- 根目录:
- kernel
- sched
- sched.h
#include <linux/sched.h>
#include <linux/sched/sysctl.h>
#include <linux/sched/rt.h>
#include <linux/sched/deadline.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/stop_machine.h>
#include <linux/tick.h>
#include <linux/slab.h>
#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;
};
extern struct mutex sched_domains_mutex;
#ifdef CONFIG_CGROUP_SCHED
#include <linux/cgroup.h>
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
int skip_clock_update;
/* 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;
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(struct rq *rq)
{
return rq->clock;
}
static inline u64 rq_clock_task(struct rq *rq)
{
return rq->clock_task;
}
#ifdef CONFIG_NUMA_BALANCING
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 <linux/static_key.h>
# 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);
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);
#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 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 */