sched.h 51.4 KB
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#include <linux/sched.h>
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#include <linux/sched/autogroup.h>
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#include <linux/sched/sysctl.h>
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#include <linux/sched/topology.h>
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#include <linux/sched/rt.h>
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#include <linux/sched/deadline.h>
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#include <linux/sched/clock.h>
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#include <linux/sched/wake_q.h>
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#include <linux/sched/signal.h>
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#include <linux/sched/numa_balancing.h>
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#include <linux/sched/mm.h>
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#include <linux/sched/cpufreq.h>
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#include <linux/sched/stat.h>
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#include <linux/sched/nohz.h>
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#include <linux/sched/debug.h>
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#include <linux/sched/hotplug.h>
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#include <linux/sched/task.h>
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#include <linux/sched/task_stack.h>
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#include <linux/sched/cputime.h>
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#include <linux/sched/init.h>
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#include <linux/u64_stats_sync.h>
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#include <linux/kernel_stat.h>
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#include <linux/binfmts.h>
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#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/stop_machine.h>
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#include <linux/irq_work.h>
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#include <linux/tick.h>
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#include <linux/slab.h>
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#ifdef CONFIG_PARAVIRT
#include <asm/paravirt.h>
#endif

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#include "cpupri.h"
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#include "cpudeadline.h"
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#include "cpuacct.h"
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#ifdef CONFIG_SCHED_DEBUG
#define SCHED_WARN_ON(x)	WARN_ONCE(x, #x)
#else
#define SCHED_WARN_ON(x)	((void)(x))
#endif

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struct rq;
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struct cpuidle_state;
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/* task_struct::on_rq states: */
#define TASK_ON_RQ_QUEUED	1
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#define TASK_ON_RQ_MIGRATING	2
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extern __read_mostly int scheduler_running;

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extern unsigned long calc_load_update;
extern atomic_long_t calc_load_tasks;

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extern void calc_global_load_tick(struct rq *this_rq);
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extern long calc_load_fold_active(struct rq *this_rq, long adjust);
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#ifdef CONFIG_SMP
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extern void cpu_load_update_active(struct rq *this_rq);
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#else
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static inline void cpu_load_update_active(struct rq *this_rq) { }
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#endif
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/*
 * Helpers for converting nanosecond timing to jiffy resolution
 */
#define NS_TO_JIFFIES(TIME)	((unsigned long)(TIME) / (NSEC_PER_SEC / HZ))

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/*
 * 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
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 * resolution (i.e. 64bit). The costs for increasing resolution when 32bit are
 * pretty high and the returns do not justify the increased costs.
 *
 * Really only required when CONFIG_FAIR_GROUP_SCHED is also set, but to
 * increase coverage and consistency always enable it on 64bit platforms.
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 */
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#ifdef CONFIG_64BIT
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# define NICE_0_LOAD_SHIFT	(SCHED_FIXEDPOINT_SHIFT + SCHED_FIXEDPOINT_SHIFT)
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# define scale_load(w)		((w) << SCHED_FIXEDPOINT_SHIFT)
# define scale_load_down(w)	((w) >> SCHED_FIXEDPOINT_SHIFT)
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#else
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# define NICE_0_LOAD_SHIFT	(SCHED_FIXEDPOINT_SHIFT)
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# define scale_load(w)		(w)
# define scale_load_down(w)	(w)
#endif

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/*
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 * 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
 *
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 */
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#define NICE_0_LOAD		(1L << NICE_0_LOAD_SHIFT)
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/*
 * Single value that decides SCHED_DEADLINE internal math precision.
 * 10 -> just above 1us
 * 9  -> just above 0.5us
 */
#define DL_SCALE (10)

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/*
 * These are the 'tuning knobs' of the scheduler:
 */

/*
 * single value that denotes runtime == period, ie unlimited time.
 */
#define RUNTIME_INF	((u64)~0ULL)

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static inline int idle_policy(int policy)
{
	return policy == SCHED_IDLE;
}
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static inline int fair_policy(int policy)
{
	return policy == SCHED_NORMAL || policy == SCHED_BATCH;
}

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static inline int rt_policy(int policy)
{
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	return policy == SCHED_FIFO || policy == SCHED_RR;
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}

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static inline int dl_policy(int policy)
{
	return policy == SCHED_DEADLINE;
}
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static inline bool valid_policy(int policy)
{
	return idle_policy(policy) || fair_policy(policy) ||
		rt_policy(policy) || dl_policy(policy);
}
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static inline int task_has_rt_policy(struct task_struct *p)
{
	return rt_policy(p->policy);
}

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static inline int task_has_dl_policy(struct task_struct *p)
{
	return dl_policy(p->policy);
}

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/*
 * Tells if entity @a should preempt entity @b.
 */
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static inline bool
dl_entity_preempt(struct sched_dl_entity *a, struct sched_dl_entity *b)
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{
	return dl_time_before(a->deadline, b->deadline);
}

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/*
 * 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;
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	unsigned int		rt_period_active;
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};
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void __dl_clear_params(struct task_struct *p);

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/*
 * 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)
{
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	return sysctl_sched_rt_runtime >= 0;
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}

extern struct dl_bw *dl_bw_of(int i);

struct dl_bw {
	raw_spinlock_t lock;
	u64 bw, total_bw;
};

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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;
}

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extern void init_dl_bw(struct dl_bw *dl_b);
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#ifdef CONFIG_CGROUP_SCHED

#include <linux/cgroup.h>

struct cfs_rq;
struct rt_rq;

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extern struct list_head task_groups;
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struct cfs_bandwidth {
#ifdef CONFIG_CFS_BANDWIDTH
	raw_spinlock_t lock;
	ktime_t period;
	u64 quota, runtime;
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	s64 hierarchical_quota;
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	u64 runtime_expires;

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	int idle, period_active;
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	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;

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#ifdef	CONFIG_SMP
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	/*
	 * 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;
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#endif
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#endif
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#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);
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extern void online_fair_sched_group(struct task_group *tg);
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extern void unregister_fair_sched_group(struct task_group *tg);
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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);
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extern void start_cfs_bandwidth(struct cfs_bandwidth *cfs_b);
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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);

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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);
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#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 */
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#else /* CONFIG_CGROUP_SCHED */

struct cfs_bandwidth { };

#endif	/* CONFIG_CGROUP_SCHED */

/* CFS-related fields in a runqueue */
struct cfs_rq {
	struct load_weight load;
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	unsigned int nr_running, h_nr_running;
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	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

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#ifdef CONFIG_SMP
	/*
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	 * CFS load tracking
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	 */
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	struct sched_avg avg;
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	u64 runnable_load_sum;
	unsigned long runnable_load_avg;
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#ifdef CONFIG_FAIR_GROUP_SCHED
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	unsigned long tg_load_avg_contrib;
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	unsigned long propagate_avg;
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#endif
	atomic_long_t removed_load_avg, removed_util_avg;
#ifndef CONFIG_64BIT
	u64 load_last_update_time_copy;
#endif
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#ifdef CONFIG_FAIR_GROUP_SCHED
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	/*
	 *   h_load = weight * f(tg)
	 *
	 * Where f(tg) is the recursive weight fraction assigned to
	 * this group.
	 */
	unsigned long h_load;
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	u64 last_h_load_update;
	struct sched_entity *h_load_next;
#endif /* CONFIG_FAIR_GROUP_SCHED */
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#endif /* CONFIG_SMP */

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#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;

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	u64 throttled_clock, throttled_clock_task;
	u64 throttled_clock_task_time;
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	int throttled, throttle_count;
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	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;
}

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/* RT IPI pull logic requires IRQ_WORK */
#ifdef CONFIG_IRQ_WORK
# define HAVE_RT_PUSH_IPI
#endif

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/* Real-Time classes' related field in a runqueue: */
struct rt_rq {
	struct rt_prio_array active;
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	unsigned int rt_nr_running;
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	unsigned int rr_nr_running;
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#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;
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#ifdef HAVE_RT_PUSH_IPI
	int push_flags;
	int push_cpu;
	struct irq_work push_work;
	raw_spinlock_t push_lock;
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#endif
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#endif /* CONFIG_SMP */
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	int rt_queued;

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	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
};

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/* 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;
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#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;
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#else
	struct dl_bw dl_bw;
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#endif
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};

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#ifdef CONFIG_SMP

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static inline bool sched_asym_prefer(int a, int b)
{
	return arch_asym_cpu_priority(a) > arch_asym_cpu_priority(b);
}

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/*
 * 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;

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	/* Indicate more than one runnable task for any CPU */
	bool overload;

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	/*
	 * 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;
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	struct dl_bw dl_bw;
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	struct cpudl cpudl;
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	/*
	 * 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;
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	unsigned long max_cpu_capacity;
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};

extern struct root_domain def_root_domain;
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extern struct mutex sched_domains_mutex;

extern void init_defrootdomain(void);
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extern int sched_init_domains(const struct cpumask *cpu_map);
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extern void rq_attach_root(struct rq *rq, struct root_domain *rd);
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#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.
	 */
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	unsigned int nr_running;
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#ifdef CONFIG_NUMA_BALANCING
	unsigned int nr_numa_running;
	unsigned int nr_preferred_running;
#endif
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	#define CPU_LOAD_IDX_MAX 5
	unsigned long cpu_load[CPU_LOAD_IDX_MAX];
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#ifdef CONFIG_NO_HZ_COMMON
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#ifdef CONFIG_SMP
	unsigned long last_load_update_tick;
#endif /* CONFIG_SMP */
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	unsigned long nohz_flags;
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#endif /* CONFIG_NO_HZ_COMMON */
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#ifdef CONFIG_NO_HZ_FULL
	unsigned long last_sched_tick;
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#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;
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	struct dl_rq dl;
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#ifdef CONFIG_FAIR_GROUP_SCHED
	/* list of leaf cfs_rq on this cpu: */
	struct list_head leaf_cfs_rq_list;
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	struct list_head *tmp_alone_branch;
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#endif /* CONFIG_FAIR_GROUP_SCHED */

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	/*
	 * 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;

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	unsigned int clock_update_flags;
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	u64 clock;
	u64 clock_task;

	atomic_t nr_iowait;

#ifdef CONFIG_SMP
	struct root_domain *rd;
	struct sched_domain *sd;

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	unsigned long cpu_capacity;
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	unsigned long cpu_capacity_orig;
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	struct callback_head *balance_callback;

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	unsigned char idle_balance;
	/* For active balancing */
	int active_balance;
	int push_cpu;
	struct cpu_stop_work active_balance_work;
	/* cpu of this runqueue: */
	int cpu;
	int online;

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	struct list_head cfs_tasks;

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	u64 rt_avg;
	u64 age_stamp;
	u64 idle_stamp;
	u64 avg_idle;
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	/* This is used to determine avg_idle's max value */
	u64 max_idle_balance_cost;
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#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
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#ifdef CONFIG_CPU_IDLE
	/* Must be inspected within a rcu lock section */
	struct cpuidle_state *idle_state;
#endif
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};

static inline int cpu_of(struct rq *rq)
{
#ifdef CONFIG_SMP
	return rq->cpu;
#else
	return 0;
#endif
}

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#ifdef CONFIG_SCHED_SMT

extern struct static_key_false sched_smt_present;

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

785
DECLARE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
786

787
#define cpu_rq(cpu)		(&per_cpu(runqueues, (cpu)))
788
#define this_rq()		this_cpu_ptr(&runqueues)
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#define task_rq(p)		cpu_rq(task_cpu(p))
#define cpu_curr(cpu)		(cpu_rq(cpu)->curr)
791
#define raw_rq()		raw_cpu_ptr(&runqueues)
792

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static inline u64 __rq_clock_broken(struct rq *rq)
{
795
	return READ_ONCE(rq->clock);
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}

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/*
 * 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);
}

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static inline u64 rq_clock(struct rq *rq)
{
836
	lockdep_assert_held(&rq->lock);
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	assert_clock_updated(rq);

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	return rq->clock;
}

static inline u64 rq_clock_task(struct rq *rq)
{
844
	lockdep_assert_held(&rq->lock);
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	assert_clock_updated(rq);

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	return rq->clock_task;
}

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static inline void rq_clock_skip_update(struct rq *rq, bool skip)
{
	lockdep_assert_held(&rq->lock);
	if (skip)
854
		rq->clock_update_flags |= RQCF_REQ_SKIP;
855
	else
856
		rq->clock_update_flags &= ~RQCF_REQ_SKIP;
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}

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struct rq_flags {
	unsigned long flags;
	struct pin_cookie cookie;
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#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
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};

static inline void rq_pin_lock(struct rq *rq, struct rq_flags *rf)
{
	rf->cookie = lockdep_pin_lock(&rq->lock);
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#ifdef CONFIG_SCHED_DEBUG
	rq->clock_update_flags &= (RQCF_REQ_SKIP|RQCF_ACT_SKIP);
	rf->clock_update_flags = 0;
#endif
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}

static inline void rq_unpin_lock(struct rq *rq, struct rq_flags *rf)
{
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#ifdef CONFIG_SCHED_DEBUG
	if (rq->clock_update_flags > RQCF_ACT_SKIP)
		rf->clock_update_flags = RQCF_UPDATED;
#endif

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	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);
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#ifdef CONFIG_SCHED_DEBUG
	/*
	 * Restore the value we stashed in @rf for this pin context.
	 */
	rq->clock_update_flags |= rf->clock_update_flags;
#endif
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}

904
#ifdef CONFIG_NUMA
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enum numa_topology_type {
	NUMA_DIRECT,
	NUMA_GLUELESS_MESH,
	NUMA_BACKPLANE,
};
extern enum numa_topology_type sched_numa_topology_type;
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extern int sched_max_numa_distance;
extern bool find_numa_distance(int distance);
#endif

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#ifdef CONFIG_NUMA
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);
#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) { }
#endif

925
#ifdef CONFIG_NUMA_BALANCING
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/* The regions in numa_faults array from task_struct */
enum numa_faults_stats {
	NUMA_MEM = 0,
	NUMA_CPU,
	NUMA_MEMBUF,
	NUMA_CPUBUF
};
933
extern void sched_setnuma(struct task_struct *p, int node);
934
extern int migrate_task_to(struct task_struct *p, int cpu);
935
extern int migrate_swap(struct task_struct *, struct task_struct *);
936 937
#endif /* CONFIG_NUMA_BALANCING */

938 939
#ifdef CONFIG_SMP

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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;
}

955 956
extern void sched_ttwu_pending(void);

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#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) \
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	for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); \
			__sd; __sd = __sd->parent)
971

972 973
#define for_each_lower_domain(sd) for (; sd; sd = sd->child)

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/**
 * 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;
}

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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;
}

1008
DECLARE_PER_CPU(struct sched_domain *, sd_llc);
1009
DECLARE_PER_CPU(int, sd_llc_size);
1010
DECLARE_PER_CPU(int, sd_llc_id);
1011
DECLARE_PER_CPU(struct sched_domain_shared *, sd_llc_shared);
1012
DECLARE_PER_CPU(struct sched_domain *, sd_numa);
1013
DECLARE_PER_CPU(struct sched_domain *, sd_asym);
1014

1015
struct sched_group_capacity {
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	atomic_t ref;
	/*
1018
	 * CPU capacity of this group, SCHED_CAPACITY_SCALE being max capacity
1019
	 * for a single CPU.
1020
	 */
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	unsigned long capacity;
	unsigned long min_capacity; /* Min per-CPU capacity in group */
1023
	unsigned long next_update;
1024
	int imbalance; /* XXX unrelated to capacity but shared group state */
1025

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#ifdef CONFIG_SCHED_DEBUG
	int id;
#endif

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	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;
1038
	struct sched_group_capacity *sgc;
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	int asym_prefer_cpu;		/* cpu of highest priority in group */
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	/*
	 * 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)
{
1062
	return to_cpumask(sg->sgc->cpumask);
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}

/**
 * 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));
}

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extern int group_balance_cpu(struct sched_group *sg);

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#if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL)
void register_sched_domain_sysctl(void);
void unregister_sched_domain_sysctl(void);
#else
static inline void register_sched_domain_sysctl(void)
{
}
static inline void unregister_sched_domain_sysctl(void)
{
}
#endif

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#else

static inline void sched_ttwu_pending(void) { }

1092
#endif /* CONFIG_SMP */
1093

1094
#include "stats.h"
1095
#include "autogroup.h"
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#ifdef CONFIG_CGROUP_SCHED

/*
 * Return the group to which this tasks belongs.
 *
1102 1103 1104
 * 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.
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 *
 * 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.
1111 1112 1113
 */
static inline struct task_group *task_group(struct task_struct *p)
{
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	return p->sched_task_group;
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}

/* 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
1125
	set_task_rq_fair(&p->se, p->se.cfs_rq, tg->cfs_rq[cpu]);
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	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();
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#ifdef CONFIG_THREAD_INFO_IN_TASK
	p->cpu = cpu;
#else
1159
	task_thread_info(p)->cpu = cpu;
1160
#endif
1161
	p->wake_cpu = cpu;
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#endif
}

/*
 * Tunables that become constants when CONFIG_SCHED_DEBUG is off:
 */
#ifdef CONFIG_SCHED_DEBUG
1169
# include <linux/static_key.h>
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# 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 {
1181
#include "features.h"
1182
	__SCHED_FEAT_NR,
1183 1184 1185 1186
};

#undef SCHED_FEAT

1187 1188
#if defined(CONFIG_SCHED_DEBUG) && defined(HAVE_JUMP_LABEL)
#define SCHED_FEAT(name, enabled)					\
1189
static __always_inline bool static_branch_##name(struct static_key *key) \
1190
{									\
1191
	return static_key_##enabled(key);				\
1192 1193 1194 1195 1196 1197
}

#include "features.h"

#undef SCHED_FEAT

1198
extern struct static_key sched_feat_keys[__SCHED_FEAT_NR];
1199 1200
#define sched_feat(x) (static_branch_##x(&sched_feat_keys[__SCHED_FEAT_##x]))
#else /* !(SCHED_DEBUG && HAVE_JUMP_LABEL) */
1201
#define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x))
1202
#endif /* SCHED_DEBUG && HAVE_JUMP_LABEL */
1203

1204
extern struct static_key_false sched_numa_balancing;
1205
extern struct static_key_false sched_schedstats;
1206

1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233
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
}

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static inline int task_on_rq_queued(struct task_struct *p)
{
	return p->on_rq == TASK_ON_RQ_QUEUED;
}
1238

1239 1240 1241 1242 1243
static inline int task_on_rq_migrating(struct task_struct *p)
{
	return p->on_rq == TASK_ON_RQ_MIGRATING;
}

1244 1245 1246
#ifndef prepare_arch_switch
# define prepare_arch_switch(next)	do { } while (0)
#endif
1247 1248 1249
#ifndef finish_arch_post_lock_switch
# define finish_arch_post_lock_switch()	do { } while (0)
#endif
1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269

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.
1270
	 *
1271 1272 1273
	 * In particular, the load of prev->state in finish_task_switch() must
	 * happen before this.
	 *
1274
	 * Pairs with the smp_cond_load_acquire() in try_to_wake_up().
1275
	 */
1276
	smp_store_release(&prev->on_cpu, 0);
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#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);
}

1292 1293 1294 1295 1296 1297 1298
/*
 * 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 */

1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310
/*
 * 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

1311 1312
extern const int sched_prio_to_weight[40];
extern const u32 sched_prio_to_wmult[40];
1313

1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328
/*
 * {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)
1329
 * ENQUEUE_MIGRATED  - the task was migrated during wakeup
1330 1331 1332 1333 1334 1335
 *
 */

#define DEQUEUE_SLEEP		0x01
#define DEQUEUE_SAVE		0x02 /* matches ENQUEUE_RESTORE */
#define DEQUEUE_MOVE		0x04 /* matches ENQUEUE_MOVE */
1336
#define DEQUEUE_NOCLOCK		0x08 /* matches ENQUEUE_NOCLOCK */
1337

1338
#define ENQUEUE_WAKEUP		0x01
1339 1340
#define ENQUEUE_RESTORE		0x02
#define ENQUEUE_MOVE		0x04
1341
#define ENQUEUE_NOCLOCK		0x08
1342

1343 1344
#define ENQUEUE_HEAD		0x10
#define ENQUEUE_REPLENISH	0x20
1345
#ifdef CONFIG_SMP
1346
#define ENQUEUE_MIGRATED	0x40
1347
#else
1348
#define ENQUEUE_MIGRATED	0x00
1349 1350
#endif

1351 1352
#define RETRY_TASK		((void *)-1UL)

1353 1354 1355 1356 1357 1358 1359 1360 1361 1362
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);

1363 1364 1365 1366
	/*
	 * 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.
1367 1368 1369
	 *
	 * May return RETRY_TASK when it finds a higher prio class has runnable
	 * tasks.
1370 1371
	 */
	struct task_struct * (*pick_next_task) (struct rq *rq,
1372
						struct task_struct *prev,
1373
						struct rq_flags *rf);
1374 1375 1376
	void (*put_prev_task) (struct rq *rq, struct task_struct *p);

#ifdef CONFIG_SMP
1377
	int  (*select_task_rq)(struct task_struct *p, int task_cpu, int sd_flag, int flags);
1378
	void (*migrate_task_rq)(struct task_struct *p);
1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391

	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);
1392
	void (*task_dead) (struct task_struct *p);
1393

1394 1395 1396 1397 1398
	/*
	 * 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.
	 */
1399 1400 1401 1402 1403 1404 1405 1406
	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);

1407 1408
	void (*update_curr) (struct rq *rq);

1409 1410 1411
#define TASK_SET_GROUP  0
#define TASK_MOVE_GROUP	1

1412
#ifdef CONFIG_FAIR_GROUP_SCHED
1413
	void (*task_change_group) (struct task_struct *p, int type);
1414 1415
#endif
};
1416

1417 1418 1419 1420 1421
static inline void put_prev_task(struct rq *rq, struct task_struct *prev)
{
	prev->sched_class->put_prev_task(rq, prev);
}

1422 1423 1424 1425 1426
static inline void set_curr_task(struct rq *rq, struct task_struct *curr)
{
	curr->sched_class->set_curr_task(rq);
}

1427 1428 1429 1430 1431
#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;
1432
extern const struct sched_class dl_sched_class;
1433 1434 1435 1436 1437 1438 1439
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

1440
extern void update_group_capacity(struct sched_domain *sd, int cpu);
1441

1442
extern void trigger_load_balance(struct rq *rq);
1443

1444 1445
extern void set_cpus_allowed_common(struct task_struct *p, const struct cpumask *new_mask);

1446 1447
#endif

1448 1449 1450 1451 1452 1453 1454 1455 1456
#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)
{
1457
	SCHED_WARN_ON(!rcu_read_lock_held());
1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471
	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

1472 1473
extern void schedule_idle(void);

1474 1475 1476
extern void sysrq_sched_debug_show(void);
extern void sched_init_granularity(void);
extern void update_max_interval(void);
1477 1478

extern void init_sched_dl_class(void);
1479 1480 1481
extern void init_sched_rt_class(void);
extern void init_sched_fair_class(void);

1482
extern void resched_curr(struct rq *rq);
1483 1484 1485 1486 1487
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);

1488 1489
extern struct dl_bandwidth def_dl_bandwidth;
extern void init_dl_bandwidth(struct dl_bandwidth *dl_b, u64 period, u64 runtime);
1490 1491
extern void init_dl_task_timer(struct sched_dl_entity *dl_se);

1492 1493
unsigned long to_ratio(u64 period, u64 runtime);

1494
extern void init_entity_runnable_average(struct sched_entity *se);
1495
extern void post_init_entity_util_avg(struct sched_entity *se);
1496

1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525
#ifdef CONFIG_NO_HZ_FULL
extern bool sched_can_stop_tick(struct rq *rq);

/*
 * 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 void sched_update_tick_dependency(struct rq *rq) { }
#endif

1526
static inline void add_nr_running(struct rq *rq, unsigned count)
1527
{
1528 1529 1530
	unsigned prev_nr = rq->nr_running;

	rq->nr_running = prev_nr + count;
1531

1532
	if (prev_nr < 2 && rq->nr_running >= 2) {
1533 1534 1535 1536 1537
#ifdef CONFIG_SMP
		if (!rq->rd->overload)
			rq->rd->overload = true;
#endif
	}
1538 1539

	sched_update_tick_dependency(rq);
1540 1541
}

1542
static inline void sub_nr_running(struct rq *rq, unsigned count)
1543
{
1544
	rq->nr_running -= count;
1545 1546
	/* Check if we still need preemption */
	sched_update_tick_dependency(rq);
1547 1548
}

1549 1550 1551 1552 1553 1554 1555
static inline void rq_last_tick_reset(struct rq *rq)
{
#ifdef CONFIG_NO_HZ_FULL
	rq->last_sched_tick = jiffies;
#endif
}

1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589
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);

1590 1591 1592 1593 1594 1595 1596
#else

static inline int hrtick_enabled(struct rq *rq)
{
	return 0;
}

1597 1598 1599 1600
#endif /* CONFIG_SCHED_HRTICK */

#ifdef CONFIG_SMP
extern void sched_avg_update(struct rq *rq);
1601 1602 1603 1604 1605 1606 1607 1608

#ifndef arch_scale_freq_capacity
static __always_inline
unsigned long arch_scale_freq_capacity(struct sched_domain *sd, int cpu)
{
	return SCHED_CAPACITY_SCALE;
}
#endif
1609

1610 1611 1612 1613
#ifndef arch_scale_cpu_capacity
static __always_inline
unsigned long arch_scale_cpu_capacity(struct sched_domain *sd, int cpu)
{
1614
	if (sd && (sd->flags & SD_SHARE_CPUCAPACITY) && (sd->span_weight > 1))
1615 1616 1617 1618 1619 1620
		return sd->smt_gain / sd->span_weight;

	return SCHED_CAPACITY_SCALE;
}
#endif

1621 1622
static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta)
{
1623
	rq->rt_avg += rt_delta * arch_scale_freq_capacity(NULL, cpu_of(rq));
1624 1625 1626 1627 1628 1629 1630
	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

1631
struct rq *__task_rq_lock(struct task_struct *p, struct rq_flags *rf)
1632
	__acquires(rq->lock);
1633

1634
struct rq *task_rq_lock(struct task_struct *p, struct rq_flags *rf)
1635
	__acquires(p->pi_lock)
1636
	__acquires(rq->lock);
1637

1638
static inline void __task_rq_unlock(struct rq *rq, struct rq_flags *rf)
1639 1640
	__releases(rq->lock)
{
1641
	rq_unpin_lock(rq, rf);
1642 1643 1644 1645
	raw_spin_unlock(&rq->lock);
}

static inline void
1646
task_rq_unlock(struct rq *rq, struct task_struct *p, struct rq_flags *rf)
1647 1648 1649
	__releases(rq->lock)
	__releases(p->pi_lock)
{
1650
	rq_unpin_lock(rq, rf);
1651
	raw_spin_unlock(&rq->lock);
1652
	raw_spin_unlock_irqrestore(&p->pi_lock, rf->flags);
1653 1654
}

1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710
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);
}

1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786
#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_);
}

1787 1788 1789 1790 1791 1792 1793 1794 1795
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);
}

1796 1797 1798 1799 1800 1801 1802 1803 1804
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);
}

1805 1806 1807 1808 1809 1810 1811 1812 1813
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);
}

1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855
/*
 * 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);
}

1856 1857 1858 1859
extern void set_rq_online (struct rq *rq);
extern void set_rq_offline(struct rq *rq);
extern bool sched_smp_initialized;

1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896
#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);
1897 1898

#ifdef	CONFIG_SCHED_DEBUG
1899 1900
extern void print_cfs_stats(struct seq_file *m, int cpu);
extern void print_rt_stats(struct seq_file *m, int cpu);
1901
extern void print_dl_stats(struct seq_file *m, int cpu);
1902 1903
extern void
print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq);
1904 1905 1906 1907 1908 1909 1910 1911
#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 */
1912 1913

extern void init_cfs_rq(struct cfs_rq *cfs_rq);
1914 1915
extern void init_rt_rq(struct rt_rq *rt_rq);
extern void init_dl_rq(struct dl_rq *dl_rq);
1916

1917 1918
extern void cfs_bandwidth_usage_inc(void);
extern void cfs_bandwidth_usage_dec(void);
1919

1920
#ifdef CONFIG_NO_HZ_COMMON
1921 1922 1923 1924 1925 1926
enum rq_nohz_flag_bits {
	NOHZ_TICK_STOPPED,
	NOHZ_BALANCE_KICK,
};

#define nohz_flags(cpu)	(&cpu_rq(cpu)->nohz_flags)
1927 1928 1929 1930

extern void nohz_balance_exit_idle(unsigned int cpu);
#else
static inline void nohz_balance_exit_idle(unsigned int cpu) { }
1931
#endif
1932 1933

#ifdef CONFIG_IRQ_TIME_ACCOUNTING
1934
struct irqtime {
1935
	u64			total;
1936
	u64			tick_delta;
1937 1938 1939
	u64			irq_start_time;
	struct u64_stats_sync	sync;
};
1940

1941
DECLARE_PER_CPU(struct irqtime, cpu_irqtime);
1942

1943 1944 1945 1946 1947
/*
 * 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.
 */
1948 1949
static inline u64 irq_time_read(int cpu)
{
1950 1951 1952
	struct irqtime *irqtime = &per_cpu(cpu_irqtime, cpu);
	unsigned int seq;
	u64 total;
1953 1954

	do {
1955
		seq = __u64_stats_fetch_begin(&irqtime->sync);
1956
		total = irqtime->total;
1957
	} while (__u64_stats_fetch_retry(&irqtime->sync, seq));
1958

1959
	return total;
1960 1961
}
#endif /* CONFIG_IRQ_TIME_ACCOUNTING */
1962 1963 1964 1965 1966 1967

#ifdef CONFIG_CPU_FREQ
DECLARE_PER_CPU(struct update_util_data *, cpufreq_update_util_data);

/**
 * cpufreq_update_util - Take a note about CPU utilization changes.
1968
 * @rq: Runqueue to carry out the update for.
1969
 * @flags: Update reason flags.
1970
 *
1971 1972
 * This function is called by the scheduler on the CPU whose utilization is
 * being updated.
1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987
 *
 * 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,
 * though, because they may not be coming in if RT or deadline tasks are active
 * all the time (or there are RT and DL tasks only).
 *
 * As a workaround for that issue, this function is called by the RT and DL
 * sched classes 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 and DL tasks.
 */
1988
static inline void cpufreq_update_util(struct rq *rq, unsigned int flags)
1989
{
1990 1991 1992 1993
	struct update_util_data *data;

	data = rcu_dereference_sched(*this_cpu_ptr(&cpufreq_update_util_data));
	if (data)
1994 1995 1996 1997 1998 1999 2000
		data->func(data, rq_clock(rq), flags);
}

static inline void cpufreq_update_this_cpu(struct rq *rq, unsigned int flags)
{
	if (cpu_of(rq) == smp_processor_id())
		cpufreq_update_util(rq, flags);
2001 2002
}
#else
2003 2004
static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) {}
static inline void cpufreq_update_this_cpu(struct rq *rq, unsigned int flags) {}
2005
#endif /* CONFIG_CPU_FREQ */
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#ifdef arch_scale_freq_capacity
#ifndef arch_scale_freq_invariant
#define arch_scale_freq_invariant()	(true)
#endif
#else /* arch_scale_freq_capacity */
#define arch_scale_freq_invariant()	(false)
#endif