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OpenCloudOS-Kernel/kernel/sched/sched.h

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/* SPDX-License-Identifier: GPL-2.0 */
/*
* Scheduler internal types and methods:
*/
#ifndef _KERNEL_SCHED_SCHED_H
#define _KERNEL_SCHED_SCHED_H
#include <linux/sched/affinity.h>
#include <linux/sched/autogroup.h>
#include <linux/sched/cpufreq.h>
#include <linux/sched/deadline.h>
#include <linux/sched.h>
#include <linux/sched/loadavg.h>
#include <linux/sched/mm.h>
#include <linux/sched/rseq_api.h>
#include <linux/sched/signal.h>
#include <linux/sched/smt.h>
#include <linux/sched/stat.h>
#include <linux/sched/sysctl.h>
#include <linux/sched/task_flags.h>
#include <linux/sched/task.h>
#include <linux/sched/topology.h>
#include <linux/atomic.h>
#include <linux/bitmap.h>
#include <linux/bug.h>
#include <linux/capability.h>
#include <linux/cgroup_api.h>
#include <linux/cgroup.h>
#include <linux/context_tracking.h>
#include <linux/cpufreq.h>
#include <linux/cpumask_api.h>
#include <linux/ctype.h>
#include <linux/file.h>
#include <linux/fs_api.h>
#include <linux/hrtimer_api.h>
#include <linux/interrupt.h>
#include <linux/irq_work.h>
#include <linux/jiffies.h>
#include <linux/kref_api.h>
#include <linux/kthread.h>
#include <linux/ktime_api.h>
#include <linux/lockdep_api.h>
#include <linux/lockdep.h>
#include <linux/minmax.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/mutex_api.h>
#include <linux/plist.h>
#include <linux/poll.h>
#include <linux/proc_fs.h>
#include <linux/profile.h>
#include <linux/psi.h>
#include <linux/rcupdate.h>
#include <linux/seq_file.h>
#include <linux/seqlock.h>
#include <linux/softirq.h>
#include <linux/spinlock_api.h>
#include <linux/static_key.h>
#include <linux/stop_machine.h>
#include <linux/syscalls_api.h>
#include <linux/syscalls.h>
#include <linux/tick.h>
#include <linux/topology.h>
#include <linux/types.h>
#include <linux/u64_stats_sync_api.h>
#include <linux/uaccess.h>
#include <linux/wait_api.h>
#include <linux/wait_bit.h>
#include <linux/workqueue_api.h>
#include <trace/events/power.h>
#include <trace/events/sched.h>
#include "../workqueue_internal.h"
#ifdef CONFIG_CGROUP_SCHED
#include <linux/cgroup.h>
#include <linux/psi.h>
#endif
#ifdef CONFIG_SCHED_DEBUG
# include <linux/static_key.h>
#endif
#ifdef CONFIG_PARAVIRT
# include <asm/paravirt.h>
# include <asm/paravirt_api_clock.h>
#endif
#include "cpupri.h"
#include "cpudeadline.h"
#ifdef CONFIG_SCHED_DEBUG
# define SCHED_WARN_ON(x) WARN_ONCE(x, #x)
#else
# define SCHED_WARN_ON(x) ({ (void)(x), 0; })
#endif
struct rq;
struct cpuidle_state;
/* task_struct::on_rq states: */
#define TASK_ON_RQ_QUEUED 1
#define TASK_ON_RQ_MIGRATING 2
extern __read_mostly int scheduler_running;
extern unsigned long calc_load_update;
extern atomic_long_t calc_load_tasks;
extern unsigned int sysctl_sched_child_runs_first;
extern void calc_global_load_tick(struct rq *this_rq);
extern long calc_load_fold_active(struct rq *this_rq, long adjust);
extern void call_trace_sched_update_nr_running(struct rq *rq, int count);
extern unsigned int sysctl_sched_rt_period;
extern int sysctl_sched_rt_runtime;
extern int sched_rr_timeslice;
/*
* Helpers for converting nanosecond timing to jiffy resolution
*/
#define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ))
/*
* Increase resolution of nice-level calculations for 64-bit architectures.
* The extra resolution improves shares distribution and load balancing of
* low-weight task groups (eg. nice +19 on an autogroup), deeper taskgroup
* hierarchies, especially on larger systems. This is not a user-visible change
* and does not change the user-interface for setting shares/weights.
*
* We increase resolution only if we have enough bits to allow this increased
* resolution (i.e. 64-bit). The costs for increasing resolution when 32-bit
* are pretty high and the returns do not justify the increased costs.
*
* Really only required when CONFIG_FAIR_GROUP_SCHED=y is also set, but to
* increase coverage and consistency always enable it on 64-bit platforms.
*/
#ifdef CONFIG_64BIT
# define NICE_0_LOAD_SHIFT (SCHED_FIXEDPOINT_SHIFT + SCHED_FIXEDPOINT_SHIFT)
# define scale_load(w) ((w) << SCHED_FIXEDPOINT_SHIFT)
# define scale_load_down(w) \
({ \
unsigned long __w = (w); \
if (__w) \
__w = max(2UL, __w >> SCHED_FIXEDPOINT_SHIFT); \
__w; \
})
#else
# define NICE_0_LOAD_SHIFT (SCHED_FIXEDPOINT_SHIFT)
# define scale_load(w) (w)
# define scale_load_down(w) (w)
#endif
/*
* Task weight (visible to users) and its load (invisible to users) have
* independent resolution, but they should be well calibrated. We use
* scale_load() and scale_load_down(w) to convert between them. The
* following must be true:
*
* scale_load(sched_prio_to_weight[NICE_TO_PRIO(0)-MAX_RT_PRIO]) == NICE_0_LOAD
*
*/
#define NICE_0_LOAD (1L << NICE_0_LOAD_SHIFT)
/*
* Single value that decides SCHED_DEADLINE internal math precision.
* 10 -> just above 1us
* 9 -> just above 0.5us
*/
#define DL_SCALE 10
/*
* Single value that denotes runtime == period, ie unlimited time.
*/
#define RUNTIME_INF ((u64)~0ULL)
static inline int idle_policy(int policy)
{
return policy == SCHED_IDLE;
}
static inline int fair_policy(int policy)
{
return policy == SCHED_NORMAL || policy == SCHED_BATCH;
}
static inline int rt_policy(int policy)
{
return policy == SCHED_FIFO || policy == SCHED_RR;
}
static inline int dl_policy(int policy)
{
return policy == SCHED_DEADLINE;
}
static inline bool valid_policy(int policy)
{
return idle_policy(policy) || fair_policy(policy) ||
rt_policy(policy) || dl_policy(policy);
}
static inline int task_has_idle_policy(struct task_struct *p)
{
return idle_policy(p->policy);
}
static inline int task_has_rt_policy(struct task_struct *p)
{
return rt_policy(p->policy);
}
static inline int task_has_dl_policy(struct task_struct *p)
{
return dl_policy(p->policy);
}
#define cap_scale(v, s) ((v)*(s) >> SCHED_CAPACITY_SHIFT)
static inline void update_avg(u64 *avg, u64 sample)
{
s64 diff = sample - *avg;
*avg += diff / 8;
}
/*
* Shifting a value by an exponent greater *or equal* to the size of said value
* is UB; cap at size-1.
*/
#define shr_bound(val, shift) \
(val >> min_t(typeof(shift), shift, BITS_PER_TYPE(typeof(val)) - 1))
/*
* !! For sched_setattr_nocheck() (kernel) only !!
*
* This is actually gross. :(
*
* It is used to make schedutil kworker(s) higher priority than SCHED_DEADLINE
* tasks, but still be able to sleep. We need this on platforms that cannot
* atomically change clock frequency. Remove once fast switching will be
* available on such platforms.
*
* SUGOV stands for SchedUtil GOVernor.
*/
#define SCHED_FLAG_SUGOV 0x10000000
#define SCHED_DL_FLAGS (SCHED_FLAG_RECLAIM | SCHED_FLAG_DL_OVERRUN | SCHED_FLAG_SUGOV)
static inline bool dl_entity_is_special(const struct sched_dl_entity *dl_se)
{
#ifdef CONFIG_CPU_FREQ_GOV_SCHEDUTIL
return unlikely(dl_se->flags & SCHED_FLAG_SUGOV);
#else
return false;
#endif
}
/*
* Tells if entity @a should preempt entity @b.
*/
static inline bool dl_entity_preempt(const struct sched_dl_entity *a,
const struct sched_dl_entity *b)
{
return dl_entity_is_special(a) ||
dl_time_before(a->deadline, b->deadline);
}
/*
* This is the priority-queue data structure of the RT scheduling class:
*/
struct rt_prio_array {
DECLARE_BITMAP(bitmap, MAX_RT_PRIO+1); /* include 1 bit for delimiter */
struct list_head queue[MAX_RT_PRIO];
};
struct rt_bandwidth {
/* nests inside the rq lock: */
raw_spinlock_t rt_runtime_lock;
ktime_t rt_period;
u64 rt_runtime;
struct hrtimer rt_period_timer;
unsigned int rt_period_active;
};
void __dl_clear_params(struct task_struct *p);
static inline int dl_bandwidth_enabled(void)
{
return sysctl_sched_rt_runtime >= 0;
}
/*
* To keep the bandwidth of -deadline tasks under control
* we need some place where:
* - store the maximum -deadline bandwidth of each cpu;
* - cache the fraction of bandwidth that is currently allocated in
* each root domain;
*
* 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, bandwidth is given on a per root domain basis,
* meaning that:
* - bw (< 100%) is the deadline bandwidth of each CPU;
* - total_bw is the currently allocated bandwidth in each root domain;
*/
struct dl_bw {
raw_spinlock_t lock;
u64 bw;
u64 total_bw;
};
extern void init_dl_bw(struct dl_bw *dl_b);
extern int sched_dl_global_validate(void);
extern void sched_dl_do_global(void);
extern int sched_dl_overflow(struct task_struct *p, int policy, const struct sched_attr *attr);
extern void __setparam_dl(struct task_struct *p, const struct sched_attr *attr);
extern void __getparam_dl(struct task_struct *p, struct sched_attr *attr);
extern bool __checkparam_dl(const struct sched_attr *attr);
extern bool dl_param_changed(struct task_struct *p, const struct sched_attr *attr);
extern int dl_cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial);
extern int dl_bw_check_overflow(int cpu);
#ifdef CONFIG_CGROUP_SCHED
struct cfs_rq;
struct rt_rq;
extern struct list_head task_groups;
struct cfs_bandwidth {
#ifdef CONFIG_CFS_BANDWIDTH
raw_spinlock_t lock;
ktime_t period;
u64 quota;
u64 runtime;
u64 burst;
u64 runtime_snap;
s64 hierarchical_quota;
u8 idle;
u8 period_active;
u8 slack_started;
struct hrtimer period_timer;
struct hrtimer slack_timer;
struct list_head throttled_cfs_rq;
/* Statistics: */
int nr_periods;
int nr_throttled;
int nr_burst;
u64 throttled_time;
u64 burst_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;
/* A positive value indicates that this is a SCHED_IDLE group. */
int idle;
#ifdef CONFIG_SMP
/*
* load_avg can be heavily contended at clock tick time, so put
* it in its own cacheline separated from the fields above which
* will also be accessed at each tick.
*/
atomic_long_t load_avg ____cacheline_aligned;
#endif
#endif
#ifdef CONFIG_RT_GROUP_SCHED
struct sched_rt_entity **rt_se;
struct rt_rq **rt_rq;
struct rt_bandwidth rt_bandwidth;
#endif
struct rcu_head rcu;
struct list_head list;
struct task_group *parent;
struct list_head siblings;
struct list_head children;
#ifdef CONFIG_SCHED_AUTOGROUP
struct autogroup *autogroup;
#endif
struct cfs_bandwidth cfs_bandwidth;
#ifdef CONFIG_UCLAMP_TASK_GROUP
/* The two decimal precision [%] value requested from user-space */
unsigned int uclamp_pct[UCLAMP_CNT];
/* Clamp values requested for a task group */
struct uclamp_se uclamp_req[UCLAMP_CNT];
/* Effective clamp values used for a task group */
struct uclamp_se uclamp[UCLAMP_CNT];
#endif
};
#ifdef CONFIG_FAIR_GROUP_SCHED
#define ROOT_TASK_GROUP_LOAD NICE_0_LOAD
/*
* A weight of 0 or 1 can cause arithmetics problems.
* A weight of a cfs_rq is the sum of weights of which entities
* are queued on this cfs_rq, so a weight of a entity should not be
* too large, so as the shares value of a task group.
* (The default weight is 1024 - so there's no practical
* limitation from this.)
*/
#define MIN_SHARES (1UL << 1)
#define MAX_SHARES (1UL << 18)
#endif
typedef int (*tg_visitor)(struct task_group *, void *);
extern int walk_tg_tree_from(struct task_group *from,
tg_visitor down, tg_visitor up, void *data);
/*
* Iterate the full tree, calling @down when first entering a node and @up when
* leaving it for the final time.
*
* Caller must hold rcu_lock or sufficient equivalent.
*/
static inline int walk_tg_tree(tg_visitor down, tg_visitor up, void *data)
{
return walk_tg_tree_from(&root_task_group, down, up, data);
}
extern int tg_nop(struct task_group *tg, void *data);
extern void free_fair_sched_group(struct task_group *tg);
extern int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent);
extern void online_fair_sched_group(struct task_group *tg);
extern void unregister_fair_sched_group(struct task_group *tg);
extern void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq,
struct sched_entity *se, int cpu,
struct sched_entity *parent);
extern void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b);
extern void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b);
extern void start_cfs_bandwidth(struct cfs_bandwidth *cfs_b);
extern void unthrottle_cfs_rq(struct cfs_rq *cfs_rq);
extern void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq,
struct sched_rt_entity *rt_se, int cpu,
struct sched_rt_entity *parent);
extern int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us);
extern int sched_group_set_rt_period(struct task_group *tg, u64 rt_period_us);
extern long sched_group_rt_runtime(struct task_group *tg);
extern long sched_group_rt_period(struct task_group *tg);
extern int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk);
extern struct task_group *sched_create_group(struct task_group *parent);
extern void sched_online_group(struct task_group *tg,
struct task_group *parent);
extern void sched_destroy_group(struct task_group *tg);
extern void sched_release_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);
extern int sched_group_set_idle(struct task_group *tg, long idle);
#ifdef CONFIG_SMP
extern void set_task_rq_fair(struct sched_entity *se,
struct cfs_rq *prev, struct cfs_rq *next);
#else /* !CONFIG_SMP */
static inline void set_task_rq_fair(struct sched_entity *se,
struct cfs_rq *prev, struct cfs_rq *next) { }
#endif /* CONFIG_SMP */
#endif /* CONFIG_FAIR_GROUP_SCHED */
#else /* CONFIG_CGROUP_SCHED */
struct cfs_bandwidth { };
#endif /* CONFIG_CGROUP_SCHED */
extern void unregister_rt_sched_group(struct task_group *tg);
extern void free_rt_sched_group(struct task_group *tg);
extern int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent);
/*
* u64_u32_load/u64_u32_store
*
* Use a copy of a u64 value to protect against data race. This is only
* applicable for 32-bits architectures.
*/
#ifdef CONFIG_64BIT
# define u64_u32_load_copy(var, copy) var
# define u64_u32_store_copy(var, copy, val) (var = val)
#else
# define u64_u32_load_copy(var, copy) \
({ \
u64 __val, __val_copy; \
do { \
__val_copy = copy; \
/* \
* paired with u64_u32_store_copy(), ordering access \
* to var and copy. \
*/ \
smp_rmb(); \
__val = var; \
} while (__val != __val_copy); \
__val; \
})
# define u64_u32_store_copy(var, copy, val) \
do { \
typeof(val) __val = (val); \
var = __val; \
/* \
* paired with u64_u32_load_copy(), ordering access to var and \
* copy. \
*/ \
smp_wmb(); \
copy = __val; \
} while (0)
#endif
# define u64_u32_load(var) u64_u32_load_copy(var, var##_copy)
# define u64_u32_store(var, val) u64_u32_store_copy(var, var##_copy, val)
/* CFS-related fields in a runqueue */
struct cfs_rq {
struct load_weight load;
unsigned int nr_running;
unsigned int h_nr_running; /* SCHED_{NORMAL,BATCH,IDLE} */
unsigned int idle_nr_running; /* SCHED_IDLE */
unsigned int idle_h_nr_running; /* SCHED_IDLE */
u64 exec_clock;
u64 min_vruntime;
#ifdef CONFIG_SCHED_CORE
unsigned int forceidle_seq;
u64 min_vruntime_fi;
#endif
#ifndef CONFIG_64BIT
u64 min_vruntime_copy;
#endif
struct rb_root_cached tasks_timeline;
/*
* 'curr' points to currently running entity on this cfs_rq.
* It is set to NULL otherwise (i.e when none are currently running).
*/
struct sched_entity *curr;
struct sched_entity *next;
struct sched_entity *last;
struct sched_entity *skip;
#ifdef CONFIG_SCHED_DEBUG
unsigned int nr_spread_over;
#endif
#ifdef CONFIG_SMP
/*
* CFS load tracking
*/
struct sched_avg avg;
#ifndef CONFIG_64BIT
u64 last_update_time_copy;
#endif
struct {
raw_spinlock_t lock ____cacheline_aligned;
int nr;
unsigned long load_avg;
unsigned long util_avg;
unsigned long runnable_avg;
} removed;
#ifdef CONFIG_FAIR_GROUP_SCHED
unsigned long tg_load_avg_contrib;
long propagate;
long prop_runnable_sum;
/*
* h_load = weight * f(tg)
*
* Where f(tg) is the recursive weight fraction assigned to
* this group.
*/
unsigned long h_load;
u64 last_h_load_update;
struct sched_entity *h_load_next;
#endif /* CONFIG_FAIR_GROUP_SCHED */
#endif /* CONFIG_SMP */
#ifdef CONFIG_FAIR_GROUP_SCHED
struct rq *rq; /* CPU runqueue to which this cfs_rq is attached */
/*
* leaf cfs_rqs are those that hold tasks (lowest schedulable entity in
* a hierarchy). Non-leaf lrqs hold other higher schedulable entities
* (like users, containers etc.)
*
* leaf_cfs_rq_list ties together list of leaf cfs_rq's in a CPU.
* This list is used during load balance.
*/
int on_list;
struct list_head leaf_cfs_rq_list;
struct task_group *tg; /* group that "owns" this runqueue */
/* Locally cached copy of our task_group's idle value */
int idle;
#ifdef CONFIG_CFS_BANDWIDTH
int runtime_enabled;
s64 runtime_remaining;
u64 throttled_pelt_idle;
#ifndef CONFIG_64BIT
u64 throttled_pelt_idle_copy;
#endif
u64 throttled_clock;
u64 throttled_clock_pelt;
u64 throttled_clock_pelt_time;
int throttled;
int throttle_count;
struct list_head throttled_list;
#ifdef CONFIG_SMP
struct list_head throttled_csd_list;
#endif
#endif /* CONFIG_CFS_BANDWIDTH */
#endif /* CONFIG_FAIR_GROUP_SCHED */
};
static inline int rt_bandwidth_enabled(void)
{
return sysctl_sched_rt_runtime >= 0;
}
/* RT IPI pull logic requires IRQ_WORK */
#if defined(CONFIG_IRQ_WORK) && defined(CONFIG_SMP)
# define HAVE_RT_PUSH_IPI
#endif
/* Real-Time classes' related field in a runqueue: */
struct rt_rq {
struct rt_prio_array active;
unsigned int rt_nr_running;
unsigned int rr_nr_running;
#if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
struct {
int curr; /* highest queued rt task prio */
#ifdef CONFIG_SMP
int next; /* next highest */
#endif
} highest_prio;
#endif
#ifdef CONFIG_SMP
unsigned int rt_nr_migratory;
unsigned int rt_nr_total;
int overloaded;
struct plist_head pushable_tasks;
#endif /* CONFIG_SMP */
int rt_queued;
int rt_throttled;
u64 rt_time;
u64 rt_runtime;
/* Nests inside the rq lock: */
raw_spinlock_t rt_runtime_lock;
#ifdef CONFIG_RT_GROUP_SCHED
unsigned int rt_nr_boosted;
struct rq *rq;
struct task_group *tg;
#endif
};
static inline bool rt_rq_is_runnable(struct rt_rq *rt_rq)
{
return rt_rq->rt_queued && rt_rq->rt_nr_running;
}
/* Deadline class' related fields in a runqueue */
struct dl_rq {
/* runqueue is an rbtree, ordered by deadline */
struct rb_root_cached root;
unsigned int dl_nr_running;
#ifdef CONFIG_SMP
/*
* Deadline values of the currently executing and the
* earliest ready task on this rq. Caching these facilitates
* the decision whether or not a ready but not running task
* should migrate somewhere else.
*/
struct {
u64 curr;
u64 next;
} earliest_dl;
unsigned int dl_nr_migratory;
int overloaded;
/*
* Tasks on this rq that can be pushed away. They are kept in
* an rb-tree, ordered by tasks' deadlines, with caching
* of the leftmost (earliest deadline) element.
*/
struct rb_root_cached pushable_dl_tasks_root;
#else
struct dl_bw dl_bw;
#endif
/*
* "Active utilization" for this runqueue: increased when a
* task wakes up (becomes TASK_RUNNING) and decreased when a
* task blocks
*/
u64 running_bw;
/*
* Utilization of the tasks "assigned" to this runqueue (including
* the tasks that are in runqueue and the tasks that executed on this
* CPU and blocked). Increased when a task moves to this runqueue, and
* decreased when the task moves away (migrates, changes scheduling
* policy, or terminates).
* This is needed to compute the "inactive utilization" for the
* runqueue (inactive utilization = this_bw - running_bw).
*/
u64 this_bw;
u64 extra_bw;
/*
* Maximum available bandwidth for reclaiming by SCHED_FLAG_RECLAIM
* tasks of this rq. Used in calculation of reclaimable bandwidth(GRUB).
*/
u64 max_bw;
/*
* Inverse of the fraction of CPU utilization that can be reclaimed
* by the GRUB algorithm.
*/
u64 bw_ratio;
};
#ifdef CONFIG_FAIR_GROUP_SCHED
/* An entity is a task if it doesn't "own" a runqueue */
#define entity_is_task(se) (!se->my_q)
static inline void se_update_runnable(struct sched_entity *se)
{
if (!entity_is_task(se))
se->runnable_weight = se->my_q->h_nr_running;
}
static inline long se_runnable(struct sched_entity *se)
{
if (entity_is_task(se))
return !!se->on_rq;
else
return se->runnable_weight;
}
#else
#define entity_is_task(se) 1
static inline void se_update_runnable(struct sched_entity *se) {}
static inline long se_runnable(struct sched_entity *se)
{
return !!se->on_rq;
}
#endif
#ifdef CONFIG_SMP
/*
* XXX we want to get rid of these helpers and use the full load resolution.
*/
static inline long se_weight(struct sched_entity *se)
{
return scale_load_down(se->load.weight);
}
static inline bool sched_asym_prefer(int a, int b)
{
return arch_asym_cpu_priority(a) > arch_asym_cpu_priority(b);
}
struct perf_domain {
struct em_perf_domain *em_pd;
struct perf_domain *next;
struct rcu_head rcu;
};
/* Scheduling group status flags */
#define SG_OVERLOAD 0x1 /* More than one runnable task on a CPU. */
#define SG_OVERUTILIZED 0x2 /* One or more CPUs are over-utilized. */
/*
* We add the notion of a root-domain which will be used to define per-domain
* variables. Each exclusive cpuset essentially defines an island domain by
* fully partitioning the member CPUs from any other cpuset. Whenever a new
* exclusive cpuset is created, we also create and attach a new root-domain
* object.
*
*/
struct root_domain {
atomic_t refcount;
atomic_t rto_count;
struct rcu_head rcu;
cpumask_var_t span;
cpumask_var_t online;
/*
* Indicate pullable load on at least one CPU, e.g:
* - More than one runnable task
* - Running task is misfit
*/
int overload;
/* Indicate one or more cpus over-utilized (tipping point) */
int overutilized;
/*
* The bit corresponding to a CPU gets set here if such CPU has more
* than one runnable -deadline task (as it is below for RT tasks).
*/
cpumask_var_t dlo_mask;
atomic_t dlo_count;
struct dl_bw dl_bw;
struct cpudl cpudl;
/*
* Indicate whether a root_domain's dl_bw has been checked or
* updated. It's monotonously increasing value.
*
* Also, some corner cases, like 'wrap around' is dangerous, but given
* that u64 is 'big enough'. So that shouldn't be a concern.
*/
u64 visit_gen;
#ifdef HAVE_RT_PUSH_IPI
/*
* For IPI pull requests, loop across the rto_mask.
*/
struct irq_work rto_push_work;
raw_spinlock_t rto_lock;
/* These are only updated and read within rto_lock */
int rto_loop;
int rto_cpu;
/* These atomics are updated outside of a lock */
atomic_t rto_loop_next;
atomic_t rto_loop_start;
#endif
/*
* The "RT overload" flag: it gets set if a CPU has more than
* one runnable RT task.
*/
cpumask_var_t rto_mask;
struct cpupri cpupri;
unsigned long max_cpu_capacity;
/*
* NULL-terminated list of performance domains intersecting with the
* CPUs of the rd. Protected by RCU.
*/
struct perf_domain __rcu *pd;
};
extern void init_defrootdomain(void);
extern int sched_init_domains(const struct cpumask *cpu_map);
extern void rq_attach_root(struct rq *rq, struct root_domain *rd);
extern void sched_get_rd(struct root_domain *rd);
extern void sched_put_rd(struct root_domain *rd);
#ifdef HAVE_RT_PUSH_IPI
extern void rto_push_irq_work_func(struct irq_work *work);
#endif
#endif /* CONFIG_SMP */
#ifdef CONFIG_UCLAMP_TASK
/*
* struct uclamp_bucket - Utilization clamp bucket
* @value: utilization clamp value for tasks on this clamp bucket
* @tasks: number of RUNNABLE tasks on this clamp bucket
*
* Keep track of how many tasks are RUNNABLE for a given utilization
* clamp value.
*/
struct uclamp_bucket {
unsigned long value : bits_per(SCHED_CAPACITY_SCALE);
unsigned long tasks : BITS_PER_LONG - bits_per(SCHED_CAPACITY_SCALE);
};
/*
* struct uclamp_rq - rq's utilization clamp
* @value: currently active clamp values for a rq
* @bucket: utilization clamp buckets affecting a rq
*
* Keep track of RUNNABLE tasks on a rq to aggregate their clamp values.
* A clamp value is affecting a rq when there is at least one task RUNNABLE
* (or actually running) with that value.
*
* There are up to UCLAMP_CNT possible different clamp values, currently there
* are only two: minimum utilization and maximum utilization.
*
* All utilization clamping values are MAX aggregated, since:
* - for util_min: we want to run the CPU at least at the max of the minimum
* utilization required by its currently RUNNABLE tasks.
* - for util_max: we want to allow the CPU to run up to the max of the
* maximum utilization allowed by its currently RUNNABLE tasks.
*
* Since on each system we expect only a limited number of different
* utilization clamp values (UCLAMP_BUCKETS), use a simple array to track
* the metrics required to compute all the per-rq utilization clamp values.
*/
struct uclamp_rq {
unsigned int value;
struct uclamp_bucket bucket[UCLAMP_BUCKETS];
};
DECLARE_STATIC_KEY_FALSE(sched_uclamp_used);
#endif /* CONFIG_UCLAMP_TASK */
struct rq;
struct balance_callback {
struct balance_callback *next;
void (*func)(struct rq *rq);
};
/*
* This is the main, per-CPU runqueue data structure.
*
* Locking rule: those places that want to lock multiple runqueues
* (such as the load balancing or the thread migration code), lock
* acquire operations must be ordered by ascending &runqueue.
*/
struct rq {
/* runqueue lock: */
raw_spinlock_t __lock;
/*
* nr_running and cpu_load should be in the same cacheline because
* remote CPUs use both these fields when doing load calculation.
*/
unsigned int nr_running;
#ifdef CONFIG_NUMA_BALANCING
unsigned int nr_numa_running;
unsigned int nr_preferred_running;
unsigned int numa_migrate_on;
#endif
#ifdef CONFIG_NO_HZ_COMMON
#ifdef CONFIG_SMP
unsigned long last_blocked_load_update_tick;
unsigned int has_blocked_load;
call_single_data_t nohz_csd;
#endif /* CONFIG_SMP */
unsigned int nohz_tick_stopped;
atomic_t nohz_flags;
#endif /* CONFIG_NO_HZ_COMMON */
#ifdef CONFIG_SMP
unsigned int ttwu_pending;
#endif
u64 nr_switches;
#ifdef CONFIG_UCLAMP_TASK
/* Utilization clamp values based on CPU's RUNNABLE tasks */
struct uclamp_rq uclamp[UCLAMP_CNT] ____cacheline_aligned;
unsigned int uclamp_flags;
#define UCLAMP_FLAG_IDLE 0x01
#endif
struct cfs_rq cfs;
struct rt_rq rt;
struct dl_rq dl;
#ifdef CONFIG_FAIR_GROUP_SCHED
/* list of leaf cfs_rq on this CPU: */
struct list_head leaf_cfs_rq_list;
struct list_head *tmp_alone_branch;
#endif /* CONFIG_FAIR_GROUP_SCHED */
/*
* This is part of a global counter where only the total sum
* over all CPUs matters. A task can increase this counter on
* one CPU and if it got migrated afterwards it may decrease
* it on another CPU. Always updated under the runqueue lock:
*/
unsigned int nr_uninterruptible;
struct task_struct __rcu *curr;
struct task_struct *idle;
struct task_struct *stop;
unsigned long next_balance;
struct mm_struct *prev_mm;
unsigned int clock_update_flags;
u64 clock;
/* Ensure that all clocks are in the same cache line */
u64 clock_task ____cacheline_aligned;
u64 clock_pelt;
unsigned long lost_idle_time;
u64 clock_pelt_idle;
u64 clock_idle;
#ifndef CONFIG_64BIT
u64 clock_pelt_idle_copy;
u64 clock_idle_copy;
#endif
atomic_t nr_iowait;
#ifdef CONFIG_SCHED_DEBUG
u64 last_seen_need_resched_ns;
int ticks_without_resched;
#endif
#ifdef CONFIG_MEMBARRIER
int membarrier_state;
#endif
#ifdef CONFIG_SMP
struct root_domain *rd;
struct sched_domain __rcu *sd;
unsigned long cpu_capacity;
unsigned long cpu_capacity_orig;
struct balance_callback *balance_callback;
unsigned char nohz_idle_balance;
unsigned char idle_balance;
unsigned long misfit_task_load;
/* For active balancing */
int active_balance;
int push_cpu;
struct cpu_stop_work active_balance_work;
/* CPU of this runqueue: */
int cpu;
int online;
struct list_head cfs_tasks;
struct sched_avg avg_rt;
struct sched_avg avg_dl;
#ifdef CONFIG_HAVE_SCHED_AVG_IRQ
struct sched_avg avg_irq;
#endif
#ifdef CONFIG_SCHED_THERMAL_PRESSURE
struct sched_avg avg_thermal;
#endif
u64 idle_stamp;
u64 avg_idle;
unsigned long wake_stamp;
u64 wake_avg_idle;
/* This is used to determine avg_idle's max value */
u64 max_idle_balance_cost;
#ifdef CONFIG_HOTPLUG_CPU
struct rcuwait hotplug_wait;
#endif
#endif /* CONFIG_SMP */
#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
call_single_data_t hrtick_csd;
#endif
struct hrtimer hrtick_timer;
ktime_t hrtick_time;
#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_CPU_IDLE
/* Must be inspected within a rcu lock section */
struct cpuidle_state *idle_state;
#endif
#ifdef CONFIG_SMP
unsigned int nr_pinned;
#endif
unsigned int push_busy;
struct cpu_stop_work push_work;
#ifdef CONFIG_SCHED_CORE
/* per rq */
struct rq *core;
struct task_struct *core_pick;
unsigned int core_enabled;
unsigned int core_sched_seq;
struct rb_root core_tree;
/* shared state -- careful with sched_core_cpu_deactivate() */
unsigned int core_task_seq;
unsigned int core_pick_seq;
unsigned long core_cookie;
unsigned int core_forceidle_count;
unsigned int core_forceidle_seq;
unsigned int core_forceidle_occupation;
u64 core_forceidle_start;
#endif
/* Scratch cpumask to be temporarily used under rq_lock */
cpumask_var_t scratch_mask;
#if defined(CONFIG_CFS_BANDWIDTH) && defined(CONFIG_SMP)
call_single_data_t cfsb_csd;
struct list_head cfsb_csd_list;
#endif
};
#ifdef CONFIG_FAIR_GROUP_SCHED
/* CPU runqueue to which this cfs_rq is attached */
static inline struct rq *rq_of(struct cfs_rq *cfs_rq)
{
return cfs_rq->rq;
}
#else
static inline struct rq *rq_of(struct cfs_rq *cfs_rq)
{
return container_of(cfs_rq, struct rq, cfs);
}
#endif
static inline int cpu_of(struct rq *rq)
{
#ifdef CONFIG_SMP
return rq->cpu;
#else
return 0;
#endif
}
#define MDF_PUSH 0x01
static inline bool is_migration_disabled(struct task_struct *p)
{
#ifdef CONFIG_SMP
return p->migration_disabled;
#else
return false;
#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)
struct sched_group;
#ifdef CONFIG_SCHED_CORE
static inline struct cpumask *sched_group_span(struct sched_group *sg);
DECLARE_STATIC_KEY_FALSE(__sched_core_enabled);
static inline bool sched_core_enabled(struct rq *rq)
{
return static_branch_unlikely(&__sched_core_enabled) && rq->core_enabled;
}
static inline bool sched_core_disabled(void)
{
return !static_branch_unlikely(&__sched_core_enabled);
}
/*
* Be careful with this function; not for general use. The return value isn't
* stable unless you actually hold a relevant rq->__lock.
*/
static inline raw_spinlock_t *rq_lockp(struct rq *rq)
{
if (sched_core_enabled(rq))
return &rq->core->__lock;
return &rq->__lock;
}
static inline raw_spinlock_t *__rq_lockp(struct rq *rq)
{
if (rq->core_enabled)
return &rq->core->__lock;
return &rq->__lock;
}
bool cfs_prio_less(const struct task_struct *a, const struct task_struct *b,
bool fi);
/*
* Helpers to check if the CPU's core cookie matches with the task's cookie
* when core scheduling is enabled.
* A special case is that the task's cookie always matches with CPU's core
* cookie if the CPU is in an idle core.
*/
static inline bool sched_cpu_cookie_match(struct rq *rq, struct task_struct *p)
{
/* Ignore cookie match if core scheduler is not enabled on the CPU. */
if (!sched_core_enabled(rq))
return true;
return rq->core->core_cookie == p->core_cookie;
}
static inline bool sched_core_cookie_match(struct rq *rq, struct task_struct *p)
{
bool idle_core = true;
int cpu;
/* Ignore cookie match if core scheduler is not enabled on the CPU. */
if (!sched_core_enabled(rq))
return true;
for_each_cpu(cpu, cpu_smt_mask(cpu_of(rq))) {
if (!available_idle_cpu(cpu)) {
idle_core = false;
break;
}
}
/*
* A CPU in an idle core is always the best choice for tasks with
* cookies.
*/
return idle_core || rq->core->core_cookie == p->core_cookie;
}
static inline bool sched_group_cookie_match(struct rq *rq,
struct task_struct *p,
struct sched_group *group)
{
int cpu;
/* Ignore cookie match if core scheduler is not enabled on the CPU. */
if (!sched_core_enabled(rq))
return true;
for_each_cpu_and(cpu, sched_group_span(group), p->cpus_ptr) {
if (sched_core_cookie_match(cpu_rq(cpu), p))
return true;
}
return false;
}
static inline bool sched_core_enqueued(struct task_struct *p)
{
return !RB_EMPTY_NODE(&p->core_node);
}
extern void sched_core_enqueue(struct rq *rq, struct task_struct *p);
extern void sched_core_dequeue(struct rq *rq, struct task_struct *p, int flags);
extern void sched_core_get(void);
extern void sched_core_put(void);
#else /* !CONFIG_SCHED_CORE */
static inline bool sched_core_enabled(struct rq *rq)
{
return false;
}
static inline bool sched_core_disabled(void)
{
return true;
}
static inline raw_spinlock_t *rq_lockp(struct rq *rq)
{
return &rq->__lock;
}
static inline raw_spinlock_t *__rq_lockp(struct rq *rq)
{
return &rq->__lock;
}
static inline bool sched_cpu_cookie_match(struct rq *rq, struct task_struct *p)
{
return true;
}
static inline bool sched_core_cookie_match(struct rq *rq, struct task_struct *p)
{
return true;
}
static inline bool sched_group_cookie_match(struct rq *rq,
struct task_struct *p,
struct sched_group *group)
{
return true;
}
#endif /* CONFIG_SCHED_CORE */
static inline void lockdep_assert_rq_held(struct rq *rq)
{
lockdep_assert_held(__rq_lockp(rq));
}
extern void raw_spin_rq_lock_nested(struct rq *rq, int subclass);
extern bool raw_spin_rq_trylock(struct rq *rq);
extern void raw_spin_rq_unlock(struct rq *rq);
static inline void raw_spin_rq_lock(struct rq *rq)
{
raw_spin_rq_lock_nested(rq, 0);
}
static inline void raw_spin_rq_lock_irq(struct rq *rq)
{
local_irq_disable();
raw_spin_rq_lock(rq);
}
static inline void raw_spin_rq_unlock_irq(struct rq *rq)
{
raw_spin_rq_unlock(rq);
local_irq_enable();
}
static inline unsigned long _raw_spin_rq_lock_irqsave(struct rq *rq)
{
unsigned long flags;
local_irq_save(flags);
raw_spin_rq_lock(rq);
return flags;
}
static inline void raw_spin_rq_unlock_irqrestore(struct rq *rq, unsigned long flags)
{
raw_spin_rq_unlock(rq);
local_irq_restore(flags);
}
#define raw_spin_rq_lock_irqsave(rq, flags) \
do { \
flags = _raw_spin_rq_lock_irqsave(rq); \
} while (0)
#ifdef CONFIG_SCHED_SMT
extern void __update_idle_core(struct rq *rq);
static inline void update_idle_core(struct rq *rq)
{
if (static_branch_unlikely(&sched_smt_present))
__update_idle_core(rq);
}
#else
static inline void update_idle_core(struct rq *rq) { }
#endif
#ifdef CONFIG_FAIR_GROUP_SCHED
static inline struct task_struct *task_of(struct sched_entity *se)
{
SCHED_WARN_ON(!entity_is_task(se));
return container_of(se, struct task_struct, se);
}
static inline struct cfs_rq *task_cfs_rq(struct task_struct *p)
{
return p->se.cfs_rq;
}
/* runqueue on which this entity is (to be) queued */
static inline struct cfs_rq *cfs_rq_of(const struct sched_entity *se)
{
return se->cfs_rq;
}
/* runqueue "owned" by this group */
static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp)
{
return grp->my_q;
}
#else
#define task_of(_se) container_of(_se, struct task_struct, se)
static inline struct cfs_rq *task_cfs_rq(const struct task_struct *p)
{
return &task_rq(p)->cfs;
}
static inline struct cfs_rq *cfs_rq_of(const struct sched_entity *se)
{
const struct task_struct *p = task_of(se);
struct rq *rq = task_rq(p);
return &rq->cfs;
}
/* runqueue "owned" by this group */
static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp)
{
return NULL;
}
#endif
extern void update_rq_clock(struct rq *rq);
/*
* 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_UPDATED is set. It'll never be shifted more than
* one position though, because the next rq_unpin_lock() will shift it
* back.
*/
#define RQCF_REQ_SKIP 0x01
#define RQCF_ACT_SKIP 0x02
#define RQCF_UPDATED 0x04
static inline void assert_clock_updated(struct rq *rq)
{
/*
* The only reason for not seeing a clock update since the
* last rq_pin_lock() is if we're currently skipping updates.
*/
SCHED_WARN_ON(rq->clock_update_flags < RQCF_ACT_SKIP);
}
static inline u64 rq_clock(struct rq *rq)
{
lockdep_assert_rq_held(rq);
assert_clock_updated(rq);
return rq->clock;
}
static inline u64 rq_clock_task(struct rq *rq)
{
lockdep_assert_rq_held(rq);
assert_clock_updated(rq);
return rq->clock_task;
}
/**
* By default the decay is the default pelt decay period.
* The decay shift can change the decay period in
* multiples of 32.
* Decay shift Decay period(ms)
* 0 32
* 1 64
* 2 128
* 3 256
* 4 512
*/
extern int sched_thermal_decay_shift;
static inline u64 rq_clock_thermal(struct rq *rq)
{
return rq_clock_task(rq) >> sched_thermal_decay_shift;
}
static inline void rq_clock_skip_update(struct rq *rq)
{
lockdep_assert_rq_held(rq);
rq->clock_update_flags |= RQCF_REQ_SKIP;
}
/*
* See rt task throttling, which is the only time a skip
* request is canceled.
*/
static inline void rq_clock_cancel_skipupdate(struct rq *rq)
{
lockdep_assert_rq_held(rq);
rq->clock_update_flags &= ~RQCF_REQ_SKIP;
}
/*
* During cpu offlining and rq wide unthrottling, we can trigger
* an update_rq_clock() for several cfs and rt runqueues (Typically
* when using list_for_each_entry_*)
* rq_clock_start_loop_update() can be called after updating the clock
* once and before iterating over the list to prevent multiple update.
* After the iterative traversal, we need to call rq_clock_stop_loop_update()
* to clear RQCF_ACT_SKIP of rq->clock_update_flags.
*/
static inline void rq_clock_start_loop_update(struct rq *rq)
{
lockdep_assert_rq_held(rq);
SCHED_WARN_ON(rq->clock_update_flags & RQCF_ACT_SKIP);
rq->clock_update_flags |= RQCF_ACT_SKIP;
}
static inline void rq_clock_stop_loop_update(struct rq *rq)
{
lockdep_assert_rq_held(rq);
rq->clock_update_flags &= ~RQCF_ACT_SKIP;
}
struct rq_flags {
unsigned long flags;
struct pin_cookie cookie;
#ifdef CONFIG_SCHED_DEBUG
/*
* A copy of (rq::clock_update_flags & RQCF_UPDATED) for the
* current pin context is stashed here in case it needs to be
* restored in rq_repin_lock().
*/
unsigned int clock_update_flags;
#endif
};
extern struct balance_callback balance_push_callback;
/*
* Lockdep annotation that avoids accidental unlocks; it's like a
* sticky/continuous lockdep_assert_held().
*
* This avoids code that has access to 'struct rq *rq' (basically everything in
* the scheduler) from accidentally unlocking the rq if they do not also have a
* copy of the (on-stack) 'struct rq_flags rf'.
*
* Also see Documentation/locking/lockdep-design.rst.
*/
static inline void rq_pin_lock(struct rq *rq, struct rq_flags *rf)
{
rf->cookie = lockdep_pin_lock(__rq_lockp(rq));
#ifdef CONFIG_SCHED_DEBUG
rq->clock_update_flags &= (RQCF_REQ_SKIP|RQCF_ACT_SKIP);
rf->clock_update_flags = 0;
#ifdef CONFIG_SMP
SCHED_WARN_ON(rq->balance_callback && rq->balance_callback != &balance_push_callback);
#endif
#endif
}
static inline void rq_unpin_lock(struct rq *rq, struct rq_flags *rf)
{
#ifdef CONFIG_SCHED_DEBUG
if (rq->clock_update_flags > RQCF_ACT_SKIP)
rf->clock_update_flags = RQCF_UPDATED;
#endif
lockdep_unpin_lock(__rq_lockp(rq), rf->cookie);
}
static inline void rq_repin_lock(struct rq *rq, struct rq_flags *rf)
{
lockdep_repin_lock(__rq_lockp(rq), rf->cookie);
#ifdef CONFIG_SCHED_DEBUG
/*
* Restore the value we stashed in @rf for this pin context.
*/
rq->clock_update_flags |= rf->clock_update_flags;
#endif
}
struct rq *__task_rq_lock(struct task_struct *p, struct rq_flags *rf)
__acquires(rq->lock);
struct rq *task_rq_lock(struct task_struct *p, struct rq_flags *rf)
__acquires(p->pi_lock)
__acquires(rq->lock);
static inline void __task_rq_unlock(struct rq *rq, struct rq_flags *rf)
__releases(rq->lock)
{
rq_unpin_lock(rq, rf);
raw_spin_rq_unlock(rq);
}
static inline void
task_rq_unlock(struct rq *rq, struct task_struct *p, struct rq_flags *rf)
__releases(rq->lock)
__releases(p->pi_lock)
{
rq_unpin_lock(rq, rf);
raw_spin_rq_unlock(rq);
raw_spin_unlock_irqrestore(&p->pi_lock, rf->flags);
}
static inline void
rq_lock_irqsave(struct rq *rq, struct rq_flags *rf)
__acquires(rq->lock)
{
raw_spin_rq_lock_irqsave(rq, 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_rq_lock_irq(rq);
rq_pin_lock(rq, rf);
}
static inline void
rq_lock(struct rq *rq, struct rq_flags *rf)
__acquires(rq->lock)
{
raw_spin_rq_lock(rq);
rq_pin_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_rq_unlock_irqrestore(rq, 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_rq_unlock_irq(rq);
}
static inline void
rq_unlock(struct rq *rq, struct rq_flags *rf)
__releases(rq->lock)
{
rq_unpin_lock(rq, rf);
raw_spin_rq_unlock(rq);
}
static inline struct rq *
this_rq_lock_irq(struct rq_flags *rf)
__acquires(rq->lock)
{
struct rq *rq;
local_irq_disable();
rq = this_rq();
rq_lock(rq, rf);
return rq;
}
#ifdef CONFIG_NUMA
enum numa_topology_type {
NUMA_DIRECT,
NUMA_GLUELESS_MESH,
NUMA_BACKPLANE,
};
extern enum numa_topology_type sched_numa_topology_type;
extern int sched_max_numa_distance;
extern bool find_numa_distance(int distance);
extern void sched_init_numa(int offline_node);
extern void sched_update_numa(int cpu, bool online);
extern void sched_domains_numa_masks_set(unsigned int cpu);
extern void sched_domains_numa_masks_clear(unsigned int cpu);
extern int sched_numa_find_closest(const struct cpumask *cpus, int cpu);
#else
static inline void sched_init_numa(int offline_node) { }
static inline void sched_update_numa(int cpu, bool online) { }
static inline void sched_domains_numa_masks_set(unsigned int cpu) { }
static inline void sched_domains_numa_masks_clear(unsigned int cpu) { }
static inline int sched_numa_find_closest(const struct cpumask *cpus, int cpu)
{
return nr_cpu_ids;
}
#endif
#ifdef CONFIG_NUMA_BALANCING
/* The regions in numa_faults array from task_struct */
enum numa_faults_stats {
NUMA_MEM = 0,
NUMA_CPU,
NUMA_MEMBUF,
NUMA_CPUBUF
};
extern void sched_setnuma(struct task_struct *p, int node);
extern int migrate_task_to(struct task_struct *p, int cpu);
extern int migrate_swap(struct task_struct *p, struct task_struct *t,
int cpu, int scpu);
extern void init_numa_balancing(unsigned long clone_flags, struct task_struct *p);
#else
static inline void
init_numa_balancing(unsigned long clone_flags, struct task_struct *p)
{
}
#endif /* CONFIG_NUMA_BALANCING */
#ifdef CONFIG_SMP
static inline void
queue_balance_callback(struct rq *rq,
struct balance_callback *head,
void (*func)(struct rq *rq))
{
lockdep_assert_rq_held(rq);
/*
* Don't (re)queue an already queued item; nor queue anything when
* balance_push() is active, see the comment with
* balance_push_callback.
*/
if (unlikely(head->next || rq->balance_callback == &balance_push_callback))
return;
head->func = func;
head->next = rq->balance_callback;
rq->balance_callback = head;
}
#define rcu_dereference_check_sched_domain(p) \
rcu_dereference_check((p), \
lockdep_is_held(&sched_domains_mutex))
/*
* The domain tree (rq->sd) is protected by RCU's quiescent state transition.
* See destroy_sched_domains: call_rcu for details.
*
* The domain tree of any CPU may only be accessed from within
* preempt-disabled sections.
*/
#define for_each_domain(cpu, __sd) \
for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); \
__sd; __sd = __sd->parent)
/* A mask of all the SD flags that have the SDF_SHARED_CHILD metaflag */
#define SD_FLAG(name, mflags) (name * !!((mflags) & SDF_SHARED_CHILD)) |
static const unsigned int SD_SHARED_CHILD_MASK =
#include <linux/sched/sd_flags.h>
0;
#undef SD_FLAG
/**
* 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 @flag. If @flag has
* the SDF_SHARED_CHILD metaflag, all the children domains also have @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) {
hsd = sd;
continue;
}
/*
* Stop the search if @flag is known to be shared at lower
* levels. It will not be found further up.
*/
if (flag & SD_SHARED_CHILD_MASK)
break;
}
return hsd;
}
static inline struct sched_domain *lowest_flag_domain(int cpu, int flag)
{
struct sched_domain *sd;
for_each_domain(cpu, sd) {
if (sd->flags & flag)
break;
}
return sd;
}
DECLARE_PER_CPU(struct sched_domain __rcu *, sd_llc);
DECLARE_PER_CPU(int, sd_llc_size);
DECLARE_PER_CPU(int, sd_llc_id);
DECLARE_PER_CPU(struct sched_domain_shared __rcu *, sd_llc_shared);
DECLARE_PER_CPU(struct sched_domain __rcu *, sd_numa);
DECLARE_PER_CPU(struct sched_domain __rcu *, sd_asym_packing);
DECLARE_PER_CPU(struct sched_domain __rcu *, sd_asym_cpucapacity);
extern struct static_key_false sched_asym_cpucapacity;
static __always_inline bool sched_asym_cpucap_active(void)
{
return static_branch_unlikely(&sched_asym_cpucapacity);
}
struct sched_group_capacity {
atomic_t ref;
/*
* CPU capacity of this group, SCHED_CAPACITY_SCALE being max capacity
* for a single CPU.
*/
unsigned long capacity;
unsigned long min_capacity; /* Min per-CPU capacity in group */
unsigned long max_capacity; /* Max per-CPU capacity in group */
unsigned long next_update;
int imbalance; /* XXX unrelated to capacity but shared group state */
#ifdef CONFIG_SCHED_DEBUG
int id;
#endif
unsigned long cpumask[]; /* Balance mask */
};
struct sched_group {
struct sched_group *next; /* Must be a circular list */
atomic_t ref;
unsigned int group_weight;
struct sched_group_capacity *sgc;
int asym_prefer_cpu; /* CPU of highest priority in group */
int flags;
/*
* 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[];
};
static inline struct cpumask *sched_group_span(struct sched_group *sg)
{
return to_cpumask(sg->cpumask);
}
/*
* See build_balance_mask().
*/
static inline struct cpumask *group_balance_mask(struct sched_group *sg)
{
return to_cpumask(sg->sgc->cpumask);
}
extern int group_balance_cpu(struct sched_group *sg);
#ifdef CONFIG_SCHED_DEBUG
void update_sched_domain_debugfs(void);
void dirty_sched_domain_sysctl(int cpu);
#else
static inline void update_sched_domain_debugfs(void)
{
}
static inline void dirty_sched_domain_sysctl(int cpu)
{
}
#endif
extern int sched_update_scaling(void);
static inline const struct cpumask *task_user_cpus(struct task_struct *p)
{
if (!p->user_cpus_ptr)
return cpu_possible_mask; /* &init_task.cpus_mask */
return p->user_cpus_ptr;
}
#endif /* CONFIG_SMP */
#include "stats.h"
#if defined(CONFIG_SCHED_CORE) && defined(CONFIG_SCHEDSTATS)
extern void __sched_core_account_forceidle(struct rq *rq);
static inline void sched_core_account_forceidle(struct rq *rq)
{
if (schedstat_enabled())
__sched_core_account_forceidle(rq);
}
extern void __sched_core_tick(struct rq *rq);
static inline void sched_core_tick(struct rq *rq)
{
if (sched_core_enabled(rq) && schedstat_enabled())
__sched_core_tick(rq);
}
#else
static inline void sched_core_account_forceidle(struct rq *rq) {}
static inline void sched_core_tick(struct rq *rq) {}
#endif /* CONFIG_SCHED_CORE && CONFIG_SCHEDSTATS */
#ifdef CONFIG_CGROUP_SCHED
/*
* Return the group to which this tasks belongs.
*
* We cannot use task_css() and friends because the cgroup subsystem
* changes that value before the cgroup_subsys::attach() method is called,
* therefore we cannot pin it and might observe the wrong value.
*
* The same is true for autogroup's p->signal->autogroup->tg, the autogroup
* core changes this before calling sched_move_task().
*
* Instead we use a 'copy' which is updated from sched_move_task() while
* holding both task_struct::pi_lock and rq::lock.
*/
static inline struct task_group *task_group(struct task_struct *p)
{
return p->sched_task_group;
}
/* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */
static inline void set_task_rq(struct task_struct *p, unsigned int cpu)
{
#if defined(CONFIG_FAIR_GROUP_SCHED) || defined(CONFIG_RT_GROUP_SCHED)
struct task_group *tg = task_group(p);
#endif
#ifdef CONFIG_FAIR_GROUP_SCHED
set_task_rq_fair(&p->se, p->se.cfs_rq, tg->cfs_rq[cpu]);
p->se.cfs_rq = tg->cfs_rq[cpu];
p->se.parent = tg->se[cpu];
p->se.depth = tg->se[cpu] ? tg->se[cpu]->depth + 1 : 0;
#endif
#ifdef CONFIG_RT_GROUP_SCHED
p->rt.rt_rq = tg->rt_rq[cpu];
p->rt.parent = tg->rt_se[cpu];
#endif
}
#else /* CONFIG_CGROUP_SCHED */
static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { }
static inline struct task_group *task_group(struct task_struct *p)
{
return NULL;
}
#endif /* CONFIG_CGROUP_SCHED */
static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
{
set_task_rq(p, cpu);
#ifdef CONFIG_SMP
/*
* After ->cpu is set up to a new value, task_rq_lock(p, ...) can be
* successfully executed on another CPU. We must ensure that updates of
* per-task data have been completed by this moment.
*/
smp_wmb();
WRITE_ONCE(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
# define const_debug __read_mostly
#else
# define const_debug const
#endif
#define SCHED_FEAT(name, enabled) \
__SCHED_FEAT_##name ,
enum {
#include "features.h"
__SCHED_FEAT_NR,
};
#undef SCHED_FEAT
#ifdef CONFIG_SCHED_DEBUG
/*
* To support run-time toggling of sched features, all the translation units
* (but core.c) reference the sysctl_sched_features defined in core.c.
*/
extern const_debug unsigned int sysctl_sched_features;
#ifdef CONFIG_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 /* !CONFIG_JUMP_LABEL */
#define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x))
#endif /* CONFIG_JUMP_LABEL */
#else /* !SCHED_DEBUG */
/*
* Each translation unit has its own copy of sysctl_sched_features to allow
* constants propagation at compile time and compiler optimization based on
* features default.
*/
#define SCHED_FEAT(name, enabled) \
(1UL << __SCHED_FEAT_##name) * enabled |
static const_debug __maybe_unused unsigned int sysctl_sched_features =
#include "features.h"
0;
#undef SCHED_FEAT
#define sched_feat(x) !!(sysctl_sched_features & (1UL << __SCHED_FEAT_##x))
#endif /* SCHED_DEBUG */
extern struct static_key_false sched_numa_balancing;
extern struct static_key_false sched_schedstats;
static inline u64 global_rt_period(void)
{
return (u64)sysctl_sched_rt_period * NSEC_PER_USEC;
}
static inline u64 global_rt_runtime(void)
{
if (sysctl_sched_rt_runtime < 0)
return RUNTIME_INF;
return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC;
}
static inline int task_current(struct rq *rq, struct task_struct *p)
{
return rq->curr == p;
}
static inline int task_on_cpu(struct rq *rq, struct task_struct *p)
{
#ifdef CONFIG_SMP
return p->on_cpu;
#else
return task_current(rq, p);
#endif
}
static inline int task_on_rq_queued(struct task_struct *p)
{
return p->on_rq == TASK_ON_RQ_QUEUED;
}
static inline int task_on_rq_migrating(struct task_struct *p)
{
return READ_ONCE(p->on_rq) == TASK_ON_RQ_MIGRATING;
}
/* Wake flags. The first three directly map to some SD flag value */
#define WF_EXEC 0x02 /* Wakeup after exec; maps to SD_BALANCE_EXEC */
#define WF_FORK 0x04 /* Wakeup after fork; maps to SD_BALANCE_FORK */
#define WF_TTWU 0x08 /* Wakeup; maps to SD_BALANCE_WAKE */
#define WF_SYNC 0x10 /* Waker goes to sleep after wakeup */
#define WF_MIGRATED 0x20 /* Internal use, task got migrated */
#ifdef CONFIG_SMP
static_assert(WF_EXEC == SD_BALANCE_EXEC);
static_assert(WF_FORK == SD_BALANCE_FORK);
static_assert(WF_TTWU == SD_BALANCE_WAKE);
#endif
/*
* To aid in avoiding the subversion of "niceness" due to uneven distribution
* of tasks with abnormal "nice" values across CPUs the contribution that
* each task makes to its run queue's load is weighted according to its
* scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a
* scaled version of the new time slice allocation that they receive on time
* slice expiry etc.
*/
#define WEIGHT_IDLEPRIO 3
#define WMULT_IDLEPRIO 1431655765
extern const int sched_prio_to_weight[40];
extern const u32 sched_prio_to_wmult[40];
/*
* {de,en}queue flags:
*
* DEQUEUE_SLEEP - task is no longer runnable
* ENQUEUE_WAKEUP - task just became runnable
*
* SAVE/RESTORE - an otherwise spurious dequeue/enqueue, done to ensure tasks
* are in a known state which allows modification. Such pairs
* should preserve as much state as possible.
*
* MOVE - paired with SAVE/RESTORE, explicitly does not preserve the location
* in the runqueue.
*
* ENQUEUE_HEAD - place at front of runqueue (tail if not specified)
* ENQUEUE_REPLENISH - CBS (replenish runtime and postpone deadline)
* ENQUEUE_MIGRATED - the task was migrated during wakeup
*
*/
#define DEQUEUE_SLEEP 0x01
#define DEQUEUE_SAVE 0x02 /* Matches ENQUEUE_RESTORE */
#define DEQUEUE_MOVE 0x04 /* Matches ENQUEUE_MOVE */
#define DEQUEUE_NOCLOCK 0x08 /* Matches ENQUEUE_NOCLOCK */
#define ENQUEUE_WAKEUP 0x01
#define ENQUEUE_RESTORE 0x02
#define ENQUEUE_MOVE 0x04
#define ENQUEUE_NOCLOCK 0x08
#define ENQUEUE_HEAD 0x10
#define ENQUEUE_REPLENISH 0x20
#ifdef CONFIG_SMP
#define ENQUEUE_MIGRATED 0x40
#else
#define ENQUEUE_MIGRATED 0x00
#endif
#define RETRY_TASK ((void *)-1UL)
struct affinity_context {
const struct cpumask *new_mask;
struct cpumask *user_mask;
unsigned int flags;
};
struct sched_class {
#ifdef CONFIG_UCLAMP_TASK
int uclamp_enabled;
#endif
void (*enqueue_task) (struct rq *rq, struct task_struct *p, int flags);
void (*dequeue_task) (struct rq *rq, struct task_struct *p, int flags);
void (*yield_task) (struct rq *rq);
bool (*yield_to_task)(struct rq *rq, struct task_struct *p);
void (*check_preempt_curr)(struct rq *rq, struct task_struct *p, int flags);
struct task_struct *(*pick_next_task)(struct rq *rq);
void (*put_prev_task)(struct rq *rq, struct task_struct *p);
void (*set_next_task)(struct rq *rq, struct task_struct *p, bool first);
#ifdef CONFIG_SMP
int (*balance)(struct rq *rq, struct task_struct *prev, struct rq_flags *rf);
int (*select_task_rq)(struct task_struct *p, int task_cpu, int flags);
struct task_struct * (*pick_task)(struct rq *rq);
void (*migrate_task_rq)(struct task_struct *p, int new_cpu);
void (*task_woken)(struct rq *this_rq, struct task_struct *task);
void (*set_cpus_allowed)(struct task_struct *p, struct affinity_context *ctx);
void (*rq_online)(struct rq *rq);
void (*rq_offline)(struct rq *rq);
struct rq *(*find_lock_rq)(struct task_struct *p, struct rq *rq);
#endif
void (*task_tick)(struct rq *rq, struct task_struct *p, int queued);
void (*task_fork)(struct task_struct *p);
void (*task_dead)(struct task_struct *p);
/*
* The switched_from() call is allowed to drop rq->lock, therefore we
* cannot assume the switched_from/switched_to pair is serialized by
* rq->lock. They are however serialized by p->pi_lock.
*/
void (*switched_from)(struct rq *this_rq, struct task_struct *task);
void (*switched_to) (struct rq *this_rq, struct task_struct *task);
void (*prio_changed) (struct rq *this_rq, struct task_struct *task,
int oldprio);
unsigned int (*get_rr_interval)(struct rq *rq,
struct task_struct *task);
void (*update_curr)(struct rq *rq);
#ifdef CONFIG_FAIR_GROUP_SCHED
void (*task_change_group)(struct task_struct *p);
#endif
#ifdef CONFIG_SCHED_CORE
int (*task_is_throttled)(struct task_struct *p, int cpu);
#endif
};
static inline void put_prev_task(struct rq *rq, struct task_struct *prev)
{
WARN_ON_ONCE(rq->curr != prev);
prev->sched_class->put_prev_task(rq, prev);
}
static inline void set_next_task(struct rq *rq, struct task_struct *next)
{
next->sched_class->set_next_task(rq, next, false);
}
/*
* Helper to define a sched_class instance; each one is placed in a separate
* section which is ordered by the linker script:
*
* include/asm-generic/vmlinux.lds.h
*
* *CAREFUL* they are laid out in *REVERSE* order!!!
*
* Also enforce alignment on the instance, not the type, to guarantee layout.
*/
#define DEFINE_SCHED_CLASS(name) \
const struct sched_class name##_sched_class \
__aligned(__alignof__(struct sched_class)) \
__section("__" #name "_sched_class")
/* Defined in include/asm-generic/vmlinux.lds.h */
extern struct sched_class __sched_class_highest[];
extern struct sched_class __sched_class_lowest[];
#define for_class_range(class, _from, _to) \
for (class = (_from); class < (_to); class++)
#define for_each_class(class) \
for_class_range(class, __sched_class_highest, __sched_class_lowest)
#define sched_class_above(_a, _b) ((_a) < (_b))
extern const struct sched_class stop_sched_class;
extern const struct sched_class dl_sched_class;
extern const struct sched_class rt_sched_class;
extern const struct sched_class fair_sched_class;
extern const struct sched_class idle_sched_class;
static inline bool sched_stop_runnable(struct rq *rq)
{
return rq->stop && task_on_rq_queued(rq->stop);
}
static inline bool sched_dl_runnable(struct rq *rq)
{
return rq->dl.dl_nr_running > 0;
}
static inline bool sched_rt_runnable(struct rq *rq)
{
return rq->rt.rt_queued > 0;
}
static inline bool sched_fair_runnable(struct rq *rq)
{
return rq->cfs.nr_running > 0;
}
extern struct task_struct *pick_next_task_fair(struct rq *rq, struct task_struct *prev, struct rq_flags *rf);
extern struct task_struct *pick_next_task_idle(struct rq *rq);
#define SCA_CHECK 0x01
#define SCA_MIGRATE_DISABLE 0x02
#define SCA_MIGRATE_ENABLE 0x04
#define SCA_USER 0x08
#ifdef CONFIG_SMP
extern void update_group_capacity(struct sched_domain *sd, int cpu);
extern void trigger_load_balance(struct rq *rq);
extern void set_cpus_allowed_common(struct task_struct *p, struct affinity_context *ctx);
static inline struct task_struct *get_push_task(struct rq *rq)
{
struct task_struct *p = rq->curr;
lockdep_assert_rq_held(rq);
if (rq->push_busy)
return NULL;
if (p->nr_cpus_allowed == 1)
return NULL;
if (p->migration_disabled)
return NULL;
rq->push_busy = true;
return get_task_struct(p);
}
extern int push_cpu_stop(void *arg);
#endif
#ifdef CONFIG_CPU_IDLE
static inline void idle_set_state(struct rq *rq,
struct cpuidle_state *idle_state)
{
rq->idle_state = idle_state;
}
static inline struct cpuidle_state *idle_get_state(struct rq *rq)
{
SCHED_WARN_ON(!rcu_read_lock_held());
return rq->idle_state;
}
#else
static inline void idle_set_state(struct rq *rq,
struct cpuidle_state *idle_state)
{
}
static inline struct cpuidle_state *idle_get_state(struct rq *rq)
{
return NULL;
}
#endif
extern void schedule_idle(void);
extern void sysrq_sched_debug_show(void);
extern void sched_init_granularity(void);
extern void update_max_interval(void);
extern void init_sched_dl_class(void);
extern void init_sched_rt_class(void);
extern void init_sched_fair_class(void);
extern void reweight_task(struct task_struct *p, int prio);
extern void resched_curr(struct rq *rq);
extern void resched_cpu(int cpu);
extern struct rt_bandwidth def_rt_bandwidth;
extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime);
extern bool sched_rt_bandwidth_account(struct rt_rq *rt_rq);
extern void init_dl_task_timer(struct sched_dl_entity *dl_se);
extern void init_dl_inactive_task_timer(struct sched_dl_entity *dl_se);
#define BW_SHIFT 20
#define BW_UNIT (1 << BW_SHIFT)
#define RATIO_SHIFT 8
#define MAX_BW_BITS (64 - BW_SHIFT)
#define MAX_BW ((1ULL << MAX_BW_BITS) - 1)
unsigned long to_ratio(u64 period, u64 runtime);
extern void init_entity_runnable_average(struct sched_entity *se);
extern void post_init_entity_util_avg(struct task_struct *p);
#ifdef CONFIG_NO_HZ_FULL
extern bool sched_can_stop_tick(struct rq *rq);
extern int __init sched_tick_offload_init(void);
/*
* Tick may be needed by tasks in the runqueue depending on their policy and
* requirements. If tick is needed, lets send the target an IPI to kick it out of
* nohz mode if necessary.
*/
static inline void sched_update_tick_dependency(struct rq *rq)
{
int cpu = cpu_of(rq);
if (!tick_nohz_full_cpu(cpu))
return;
if (sched_can_stop_tick(rq))
tick_nohz_dep_clear_cpu(cpu, TICK_DEP_BIT_SCHED);
else
tick_nohz_dep_set_cpu(cpu, TICK_DEP_BIT_SCHED);
}
#else
static inline int sched_tick_offload_init(void) { return 0; }
static inline void sched_update_tick_dependency(struct rq *rq) { }
#endif
static inline void add_nr_running(struct rq *rq, unsigned count)
{
unsigned prev_nr = rq->nr_running;
rq->nr_running = prev_nr + count;
if (trace_sched_update_nr_running_tp_enabled()) {
call_trace_sched_update_nr_running(rq, count);
}
#ifdef CONFIG_SMP
if (prev_nr < 2 && rq->nr_running >= 2) {
if (!READ_ONCE(rq->rd->overload))
WRITE_ONCE(rq->rd->overload, 1);
}
#endif
sched_update_tick_dependency(rq);
}
static inline void sub_nr_running(struct rq *rq, unsigned count)
{
rq->nr_running -= count;
if (trace_sched_update_nr_running_tp_enabled()) {
call_trace_sched_update_nr_running(rq, -count);
}
/* Check if we still need preemption */
sched_update_tick_dependency(rq);
}
extern void activate_task(struct rq *rq, struct task_struct *p, int flags);
extern void deactivate_task(struct rq *rq, struct task_struct *p, int flags);
extern void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags);
#ifdef CONFIG_PREEMPT_RT
#define SCHED_NR_MIGRATE_BREAK 8
#else
#define SCHED_NR_MIGRATE_BREAK 32
#endif
extern const_debug unsigned int sysctl_sched_nr_migrate;
extern const_debug unsigned int sysctl_sched_migration_cost;
#ifdef CONFIG_SCHED_DEBUG
extern unsigned int sysctl_sched_latency;
extern unsigned int sysctl_sched_min_granularity;
extern unsigned int sysctl_sched_idle_min_granularity;
extern unsigned int sysctl_sched_wakeup_granularity;
extern int sysctl_resched_latency_warn_ms;
extern int sysctl_resched_latency_warn_once;
extern unsigned int sysctl_sched_tunable_scaling;
extern unsigned int sysctl_numa_balancing_scan_delay;
extern unsigned int sysctl_numa_balancing_scan_period_min;
extern unsigned int sysctl_numa_balancing_scan_period_max;
extern unsigned int sysctl_numa_balancing_scan_size;
extern unsigned int sysctl_numa_balancing_hot_threshold;
#endif
#ifdef CONFIG_SCHED_HRTICK
/*
* Use hrtick when:
* - enabled by features
* - hrtimer is actually high res
*/
static inline int hrtick_enabled(struct rq *rq)
{
if (!cpu_active(cpu_of(rq)))
return 0;
return hrtimer_is_hres_active(&rq->hrtick_timer);
}
static inline int hrtick_enabled_fair(struct rq *rq)
{
if (!sched_feat(HRTICK))
return 0;
return hrtick_enabled(rq);
}
static inline int hrtick_enabled_dl(struct rq *rq)
{
if (!sched_feat(HRTICK_DL))
return 0;
return hrtick_enabled(rq);
}
void hrtick_start(struct rq *rq, u64 delay);
#else
static inline int hrtick_enabled_fair(struct rq *rq)
{
return 0;
}
static inline int hrtick_enabled_dl(struct rq *rq)
{
return 0;
}
static inline int hrtick_enabled(struct rq *rq)
{
return 0;
}
#endif /* CONFIG_SCHED_HRTICK */
#ifndef arch_scale_freq_tick
static __always_inline
void arch_scale_freq_tick(void)
{
}
#endif
#ifndef arch_scale_freq_capacity
/**
* arch_scale_freq_capacity - get the frequency scale factor of a given CPU.
* @cpu: the CPU in question.
*
* Return: the frequency scale factor normalized against SCHED_CAPACITY_SCALE, i.e.
*
* f_curr
* ------ * SCHED_CAPACITY_SCALE
* f_max
*/
static __always_inline
unsigned long arch_scale_freq_capacity(int cpu)
{
return SCHED_CAPACITY_SCALE;
}
#endif
#ifdef CONFIG_SCHED_DEBUG
/*
* In double_lock_balance()/double_rq_lock(), we use raw_spin_rq_lock() to
* acquire rq lock instead of rq_lock(). So at the end of these two functions
* we need to call double_rq_clock_clear_update() to clear RQCF_UPDATED of
* rq->clock_update_flags to avoid the WARN_DOUBLE_CLOCK warning.
*/
static inline void double_rq_clock_clear_update(struct rq *rq1, struct rq *rq2)
{
rq1->clock_update_flags &= (RQCF_REQ_SKIP|RQCF_ACT_SKIP);
/* rq1 == rq2 for !CONFIG_SMP, so just clear RQCF_UPDATED once. */
#ifdef CONFIG_SMP
rq2->clock_update_flags &= (RQCF_REQ_SKIP|RQCF_ACT_SKIP);
#endif
}
#else
static inline void double_rq_clock_clear_update(struct rq *rq1, struct rq *rq2) {}
#endif
#ifdef CONFIG_SMP
static inline bool rq_order_less(struct rq *rq1, struct rq *rq2)
{
#ifdef CONFIG_SCHED_CORE
/*
* In order to not have {0,2},{1,3} turn into into an AB-BA,
* order by core-id first and cpu-id second.
*
* Notably:
*
* double_rq_lock(0,3); will take core-0, core-1 lock
* double_rq_lock(1,2); will take core-1, core-0 lock
*
* when only cpu-id is considered.
*/
if (rq1->core->cpu < rq2->core->cpu)
return true;
if (rq1->core->cpu > rq2->core->cpu)
return false;
/*
* __sched_core_flip() relies on SMT having cpu-id lock order.
*/
#endif
return rq1->cpu < rq2->cpu;
}
extern void double_rq_lock(struct rq *rq1, struct rq *rq2);
#ifdef CONFIG_PREEMPTION
/*
* 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_rq_unlock(this_rq);
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)
{
if (__rq_lockp(this_rq) == __rq_lockp(busiest) ||
likely(raw_spin_rq_trylock(busiest))) {
double_rq_clock_clear_update(this_rq, busiest);
return 0;
}
if (rq_order_less(this_rq, busiest)) {
raw_spin_rq_lock_nested(busiest, SINGLE_DEPTH_NESTING);
double_rq_clock_clear_update(this_rq, busiest);
return 0;
}
raw_spin_rq_unlock(this_rq);
double_rq_lock(this_rq, busiest);
return 1;
}
#endif /* CONFIG_PREEMPTION */
/*
* double_lock_balance - lock the busiest runqueue, this_rq is locked already.
*/
static inline int double_lock_balance(struct rq *this_rq, struct rq *busiest)
{
lockdep_assert_irqs_disabled();
return _double_lock_balance(this_rq, busiest);
}
static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest)
__releases(busiest->lock)
{
if (__rq_lockp(this_rq) != __rq_lockp(busiest))
raw_spin_rq_unlock(busiest);
lock_set_subclass(&__rq_lockp(this_rq)->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_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)
{
if (__rq_lockp(rq1) != __rq_lockp(rq2))
raw_spin_rq_unlock(rq2);
else
__release(rq2->lock);
raw_spin_rq_unlock(rq1);
}
extern void set_rq_online (struct rq *rq);
extern void set_rq_offline(struct rq *rq);
extern bool sched_smp_initialized;
#else /* CONFIG_SMP */
/*
* double_rq_lock - safely lock two runqueues
*
* Note this does not disable interrupts like task_rq_lock,
* you need to do so manually before calling.
*/
static inline void double_rq_lock(struct rq *rq1, struct rq *rq2)
__acquires(rq1->lock)
__acquires(rq2->lock)
{
WARN_ON_ONCE(!irqs_disabled());
WARN_ON_ONCE(rq1 != rq2);
raw_spin_rq_lock(rq1);
__acquire(rq2->lock); /* Fake it out ;) */
double_rq_clock_clear_update(rq1, rq2);
}
/*
* 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)
{
WARN_ON_ONCE(rq1 != rq2);
raw_spin_rq_unlock(rq1);
__release(rq2->lock);
}
#endif
extern struct sched_entity *__pick_first_entity(struct cfs_rq *cfs_rq);
extern struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq);
#ifdef CONFIG_SCHED_DEBUG
extern bool sched_debug_verbose;
extern void print_cfs_stats(struct seq_file *m, int cpu);
extern void print_rt_stats(struct seq_file *m, int cpu);
extern void print_dl_stats(struct seq_file *m, int cpu);
extern void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq);
extern void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq);
extern void print_dl_rq(struct seq_file *m, int cpu, struct dl_rq *dl_rq);
extern void resched_latency_warn(int cpu, u64 latency);
#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 */
#else
static inline void resched_latency_warn(int cpu, u64 latency) {}
#endif /* CONFIG_SCHED_DEBUG */
extern void init_cfs_rq(struct cfs_rq *cfs_rq);
extern void init_rt_rq(struct rt_rq *rt_rq);
extern void init_dl_rq(struct dl_rq *dl_rq);
extern void cfs_bandwidth_usage_inc(void);
extern void cfs_bandwidth_usage_dec(void);
#ifdef CONFIG_NO_HZ_COMMON
#define NOHZ_BALANCE_KICK_BIT 0
#define NOHZ_STATS_KICK_BIT 1
#define NOHZ_NEWILB_KICK_BIT 2
#define NOHZ_NEXT_KICK_BIT 3
/* Run rebalance_domains() */
#define NOHZ_BALANCE_KICK BIT(NOHZ_BALANCE_KICK_BIT)
/* Update blocked load */
#define NOHZ_STATS_KICK BIT(NOHZ_STATS_KICK_BIT)
/* Update blocked load when entering idle */
#define NOHZ_NEWILB_KICK BIT(NOHZ_NEWILB_KICK_BIT)
/* Update nohz.next_balance */
#define NOHZ_NEXT_KICK BIT(NOHZ_NEXT_KICK_BIT)
#define NOHZ_KICK_MASK (NOHZ_BALANCE_KICK | NOHZ_STATS_KICK | NOHZ_NEXT_KICK)
#define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags)
extern void nohz_balance_exit_idle(struct rq *rq);
#else
static inline void nohz_balance_exit_idle(struct rq *rq) { }
#endif
#if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON)
extern void nohz_run_idle_balance(int cpu);
#else
static inline void nohz_run_idle_balance(int cpu) { }
#endif
#ifdef CONFIG_IRQ_TIME_ACCOUNTING
struct irqtime {
u64 total;
u64 tick_delta;
u64 irq_start_time;
struct u64_stats_sync sync;
};
DECLARE_PER_CPU(struct irqtime, cpu_irqtime);
/*
* Returns the irqtime minus the softirq time computed by ksoftirqd.
* Otherwise ksoftirqd's sum_exec_runtime is subtracted its own runtime
* and never move forward.
*/
static inline u64 irq_time_read(int cpu)
{
struct irqtime *irqtime = &per_cpu(cpu_irqtime, cpu);
unsigned int seq;
u64 total;
do {
seq = __u64_stats_fetch_begin(&irqtime->sync);
total = irqtime->total;
} while (__u64_stats_fetch_retry(&irqtime->sync, seq));
return total;
}
#endif /* CONFIG_IRQ_TIME_ACCOUNTING */
#ifdef CONFIG_CPU_FREQ
DECLARE_PER_CPU(struct update_util_data __rcu *, cpufreq_update_util_data);
/**
* cpufreq_update_util - Take a note about CPU utilization changes.
* @rq: Runqueue to carry out the update for.
* @flags: Update reason flags.
*
* This function is called by the scheduler on the CPU whose utilization is
* being updated.
*
* It can only be called from RCU-sched read-side critical sections.
*
* The way cpufreq is currently arranged requires it to evaluate the CPU
* performance state (frequency/voltage) on a regular basis to prevent it from
* being stuck in a completely inadequate performance level for too long.
* That is not guaranteed to happen if the updates are only triggered from CFS
* and DL, though, because they may not be coming in if only RT tasks are
* active all the time (or there are RT tasks only).
*
* As a workaround for that issue, this function is called periodically by the
* RT sched class to trigger extra cpufreq updates to prevent it from stalling,
* but that really is a band-aid. Going forward it should be replaced with
* solutions targeted more specifically at RT tasks.
*/
static inline void cpufreq_update_util(struct rq *rq, unsigned int flags)
{
struct update_util_data *data;
data = rcu_dereference_sched(*per_cpu_ptr(&cpufreq_update_util_data,
cpu_of(rq)));
if (data)
data->func(data, rq_clock(rq), flags);
}
#else
static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) {}
#endif /* CONFIG_CPU_FREQ */
#ifdef arch_scale_freq_capacity
# ifndef arch_scale_freq_invariant
# define arch_scale_freq_invariant() true
# endif
#else
# define arch_scale_freq_invariant() false
#endif
#ifdef CONFIG_SMP
static inline unsigned long capacity_orig_of(int cpu)
{
return cpu_rq(cpu)->cpu_capacity_orig;
}
/**
* enum cpu_util_type - CPU utilization type
* @FREQUENCY_UTIL: Utilization used to select frequency
* @ENERGY_UTIL: Utilization used during energy calculation
*
* The utilization signals of all scheduling classes (CFS/RT/DL) and IRQ time
* need to be aggregated differently depending on the usage made of them. This
* enum is used within effective_cpu_util() to differentiate the types of
* utilization expected by the callers, and adjust the aggregation accordingly.
*/
enum cpu_util_type {
FREQUENCY_UTIL,
ENERGY_UTIL,
};
unsigned long effective_cpu_util(int cpu, unsigned long util_cfs,
enum cpu_util_type type,
struct task_struct *p);
/*
* Verify the fitness of task @p to run on @cpu taking into account the
* CPU original capacity and the runtime/deadline ratio of the task.
*
* The function will return true if the original capacity of @cpu is
* greater than or equal to task's deadline density right shifted by
* (BW_SHIFT - SCHED_CAPACITY_SHIFT) and false otherwise.
*/
static inline bool dl_task_fits_capacity(struct task_struct *p, int cpu)
{
unsigned long cap = arch_scale_cpu_capacity(cpu);
return cap >= p->dl.dl_density >> (BW_SHIFT - SCHED_CAPACITY_SHIFT);
}
static inline unsigned long cpu_bw_dl(struct rq *rq)
{
return (rq->dl.running_bw * SCHED_CAPACITY_SCALE) >> BW_SHIFT;
}
static inline unsigned long cpu_util_dl(struct rq *rq)
{
return READ_ONCE(rq->avg_dl.util_avg);
}
extern unsigned long cpu_util_cfs(int cpu);
extern unsigned long cpu_util_cfs_boost(int cpu);
static inline unsigned long cpu_util_rt(struct rq *rq)
{
return READ_ONCE(rq->avg_rt.util_avg);
}
#endif
#ifdef CONFIG_UCLAMP_TASK
unsigned long uclamp_eff_value(struct task_struct *p, enum uclamp_id clamp_id);
static inline unsigned long uclamp_rq_get(struct rq *rq,
enum uclamp_id clamp_id)
{
return READ_ONCE(rq->uclamp[clamp_id].value);
}
static inline void uclamp_rq_set(struct rq *rq, enum uclamp_id clamp_id,
unsigned int value)
{
WRITE_ONCE(rq->uclamp[clamp_id].value, value);
}
static inline bool uclamp_rq_is_idle(struct rq *rq)
{
return rq->uclamp_flags & UCLAMP_FLAG_IDLE;
}
/**
* uclamp_rq_util_with - clamp @util with @rq and @p effective uclamp values.
* @rq: The rq to clamp against. Must not be NULL.
* @util: The util value to clamp.
* @p: The task to clamp against. Can be NULL if you want to clamp
* against @rq only.
*
* Clamps the passed @util to the max(@rq, @p) effective uclamp values.
*
* If sched_uclamp_used static key is disabled, then just return the util
* without any clamping since uclamp aggregation at the rq level in the fast
* path is disabled, rendering this operation a NOP.
*
* Use uclamp_eff_value() if you don't care about uclamp values at rq level. It
* will return the correct effective uclamp value of the task even if the
* static key is disabled.
*/
static __always_inline
unsigned long uclamp_rq_util_with(struct rq *rq, unsigned long util,
struct task_struct *p)
{
unsigned long min_util = 0;
unsigned long max_util = 0;
if (!static_branch_likely(&sched_uclamp_used))
return util;
if (p) {
min_util = uclamp_eff_value(p, UCLAMP_MIN);
max_util = uclamp_eff_value(p, UCLAMP_MAX);
/*
* Ignore last runnable task's max clamp, as this task will
* reset it. Similarly, no need to read the rq's min clamp.
*/
if (uclamp_rq_is_idle(rq))
goto out;
}
min_util = max_t(unsigned long, min_util, uclamp_rq_get(rq, UCLAMP_MIN));
max_util = max_t(unsigned long, max_util, uclamp_rq_get(rq, UCLAMP_MAX));
out:
/*
* Since CPU's {min,max}_util clamps are MAX aggregated considering
* RUNNABLE tasks with _different_ clamps, we can end up with an
* inversion. Fix it now when the clamps are applied.
*/
if (unlikely(min_util >= max_util))
return min_util;
return clamp(util, min_util, max_util);
}
/* Is the rq being capped/throttled by uclamp_max? */
static inline bool uclamp_rq_is_capped(struct rq *rq)
{
unsigned long rq_util;
unsigned long max_util;
if (!static_branch_likely(&sched_uclamp_used))
return false;
rq_util = cpu_util_cfs(cpu_of(rq)) + cpu_util_rt(rq);
max_util = READ_ONCE(rq->uclamp[UCLAMP_MAX].value);
return max_util != SCHED_CAPACITY_SCALE && rq_util >= max_util;
}
/*
* When uclamp is compiled in, the aggregation at rq level is 'turned off'
* by default in the fast path and only gets turned on once userspace performs
* an operation that requires it.
*
* Returns true if userspace opted-in to use uclamp and aggregation at rq level
* hence is active.
*/
static inline bool uclamp_is_used(void)
{
return static_branch_likely(&sched_uclamp_used);
}
#else /* CONFIG_UCLAMP_TASK */
static inline unsigned long uclamp_eff_value(struct task_struct *p,
enum uclamp_id clamp_id)
{
if (clamp_id == UCLAMP_MIN)
return 0;
return SCHED_CAPACITY_SCALE;
}
static inline
unsigned long uclamp_rq_util_with(struct rq *rq, unsigned long util,
struct task_struct *p)
{
return util;
}
static inline bool uclamp_rq_is_capped(struct rq *rq) { return false; }
static inline bool uclamp_is_used(void)
{
return false;
}
static inline unsigned long uclamp_rq_get(struct rq *rq,
enum uclamp_id clamp_id)
{
if (clamp_id == UCLAMP_MIN)
return 0;
return SCHED_CAPACITY_SCALE;
}
static inline void uclamp_rq_set(struct rq *rq, enum uclamp_id clamp_id,
unsigned int value)
{
}
static inline bool uclamp_rq_is_idle(struct rq *rq)
{
return false;
}
#endif /* CONFIG_UCLAMP_TASK */
#ifdef CONFIG_HAVE_SCHED_AVG_IRQ
static inline unsigned long cpu_util_irq(struct rq *rq)
{
return rq->avg_irq.util_avg;
}
static inline
unsigned long scale_irq_capacity(unsigned long util, unsigned long irq, unsigned long max)
{
util *= (max - irq);
util /= max;
return util;
}
#else
static inline unsigned long cpu_util_irq(struct rq *rq)
{
return 0;
}
static inline
unsigned long scale_irq_capacity(unsigned long util, unsigned long irq, unsigned long max)
{
return util;
}
#endif
#if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_CPU_FREQ_GOV_SCHEDUTIL)
#define perf_domain_span(pd) (to_cpumask(((pd)->em_pd->cpus)))
DECLARE_STATIC_KEY_FALSE(sched_energy_present);
static inline bool sched_energy_enabled(void)
{
return static_branch_unlikely(&sched_energy_present);
}
#else /* ! (CONFIG_ENERGY_MODEL && CONFIG_CPU_FREQ_GOV_SCHEDUTIL) */
#define perf_domain_span(pd) NULL
static inline bool sched_energy_enabled(void) { return false; }
#endif /* CONFIG_ENERGY_MODEL && CONFIG_CPU_FREQ_GOV_SCHEDUTIL */
#ifdef CONFIG_MEMBARRIER
/*
* The scheduler provides memory barriers required by membarrier between:
* - prior user-space memory accesses and store to rq->membarrier_state,
* - store to rq->membarrier_state and following user-space memory accesses.
* In the same way it provides those guarantees around store to rq->curr.
*/
static inline void membarrier_switch_mm(struct rq *rq,
struct mm_struct *prev_mm,
struct mm_struct *next_mm)
{
int membarrier_state;
if (prev_mm == next_mm)
return;
membarrier_state = atomic_read(&next_mm->membarrier_state);
if (READ_ONCE(rq->membarrier_state) == membarrier_state)
return;
WRITE_ONCE(rq->membarrier_state, membarrier_state);
}
#else
static inline void membarrier_switch_mm(struct rq *rq,
struct mm_struct *prev_mm,
struct mm_struct *next_mm)
{
}
#endif
#ifdef CONFIG_SMP
static inline bool is_per_cpu_kthread(struct task_struct *p)
{
if (!(p->flags & PF_KTHREAD))
return false;
if (p->nr_cpus_allowed != 1)
return false;
return true;
}
#endif
extern void swake_up_all_locked(struct swait_queue_head *q);
extern void __prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait);
#ifdef CONFIG_PREEMPT_DYNAMIC
extern int preempt_dynamic_mode;
extern int sched_dynamic_mode(const char *str);
extern void sched_dynamic_update(int mode);
#endif
static inline void update_current_exec_runtime(struct task_struct *curr,
u64 now, u64 delta_exec)
{
curr->se.sum_exec_runtime += delta_exec;
account_group_exec_runtime(curr, delta_exec);
curr->se.exec_start = now;
cgroup_account_cputime(curr, delta_exec);
}
#ifdef CONFIG_SCHED_MM_CID
#define SCHED_MM_CID_PERIOD_NS (100ULL * 1000000) /* 100ms */
#define MM_CID_SCAN_DELAY 100 /* 100ms */
extern raw_spinlock_t cid_lock;
extern int use_cid_lock;
extern void sched_mm_cid_migrate_from(struct task_struct *t);
extern void sched_mm_cid_migrate_to(struct rq *dst_rq, struct task_struct *t);
extern void task_tick_mm_cid(struct rq *rq, struct task_struct *curr);
extern void init_sched_mm_cid(struct task_struct *t);
static inline void __mm_cid_put(struct mm_struct *mm, int cid)
{
if (cid < 0)
return;
cpumask_clear_cpu(cid, mm_cidmask(mm));
}
/*
* The per-mm/cpu cid can have the MM_CID_LAZY_PUT flag set or transition to
* the MM_CID_UNSET state without holding the rq lock, but the rq lock needs to
* be held to transition to other states.
*
* State transitions synchronized with cmpxchg or try_cmpxchg need to be
* consistent across cpus, which prevents use of this_cpu_cmpxchg.
*/
static inline void mm_cid_put_lazy(struct task_struct *t)
{
struct mm_struct *mm = t->mm;
struct mm_cid __percpu *pcpu_cid = mm->pcpu_cid;
int cid;
lockdep_assert_irqs_disabled();
cid = __this_cpu_read(pcpu_cid->cid);
if (!mm_cid_is_lazy_put(cid) ||
!try_cmpxchg(&this_cpu_ptr(pcpu_cid)->cid, &cid, MM_CID_UNSET))
return;
__mm_cid_put(mm, mm_cid_clear_lazy_put(cid));
}
static inline int mm_cid_pcpu_unset(struct mm_struct *mm)
{
struct mm_cid __percpu *pcpu_cid = mm->pcpu_cid;
int cid, res;
lockdep_assert_irqs_disabled();
cid = __this_cpu_read(pcpu_cid->cid);
for (;;) {
if (mm_cid_is_unset(cid))
return MM_CID_UNSET;
/*
* Attempt transition from valid or lazy-put to unset.
*/
res = cmpxchg(&this_cpu_ptr(pcpu_cid)->cid, cid, MM_CID_UNSET);
if (res == cid)
break;
cid = res;
}
return cid;
}
static inline void mm_cid_put(struct mm_struct *mm)
{
int cid;
lockdep_assert_irqs_disabled();
cid = mm_cid_pcpu_unset(mm);
if (cid == MM_CID_UNSET)
return;
__mm_cid_put(mm, mm_cid_clear_lazy_put(cid));
}
static inline int __mm_cid_try_get(struct mm_struct *mm)
{
struct cpumask *cpumask;
int cid;
cpumask = mm_cidmask(mm);
/*
* Retry finding first zero bit if the mask is temporarily
* filled. This only happens during concurrent remote-clear
* which owns a cid without holding a rq lock.
*/
for (;;) {
cid = cpumask_first_zero(cpumask);
if (cid < nr_cpu_ids)
break;
cpu_relax();
}
if (cpumask_test_and_set_cpu(cid, cpumask))
return -1;
return cid;
}
/*
* Save a snapshot of the current runqueue time of this cpu
* with the per-cpu cid value, allowing to estimate how recently it was used.
*/
static inline void mm_cid_snapshot_time(struct rq *rq, struct mm_struct *mm)
{
struct mm_cid *pcpu_cid = per_cpu_ptr(mm->pcpu_cid, cpu_of(rq));
lockdep_assert_rq_held(rq);
WRITE_ONCE(pcpu_cid->time, rq->clock);
}
static inline int __mm_cid_get(struct rq *rq, struct mm_struct *mm)
{
int cid;
/*
* All allocations (even those using the cid_lock) are lock-free. If
* use_cid_lock is set, hold the cid_lock to perform cid allocation to
* guarantee forward progress.
*/
if (!READ_ONCE(use_cid_lock)) {
cid = __mm_cid_try_get(mm);
if (cid >= 0)
goto end;
raw_spin_lock(&cid_lock);
} else {
raw_spin_lock(&cid_lock);
cid = __mm_cid_try_get(mm);
if (cid >= 0)
goto unlock;
}
/*
* cid concurrently allocated. Retry while forcing following
* allocations to use the cid_lock to ensure forward progress.
*/
WRITE_ONCE(use_cid_lock, 1);
/*
* Set use_cid_lock before allocation. Only care about program order
* because this is only required for forward progress.
*/
barrier();
/*
* Retry until it succeeds. It is guaranteed to eventually succeed once
* all newcoming allocations observe the use_cid_lock flag set.
*/
do {
cid = __mm_cid_try_get(mm);
cpu_relax();
} while (cid < 0);
/*
* Allocate before clearing use_cid_lock. Only care about
* program order because this is for forward progress.
*/
barrier();
WRITE_ONCE(use_cid_lock, 0);
unlock:
raw_spin_unlock(&cid_lock);
end:
mm_cid_snapshot_time(rq, mm);
return cid;
}
static inline int mm_cid_get(struct rq *rq, struct mm_struct *mm)
{
struct mm_cid __percpu *pcpu_cid = mm->pcpu_cid;
struct cpumask *cpumask;
int cid;
lockdep_assert_rq_held(rq);
cpumask = mm_cidmask(mm);
cid = __this_cpu_read(pcpu_cid->cid);
if (mm_cid_is_valid(cid)) {
mm_cid_snapshot_time(rq, mm);
return cid;
}
if (mm_cid_is_lazy_put(cid)) {
if (try_cmpxchg(&this_cpu_ptr(pcpu_cid)->cid, &cid, MM_CID_UNSET))
__mm_cid_put(mm, mm_cid_clear_lazy_put(cid));
}
cid = __mm_cid_get(rq, mm);
__this_cpu_write(pcpu_cid->cid, cid);
return cid;
}
static inline void switch_mm_cid(struct rq *rq,
struct task_struct *prev,
struct task_struct *next)
{
/*
* Provide a memory barrier between rq->curr store and load of
* {prev,next}->mm->pcpu_cid[cpu] on rq->curr->mm transition.
*
* Should be adapted if context_switch() is modified.
*/
if (!next->mm) { // to kernel
/*
* user -> kernel transition does not guarantee a barrier, but
* we can use the fact that it performs an atomic operation in
* mmgrab().
*/
if (prev->mm) // from user
smp_mb__after_mmgrab();
/*
* kernel -> kernel transition does not change rq->curr->mm
* state. It stays NULL.
*/
} else { // to user
/*
* kernel -> user transition does not provide a barrier
* between rq->curr store and load of {prev,next}->mm->pcpu_cid[cpu].
* Provide it here.
*/
if (!prev->mm) // from kernel
smp_mb();
/*
* user -> user transition guarantees a memory barrier through
* switch_mm() when current->mm changes. If current->mm is
* unchanged, no barrier is needed.
*/
}
if (prev->mm_cid_active) {
mm_cid_snapshot_time(rq, prev->mm);
mm_cid_put_lazy(prev);
prev->mm_cid = -1;
}
if (next->mm_cid_active)
next->last_mm_cid = next->mm_cid = mm_cid_get(rq, next->mm);
}
#else
static inline void switch_mm_cid(struct rq *rq, struct task_struct *prev, struct task_struct *next) { }
static inline void sched_mm_cid_migrate_from(struct task_struct *t) { }
static inline void sched_mm_cid_migrate_to(struct rq *dst_rq, struct task_struct *t) { }
static inline void task_tick_mm_cid(struct rq *rq, struct task_struct *curr) { }
static inline void init_sched_mm_cid(struct task_struct *t) { }
#endif
#endif /* _KERNEL_SCHED_SCHED_H */
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