#define CREATE_TRACE_POINTS
#include <trace/events/sched.h>
-void start_bandwidth_timer(struct hrtimer *period_timer, ktime_t period)
-{
- unsigned long delta;
- ktime_t soft, hard, now;
-
- for (;;) {
- if (hrtimer_active(period_timer))
- break;
-
- now = hrtimer_cb_get_time(period_timer);
- hrtimer_forward(period_timer, now, period);
-
- soft = hrtimer_get_softexpires(period_timer);
- hard = hrtimer_get_expires(period_timer);
- delta = ktime_to_ns(ktime_sub(hard, soft));
- __hrtimer_start_range_ns(period_timer, soft, delta,
- HRTIMER_MODE_ABS_PINNED, 0);
- }
-}
-
DEFINE_MUTEX(sched_domains_mutex);
DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
#ifdef CONFIG_SMP
-static int __hrtick_restart(struct rq *rq)
+static void __hrtick_restart(struct rq *rq)
{
struct hrtimer *timer = &rq->hrtick_timer;
- ktime_t time = hrtimer_get_softexpires(timer);
- return __hrtimer_start_range_ns(timer, time, 0, HRTIMER_MODE_ABS_PINNED, 0);
+ hrtimer_start_expires(timer, HRTIMER_MODE_ABS_PINNED);
}
/*
* doesn't make sense. Rely on vruntime for fairness.
*/
delay = max_t(u64, delay, 10000LL);
- __hrtimer_start_range_ns(&rq->hrtick_timer, ns_to_ktime(delay), 0,
- HRTIMER_MODE_REL_PINNED, 0);
+ hrtimer_start(&rq->hrtick_timer, ns_to_ktime(delay),
+ HRTIMER_MODE_REL_PINNED);
}
static inline void init_hrtick(void)
static bool set_nr_if_polling(struct task_struct *p)
{
struct thread_info *ti = task_thread_info(p);
- typeof(ti->flags) old, val = ACCESS_ONCE(ti->flags);
+ typeof(ti->flags) old, val = READ_ONCE(ti->flags);
for (;;) {
if (!(val & _TIF_POLLING_NRFLAG))
#endif
#endif
+void wake_q_add(struct wake_q_head *head, struct task_struct *task)
+{
+ struct wake_q_node *node = &task->wake_q;
+
+ /*
+ * Atomically grab the task, if ->wake_q is !nil already it means
+ * its already queued (either by us or someone else) and will get the
+ * wakeup due to that.
+ *
+ * This cmpxchg() implies a full barrier, which pairs with the write
+ * barrier implied by the wakeup in wake_up_list().
+ */
+ if (cmpxchg(&node->next, NULL, WAKE_Q_TAIL))
+ return;
+
+ get_task_struct(task);
+
+ /*
+ * The head is context local, there can be no concurrency.
+ */
+ *head->lastp = node;
+ head->lastp = &node->next;
+}
+
+void wake_up_q(struct wake_q_head *head)
+{
+ struct wake_q_node *node = head->first;
+
+ while (node != WAKE_Q_TAIL) {
+ struct task_struct *task;
+
+ task = container_of(node, struct task_struct, wake_q);
+ BUG_ON(!task);
+ /* task can safely be re-inserted now */
+ node = node->next;
+ task->wake_q.next = NULL;
+
+ /*
+ * wake_up_process() implies a wmb() to pair with the queueing
+ * in wake_q_add() so as not to miss wakeups.
+ */
+ wake_up_process(task);
+ put_task_struct(task);
+ }
+}
+
/*
* resched_curr - mark rq's current task 'to be rescheduled now'.
*
* selecting an idle cpu will add more delays to the timers than intended
* (as that cpu's timer base may not be uptodate wrt jiffies etc).
*/
-int get_nohz_timer_target(int pinned)
+int get_nohz_timer_target(void)
{
- int cpu = smp_processor_id();
- int i;
+ int i, cpu = smp_processor_id();
struct sched_domain *sd;
- if (pinned || !get_sysctl_timer_migration() || !idle_cpu(cpu))
+ if (!idle_cpu(cpu))
return cpu;
rcu_read_lock();
if (p->sched_class->migrate_task_rq)
p->sched_class->migrate_task_rq(p, new_cpu);
p->se.nr_migrations++;
- perf_sw_event_sched(PERF_COUNT_SW_CPU_MIGRATIONS, 1, 0);
+ perf_event_task_migrate(p);
}
__set_task_cpu(p, new_cpu);
#ifdef CONFIG_PREEMPT_NOTIFIERS
+static struct static_key preempt_notifier_key = STATIC_KEY_INIT_FALSE;
+
/**
* preempt_notifier_register - tell me when current is being preempted & rescheduled
* @notifier: notifier struct to register
*/
void preempt_notifier_register(struct preempt_notifier *notifier)
{
+ static_key_slow_inc(&preempt_notifier_key);
hlist_add_head(¬ifier->link, ¤t->preempt_notifiers);
}
EXPORT_SYMBOL_GPL(preempt_notifier_register);
* preempt_notifier_unregister - no longer interested in preemption notifications
* @notifier: notifier struct to unregister
*
- * This is safe to call from within a preemption notifier.
+ * This is *not* safe to call from within a preemption notifier.
*/
void preempt_notifier_unregister(struct preempt_notifier *notifier)
{
hlist_del(¬ifier->link);
+ static_key_slow_dec(&preempt_notifier_key);
}
EXPORT_SYMBOL_GPL(preempt_notifier_unregister);
-static void fire_sched_in_preempt_notifiers(struct task_struct *curr)
+static void __fire_sched_in_preempt_notifiers(struct task_struct *curr)
{
struct preempt_notifier *notifier;
notifier->ops->sched_in(notifier, raw_smp_processor_id());
}
+static __always_inline void fire_sched_in_preempt_notifiers(struct task_struct *curr)
+{
+ if (static_key_false(&preempt_notifier_key))
+ __fire_sched_in_preempt_notifiers(curr);
+}
+
static void
-fire_sched_out_preempt_notifiers(struct task_struct *curr,
- struct task_struct *next)
+__fire_sched_out_preempt_notifiers(struct task_struct *curr,
+ struct task_struct *next)
{
struct preempt_notifier *notifier;
notifier->ops->sched_out(notifier, next);
}
+static __always_inline void
+fire_sched_out_preempt_notifiers(struct task_struct *curr,
+ struct task_struct *next)
+{
+ if (static_key_false(&preempt_notifier_key))
+ __fire_sched_out_preempt_notifiers(curr, next);
+}
+
#else /* !CONFIG_PREEMPT_NOTIFIERS */
-static void fire_sched_in_preempt_notifiers(struct task_struct *curr)
+static inline void fire_sched_in_preempt_notifiers(struct task_struct *curr)
{
}
-static void
+static inline void
fire_sched_out_preempt_notifiers(struct task_struct *curr,
struct task_struct *next)
{
void get_iowait_load(unsigned long *nr_waiters, unsigned long *load)
{
- struct rq *this = this_rq();
- *nr_waiters = atomic_read(&this->nr_iowait);
- *load = this->cpu_load[0];
+ struct rq *rq = this_rq();
+ *nr_waiters = atomic_read(&rq->nr_iowait);
+ *load = rq->load.weight;
}
#ifdef CONFIG_SMP
update_rq_clock(rq);
curr->sched_class->task_tick(rq, curr, 0);
update_cpu_load_active(rq);
+ calc_global_load_tick(rq);
raw_spin_unlock(&rq->lock);
perf_event_task_tick();
u64 scheduler_tick_max_deferment(void)
{
struct rq *rq = this_rq();
- unsigned long next, now = ACCESS_ONCE(jiffies);
+ unsigned long next, now = READ_ONCE(jiffies);
next = rq->last_sched_tick + HZ;
* - return from syscall or exception to user-space
* - return from interrupt-handler to user-space
*
- * WARNING: all callers must re-check need_resched() afterward and reschedule
- * accordingly in case an event triggered the need for rescheduling (such as
- * an interrupt waking up a task) while preemption was disabled in __schedule().
+ * WARNING: must be called with preemption disabled!
*/
static void __sched __schedule(void)
{
struct rq *rq;
int cpu;
- preempt_disable();
cpu = smp_processor_id();
rq = cpu_rq(cpu);
rcu_note_context_switch();
raw_spin_unlock_irq(&rq->lock);
post_schedule(rq);
-
- sched_preempt_enable_no_resched();
}
static inline void sched_submit_work(struct task_struct *tsk)
sched_submit_work(tsk);
do {
+ preempt_disable();
__schedule();
+ sched_preempt_enable_no_resched();
} while (need_resched());
}
EXPORT_SYMBOL(schedule);
static void __sched notrace preempt_schedule_common(void)
{
do {
- __preempt_count_add(PREEMPT_ACTIVE);
+ preempt_active_enter();
__schedule();
- __preempt_count_sub(PREEMPT_ACTIVE);
+ preempt_active_exit();
/*
* Check again in case we missed a preemption opportunity
* between schedule and now.
*/
- barrier();
} while (need_resched());
}
NOKPROBE_SYMBOL(preempt_schedule);
EXPORT_SYMBOL(preempt_schedule);
-#ifdef CONFIG_CONTEXT_TRACKING
/**
- * preempt_schedule_context - preempt_schedule called by tracing
+ * preempt_schedule_notrace - preempt_schedule called by tracing
*
* The tracing infrastructure uses preempt_enable_notrace to prevent
* recursion and tracing preempt enabling caused by the tracing
* instead of preempt_schedule() to exit user context if needed before
* calling the scheduler.
*/
-asmlinkage __visible void __sched notrace preempt_schedule_context(void)
+asmlinkage __visible void __sched notrace preempt_schedule_notrace(void)
{
enum ctx_state prev_ctx;
return;
do {
- __preempt_count_add(PREEMPT_ACTIVE);
+ /*
+ * Use raw __prempt_count() ops that don't call function.
+ * We can't call functions before disabling preemption which
+ * disarm preemption tracing recursions.
+ */
+ __preempt_count_add(PREEMPT_ACTIVE + PREEMPT_DISABLE_OFFSET);
+ barrier();
/*
* Needs preempt disabled in case user_exit() is traced
* and the tracer calls preempt_enable_notrace() causing
__schedule();
exception_exit(prev_ctx);
- __preempt_count_sub(PREEMPT_ACTIVE);
barrier();
+ __preempt_count_sub(PREEMPT_ACTIVE + PREEMPT_DISABLE_OFFSET);
} while (need_resched());
}
-EXPORT_SYMBOL_GPL(preempt_schedule_context);
-#endif /* CONFIG_CONTEXT_TRACKING */
+EXPORT_SYMBOL_GPL(preempt_schedule_notrace);
#endif /* CONFIG_PREEMPT */
prev_state = exception_enter();
do {
- __preempt_count_add(PREEMPT_ACTIVE);
+ preempt_active_enter();
local_irq_enable();
__schedule();
local_irq_disable();
- __preempt_count_sub(PREEMPT_ACTIVE);
-
- /*
- * Check again in case we missed a preemption opportunity
- * between schedule and now.
- */
- barrier();
+ preempt_active_exit();
} while (need_resched());
exception_exit(prev_state);
if (!dl_prio(p->normal_prio) ||
(pi_task && dl_entity_preempt(&pi_task->dl, &p->dl))) {
p->dl.dl_boosted = 1;
- p->dl.dl_throttled = 0;
enqueue_flag = ENQUEUE_REPLENISH;
} else
p->dl.dl_boosted = 0;
/* Actually do priority change: must hold pi & rq lock. */
static void __setscheduler(struct rq *rq, struct task_struct *p,
- const struct sched_attr *attr)
+ const struct sched_attr *attr, bool keep_boost)
{
__setscheduler_params(p, attr);
/*
- * If we get here, there was no pi waiters boosting the
- * task. It is safe to use the normal prio.
+ * Keep a potential priority boosting if called from
+ * sched_setscheduler().
*/
- p->prio = normal_prio(p);
+ if (keep_boost)
+ p->prio = rt_mutex_get_effective_prio(p, normal_prio(p));
+ else
+ p->prio = normal_prio(p);
if (dl_prio(p->prio))
p->sched_class = &dl_sched_class;
int newprio = dl_policy(attr->sched_policy) ? MAX_DL_PRIO - 1 :
MAX_RT_PRIO - 1 - attr->sched_priority;
int retval, oldprio, oldpolicy = -1, queued, running;
- int policy = attr->sched_policy;
+ int new_effective_prio, policy = attr->sched_policy;
unsigned long flags;
const struct sched_class *prev_class;
struct rq *rq;
oldprio = p->prio;
/*
- * Special case for priority boosted tasks.
- *
- * If the new priority is lower or equal (user space view)
- * than the current (boosted) priority, we just store the new
+ * Take priority boosted tasks into account. If the new
+ * effective priority is unchanged, we just store the new
* normal parameters and do not touch the scheduler class and
* the runqueue. This will be done when the task deboost
* itself.
*/
- if (rt_mutex_check_prio(p, newprio)) {
+ new_effective_prio = rt_mutex_get_effective_prio(p, newprio);
+ if (new_effective_prio == oldprio) {
__setscheduler_params(p, attr);
task_rq_unlock(rq, p, &flags);
return 0;
put_prev_task(rq, p);
prev_class = p->sched_class;
- __setscheduler(rq, p, attr);
+ __setscheduler(rq, p, attr, true);
if (running)
p->sched_class->set_curr_task(rq);
long ret;
current->in_iowait = 1;
- if (old_iowait)
- blk_schedule_flush_plug(current);
- else
- blk_flush_plug(current);
+ blk_schedule_flush_plug(current);
delayacct_blkio_start();
rq = raw_rq();
.priority = CPU_PRI_MIGRATION,
};
-static void __cpuinit set_cpu_rq_start_time(void)
+static void set_cpu_rq_start_time(void)
{
int cpu = smp_processor_id();
struct rq *rq = cpu_rq(cpu);
unsigned long flags;
long cpu = (long)hcpu;
struct dl_bw *dl_b;
+ bool overflow;
+ int cpus;
- switch (action & ~CPU_TASKS_FROZEN) {
+ switch (action) {
case CPU_DOWN_PREPARE:
- /* explicitly allow suspend */
- if (!(action & CPU_TASKS_FROZEN)) {
- bool overflow;
- int cpus;
-
- rcu_read_lock_sched();
- dl_b = dl_bw_of(cpu);
+ rcu_read_lock_sched();
+ dl_b = dl_bw_of(cpu);
- raw_spin_lock_irqsave(&dl_b->lock, flags);
- cpus = dl_bw_cpus(cpu);
- overflow = __dl_overflow(dl_b, cpus, 0, 0);
- raw_spin_unlock_irqrestore(&dl_b->lock, flags);
+ raw_spin_lock_irqsave(&dl_b->lock, flags);
+ cpus = dl_bw_cpus(cpu);
+ overflow = __dl_overflow(dl_b, cpus, 0, 0);
+ raw_spin_unlock_irqrestore(&dl_b->lock, flags);
- rcu_read_unlock_sched();
+ rcu_read_unlock_sched();
- if (overflow)
- return notifier_from_errno(-EBUSY);
- }
+ if (overflow)
+ return notifier_from_errno(-EBUSY);
cpuset_update_active_cpus(false);
break;
case CPU_DOWN_PREPARE_FROZEN:
}
#endif /* CONFIG_SMP */
-const_debug unsigned int sysctl_timer_migration = 1;
-
int in_sched_functions(unsigned long addr)
{
return in_lock_functions(addr) ||
queued = task_on_rq_queued(p);
if (queued)
dequeue_task(rq, p, 0);
- __setscheduler(rq, p, &attr);
+ __setscheduler(rq, p, &attr, false);
if (queued) {
enqueue_task(rq, p, 0);
resched_curr(rq);
return rt_runtime_us;
}
-static int sched_group_set_rt_period(struct task_group *tg, long rt_period_us)
+static int sched_group_set_rt_period(struct task_group *tg, u64 rt_period_us)
{
u64 rt_runtime, rt_period;
- rt_period = (u64)rt_period_us * NSEC_PER_USEC;
+ rt_period = rt_period_us * NSEC_PER_USEC;
rt_runtime = tg->rt_bandwidth.rt_runtime;
return tg_set_rt_bandwidth(tg, rt_period, rt_runtime);
__refill_cfs_bandwidth_runtime(cfs_b);
/* restart the period timer (if active) to handle new period expiry */
- if (runtime_enabled && cfs_b->timer_active) {
- /* force a reprogram */
- __start_cfs_bandwidth(cfs_b, true);
- }
+ if (runtime_enabled)
+ start_cfs_bandwidth(cfs_b);
raw_spin_unlock_irq(&cfs_b->lock);
for_each_online_cpu(i) {
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