![Peter Zijlstra](/assets/img/avatar_default.png)
While investigating why the load-balancer did funny I found that the rq->cpu_load[] tables were completely screwy.. a bit more digging revealed that the updates that got through were missing ticks followed by a catchup of 2 ticks. The catchup assumes the cpu was idle during that time (since only nohz can cause missed ticks and the machine is idle etc..) this means that esp. the higher indices were significantly lower than they ought to be. The reason for this is that its not correct to compare against jiffies on every jiffy on any other cpu than the cpu that updates jiffies. This patch cludges around it by only doing the catch-up stuff from nohz_idle_balance() and doing the regular stuff unconditionally from the tick. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: pjt@google.com Cc: Venkatesh Pallipadi <venki@google.com> Link: http://lkml.kernel.org/n/tip-tp4kj18xdd5aj4vvj0qg55s2@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
1159 lines
30 KiB
C
1159 lines
30 KiB
C
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#include <linux/sched.h>
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#include <linux/mutex.h>
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#include <linux/spinlock.h>
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#include <linux/stop_machine.h>
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#include "cpupri.h"
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extern __read_mostly int scheduler_running;
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/*
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* Convert user-nice values [ -20 ... 0 ... 19 ]
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* to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ],
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* and back.
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*/
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#define NICE_TO_PRIO(nice) (MAX_RT_PRIO + (nice) + 20)
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#define PRIO_TO_NICE(prio) ((prio) - MAX_RT_PRIO - 20)
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#define TASK_NICE(p) PRIO_TO_NICE((p)->static_prio)
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/*
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* 'User priority' is the nice value converted to something we
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* can work with better when scaling various scheduler parameters,
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* it's a [ 0 ... 39 ] range.
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*/
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#define USER_PRIO(p) ((p)-MAX_RT_PRIO)
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#define TASK_USER_PRIO(p) USER_PRIO((p)->static_prio)
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#define MAX_USER_PRIO (USER_PRIO(MAX_PRIO))
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/*
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* Helpers for converting nanosecond timing to jiffy resolution
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*/
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#define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ))
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#define NICE_0_LOAD SCHED_LOAD_SCALE
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#define NICE_0_SHIFT SCHED_LOAD_SHIFT
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/*
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* These are the 'tuning knobs' of the scheduler:
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*/
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/*
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* single value that denotes runtime == period, ie unlimited time.
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*/
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#define RUNTIME_INF ((u64)~0ULL)
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static inline int rt_policy(int policy)
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{
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if (policy == SCHED_FIFO || policy == SCHED_RR)
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return 1;
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return 0;
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}
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static inline int task_has_rt_policy(struct task_struct *p)
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{
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return rt_policy(p->policy);
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}
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/*
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* This is the priority-queue data structure of the RT scheduling class:
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*/
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struct rt_prio_array {
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DECLARE_BITMAP(bitmap, MAX_RT_PRIO+1); /* include 1 bit for delimiter */
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struct list_head queue[MAX_RT_PRIO];
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};
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struct rt_bandwidth {
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/* nests inside the rq lock: */
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raw_spinlock_t rt_runtime_lock;
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ktime_t rt_period;
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u64 rt_runtime;
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struct hrtimer rt_period_timer;
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};
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extern struct mutex sched_domains_mutex;
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#ifdef CONFIG_CGROUP_SCHED
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#include <linux/cgroup.h>
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struct cfs_rq;
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struct rt_rq;
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static LIST_HEAD(task_groups);
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struct cfs_bandwidth {
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#ifdef CONFIG_CFS_BANDWIDTH
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raw_spinlock_t lock;
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ktime_t period;
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u64 quota, runtime;
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s64 hierarchal_quota;
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u64 runtime_expires;
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int idle, timer_active;
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struct hrtimer period_timer, slack_timer;
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struct list_head throttled_cfs_rq;
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/* statistics */
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int nr_periods, nr_throttled;
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u64 throttled_time;
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#endif
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};
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/* task group related information */
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struct task_group {
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struct cgroup_subsys_state css;
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#ifdef CONFIG_FAIR_GROUP_SCHED
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/* schedulable entities of this group on each cpu */
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struct sched_entity **se;
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/* runqueue "owned" by this group on each cpu */
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struct cfs_rq **cfs_rq;
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unsigned long shares;
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atomic_t load_weight;
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#endif
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#ifdef CONFIG_RT_GROUP_SCHED
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struct sched_rt_entity **rt_se;
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struct rt_rq **rt_rq;
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struct rt_bandwidth rt_bandwidth;
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#endif
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struct rcu_head rcu;
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struct list_head list;
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struct task_group *parent;
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struct list_head siblings;
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struct list_head children;
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#ifdef CONFIG_SCHED_AUTOGROUP
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struct autogroup *autogroup;
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#endif
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struct cfs_bandwidth cfs_bandwidth;
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};
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#ifdef CONFIG_FAIR_GROUP_SCHED
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#define ROOT_TASK_GROUP_LOAD NICE_0_LOAD
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/*
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* A weight of 0 or 1 can cause arithmetics problems.
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* A weight of a cfs_rq is the sum of weights of which entities
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* are queued on this cfs_rq, so a weight of a entity should not be
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* too large, so as the shares value of a task group.
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* (The default weight is 1024 - so there's no practical
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* limitation from this.)
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*/
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#define MIN_SHARES (1UL << 1)
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#define MAX_SHARES (1UL << 18)
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#endif
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/* Default task group.
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* Every task in system belong to this group at bootup.
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*/
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extern struct task_group root_task_group;
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typedef int (*tg_visitor)(struct task_group *, void *);
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extern int walk_tg_tree_from(struct task_group *from,
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tg_visitor down, tg_visitor up, void *data);
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/*
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* Iterate the full tree, calling @down when first entering a node and @up when
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* leaving it for the final time.
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*
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* Caller must hold rcu_lock or sufficient equivalent.
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*/
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static inline int walk_tg_tree(tg_visitor down, tg_visitor up, void *data)
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{
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return walk_tg_tree_from(&root_task_group, down, up, data);
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}
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extern int tg_nop(struct task_group *tg, void *data);
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extern void free_fair_sched_group(struct task_group *tg);
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extern int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent);
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extern void unregister_fair_sched_group(struct task_group *tg, int cpu);
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extern void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq,
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struct sched_entity *se, int cpu,
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struct sched_entity *parent);
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extern void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b);
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extern int sched_group_set_shares(struct task_group *tg, unsigned long shares);
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extern void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b);
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extern void __start_cfs_bandwidth(struct cfs_bandwidth *cfs_b);
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extern void unthrottle_cfs_rq(struct cfs_rq *cfs_rq);
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extern void free_rt_sched_group(struct task_group *tg);
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extern int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent);
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extern void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq,
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struct sched_rt_entity *rt_se, int cpu,
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struct sched_rt_entity *parent);
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#else /* CONFIG_CGROUP_SCHED */
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struct cfs_bandwidth { };
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#endif /* CONFIG_CGROUP_SCHED */
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/* CFS-related fields in a runqueue */
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struct cfs_rq {
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struct load_weight load;
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unsigned int nr_running, h_nr_running;
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u64 exec_clock;
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u64 min_vruntime;
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#ifndef CONFIG_64BIT
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u64 min_vruntime_copy;
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#endif
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struct rb_root tasks_timeline;
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struct rb_node *rb_leftmost;
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/*
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* 'curr' points to currently running entity on this cfs_rq.
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* It is set to NULL otherwise (i.e when none are currently running).
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*/
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struct sched_entity *curr, *next, *last, *skip;
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#ifdef CONFIG_SCHED_DEBUG
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unsigned int nr_spread_over;
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#endif
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#ifdef CONFIG_FAIR_GROUP_SCHED
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struct rq *rq; /* cpu runqueue to which this cfs_rq is attached */
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/*
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* leaf cfs_rqs are those that hold tasks (lowest schedulable entity in
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* a hierarchy). Non-leaf lrqs hold other higher schedulable entities
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* (like users, containers etc.)
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*
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* leaf_cfs_rq_list ties together list of leaf cfs_rq's in a cpu. This
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* list is used during load balance.
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*/
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int on_list;
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struct list_head leaf_cfs_rq_list;
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struct task_group *tg; /* group that "owns" this runqueue */
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#ifdef CONFIG_SMP
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/*
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* h_load = weight * f(tg)
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*
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* Where f(tg) is the recursive weight fraction assigned to
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* this group.
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*/
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unsigned long h_load;
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/*
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* Maintaining per-cpu shares distribution for group scheduling
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*
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* load_stamp is the last time we updated the load average
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* load_last is the last time we updated the load average and saw load
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* load_unacc_exec_time is currently unaccounted execution time
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*/
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u64 load_avg;
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u64 load_period;
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u64 load_stamp, load_last, load_unacc_exec_time;
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unsigned long load_contribution;
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#endif /* CONFIG_SMP */
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#ifdef CONFIG_CFS_BANDWIDTH
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int runtime_enabled;
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u64 runtime_expires;
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s64 runtime_remaining;
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u64 throttled_timestamp;
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int throttled, throttle_count;
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struct list_head throttled_list;
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#endif /* CONFIG_CFS_BANDWIDTH */
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#endif /* CONFIG_FAIR_GROUP_SCHED */
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};
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static inline int rt_bandwidth_enabled(void)
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{
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return sysctl_sched_rt_runtime >= 0;
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}
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/* Real-Time classes' related field in a runqueue: */
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struct rt_rq {
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struct rt_prio_array active;
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unsigned int rt_nr_running;
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#if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
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struct {
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int curr; /* highest queued rt task prio */
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#ifdef CONFIG_SMP
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int next; /* next highest */
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#endif
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} highest_prio;
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#endif
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#ifdef CONFIG_SMP
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unsigned long rt_nr_migratory;
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unsigned long rt_nr_total;
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int overloaded;
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struct plist_head pushable_tasks;
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#endif
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int rt_throttled;
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u64 rt_time;
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u64 rt_runtime;
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/* Nests inside the rq lock: */
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raw_spinlock_t rt_runtime_lock;
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#ifdef CONFIG_RT_GROUP_SCHED
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unsigned long rt_nr_boosted;
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struct rq *rq;
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struct list_head leaf_rt_rq_list;
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struct task_group *tg;
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#endif
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};
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#ifdef CONFIG_SMP
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/*
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* We add the notion of a root-domain which will be used to define per-domain
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* variables. Each exclusive cpuset essentially defines an island domain by
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* fully partitioning the member cpus from any other cpuset. Whenever a new
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* exclusive cpuset is created, we also create and attach a new root-domain
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* object.
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*
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*/
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struct root_domain {
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atomic_t refcount;
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atomic_t rto_count;
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struct rcu_head rcu;
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cpumask_var_t span;
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cpumask_var_t online;
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/*
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* The "RT overload" flag: it gets set if a CPU has more than
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* one runnable RT task.
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*/
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cpumask_var_t rto_mask;
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struct cpupri cpupri;
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};
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extern struct root_domain def_root_domain;
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#endif /* CONFIG_SMP */
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/*
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* This is the main, per-CPU runqueue data structure.
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*
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* Locking rule: those places that want to lock multiple runqueues
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* (such as the load balancing or the thread migration code), lock
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* acquire operations must be ordered by ascending &runqueue.
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*/
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struct rq {
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/* runqueue lock: */
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raw_spinlock_t lock;
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/*
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* nr_running and cpu_load should be in the same cacheline because
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* remote CPUs use both these fields when doing load calculation.
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*/
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unsigned int nr_running;
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#define CPU_LOAD_IDX_MAX 5
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unsigned long cpu_load[CPU_LOAD_IDX_MAX];
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unsigned long last_load_update_tick;
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#ifdef CONFIG_NO_HZ
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u64 nohz_stamp;
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unsigned long nohz_flags;
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#endif
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int skip_clock_update;
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/* capture load from *all* tasks on this cpu: */
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struct load_weight load;
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unsigned long nr_load_updates;
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u64 nr_switches;
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struct cfs_rq cfs;
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struct rt_rq rt;
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#ifdef CONFIG_FAIR_GROUP_SCHED
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/* list of leaf cfs_rq on this cpu: */
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struct list_head leaf_cfs_rq_list;
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#endif
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#ifdef CONFIG_RT_GROUP_SCHED
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struct list_head leaf_rt_rq_list;
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#endif
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/*
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* This is part of a global counter where only the total sum
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* over all CPUs matters. A task can increase this counter on
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* one CPU and if it got migrated afterwards it may decrease
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* it on another CPU. Always updated under the runqueue lock:
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*/
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unsigned long nr_uninterruptible;
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struct task_struct *curr, *idle, *stop;
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unsigned long next_balance;
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struct mm_struct *prev_mm;
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u64 clock;
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u64 clock_task;
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atomic_t nr_iowait;
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#ifdef CONFIG_SMP
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struct root_domain *rd;
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struct sched_domain *sd;
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unsigned long cpu_power;
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unsigned char idle_balance;
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/* For active balancing */
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int post_schedule;
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int active_balance;
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int push_cpu;
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struct cpu_stop_work active_balance_work;
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/* cpu of this runqueue: */
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int cpu;
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int online;
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struct list_head cfs_tasks;
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u64 rt_avg;
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u64 age_stamp;
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u64 idle_stamp;
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u64 avg_idle;
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#endif
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#ifdef CONFIG_IRQ_TIME_ACCOUNTING
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u64 prev_irq_time;
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#endif
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#ifdef CONFIG_PARAVIRT
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u64 prev_steal_time;
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#endif
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#ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING
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u64 prev_steal_time_rq;
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#endif
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/* calc_load related fields */
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unsigned long calc_load_update;
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long calc_load_active;
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#ifdef CONFIG_SCHED_HRTICK
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#ifdef CONFIG_SMP
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int hrtick_csd_pending;
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struct call_single_data hrtick_csd;
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#endif
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struct hrtimer hrtick_timer;
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#endif
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#ifdef CONFIG_SCHEDSTATS
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/* latency stats */
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struct sched_info rq_sched_info;
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unsigned long long rq_cpu_time;
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/* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */
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/* sys_sched_yield() stats */
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unsigned int yld_count;
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/* schedule() stats */
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unsigned int sched_count;
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unsigned int sched_goidle;
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/* try_to_wake_up() stats */
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unsigned int ttwu_count;
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unsigned int ttwu_local;
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#endif
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#ifdef CONFIG_SMP
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struct llist_head wake_list;
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#endif
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};
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static inline int cpu_of(struct rq *rq)
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{
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#ifdef CONFIG_SMP
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return rq->cpu;
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#else
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return 0;
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#endif
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}
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DECLARE_PER_CPU(struct rq, runqueues);
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#define cpu_rq(cpu) (&per_cpu(runqueues, (cpu)))
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#define this_rq() (&__get_cpu_var(runqueues))
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#define task_rq(p) cpu_rq(task_cpu(p))
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#define cpu_curr(cpu) (cpu_rq(cpu)->curr)
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#define raw_rq() (&__raw_get_cpu_var(runqueues))
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#ifdef CONFIG_SMP
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#define rcu_dereference_check_sched_domain(p) \
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rcu_dereference_check((p), \
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lockdep_is_held(&sched_domains_mutex))
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/*
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* The domain tree (rq->sd) is protected by RCU's quiescent state transition.
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* See detach_destroy_domains: synchronize_sched for details.
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*
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* The domain tree of any CPU may only be accessed from within
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* preempt-disabled sections.
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*/
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#define for_each_domain(cpu, __sd) \
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for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); \
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__sd; __sd = __sd->parent)
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#define for_each_lower_domain(sd) for (; sd; sd = sd->child)
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/**
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* highest_flag_domain - Return highest sched_domain containing flag.
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* @cpu: The cpu whose highest level of sched domain is to
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* be returned.
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* @flag: The flag to check for the highest sched_domain
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* for the given cpu.
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*
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* Returns the highest sched_domain of a cpu which contains the given flag.
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*/
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static inline struct sched_domain *highest_flag_domain(int cpu, int flag)
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{
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struct sched_domain *sd, *hsd = NULL;
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for_each_domain(cpu, sd) {
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if (!(sd->flags & flag))
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break;
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hsd = sd;
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}
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return hsd;
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}
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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_idle_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
|