregated up. * This allows for the description of both thread and group usage (in * the FAIR_GROUP_SCHED case). */ unsigned long runnable_load_avg, blocked_load_avg; atomic64_t decay_counter; u64 last_decay; atomic_long_t removed_load; #ifdef CONFIG_FAIR_GROUP_SCHED /* Required to track per-cpu representation of a task_group */ u32 tg_runnable_contrib; unsigned long tg_load_contrib; /* * 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; u64 runtime_expires; s64 runtime_remaining; u64 throttled_clock, throttled_clock_task; u64 throttled_clock_task_time; int throttled, 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; } /* Real-Time classes' related field in a runqueue: */ struct rt_rq { struct rt_prio_array active; unsigned int rt_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 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 }; /* Deadline class' related fields in a runqueue */ struct dl_rq { /* runqueue is an rbtree, ordered by deadline */ struct rb_root rb_root; struct rb_node *rb_leftmost; 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 wether 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 pushable_dl_tasks_root; struct rb_node *pushable_dl_tasks_leftmost; #else struct dl_bw dl_bw; #endif }; #ifdef CONFIG_SMP /* * 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 more than one runnable task for any CPU */ bool overload; /* * 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; /* * 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; }; extern struct root_domain def_root_domain; #endif /* CONFIG_SMP */ /* * 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; #endif #define CPU_LOAD_IDX_MAX 5 unsigned long cpu_load[CPU_LOAD_IDX_MAX]; unsigned long last_load_update_tick; #ifdef CONFIG_NO_HZ_COMMON u64 nohz_stamp; unsigned long nohz_flags; #endif #ifdef CONFIG_NO_HZ_FULL unsigned long last_sched_tick; #endif /* capture load from *all* tasks on this cpu: */ struct load_weight load; unsigned long nr_load_updates; u64 nr_switches; 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 sched_avg avg; #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 *curr, *idle, *stop; unsigned long next_balance; struct mm_struct *prev_mm; unsigned int clock_skip_update; u64 clock; u64 clock_task; atomic_t nr_iowait; #ifdef CONFIG_SMP struct root_domain *rd; struct sched_domain *sd; unsigned long cpu_capacity; unsigned char idle_balance; /* For active balancing */ int post_schedule; 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; u64 rt_avg; u64 age_stamp; 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; struct call_single_data 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 }; static inline int cpu_of(struct rq *rq) { #ifdef CONFIG_SMP return rq->cpu; #else return 0; #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) static inline u64 __rq_clock_broken(struct rq *rq) { return ACCESS_ONCE(rq->clock); } static inline u64 rq_clock(struct rq *rq) { lockdep_assert_held(&rq->lock); return rq->clock; } static inline u64 rq_clock_task(struct rq *rq) { lockdep_assert_held(&rq->lock); return rq->clock_task; } #define RQCF_REQ_SKIP 0x01 #define RQCF_ACT_SKIP 0x02 static inline void rq_clock_skip_update(struct rq *rq, bool skip) { lockdep_assert_held(&rq->lock); if (skip) rq->clock_skip_update |= RQCF_REQ_SKIP; else rq->clock_skip_update &= ~RQCF_REQ_SKIP; } #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); #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 *, struct task_struct *); #endif /* CONFIG_NUMA_BALANCING */ #ifdef CONFIG_SMP 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 detach_destroy_domains: synchronize_sched 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) #define for_each_lower_domain(sd) for (; sd; sd = sd->child) /** * 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 *, sd_llc); DECLARE_PER_CPU(int, sd_llc_size); DECLARE_PER_CPU(int, sd_llc_id); DECLARE_PER_CPU(struct sched_domain *, sd_numa); DECLARE_PER_CPU(struct sched_domain *, sd_busy); DECLARE_PER_CPU(struct sched_domain *, sd_asym); struct sched_group_capacity { atomic_t ref; /* * CPU capacity of this group, SCHED_LOAD_SCALE being max capacity * for a single CPU. */ unsigned int capacity, capacity_orig; unsigned long next_update; int imbalance; /* XXX unrelated to capacity but shared group state */ /* * Number of busy cpus in this group. */ atomic_t nr_busy_cpus; unsigned long cpumask[0]; /* iteration 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; /* * 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_cpus(struct sched_group *sg) { return to_cpumask(sg->cpumask); } /* * cpumask masking which cpus in the group are allowed to iterate up the domain * tree. */ static inline struct cpumask *sched_group_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_cpus(group)); } extern int group_balance_cpu(struct sched_group *sg); #else static inline void sched_ttwu_pending(void) { } #endif /* CONFIG_SMP */ #include "stats.h" #include "auto_group.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 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 * successfuly executed on another CPU. We must ensure that updates of * per-task data have been completed by this moment. */ smp_wmb(); task_thread_info(p)->cpu = cpu; 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 extern const_debug unsigned int sysctl_sched_features; #define SCHED_FEAT(name, enabled) \ __SCHED_FEAT_##name , enum { #include "features.h" __SCHED_FEAT_NR, }; #undef SCHED_FEAT #if defined(CONFIG_SCHED_DEBUG) && defined(HAVE_JUMP_LABEL) #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 && HAVE_JUMP_LABEL) */ #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x)) #endif /* SCHED_DEBUG && HAVE_JUMP_LABEL */ #ifdef CONFIG_NUMA_BALANCING #define sched_feat_numa(x) sched_feat(x) #ifdef CONFIG_SCHED_DEBUG #define numabalancing_enabled sched_feat_numa(NUMA) #else extern bool numabalancing_enabled; #endif /* CONFIG_SCHED_DEBUG */ #else #define sched_feat_numa(x) (0) #define numabalancing_enabled (0) #endif /* CONFIG_NUMA_BALANCING */ 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 p->on_rq == TASK_ON_RQ_MIGRATING; } #ifndef prepare_arch_switch # define prepare_arch_switch(next) do { } while (0) #endif #ifndef finish_arch_switch # define finish_arch_switch(prev) do { } while (0) #endif #ifndef finish_arch_post_lock_switch # define finish_arch_post_lock_switch() do { } while (0) #endif static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) { #ifdef CONFIG_SMP /* * We can optimise this out completely for !SMP, because the * SMP rebalancing from interrupt is the only thing that cares * here. */ next->on_cpu = 1; #endif } static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) { #ifdef CONFIG_SMP /* * After ->on_cpu is cleared, the task can be moved to a different CPU. * We must ensure this doesn't happen until the switch is completely * finished. */ smp_wmb(); prev->on_cpu = 0; #endif #ifdef CONFIG_DEBUG_SPINLOCK /* this is a valid case when another task releases the spinlock */ rq->lock.owner = current; #endif /* * If we are tracking spinlock dependencies then we have to * fix up the runqueue lock - which gets 'carried over' from * prev into current: */ spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_); raw_spin_unlock_irq(&rq->lock); } /* * 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 /* * Nice levels are multiplicative, with a gentle 10% change for every * nice level changed. I.e. when a CPU-bound task goes from nice 0 to * nice 1, it will get ~10% less CPU time than another CPU-bound task * that remained on nice 0. * * The "10% effect" is relative and cumulative: from _any_ nice level, * if you go up 1 level, it's -10% CPU usage, if you go down 1 level * it's +10% CPU usage. (to achieve that we use a multiplier of 1.25. * If a task goes up by ~10% and another task goes down by ~10% then * the relative distance between them is ~25%.) */ static const int prio_to_weight[40] = { /* -20 */ 88761, 71755, 56483, 46273, 36291, /* -15 */ 29154, 23254, 18705, 14949, 11916, /* -10 */ 9548, 7620, 6100, 4904, 3906, /* -5 */ 3121, 2501, 1991, 1586, 1277, /* 0 */ 1024, 820, 655, 526, 423, /* 5 */ 335, 272, 215, 172, 137, /* 10 */ 110, 87, 70, 56, 45, /* 15 */ 36, 29, 23, 18, 15, }; /* * Inverse (2^32/x) values of the prio_to_weight[] array, precalculated. * * In cases where the weight does not change often, we can use the * precalculated inverse to speed up arithmetics by turning divisions * into multiplications: */ static const u32 prio_to_wmult[40] = { /* -20 */ 48388, 59856, 76040, 92818, 118348, /* -15 */ 147320, 184698, 229616, 287308, 360437, /* -10 */ 449829, 563644, 704093, 875809, 1099582, /* -5 */ 1376151, 1717300, 2157191, 2708050, 3363326, /* 0 */ 4194304, 5237765, 6557202, 8165337, 10153587, /* 5 */ 12820798, 15790321, 19976592, 24970740, 31350126, /* 10 */ 39045157, 49367440, 61356676, 76695844, 95443717, /* 15 */ 119304647, 148102320, 186737708, 238609294, 286331153, }; #define ENQUEUE_WAKEUP 1 #define ENQUEUE_HEAD 2 #ifdef CONFIG_SMP #define ENQUEUE_WAKING 4 /* sched_class::task_waking was called */ #else #define ENQUEUE_WAKING 0 #endif #define ENQUEUE_REPLENISH 8 #define DEQUEUE_SLEEP 1 #define RETRY_TASK ((void *)-1UL) struct sched_class { const struct sched_class *next; 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); /* * It is the responsibility of the pick_next_task() method that will * return the next task to call put_prev_task() on the @prev task or * something equivalent. * * May return RETRY_TASK when it finds a higher prio class has runnable * tasks. */ struct task_struct * (*pick_next_task) (struct rq *rq, struct task_struct *prev); void (*put_prev_task) (struct rq *rq, struct task_struct *p); #ifdef CONFIG_SMP 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 next_cpu); void (*post_schedule) (struct rq *this_rq); void (*task_waking) (struct task_struct *task); 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 (*set_curr_task) (struct rq *rq); 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); #ifdef CONFIG_FAIR_GROUP_SCHED void (*task_move_group) (struct task_struct *p, int on_rq); #endif }; static inline void put_prev_task(struct rq *rq, struct task_struct *prev) { prev->sched_class->put_prev_task(rq, prev); } #define sched_class_highest (&stop_sched_class) #define for_each_class(class) \ for (class = sched_class_highest; class; class = class->next) 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; #ifdef CONFIG_SMP extern void update_group_capacity(struct sched_domain *sd, int cpu); extern void trigger_load_balance(struct rq *rq); extern void idle_enter_fair(struct rq *this_rq); extern void idle_exit_fair(struct rq *this_rq); #else static inline void idle_enter_fair(struct rq *rq) { } static inline void idle_exit_fair(struct rq *rq) { } #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) { 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 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 init_sched_dl_class(void); 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); unsigned long to_ratio(u64 period, u64 runtime); extern void update_idle_cpu_load(struct rq *this_rq); extern void init_task_runnable_average(struct task_struct *p); static inline void add_nr_running(struct rq *rq, unsigned count) { unsigned prev_nr = rq->nr_running; rq->nr_running = prev_nr + count; if (prev_nr < 2 && rq->nr_running >= 2) { #ifdef CONFIG_SMP if (!rq->rd->overload) rq->rd->overload = true; #endif #ifdef CONFIG_NO_HZ_FULL if (tick_nohz_full_cpu(rq->cpu)) { /* * Tick is needed if more than one task runs on a CPU. * Send the target an IPI to kick it out of nohz mode. * * We assume that IPI implies full memory barrier and the * new value of rq->nr_running is visible on reception * from the target. */ tick_nohz_full_kick_cpu(rq->cpu); } #endif } } static inline void sub_nr_running(struct rq *rq, unsigned count) { rq->nr_running -= count; } static inline void rq_last_tick_reset(struct rq *rq) { #ifdef CONFIG_NO_HZ_FULL rq->last_sched_tick = jiffies; #endif } extern void update_rq_clock(struct rq *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_time_avg; extern const_debug unsigned int sysctl_sched_nr_migrate; extern const_debug unsigned int sysctl_sched_migration_cost; static inline u64 sched_avg_period(void) { return (u64)sysctl_sched_time_avg * NSEC_PER_MSEC / 2; } #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 */ #ifdef CONFIG_SMP extern void sched_avg_update(struct rq *rq); static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta) { rq->rt_avg += rt_delta; sched_avg_update(rq); } #else static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta) { } static inline void sched_avg_update(struct rq *rq) { } #endif extern void start_bandwidth_timer(struct hrtimer *period_timer, ktime_t period); /* * __task_rq_lock - lock the rq @p resides on. */ static inline struct rq *__task_rq_lock(struct task_struct *p) __acquires(rq->lock) { struct rq *rq; lockdep_assert_held(&p->pi_lock); for (;;) { rq = task_rq(p); raw_spin_lock(&rq->lock); if (likely(rq == task_rq(p) && !task_on_rq_migrating(p))) return rq; raw_spin_unlock(&rq->lock); while (unlikely(task_on_rq_migrating(p))) cpu_relax(); } } /* * task_rq_lock - lock p->pi_lock and lock the rq @p resides on. */ static inline struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags) __acquires(p->pi_lock) __acquires(rq->lock) { struct rq *rq; for (;;) { raw_spin_lock_irqsave(&p->pi_lock, *flags); rq = task_rq(p); raw_spin_lock(&rq->lock); /* * move_queued_task() task_rq_lock() * * ACQUIRE (rq->lock) * [S] ->on_rq = MIGRATING [L] rq = task_rq() * WMB (__set_task_cpu()) ACQUIRE (rq->lock); * [S] ->cpu = new_cpu [L] task_rq() * [L] ->on_rq * RELEASE (rq->lock) * * If we observe the old cpu in task_rq_lock, the acquire of * the old rq->lock will fully serialize against the stores. * * If we observe the new cpu in task_rq_lock, the acquire will * pair with the WMB to ensure we must then also see migrating. */ if (likely(rq == task_rq(p) && !task_on_rq_migrating(p))) return rq; raw_spin_unlock(&rq->lock); raw_spin_unlock_irqrestore(&p->pi_lock, *flags); while (unlikely(task_on_rq_migrating(p))) cpu_relax(); } } static inline void __task_rq_unlock(struct rq *rq) __releases(rq->lock) { raw_spin_unlock(&rq->lock); } static inline void task_rq_unlock(struct rq *rq, struct task_struct *p, unsigned long *flags) __releases(rq->lock) __releases(p->pi_lock) { raw_spin_unlock(&rq->lock); raw_spin_unlock_irqrestore(&p->pi_lock, *flags); } #ifdef CONFIG_SMP #ifdef CONFIG_PREEMPT 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_PREEMPT */ /* * 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 good 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); } #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); 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 init_cfs_rq(struct cfs_rq *cfs_rq); extern void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq); extern void init_dl_rq(struct dl_rq *dl_rq, struct rq *rq); extern void cfs_bandwidth_usage_inc(void); extern void cfs_bandwidth_usage_dec(void); #ifdef CONFIG_NO_HZ_COMMON enum rq_nohz_flag_bits { NOHZ_TICK_STOPPED, NOHZ_BALANCE_KICK, }; #define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags) #endif #ifdef CONFIG_IRQ_TIME_ACCOUNTING DECLARE_PER_CPU(u64, cpu_hardirq_time); DECLARE_PER_CPU(u64, cpu_softirq_time); #ifndef CONFIG_64BIT DECLARE_PER_CPU(seqcount_t, irq_time_seq); static inline void irq_time_write_begin(void) { __this_cpu_inc(irq_time_seq.sequence); smp_wmb(); } static inline void irq_time_write_end(void) { smp_wmb(); __this_cpu_inc(irq_time_seq.sequence); } static inline u64 irq_time_read(int cpu) { u64 irq_time; unsigned seq; do { seq = read_seqcount_begin(&per_cpu(irq_time_seq, cpu)); irq_time = per_cpu(cpu_softirq_time, cpu) + per_cpu(cpu_hardirq_time, cpu); } while (read_seqcount_retry(&per_cpu(irq_time_seq, cpu), seq)); return irq_time; } #else /* CONFIG_64BIT */ static inline void irq_time_write_begin(void) { } static inline void irq_time_write_end(void) { } static inline u64 irq_time_read(int cpu) { return per_cpu(cpu_softirq_time, cpu) + per_cpu(cpu_hardirq_time, cpu); } #endif /* CONFIG_64BIT */ #endif /* CONFIG_IRQ_TIME_ACCOUNTING */