diff options
author | Srikant Patnaik | 2015-01-11 12:28:04 +0530 |
---|---|---|
committer | Srikant Patnaik | 2015-01-11 12:28:04 +0530 |
commit | 871480933a1c28f8a9fed4c4d34d06c439a7a422 (patch) | |
tree | 8718f573808810c2a1e8cb8fb6ac469093ca2784 /kernel/sched/sched.h | |
parent | 9d40ac5867b9aefe0722bc1f110b965ff294d30d (diff) | |
download | FOSSEE-netbook-kernel-source-871480933a1c28f8a9fed4c4d34d06c439a7a422.tar.gz FOSSEE-netbook-kernel-source-871480933a1c28f8a9fed4c4d34d06c439a7a422.tar.bz2 FOSSEE-netbook-kernel-source-871480933a1c28f8a9fed4c4d34d06c439a7a422.zip |
Moved, renamed, and deleted files
The original directory structure was scattered and unorganized.
Changes are basically to make it look like kernel structure.
Diffstat (limited to 'kernel/sched/sched.h')
-rw-r--r-- | kernel/sched/sched.h | 1158 |
1 files changed, 1158 insertions, 0 deletions
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h new file mode 100644 index 00000000..fb3acba4 --- /dev/null +++ b/kernel/sched/sched.h @@ -0,0 +1,1158 @@ + +#include <linux/sched.h> +#include <linux/mutex.h> +#include <linux/spinlock.h> +#include <linux/stop_machine.h> + +#include "cpupri.h" + +extern __read_mostly int scheduler_running; + +/* + * Convert user-nice values [ -20 ... 0 ... 19 ] + * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ], + * and back. + */ +#define NICE_TO_PRIO(nice) (MAX_RT_PRIO + (nice) + 20) +#define PRIO_TO_NICE(prio) ((prio) - MAX_RT_PRIO - 20) +#define TASK_NICE(p) PRIO_TO_NICE((p)->static_prio) + +/* + * 'User priority' is the nice value converted to something we + * can work with better when scaling various scheduler parameters, + * it's a [ 0 ... 39 ] range. + */ +#define USER_PRIO(p) ((p)-MAX_RT_PRIO) +#define TASK_USER_PRIO(p) USER_PRIO((p)->static_prio) +#define MAX_USER_PRIO (USER_PRIO(MAX_PRIO)) + +/* + * Helpers for converting nanosecond timing to jiffy resolution + */ +#define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ)) + +#define NICE_0_LOAD SCHED_LOAD_SCALE +#define NICE_0_SHIFT SCHED_LOAD_SHIFT + +/* + * 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 rt_policy(int policy) +{ + if (policy == SCHED_FIFO || policy == SCHED_RR) + return 1; + return 0; +} + +static inline int task_has_rt_policy(struct task_struct *p) +{ + return rt_policy(p->policy); +} + +/* + * 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; +}; + +extern struct mutex sched_domains_mutex; + +#ifdef CONFIG_CGROUP_SCHED + +#include <linux/cgroup.h> + +struct cfs_rq; +struct rt_rq; + +static LIST_HEAD(task_groups); + +struct cfs_bandwidth { +#ifdef CONFIG_CFS_BANDWIDTH + raw_spinlock_t lock; + ktime_t period; + u64 quota, runtime; + s64 hierarchal_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; + + atomic_t load_weight; +#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 + +/* Default task group. + * Every task in system belong to this group at bootup. + */ +extern struct task_group root_task_group; + +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); +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); + +#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 long 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_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_SMP + /* + * h_load = weight * f(tg) + * + * Where f(tg) is the recursive weight fraction assigned to + * this group. + */ + unsigned long h_load; + + /* + * Maintaining per-cpu shares distribution for group scheduling + * + * load_stamp is the last time we updated the load average + * load_last is the last time we updated the load average and saw load + * load_unacc_exec_time is currently unaccounted execution time + */ + u64 load_avg; + u64 load_period; + u64 load_stamp, load_last, load_unacc_exec_time; + + unsigned long load_contribution; +#endif /* CONFIG_SMP */ +#ifdef CONFIG_CFS_BANDWIDTH + int runtime_enabled; + u64 runtime_expires; + s64 runtime_remaining; + + u64 throttled_timestamp; + 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 long 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_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 list_head leaf_rt_rq_list; + struct task_group *tg; +#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; + + /* + * 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 long nr_running; + #define CPU_LOAD_IDX_MAX 5 + unsigned long cpu_load[CPU_LOAD_IDX_MAX]; + unsigned long last_load_update_tick; +#ifdef CONFIG_NO_HZ + u64 nohz_stamp; + unsigned long nohz_flags; +#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; + +#ifdef CONFIG_FAIR_GROUP_SCHED + /* list of leaf cfs_rq on this cpu: */ + struct list_head leaf_cfs_rq_list; +#endif +#ifdef CONFIG_RT_GROUP_SCHED + struct list_head leaf_rt_rq_list; +#endif + + /* + * 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_power; + + 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; +#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 +}; + +static inline int cpu_of(struct rq *rq) +{ +#ifdef CONFIG_SMP + return rq->cpu; +#else + return 0; +#endif +} + +DECLARE_PER_CPU(struct rq, runqueues); + +#define cpu_rq(cpu) (&per_cpu(runqueues, (cpu))) +#define this_rq() (&__get_cpu_var(runqueues)) +#define task_rq(p) cpu_rq(task_cpu(p)) +#define cpu_curr(cpu) (cpu_rq(cpu)->curr) +#define raw_rq() (&__raw_get_cpu_var(runqueues)) + +#ifdef CONFIG_SMP + +#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; +} + +DECLARE_PER_CPU(struct sched_domain *, sd_llc); +DECLARE_PER_CPU(int, sd_llc_id); + +#endif /* CONFIG_SMP */ + +#include "stats.h" +#include "auto_group.h" + +#ifdef CONFIG_CGROUP_SCHED + +/* + * Return the group to which this tasks belongs. + * + * We use task_subsys_state_check() and extend the RCU verification with + * pi->lock and rq->lock because cpu_cgroup_attach() holds those locks for each + * task it moves into the cgroup. Therefore by holding either of those locks, + * we pin the task to the current cgroup. + */ +static inline struct task_group *task_group(struct task_struct *p) +{ + struct task_group *tg; + struct cgroup_subsys_state *css; + + css = task_subsys_state_check(p, cpu_cgroup_subsys_id, + lockdep_is_held(&p->pi_lock) || + lockdep_is_held(&task_rq(p)->lock)); + tg = container_of(css, struct task_group, css); + + return autogroup_task_group(p, tg); +} + +/* 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; +#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) +static __always_inline bool static_branch__true(struct static_key *key) +{ + return static_key_true(key); /* Not out of line branch. */ +} + +static __always_inline bool static_branch__false(struct static_key *key) +{ + return static_key_false(key); /* Out of line branch. */ +} + +#define SCHED_FEAT(name, enabled) \ +static __always_inline bool static_branch_##name(struct static_key *key) \ +{ \ + return static_branch__##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 */ + +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 +} + + +#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 + +#ifndef __ARCH_WANT_UNLOCKED_CTXSW +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); +} + +#else /* __ARCH_WANT_UNLOCKED_CTXSW */ +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 +#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW + raw_spin_unlock_irq(&rq->lock); +#else + raw_spin_unlock(&rq->lock); +#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 +#ifndef __ARCH_WANT_INTERRUPTS_ON_CTXSW + local_irq_enable(); +#endif +} +#endif /* __ARCH_WANT_UNLOCKED_CTXSW */ + + +static inline void update_load_add(struct load_weight *lw, unsigned long inc) +{ + lw->weight += inc; + lw->inv_weight = 0; +} + +static inline void update_load_sub(struct load_weight *lw, unsigned long dec) +{ + lw->weight -= dec; + lw->inv_weight = 0; +} + +static inline void update_load_set(struct load_weight *lw, unsigned long w) +{ + lw->weight = w; + lw->inv_weight = 0; +} + +/* + * 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, +}; + +/* Time spent by the tasks of the cpu accounting group executing in ... */ +enum cpuacct_stat_index { + CPUACCT_STAT_USER, /* ... user mode */ + CPUACCT_STAT_SYSTEM, /* ... kernel mode */ + + CPUACCT_STAT_NSTATS, +}; + + +#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 rt_sched_class; +extern const struct sched_class fair_sched_class; +extern const struct sched_class idle_sched_class; + + +#ifdef CONFIG_SMP + +extern void trigger_load_balance(struct rq *rq, int cpu); +extern void idle_balance(int this_cpu, struct rq *this_rq); + +#else /* CONFIG_SMP */ + +static inline void idle_balance(int cpu, struct rq *rq) +{ +} + +#endif + +extern void sysrq_sched_debug_show(void); +extern void sched_init_granularity(void); +extern void update_max_interval(void); +extern void update_group_power(struct sched_domain *sd, int cpu); +extern int update_runtime(struct notifier_block *nfb, unsigned long action, void *hcpu); +extern void init_sched_rt_class(void); +extern void init_sched_fair_class(void); + +extern void resched_task(struct task_struct *p); +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 void update_cpu_load(struct rq *this_rq); + +#ifdef CONFIG_CGROUP_CPUACCT +#include <linux/cgroup.h> +/* track cpu usage of a group of tasks and its child groups */ +struct cpuacct { + struct cgroup_subsys_state css; + /* cpuusage holds pointer to a u64-type object on every cpu */ + u64 __percpu *cpuusage; + struct kernel_cpustat __percpu *cpustat; +}; + +/* return cpu accounting group corresponding to this container */ +static inline struct cpuacct *cgroup_ca(struct cgroup *cgrp) +{ + return container_of(cgroup_subsys_state(cgrp, cpuacct_subsys_id), + struct cpuacct, css); +} + +/* return cpu accounting group to which this task belongs */ +static inline struct cpuacct *task_ca(struct task_struct *tsk) +{ + return container_of(task_subsys_state(tsk, cpuacct_subsys_id), + struct cpuacct, css); +} + +static inline struct cpuacct *parent_ca(struct cpuacct *ca) +{ + if (!ca || !ca->css.cgroup->parent) + return NULL; + return cgroup_ca(ca->css.cgroup->parent); +} + +extern void cpuacct_charge(struct task_struct *tsk, u64 cputime); +#else +static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {} +#endif + +static inline void inc_nr_running(struct rq *rq) +{ + rq->nr_running++; +} + +static inline void dec_nr_running(struct rq *rq) +{ + rq->nr_running--; +} + +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; +} + +void calc_load_account_idle(struct rq *this_rq); + +#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_); +} + +/* + * 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 unthrottle_offline_cfs_rqs(struct rq *rq); + +extern void account_cfs_bandwidth_used(int enabled, int was_enabled); + +#ifdef CONFIG_NO_HZ +enum rq_nohz_flag_bits { + NOHZ_TICK_STOPPED, + NOHZ_BALANCE_KICK, + NOHZ_IDLE, +}; + +#define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags) +#endif |