__read_mostly int scheduler_running;
+#ifdef CONFIG_SCHED_CORE
+
+DEFINE_STATIC_KEY_FALSE(__sched_core_enabled);
+
+/* kernel prio, less is more */
+static inline int __task_prio(struct task_struct *p)
+{
+ if (p->sched_class == &stop_sched_class) /* trumps deadline */
+ return -2;
+
+ if (rt_prio(p->prio)) /* includes deadline */
+ return p->prio; /* [-1, 99] */
+
+ if (p->sched_class == &idle_sched_class)
+ return MAX_RT_PRIO + NICE_WIDTH; /* 140 */
+
+ return MAX_RT_PRIO + MAX_NICE; /* 120, squash fair */
+}
+
+/*
+ * l(a,b)
+ * le(a,b) := !l(b,a)
+ * g(a,b) := l(b,a)
+ * ge(a,b) := !l(a,b)
+ */
+
+/* real prio, less is less */
+static inline bool prio_less(struct task_struct *a, struct task_struct *b, bool in_fi)
+{
+
+ int pa = __task_prio(a), pb = __task_prio(b);
+
+ if (-pa < -pb)
+ return true;
+
+ if (-pb < -pa)
+ return false;
+
+ if (pa == -1) /* dl_prio() doesn't work because of stop_class above */
+ return !dl_time_before(a->dl.deadline, b->dl.deadline);
+
+ if (pa == MAX_RT_PRIO + MAX_NICE) /* fair */
+ return cfs_prio_less(a, b, in_fi);
+
+ return false;
+}
+
+static inline bool __sched_core_less(struct task_struct *a, struct task_struct *b)
+{
+ if (a->core_cookie < b->core_cookie)
+ return true;
+
+ if (a->core_cookie > b->core_cookie)
+ return false;
+
+ /* flip prio, so high prio is leftmost */
+ if (prio_less(b, a, task_rq(a)->core->core_forceidle))
+ return true;
+
+ return false;
+}
+
+#define __node_2_sc(node) rb_entry((node), struct task_struct, core_node)
+
+static inline bool rb_sched_core_less(struct rb_node *a, const struct rb_node *b)
+{
+ return __sched_core_less(__node_2_sc(a), __node_2_sc(b));
+}
+
+static inline int rb_sched_core_cmp(const void *key, const struct rb_node *node)
+{
+ const struct task_struct *p = __node_2_sc(node);
+ unsigned long cookie = (unsigned long)key;
+
+ if (cookie < p->core_cookie)
+ return -1;
+
+ if (cookie > p->core_cookie)
+ return 1;
+
+ return 0;
+}
+
+void sched_core_enqueue(struct rq *rq, struct task_struct *p)
+{
+ rq->core->core_task_seq++;
+
+ if (!p->core_cookie)
+ return;
+
+ rb_add(&p->core_node, &rq->core_tree, rb_sched_core_less);
+}
+
+void sched_core_dequeue(struct rq *rq, struct task_struct *p)
+{
+ rq->core->core_task_seq++;
+
+ if (!sched_core_enqueued(p))
+ return;
+
+ rb_erase(&p->core_node, &rq->core_tree);
+ RB_CLEAR_NODE(&p->core_node);
+}
+
+/*
+ * Find left-most (aka, highest priority) task matching @cookie.
+ */
+static struct task_struct *sched_core_find(struct rq *rq, unsigned long cookie)
+{
+ struct rb_node *node;
+
+ node = rb_find_first((void *)cookie, &rq->core_tree, rb_sched_core_cmp);
+ /*
+ * The idle task always matches any cookie!
+ */
+ if (!node)
+ return idle_sched_class.pick_task(rq);
+
+ return __node_2_sc(node);
+}
+
+static struct task_struct *sched_core_next(struct task_struct *p, unsigned long cookie)
+{
+ struct rb_node *node = &p->core_node;
+
+ node = rb_next(node);
+ if (!node)
+ return NULL;
+
+ p = container_of(node, struct task_struct, core_node);
+ if (p->core_cookie != cookie)
+ return NULL;
+
+ return p;
+}
+
+/*
+ * Magic required such that:
+ *
+ * raw_spin_rq_lock(rq);
+ * ...
+ * raw_spin_rq_unlock(rq);
+ *
+ * ends up locking and unlocking the _same_ lock, and all CPUs
+ * always agree on what rq has what lock.
+ *
+ * XXX entirely possible to selectively enable cores, don't bother for now.
+ */
+
+static DEFINE_MUTEX(sched_core_mutex);
+static atomic_t sched_core_count;
+static struct cpumask sched_core_mask;
+
+static void sched_core_lock(int cpu, unsigned long *flags)
+{
+ const struct cpumask *smt_mask = cpu_smt_mask(cpu);
+ int t, i = 0;
+
+ local_irq_save(*flags);
+ for_each_cpu(t, smt_mask)
+ raw_spin_lock_nested(&cpu_rq(t)->__lock, i++);
+}
+
+static void sched_core_unlock(int cpu, unsigned long *flags)
+{
+ const struct cpumask *smt_mask = cpu_smt_mask(cpu);
+ int t;
+
+ for_each_cpu(t, smt_mask)
+ raw_spin_unlock(&cpu_rq(t)->__lock);
+ local_irq_restore(*flags);
+}
+
+static void __sched_core_flip(bool enabled)
+{
+ unsigned long flags;
+ int cpu, t;
+
+ cpus_read_lock();
+
+ /*
+ * Toggle the online cores, one by one.
+ */
+ cpumask_copy(&sched_core_mask, cpu_online_mask);
+ for_each_cpu(cpu, &sched_core_mask) {
+ const struct cpumask *smt_mask = cpu_smt_mask(cpu);
+
+ sched_core_lock(cpu, &flags);
+
+ for_each_cpu(t, smt_mask)
+ cpu_rq(t)->core_enabled = enabled;
+
+ sched_core_unlock(cpu, &flags);
+
+ cpumask_andnot(&sched_core_mask, &sched_core_mask, smt_mask);
+ }
+
+ /*
+ * Toggle the offline CPUs.
+ */
+ cpumask_copy(&sched_core_mask, cpu_possible_mask);
+ cpumask_andnot(&sched_core_mask, &sched_core_mask, cpu_online_mask);
+
+ for_each_cpu(cpu, &sched_core_mask)
+ cpu_rq(cpu)->core_enabled = enabled;
+
+ cpus_read_unlock();
+}
+
+static void sched_core_assert_empty(void)
+{
+ int cpu;
+
+ for_each_possible_cpu(cpu)
+ WARN_ON_ONCE(!RB_EMPTY_ROOT(&cpu_rq(cpu)->core_tree));
+}
+
+static void __sched_core_enable(void)
+{
+ static_branch_enable(&__sched_core_enabled);
+ /*
+ * Ensure all previous instances of raw_spin_rq_*lock() have finished
+ * and future ones will observe !sched_core_disabled().
+ */
+ synchronize_rcu();
+ __sched_core_flip(true);
+ sched_core_assert_empty();
+}
+
+static void __sched_core_disable(void)
+{
+ sched_core_assert_empty();
+ __sched_core_flip(false);
+ static_branch_disable(&__sched_core_enabled);
+}
+
+void sched_core_get(void)
+{
+ if (atomic_inc_not_zero(&sched_core_count))
+ return;
+
+ mutex_lock(&sched_core_mutex);
+ if (!atomic_read(&sched_core_count))
+ __sched_core_enable();
+
+ smp_mb__before_atomic();
+ atomic_inc(&sched_core_count);
+ mutex_unlock(&sched_core_mutex);
+}
+
+static void __sched_core_put(struct work_struct *work)
+{
+ if (atomic_dec_and_mutex_lock(&sched_core_count, &sched_core_mutex)) {
+ __sched_core_disable();
+ mutex_unlock(&sched_core_mutex);
+ }
+}
+
+void sched_core_put(void)
+{
+ static DECLARE_WORK(_work, __sched_core_put);
+
+ /*
+ * "There can be only one"
+ *
+ * Either this is the last one, or we don't actually need to do any
+ * 'work'. If it is the last *again*, we rely on
+ * WORK_STRUCT_PENDING_BIT.
+ */
+ if (!atomic_add_unless(&sched_core_count, -1, 1))
+ schedule_work(&_work);
+}
+
+#else /* !CONFIG_SCHED_CORE */
+
+static inline void sched_core_enqueue(struct rq *rq, struct task_struct *p) { }
+static inline void sched_core_dequeue(struct rq *rq, struct task_struct *p) { }
+
+#endif /* CONFIG_SCHED_CORE */
+
/*
* part of the period that we allow rt tasks to run in us.
* default: 0.95s
*
*/
+void raw_spin_rq_lock_nested(struct rq *rq, int subclass)
+{
+ raw_spinlock_t *lock;
+
+ /* Matches synchronize_rcu() in __sched_core_enable() */
+ preempt_disable();
+ if (sched_core_disabled()) {
+ raw_spin_lock_nested(&rq->__lock, subclass);
+ /* preempt_count *MUST* be > 1 */
+ preempt_enable_no_resched();
+ return;
+ }
+
+ for (;;) {
+ lock = __rq_lockp(rq);
+ raw_spin_lock_nested(lock, subclass);
+ if (likely(lock == __rq_lockp(rq))) {
+ /* preempt_count *MUST* be > 1 */
+ preempt_enable_no_resched();
+ return;
+ }
+ raw_spin_unlock(lock);
+ }
+}
+
+bool raw_spin_rq_trylock(struct rq *rq)
+{
+ raw_spinlock_t *lock;
+ bool ret;
+
+ /* Matches synchronize_rcu() in __sched_core_enable() */
+ preempt_disable();
+ if (sched_core_disabled()) {
+ ret = raw_spin_trylock(&rq->__lock);
+ preempt_enable();
+ return ret;
+ }
+
+ for (;;) {
+ lock = __rq_lockp(rq);
+ ret = raw_spin_trylock(lock);
+ if (!ret || (likely(lock == __rq_lockp(rq)))) {
+ preempt_enable();
+ return ret;
+ }
+ raw_spin_unlock(lock);
+ }
+}
+
+void raw_spin_rq_unlock(struct rq *rq)
+{
+ raw_spin_unlock(rq_lockp(rq));
+}
+
+#ifdef CONFIG_SMP
+/*
+ * double_rq_lock - safely lock two runqueues
+ */
+void double_rq_lock(struct rq *rq1, struct rq *rq2)
+{
+ lockdep_assert_irqs_disabled();
+
+ if (rq_order_less(rq2, rq1))
+ swap(rq1, rq2);
+
+ raw_spin_rq_lock(rq1);
+ if (__rq_lockp(rq1) == __rq_lockp(rq2))
+ return;
+
+ raw_spin_rq_lock_nested(rq2, SINGLE_DEPTH_NESTING);
+}
+#endif
+
/*
* __task_rq_lock - lock the rq @p resides on.
*/
for (;;) {
rq = task_rq(p);
- raw_spin_lock(&rq->lock);
+ raw_spin_rq_lock(rq);
if (likely(rq == task_rq(p) && !task_on_rq_migrating(p))) {
rq_pin_lock(rq, rf);
return rq;
}
- raw_spin_unlock(&rq->lock);
+ raw_spin_rq_unlock(rq);
while (unlikely(task_on_rq_migrating(p)))
cpu_relax();
for (;;) {
raw_spin_lock_irqsave(&p->pi_lock, rf->flags);
rq = task_rq(p);
- raw_spin_lock(&rq->lock);
+ raw_spin_rq_lock(rq);
/*
* move_queued_task() task_rq_lock()
*
rq_pin_lock(rq, rf);
return rq;
}
- raw_spin_unlock(&rq->lock);
+ raw_spin_rq_unlock(rq);
raw_spin_unlock_irqrestore(&p->pi_lock, rf->flags);
while (unlikely(task_on_rq_migrating(p)))
{
s64 delta;
- lockdep_assert_held(&rq->lock);
+ lockdep_assert_rq_held(rq);
if (rq->clock_update_flags & RQCF_ACT_SKIP)
return;
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;
struct task_struct *curr = rq->curr;
int cpu;
- lockdep_assert_held(&rq->lock);
+ lockdep_assert_rq_held(rq);
if (test_tsk_need_resched(curr))
return;
struct rq *rq = cpu_rq(cpu);
unsigned long flags;
- raw_spin_lock_irqsave(&rq->lock, flags);
+ raw_spin_rq_lock_irqsave(rq, flags);
if (cpu_online(cpu) || cpu == smp_processor_id())
resched_curr(rq);
- raw_spin_unlock_irqrestore(&rq->lock, flags);
+ raw_spin_rq_unlock_irqrestore(rq, flags);
}
#ifdef CONFIG_SMP
static inline struct uclamp_se
uclamp_tg_restrict(struct task_struct *p, enum uclamp_id clamp_id)
{
+ /* Copy by value as we could modify it */
struct uclamp_se uc_req = p->uclamp_req[clamp_id];
#ifdef CONFIG_UCLAMP_TASK_GROUP
- struct uclamp_se uc_max;
+ unsigned int tg_min, tg_max, value;
/*
* Tasks in autogroups or root task group will be
if (task_group(p) == &root_task_group)
return uc_req;
- uc_max = task_group(p)->uclamp[clamp_id];
- if (uc_req.value > uc_max.value || !uc_req.user_defined)
- return uc_max;
+ tg_min = task_group(p)->uclamp[UCLAMP_MIN].value;
+ tg_max = task_group(p)->uclamp[UCLAMP_MAX].value;
+ value = uc_req.value;
+ value = clamp(value, tg_min, tg_max);
+ uclamp_se_set(&uc_req, value, false);
#endif
return uc_req;
struct uclamp_se *uc_se = &p->uclamp[clamp_id];
struct uclamp_bucket *bucket;
- lockdep_assert_held(&rq->lock);
+ lockdep_assert_rq_held(rq);
/* Update task effective clamp */
p->uclamp[clamp_id] = uclamp_eff_get(p, clamp_id);
unsigned int bkt_clamp;
unsigned int rq_clamp;
- lockdep_assert_held(&rq->lock);
+ lockdep_assert_rq_held(rq);
/*
* If sched_uclamp_used was enabled after task @p was enqueued,
}
static inline void
-uclamp_update_active(struct task_struct *p, enum uclamp_id clamp_id)
+uclamp_update_active(struct task_struct *p)
{
+ enum uclamp_id clamp_id;
struct rq_flags rf;
struct rq *rq;
* affecting a valid clamp bucket, the next time it's enqueued,
* it will already see the updated clamp bucket value.
*/
- if (p->uclamp[clamp_id].active) {
- uclamp_rq_dec_id(rq, p, clamp_id);
- uclamp_rq_inc_id(rq, p, clamp_id);
+ for_each_clamp_id(clamp_id) {
+ if (p->uclamp[clamp_id].active) {
+ uclamp_rq_dec_id(rq, p, clamp_id);
+ uclamp_rq_inc_id(rq, p, clamp_id);
+ }
}
task_rq_unlock(rq, p, &rf);
#ifdef CONFIG_UCLAMP_TASK_GROUP
static inline void
-uclamp_update_active_tasks(struct cgroup_subsys_state *css,
- unsigned int clamps)
+uclamp_update_active_tasks(struct cgroup_subsys_state *css)
{
- enum uclamp_id clamp_id;
struct css_task_iter it;
struct task_struct *p;
css_task_iter_start(css, 0, &it);
- while ((p = css_task_iter_next(&it))) {
- for_each_clamp_id(clamp_id) {
- if ((0x1 << clamp_id) & clamps)
- uclamp_update_active(p, clamp_id);
- }
- }
+ while ((p = css_task_iter_next(&it)))
+ uclamp_update_active(p);
css_task_iter_end(&it);
}
static inline void init_uclamp(void) { }
#endif /* CONFIG_UCLAMP_TASK */
+bool sched_task_on_rq(struct task_struct *p)
+{
+ return task_on_rq_queued(p);
+}
+
static inline void enqueue_task(struct rq *rq, struct task_struct *p, int flags)
{
if (!(flags & ENQUEUE_NOCLOCK))
update_rq_clock(rq);
if (!(flags & ENQUEUE_RESTORE)) {
- sched_info_queued(rq, p);
+ sched_info_enqueue(rq, p);
psi_enqueue(p, flags & ENQUEUE_WAKEUP);
}
uclamp_rq_inc(rq, p);
p->sched_class->enqueue_task(rq, p, flags);
+
+ if (sched_core_enabled(rq))
+ sched_core_enqueue(rq, p);
}
static inline void dequeue_task(struct rq *rq, struct task_struct *p, int flags)
{
+ if (sched_core_enabled(rq))
+ sched_core_dequeue(rq, p);
+
if (!(flags & DEQUEUE_NOCLOCK))
update_rq_clock(rq);
if (!(flags & DEQUEUE_SAVE)) {
- sched_info_dequeued(rq, p);
+ sched_info_dequeue(rq, p);
psi_dequeue(p, flags & DEQUEUE_SLEEP);
}
dequeue_task(rq, p, flags);
}
-/*
- * __normal_prio - return the priority that is based on the static prio
- */
-static inline int __normal_prio(struct task_struct *p)
+static inline int __normal_prio(int policy, int rt_prio, int nice)
{
- return p->static_prio;
+ int prio;
+
+ if (dl_policy(policy))
+ prio = MAX_DL_PRIO - 1;
+ else if (rt_policy(policy))
+ prio = MAX_RT_PRIO - 1 - rt_prio;
+ else
+ prio = NICE_TO_PRIO(nice);
+
+ return prio;
}
/*
*/
static inline int normal_prio(struct task_struct *p)
{
- int prio;
-
- if (task_has_dl_policy(p))
- prio = MAX_DL_PRIO-1;
- else if (task_has_rt_policy(p))
- prio = MAX_RT_PRIO-1 - p->rt_priority;
- else
- prio = __normal_prio(p);
- return prio;
+ return __normal_prio(p->policy, p->rt_priority, PRIO_TO_NICE(p->static_prio));
}
/*
static struct rq *move_queued_task(struct rq *rq, struct rq_flags *rf,
struct task_struct *p, int new_cpu)
{
- lockdep_assert_held(&rq->lock);
+ lockdep_assert_rq_held(rq);
deactivate_task(rq, p, DEQUEUE_NOCLOCK);
set_task_cpu(p, new_cpu);
struct migration_arg *arg = data;
struct set_affinity_pending *pending = arg->pending;
struct task_struct *p = arg->task;
- int dest_cpu = arg->dest_cpu;
struct rq *rq = this_rq();
bool complete = false;
struct rq_flags rf;
if (pending) {
p->migration_pending = NULL;
complete = true;
- }
- if (dest_cpu < 0) {
if (cpumask_test_cpu(task_cpu(p), &p->cpus_mask))
goto out;
-
- dest_cpu = cpumask_any_distribute(&p->cpus_mask);
}
if (task_on_rq_queued(p))
- rq = __migrate_task(rq, &rf, p, dest_cpu);
+ rq = __migrate_task(rq, &rf, p, arg->dest_cpu);
else
- p->wake_cpu = dest_cpu;
+ p->wake_cpu = arg->dest_cpu;
/*
* XXX __migrate_task() can fail, at which point we might end
struct task_struct *p = arg;
raw_spin_lock_irq(&p->pi_lock);
- raw_spin_lock(&rq->lock);
+ raw_spin_rq_lock(rq);
if (task_rq(p) != rq)
goto out_unlock;
out_unlock:
rq->push_busy = false;
- raw_spin_unlock(&rq->lock);
+ raw_spin_rq_unlock(rq);
raw_spin_unlock_irq(&p->pi_lock);
put_task_struct(p);
* Because __kthread_bind() calls this on blocked tasks without
* holding rq->lock.
*/
- lockdep_assert_held(&rq->lock);
+ lockdep_assert_rq_held(rq);
dequeue_task(rq, p, DEQUEUE_SAVE | DEQUEUE_NOCLOCK);
}
if (running)
init_completion(&my_pending.done);
my_pending.arg = (struct migration_arg) {
.task = p,
- .dest_cpu = -1, /* any */
+ .dest_cpu = dest_cpu,
.pending = &my_pending,
};
} else {
pending = p->migration_pending;
refcount_inc(&pending->refs);
+ /*
+ * Affinity has changed, but we've already installed a
+ * pending. migration_cpu_stop() *must* see this, else
+ * we risk a completion of the pending despite having a
+ * task on a disallowed CPU.
+ *
+ * Serialized by p->pi_lock, so this is safe.
+ */
+ pending->arg.dest_cpu = dest_cpu;
}
}
pending = p->migration_pending;
return -EINVAL;
}
- if (task_running(rq, p) || p->state == TASK_WAKING) {
+ if (task_running(rq, p) || READ_ONCE(p->__state) == TASK_WAKING) {
/*
* MIGRATE_ENABLE gets here because 'p == current', but for
* anything else we cannot do is_migration_disabled(), punt
void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
{
#ifdef CONFIG_SCHED_DEBUG
+ unsigned int state = READ_ONCE(p->__state);
+
/*
* We should never call set_task_cpu() on a blocked task,
* ttwu() will sort out the placement.
*/
- WARN_ON_ONCE(p->state != TASK_RUNNING && p->state != TASK_WAKING &&
- !p->on_rq);
+ WARN_ON_ONCE(state != TASK_RUNNING && state != TASK_WAKING && !p->on_rq);
/*
* Migrating fair class task must have p->on_rq = TASK_ON_RQ_MIGRATING,
* because schedstat_wait_{start,end} rebase migrating task's wait_start
* time relying on p->on_rq.
*/
- WARN_ON_ONCE(p->state == TASK_RUNNING &&
+ WARN_ON_ONCE(state == TASK_RUNNING &&
p->sched_class == &fair_sched_class &&
(p->on_rq && !task_on_rq_migrating(p)));
* task_rq_lock().
*/
WARN_ON_ONCE(debug_locks && !(lockdep_is_held(&p->pi_lock) ||
- lockdep_is_held(&task_rq(p)->lock)));
+ lockdep_is_held(__rq_lockp(task_rq(p)))));
#endif
/*
* Clearly, migrating tasks to offline CPUs is a fairly daft thing.
* smp_call_function() if an IPI is sent by the same process we are
* waiting to become inactive.
*/
-unsigned long wait_task_inactive(struct task_struct *p, long match_state)
+unsigned long wait_task_inactive(struct task_struct *p, unsigned int match_state)
{
int running, queued;
struct rq_flags rf;
* is actually now running somewhere else!
*/
while (task_running(rq, p)) {
- if (match_state && unlikely(p->state != match_state))
+ if (match_state && unlikely(READ_ONCE(p->__state) != match_state))
return 0;
cpu_relax();
}
running = task_running(rq, p);
queued = task_on_rq_queued(p);
ncsw = 0;
- if (!match_state || p->state == match_state)
+ if (!match_state || READ_ONCE(p->__state) == match_state)
ncsw = p->nvcsw | LONG_MIN; /* sets MSB */
task_rq_unlock(rq, p, &rf);
struct rq_flags *rf)
{
check_preempt_curr(rq, p, wake_flags);
- p->state = TASK_RUNNING;
+ WRITE_ONCE(p->__state, TASK_RUNNING);
trace_sched_wakeup(p);
#ifdef CONFIG_SMP
if (rq->avg_idle > max)
rq->avg_idle = max;
+ rq->wake_stamp = jiffies;
+ rq->wake_avg_idle = rq->avg_idle / 2;
+
rq->idle_stamp = 0;
}
#endif
{
int en_flags = ENQUEUE_WAKEUP | ENQUEUE_NOCLOCK;
- lockdep_assert_held(&rq->lock);
+ lockdep_assert_rq_held(rq);
if (p->sched_contributes_to_load)
rq->nr_uninterruptible--;
* - we're serialized against set_special_state() by virtue of
* it disabling IRQs (this allows not taking ->pi_lock).
*/
- if (!(p->state & state))
+ if (!(READ_ONCE(p->__state) & state))
goto out;
success = 1;
trace_sched_waking(p);
- p->state = TASK_RUNNING;
+ WRITE_ONCE(p->__state, TASK_RUNNING);
trace_sched_wakeup(p);
goto out;
}
*/
raw_spin_lock_irqsave(&p->pi_lock, flags);
smp_mb__after_spinlock();
- if (!(p->state & state))
+ if (!(READ_ONCE(p->__state) & state))
goto unlock;
trace_sched_waking(p);
* TASK_WAKING such that we can unlock p->pi_lock before doing the
* enqueue, such as ttwu_queue_wakelist().
*/
- p->state = TASK_WAKING;
+ WRITE_ONCE(p->__state, TASK_WAKING);
/*
* If the owning (remote) CPU is still in the middle of schedule() with
ret = func(p, arg);
rq_unlock(rq, &rf);
} else {
- switch (p->state) {
+ switch (READ_ONCE(p->__state)) {
case TASK_RUNNING:
case TASK_WAKING:
break;
#ifdef CONFIG_SCHEDSTATS
DEFINE_STATIC_KEY_FALSE(sched_schedstats);
-static bool __initdata __sched_schedstats = false;
static void set_schedstats(bool enabled)
{
if (!str)
goto out;
- /*
- * This code is called before jump labels have been set up, so we can't
- * change the static branch directly just yet. Instead set a temporary
- * variable so init_schedstats() can do it later.
- */
if (!strcmp(str, "enable")) {
- __sched_schedstats = true;
+ set_schedstats(true);
ret = 1;
} else if (!strcmp(str, "disable")) {
- __sched_schedstats = false;
+ set_schedstats(false);
ret = 1;
}
out:
}
__setup("schedstats=", setup_schedstats);
-static void __init init_schedstats(void)
-{
- set_schedstats(__sched_schedstats);
-}
-
#ifdef CONFIG_PROC_SYSCTL
int sysctl_schedstats(struct ctl_table *table, int write, void *buffer,
size_t *lenp, loff_t *ppos)
return err;
}
#endif /* CONFIG_PROC_SYSCTL */
-#else /* !CONFIG_SCHEDSTATS */
-static inline void init_schedstats(void) {}
#endif /* CONFIG_SCHEDSTATS */
/*
* nobody will actually run it, and a signal or other external
* event cannot wake it up and insert it on the runqueue either.
*/
- p->state = TASK_NEW;
+ p->__state = TASK_NEW;
/*
* Make sure we do not leak PI boosting priority to the child.
} else if (PRIO_TO_NICE(p->static_prio) < 0)
p->static_prio = NICE_TO_PRIO(0);
- p->prio = p->normal_prio = __normal_prio(p);
+ p->prio = p->normal_prio = p->static_prio;
set_load_weight(p, false);
/*
struct rq *rq;
raw_spin_lock_irqsave(&p->pi_lock, rf.flags);
- p->state = TASK_RUNNING;
+ WRITE_ONCE(p->__state, TASK_RUNNING);
#ifdef CONFIG_SMP
/*
* Fork balancing, do it here and not earlier because:
void (*func)(struct rq *rq);
struct callback_head *next;
- lockdep_assert_held(&rq->lock);
+ lockdep_assert_rq_held(rq);
while (head) {
func = (void (*)(struct rq *))head->func;
{
struct callback_head *head = rq->balance_callback;
- lockdep_assert_held(&rq->lock);
+ lockdep_assert_rq_held(rq);
if (head)
rq->balance_callback = NULL;
unsigned long flags;
if (unlikely(head)) {
- raw_spin_lock_irqsave(&rq->lock, flags);
+ raw_spin_rq_lock_irqsave(rq, flags);
do_balance_callbacks(rq, head);
- raw_spin_unlock_irqrestore(&rq->lock, flags);
+ raw_spin_rq_unlock_irqrestore(rq, flags);
}
}
* do an early lockdep release here:
*/
rq_unpin_lock(rq, rf);
- spin_release(&rq->lock.dep_map, _THIS_IP_);
+ spin_release(&__rq_lockp(rq)->dep_map, _THIS_IP_);
#ifdef CONFIG_DEBUG_SPINLOCK
/* this is a valid case when another task releases the spinlock */
- rq->lock.owner = next;
+ rq_lockp(rq)->owner = next;
#endif
}
* fix up the runqueue lock - which gets 'carried over' from
* prev into current:
*/
- spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_);
+ spin_acquire(&__rq_lockp(rq)->dep_map, 0, 0, _THIS_IP_);
__balance_callbacks(rq);
- raw_spin_unlock_irq(&rq->lock);
+ raw_spin_rq_unlock_irq(rq);
}
/*
* running on another CPU and we could rave with its RUNNING -> DEAD
* transition, resulting in a double drop.
*/
- prev_state = prev->state;
+ prev_state = READ_ONCE(prev->__state);
vtime_task_switch(prev);
perf_event_task_sched_in(prev, current);
finish_task(prev);
+ tick_nohz_task_switch();
finish_lock_switch(rq);
finish_arch_post_lock_switch();
kcov_finish_switch(current);
put_task_struct_rcu_user(prev);
}
- tick_nohz_task_switch();
return rq;
}
* externally visible scheduler statistics: current number of runnable
* threads, total number of context switches performed since bootup.
*/
-unsigned long nr_running(void)
+unsigned int nr_running(void)
{
- unsigned long i, sum = 0;
+ unsigned int i, sum = 0;
for_each_online_cpu(i)
sum += cpu_rq(i)->nr_running;
* it does become runnable.
*/
-unsigned long nr_iowait_cpu(int cpu)
+unsigned int nr_iowait_cpu(int cpu)
{
return atomic_read(&cpu_rq(cpu)->nr_iowait);
}
* Task CPU affinities can make all that even more 'interesting'.
*/
-unsigned long nr_iowait(void)
+unsigned int nr_iowait(void)
{
- unsigned long i, sum = 0;
+ unsigned int i, sum = 0;
for_each_possible_cpu(i)
sum += nr_iowait_cpu(i);
#endif
#ifdef CONFIG_DEBUG_ATOMIC_SLEEP
- if (!preempt && prev->state && prev->non_block_count) {
+ if (!preempt && READ_ONCE(prev->__state) && prev->non_block_count) {
printk(KERN_ERR "BUG: scheduling in a non-blocking section: %s/%d/%i\n",
prev->comm, prev->pid, prev->non_block_count);
dump_stack();
* Pick up the highest-prio task:
*/
static inline struct task_struct *
-pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
+__pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
{
const struct sched_class *class;
struct task_struct *p;
if (unlikely(p == RETRY_TASK))
goto restart;
- /* Assumes fair_sched_class->next == idle_sched_class */
+ /* Assume the next prioritized class is idle_sched_class */
if (!p) {
put_prev_task(rq, prev);
p = pick_next_task_idle(rq);
BUG();
}
+#ifdef CONFIG_SCHED_CORE
+static inline bool is_task_rq_idle(struct task_struct *t)
+{
+ return (task_rq(t)->idle == t);
+}
+
+static inline bool cookie_equals(struct task_struct *a, unsigned long cookie)
+{
+ return is_task_rq_idle(a) || (a->core_cookie == cookie);
+}
+
+static inline bool cookie_match(struct task_struct *a, struct task_struct *b)
+{
+ if (is_task_rq_idle(a) || is_task_rq_idle(b))
+ return true;
+
+ return a->core_cookie == b->core_cookie;
+}
+
+// XXX fairness/fwd progress conditions
/*
- * __schedule() is the main scheduler function.
- *
- * The main means of driving the scheduler and thus entering this function are:
- *
- * 1. Explicit blocking: mutex, semaphore, waitqueue, etc.
- *
- * 2. TIF_NEED_RESCHED flag is checked on interrupt and userspace return
- * paths. For example, see arch/x86/entry_64.S.
- *
- * To drive preemption between tasks, the scheduler sets the flag in timer
- * interrupt handler scheduler_tick().
- *
- * 3. Wakeups don't really cause entry into schedule(). They add a
- * task to the run-queue and that's it.
- *
- * Now, if the new task added to the run-queue preempts the current
- * task, then the wakeup sets TIF_NEED_RESCHED and schedule() gets
- * called on the nearest possible occasion:
- *
- * - If the kernel is preemptible (CONFIG_PREEMPTION=y):
- *
+ * Returns
+ * - NULL if there is no runnable task for this class.
+ * - the highest priority task for this runqueue if it matches
+ * rq->core->core_cookie or its priority is greater than max.
+ * - Else returns idle_task.
+ */
+static struct task_struct *
+pick_task(struct rq *rq, const struct sched_class *class, struct task_struct *max, bool in_fi)
+{
+ struct task_struct *class_pick, *cookie_pick;
+ unsigned long cookie = rq->core->core_cookie;
+
+ class_pick = class->pick_task(rq);
+ if (!class_pick)
+ return NULL;
+
+ if (!cookie) {
+ /*
+ * If class_pick is tagged, return it only if it has
+ * higher priority than max.
+ */
+ if (max && class_pick->core_cookie &&
+ prio_less(class_pick, max, in_fi))
+ return idle_sched_class.pick_task(rq);
+
+ return class_pick;
+ }
+
+ /*
+ * If class_pick is idle or matches cookie, return early.
+ */
+ if (cookie_equals(class_pick, cookie))
+ return class_pick;
+
+ cookie_pick = sched_core_find(rq, cookie);
+
+ /*
+ * If class > max && class > cookie, it is the highest priority task on
+ * the core (so far) and it must be selected, otherwise we must go with
+ * the cookie pick in order to satisfy the constraint.
+ */
+ if (prio_less(cookie_pick, class_pick, in_fi) &&
+ (!max || prio_less(max, class_pick, in_fi)))
+ return class_pick;
+
+ return cookie_pick;
+}
+
+extern void task_vruntime_update(struct rq *rq, struct task_struct *p, bool in_fi);
+
+static struct task_struct *
+pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
+{
+ struct task_struct *next, *max = NULL;
+ const struct sched_class *class;
+ const struct cpumask *smt_mask;
+ bool fi_before = false;
+ int i, j, cpu, occ = 0;
+ bool need_sync;
+
+ if (!sched_core_enabled(rq))
+ return __pick_next_task(rq, prev, rf);
+
+ cpu = cpu_of(rq);
+
+ /* Stopper task is switching into idle, no need core-wide selection. */
+ if (cpu_is_offline(cpu)) {
+ /*
+ * Reset core_pick so that we don't enter the fastpath when
+ * coming online. core_pick would already be migrated to
+ * another cpu during offline.
+ */
+ rq->core_pick = NULL;
+ return __pick_next_task(rq, prev, rf);
+ }
+
+ /*
+ * If there were no {en,de}queues since we picked (IOW, the task
+ * pointers are all still valid), and we haven't scheduled the last
+ * pick yet, do so now.
+ *
+ * rq->core_pick can be NULL if no selection was made for a CPU because
+ * it was either offline or went offline during a sibling's core-wide
+ * selection. In this case, do a core-wide selection.
+ */
+ if (rq->core->core_pick_seq == rq->core->core_task_seq &&
+ rq->core->core_pick_seq != rq->core_sched_seq &&
+ rq->core_pick) {
+ WRITE_ONCE(rq->core_sched_seq, rq->core->core_pick_seq);
+
+ next = rq->core_pick;
+ if (next != prev) {
+ put_prev_task(rq, prev);
+ set_next_task(rq, next);
+ }
+
+ rq->core_pick = NULL;
+ return next;
+ }
+
+ put_prev_task_balance(rq, prev, rf);
+
+ smt_mask = cpu_smt_mask(cpu);
+ need_sync = !!rq->core->core_cookie;
+
+ /* reset state */
+ rq->core->core_cookie = 0UL;
+ if (rq->core->core_forceidle) {
+ need_sync = true;
+ fi_before = true;
+ rq->core->core_forceidle = false;
+ }
+
+ /*
+ * core->core_task_seq, core->core_pick_seq, rq->core_sched_seq
+ *
+ * @task_seq guards the task state ({en,de}queues)
+ * @pick_seq is the @task_seq we did a selection on
+ * @sched_seq is the @pick_seq we scheduled
+ *
+ * However, preemptions can cause multiple picks on the same task set.
+ * 'Fix' this by also increasing @task_seq for every pick.
+ */
+ rq->core->core_task_seq++;
+
+ /*
+ * Optimize for common case where this CPU has no cookies
+ * and there are no cookied tasks running on siblings.
+ */
+ if (!need_sync) {
+ for_each_class(class) {
+ next = class->pick_task(rq);
+ if (next)
+ break;
+ }
+
+ if (!next->core_cookie) {
+ rq->core_pick = NULL;
+ /*
+ * For robustness, update the min_vruntime_fi for
+ * unconstrained picks as well.
+ */
+ WARN_ON_ONCE(fi_before);
+ task_vruntime_update(rq, next, false);
+ goto done;
+ }
+ }
+
+ for_each_cpu(i, smt_mask) {
+ struct rq *rq_i = cpu_rq(i);
+
+ rq_i->core_pick = NULL;
+
+ if (i != cpu)
+ update_rq_clock(rq_i);
+ }
+
+ /*
+ * Try and select tasks for each sibling in descending sched_class
+ * order.
+ */
+ for_each_class(class) {
+again:
+ for_each_cpu_wrap(i, smt_mask, cpu) {
+ struct rq *rq_i = cpu_rq(i);
+ struct task_struct *p;
+
+ if (rq_i->core_pick)
+ continue;
+
+ /*
+ * If this sibling doesn't yet have a suitable task to
+ * run; ask for the most eligible task, given the
+ * highest priority task already selected for this
+ * core.
+ */
+ p = pick_task(rq_i, class, max, fi_before);
+ if (!p)
+ continue;
+
+ if (!is_task_rq_idle(p))
+ occ++;
+
+ rq_i->core_pick = p;
+ if (rq_i->idle == p && rq_i->nr_running) {
+ rq->core->core_forceidle = true;
+ if (!fi_before)
+ rq->core->core_forceidle_seq++;
+ }
+
+ /*
+ * If this new candidate is of higher priority than the
+ * previous; and they're incompatible; we need to wipe
+ * the slate and start over. pick_task makes sure that
+ * p's priority is more than max if it doesn't match
+ * max's cookie.
+ *
+ * NOTE: this is a linear max-filter and is thus bounded
+ * in execution time.
+ */
+ if (!max || !cookie_match(max, p)) {
+ struct task_struct *old_max = max;
+
+ rq->core->core_cookie = p->core_cookie;
+ max = p;
+
+ if (old_max) {
+ rq->core->core_forceidle = false;
+ for_each_cpu(j, smt_mask) {
+ if (j == i)
+ continue;
+
+ cpu_rq(j)->core_pick = NULL;
+ }
+ occ = 1;
+ goto again;
+ }
+ }
+ }
+ }
+
+ rq->core->core_pick_seq = rq->core->core_task_seq;
+ next = rq->core_pick;
+ rq->core_sched_seq = rq->core->core_pick_seq;
+
+ /* Something should have been selected for current CPU */
+ WARN_ON_ONCE(!next);
+
+ /*
+ * Reschedule siblings
+ *
+ * NOTE: L1TF -- at this point we're no longer running the old task and
+ * sending an IPI (below) ensures the sibling will no longer be running
+ * their task. This ensures there is no inter-sibling overlap between
+ * non-matching user state.
+ */
+ for_each_cpu(i, smt_mask) {
+ struct rq *rq_i = cpu_rq(i);
+
+ /*
+ * An online sibling might have gone offline before a task
+ * could be picked for it, or it might be offline but later
+ * happen to come online, but its too late and nothing was
+ * picked for it. That's Ok - it will pick tasks for itself,
+ * so ignore it.
+ */
+ if (!rq_i->core_pick)
+ continue;
+
+ /*
+ * Update for new !FI->FI transitions, or if continuing to be in !FI:
+ * fi_before fi update?
+ * 0 0 1
+ * 0 1 1
+ * 1 0 1
+ * 1 1 0
+ */
+ if (!(fi_before && rq->core->core_forceidle))
+ task_vruntime_update(rq_i, rq_i->core_pick, rq->core->core_forceidle);
+
+ rq_i->core_pick->core_occupation = occ;
+
+ if (i == cpu) {
+ rq_i->core_pick = NULL;
+ continue;
+ }
+
+ /* Did we break L1TF mitigation requirements? */
+ WARN_ON_ONCE(!cookie_match(next, rq_i->core_pick));
+
+ if (rq_i->curr == rq_i->core_pick) {
+ rq_i->core_pick = NULL;
+ continue;
+ }
+
+ resched_curr(rq_i);
+ }
+
+done:
+ set_next_task(rq, next);
+ return next;
+}
+
+static bool try_steal_cookie(int this, int that)
+{
+ struct rq *dst = cpu_rq(this), *src = cpu_rq(that);
+ struct task_struct *p;
+ unsigned long cookie;
+ bool success = false;
+
+ local_irq_disable();
+ double_rq_lock(dst, src);
+
+ cookie = dst->core->core_cookie;
+ if (!cookie)
+ goto unlock;
+
+ if (dst->curr != dst->idle)
+ goto unlock;
+
+ p = sched_core_find(src, cookie);
+ if (p == src->idle)
+ goto unlock;
+
+ do {
+ if (p == src->core_pick || p == src->curr)
+ goto next;
+
+ if (!cpumask_test_cpu(this, &p->cpus_mask))
+ goto next;
+
+ if (p->core_occupation > dst->idle->core_occupation)
+ goto next;
+
+ p->on_rq = TASK_ON_RQ_MIGRATING;
+ deactivate_task(src, p, 0);
+ set_task_cpu(p, this);
+ activate_task(dst, p, 0);
+ p->on_rq = TASK_ON_RQ_QUEUED;
+
+ resched_curr(dst);
+
+ success = true;
+ break;
+
+next:
+ p = sched_core_next(p, cookie);
+ } while (p);
+
+unlock:
+ double_rq_unlock(dst, src);
+ local_irq_enable();
+
+ return success;
+}
+
+static bool steal_cookie_task(int cpu, struct sched_domain *sd)
+{
+ int i;
+
+ for_each_cpu_wrap(i, sched_domain_span(sd), cpu) {
+ if (i == cpu)
+ continue;
+
+ if (need_resched())
+ break;
+
+ if (try_steal_cookie(cpu, i))
+ return true;
+ }
+
+ return false;
+}
+
+static void sched_core_balance(struct rq *rq)
+{
+ struct sched_domain *sd;
+ int cpu = cpu_of(rq);
+
+ preempt_disable();
+ rcu_read_lock();
+ raw_spin_rq_unlock_irq(rq);
+ for_each_domain(cpu, sd) {
+ if (need_resched())
+ break;
+
+ if (steal_cookie_task(cpu, sd))
+ break;
+ }
+ raw_spin_rq_lock_irq(rq);
+ rcu_read_unlock();
+ preempt_enable();
+}
+
+static DEFINE_PER_CPU(struct callback_head, core_balance_head);
+
+void queue_core_balance(struct rq *rq)
+{
+ if (!sched_core_enabled(rq))
+ return;
+
+ if (!rq->core->core_cookie)
+ return;
+
+ if (!rq->nr_running) /* not forced idle */
+ return;
+
+ queue_balance_callback(rq, &per_cpu(core_balance_head, rq->cpu), sched_core_balance);
+}
+
+static void sched_core_cpu_starting(unsigned int cpu)
+{
+ const struct cpumask *smt_mask = cpu_smt_mask(cpu);
+ struct rq *rq = cpu_rq(cpu), *core_rq = NULL;
+ unsigned long flags;
+ int t;
+
+ sched_core_lock(cpu, &flags);
+
+ WARN_ON_ONCE(rq->core != rq);
+
+ /* if we're the first, we'll be our own leader */
+ if (cpumask_weight(smt_mask) == 1)
+ goto unlock;
+
+ /* find the leader */
+ for_each_cpu(t, smt_mask) {
+ if (t == cpu)
+ continue;
+ rq = cpu_rq(t);
+ if (rq->core == rq) {
+ core_rq = rq;
+ break;
+ }
+ }
+
+ if (WARN_ON_ONCE(!core_rq)) /* whoopsie */
+ goto unlock;
+
+ /* install and validate core_rq */
+ for_each_cpu(t, smt_mask) {
+ rq = cpu_rq(t);
+
+ if (t == cpu)
+ rq->core = core_rq;
+
+ WARN_ON_ONCE(rq->core != core_rq);
+ }
+
+unlock:
+ sched_core_unlock(cpu, &flags);
+}
+
+static void sched_core_cpu_deactivate(unsigned int cpu)
+{
+ const struct cpumask *smt_mask = cpu_smt_mask(cpu);
+ struct rq *rq = cpu_rq(cpu), *core_rq = NULL;
+ unsigned long flags;
+ int t;
+
+ sched_core_lock(cpu, &flags);
+
+ /* if we're the last man standing, nothing to do */
+ if (cpumask_weight(smt_mask) == 1) {
+ WARN_ON_ONCE(rq->core != rq);
+ goto unlock;
+ }
+
+ /* if we're not the leader, nothing to do */
+ if (rq->core != rq)
+ goto unlock;
+
+ /* find a new leader */
+ for_each_cpu(t, smt_mask) {
+ if (t == cpu)
+ continue;
+ core_rq = cpu_rq(t);
+ break;
+ }
+
+ if (WARN_ON_ONCE(!core_rq)) /* impossible */
+ goto unlock;
+
+ /* copy the shared state to the new leader */
+ core_rq->core_task_seq = rq->core_task_seq;
+ core_rq->core_pick_seq = rq->core_pick_seq;
+ core_rq->core_cookie = rq->core_cookie;
+ core_rq->core_forceidle = rq->core_forceidle;
+ core_rq->core_forceidle_seq = rq->core_forceidle_seq;
+
+ /* install new leader */
+ for_each_cpu(t, smt_mask) {
+ rq = cpu_rq(t);
+ rq->core = core_rq;
+ }
+
+unlock:
+ sched_core_unlock(cpu, &flags);
+}
+
+static inline void sched_core_cpu_dying(unsigned int cpu)
+{
+ struct rq *rq = cpu_rq(cpu);
+
+ if (rq->core != rq)
+ rq->core = rq;
+}
+
+#else /* !CONFIG_SCHED_CORE */
+
+static inline void sched_core_cpu_starting(unsigned int cpu) {}
+static inline void sched_core_cpu_deactivate(unsigned int cpu) {}
+static inline void sched_core_cpu_dying(unsigned int cpu) {}
+
+static struct task_struct *
+pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
+{
+ return __pick_next_task(rq, prev, rf);
+}
+
+#endif /* CONFIG_SCHED_CORE */
+
+/*
+ * __schedule() is the main scheduler function.
+ *
+ * The main means of driving the scheduler and thus entering this function are:
+ *
+ * 1. Explicit blocking: mutex, semaphore, waitqueue, etc.
+ *
+ * 2. TIF_NEED_RESCHED flag is checked on interrupt and userspace return
+ * paths. For example, see arch/x86/entry_64.S.
+ *
+ * To drive preemption between tasks, the scheduler sets the flag in timer
+ * interrupt handler scheduler_tick().
+ *
+ * 3. Wakeups don't really cause entry into schedule(). They add a
+ * task to the run-queue and that's it.
+ *
+ * Now, if the new task added to the run-queue preempts the current
+ * task, then the wakeup sets TIF_NEED_RESCHED and schedule() gets
+ * called on the nearest possible occasion:
+ *
+ * - If the kernel is preemptible (CONFIG_PREEMPTION=y):
+ *
* - in syscall or exception context, at the next outmost
* preempt_enable(). (this might be as soon as the wake_up()'s
* spin_unlock()!)
* - we form a control dependency vs deactivate_task() below.
* - ptrace_{,un}freeze_traced() can change ->state underneath us.
*/
- prev_state = prev->state;
+ prev_state = READ_ONCE(prev->__state);
if (!preempt && prev_state) {
if (signal_pending_state(prev_state, prev)) {
- prev->state = TASK_RUNNING;
+ WRITE_ONCE(prev->__state, TASK_RUNNING);
} else {
prev->sched_contributes_to_load =
(prev_state & TASK_UNINTERRUPTIBLE) &&
rq_unpin_lock(rq, &rf);
__balance_callbacks(rq);
- raw_spin_unlock_irq(&rq->lock);
+ raw_spin_rq_unlock_irq(rq);
}
}
{
unsigned int task_flags;
- if (!tsk->state)
+ if (task_is_running(tsk))
return;
task_flags = tsk->flags;
* current task can be in any other state. Note, idle is always in the
* TASK_RUNNING state.
*/
- WARN_ON_ONCE(current->state);
+ WARN_ON_ONCE(current->__state);
do {
__schedule(false);
} while (need_resched());
}
EXPORT_SYMBOL(default_wake_function);
+static void __setscheduler_prio(struct task_struct *p, int prio)
+{
+ if (dl_prio(prio))
+ p->sched_class = &dl_sched_class;
+ else if (rt_prio(prio))
+ p->sched_class = &rt_sched_class;
+ else
+ p->sched_class = &fair_sched_class;
+
+ p->prio = prio;
+}
+
#ifdef CONFIG_RT_MUTEXES
static inline int __rt_effective_prio(struct task_struct *pi_task, int prio)
} else {
p->dl.pi_se = &p->dl;
}
- p->sched_class = &dl_sched_class;
} else if (rt_prio(prio)) {
if (dl_prio(oldprio))
p->dl.pi_se = &p->dl;
if (oldprio < prio)
queue_flag |= ENQUEUE_HEAD;
- p->sched_class = &rt_sched_class;
} else {
if (dl_prio(oldprio))
p->dl.pi_se = &p->dl;
if (rt_prio(oldprio))
p->rt.timeout = 0;
- p->sched_class = &fair_sched_class;
}
- p->prio = prio;
+ __setscheduler_prio(p, prio);
if (queued)
enqueue_task(rq, p, queue_flag);
rq_unpin_lock(rq, &rf);
__balance_callbacks(rq);
- raw_spin_unlock(&rq->lock);
+ raw_spin_rq_unlock(rq);
preempt_enable();
}
set_load_weight(p, true);
}
-/* Actually do priority change: must hold pi & rq lock. */
-static void __setscheduler(struct rq *rq, struct task_struct *p,
- const struct sched_attr *attr, bool keep_boost)
-{
- /*
- * If params can't change scheduling class changes aren't allowed
- * either.
- */
- if (attr->sched_flags & SCHED_FLAG_KEEP_PARAMS)
- return;
-
- __setscheduler_params(p, attr);
-
- /*
- * Keep a potential priority boosting if called from
- * sched_setscheduler().
- */
- p->prio = normal_prio(p);
- if (keep_boost)
- p->prio = rt_effective_prio(p, p->prio);
-
- if (dl_prio(p->prio))
- p->sched_class = &dl_sched_class;
- else if (rt_prio(p->prio))
- p->sched_class = &rt_sched_class;
- else
- p->sched_class = &fair_sched_class;
-}
-
/*
* Check the target process has a UID that matches the current process's:
*/
const struct sched_attr *attr,
bool user, bool pi)
{
- 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 new_effective_prio, policy = attr->sched_policy;
+ int oldpolicy = -1, policy = attr->sched_policy;
+ int retval, oldprio, newprio, queued, running;
const struct sched_class *prev_class;
struct callback_head *head;
struct rq_flags rf;
p->sched_reset_on_fork = reset_on_fork;
oldprio = p->prio;
+ newprio = __normal_prio(policy, attr->sched_priority, attr->sched_nice);
if (pi) {
/*
* Take priority boosted tasks into account. If the new
* the runqueue. This will be done when the task deboost
* itself.
*/
- new_effective_prio = rt_effective_prio(p, newprio);
- if (new_effective_prio == oldprio)
+ newprio = rt_effective_prio(p, newprio);
+ if (newprio == oldprio)
queue_flags &= ~DEQUEUE_MOVE;
}
prev_class = p->sched_class;
- __setscheduler(rq, p, attr, pi);
+ if (!(attr->sched_flags & SCHED_FLAG_KEEP_PARAMS)) {
+ __setscheduler_params(p, attr);
+ __setscheduler_prio(p, newprio);
+ }
__setscheduler_uclamp(p, attr);
if (queued) {
{
return __sched_setscheduler(p, attr, false, true);
}
+EXPORT_SYMBOL_GPL(sched_setattr_nocheck);
/**
* sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernelspace.
if (curr->sched_class != p->sched_class)
goto out_unlock;
- if (task_running(p_rq, p) || p->state)
+ if (task_running(p_rq, p) || !task_is_running(p))
goto out_unlock;
yielded = curr->sched_class->yield_to_task(rq, p);
pr_info("task:%-15.15s state:%c", p->comm, task_state_to_char(p));
- if (p->state == TASK_RUNNING)
+ if (task_is_running(p))
pr_cont(" running task ");
#ifdef CONFIG_DEBUG_STACK_USAGE
free = stack_not_used(p);
static inline bool
state_filter_match(unsigned long state_filter, struct task_struct *p)
{
+ unsigned int state = READ_ONCE(p->__state);
+
/* no filter, everything matches */
if (!state_filter)
return true;
/* filter, but doesn't match */
- if (!(p->state & state_filter))
+ if (!(state & state_filter))
return false;
/*
* When looking for TASK_UNINTERRUPTIBLE skip TASK_IDLE (allows
* TASK_KILLABLE).
*/
- if (state_filter == TASK_UNINTERRUPTIBLE && p->state == TASK_IDLE)
+ if (state_filter == TASK_UNINTERRUPTIBLE && state == TASK_IDLE)
return false;
return true;
}
-void show_state_filter(unsigned long state_filter)
+void show_state_filter(unsigned int state_filter)
{
struct task_struct *g, *p;
* NOTE: this function does not set the idle thread's NEED_RESCHED
* flag, to make booting more robust.
*/
-void init_idle(struct task_struct *idle, int cpu)
+void __init init_idle(struct task_struct *idle, int cpu)
{
struct rq *rq = cpu_rq(cpu);
unsigned long flags;
__sched_fork(0, idle);
+ /*
+ * The idle task doesn't need the kthread struct to function, but it
+ * is dressed up as a per-CPU kthread and thus needs to play the part
+ * if we want to avoid special-casing it in code that deals with per-CPU
+ * kthreads.
+ */
+ set_kthread_struct(idle);
+
raw_spin_lock_irqsave(&idle->pi_lock, flags);
- raw_spin_lock(&rq->lock);
+ raw_spin_rq_lock(rq);
- idle->state = TASK_RUNNING;
+ idle->__state = TASK_RUNNING;
idle->se.exec_start = sched_clock();
- idle->flags |= PF_IDLE;
+ /*
+ * PF_KTHREAD should already be set at this point; regardless, make it
+ * look like a proper per-CPU kthread.
+ */
+ idle->flags |= PF_IDLE | PF_KTHREAD | PF_NO_SETAFFINITY;
+ kthread_set_per_cpu(idle, cpu);
scs_task_reset(idle);
kasan_unpoison_task_stack(idle);
#ifdef CONFIG_SMP
idle->on_cpu = 1;
#endif
- raw_spin_unlock(&rq->lock);
+ raw_spin_rq_unlock(rq);
raw_spin_unlock_irqrestore(&idle->pi_lock, flags);
/* Set the preempt count _outside_ the spinlocks! */
{
struct task_struct *push_task = rq->curr;
- lockdep_assert_held(&rq->lock);
- SCHED_WARN_ON(rq->cpu != smp_processor_id());
+ lockdep_assert_rq_held(rq);
/*
* Ensure the thing is persistent until balance_push_set(.on = false);
rq->balance_callback = &balance_push_callback;
/*
- * Only active while going offline.
+ * Only active while going offline and when invoked on the outgoing
+ * CPU.
*/
- if (!cpu_dying(rq->cpu))
+ if (!cpu_dying(rq->cpu) || rq != this_rq())
return;
/*
* Both the cpu-hotplug and stop task are in this case and are
* required to complete the hotplug process.
- *
- * XXX: the idle task does not match kthread_is_per_cpu() due to
- * histerical raisins.
*/
- if (rq->idle == push_task ||
- kthread_is_per_cpu(push_task) ||
+ if (kthread_is_per_cpu(push_task) ||
is_migration_disabled(push_task)) {
/*
*/
if (!rq->nr_running && !rq_has_pinned_tasks(rq) &&
rcuwait_active(&rq->hotplug_wait)) {
- raw_spin_unlock(&rq->lock);
+ raw_spin_rq_unlock(rq);
rcuwait_wake_up(&rq->hotplug_wait);
- raw_spin_lock(&rq->lock);
+ raw_spin_rq_lock(rq);
}
return;
}
* Temporarily drop rq->lock such that we can wake-up the stop task.
* Both preemption and IRQs are still disabled.
*/
- raw_spin_unlock(&rq->lock);
+ raw_spin_rq_unlock(rq);
stop_one_cpu_nowait(rq->cpu, __balance_push_cpu_stop, push_task,
this_cpu_ptr(&push_work));
/*
* schedule(). The next pick is obviously going to be the stop task
* which kthread_is_per_cpu() and will push this task away.
*/
- raw_spin_lock(&rq->lock);
+ raw_spin_rq_lock(rq);
}
static void balance_push_set(int cpu, bool on)
*/
if (cpumask_weight(cpu_smt_mask(cpu)) == 2)
static_branch_dec_cpuslocked(&sched_smt_present);
+
+ sched_core_cpu_deactivate(cpu);
#endif
if (!sched_smp_initialized)
int sched_cpu_starting(unsigned int cpu)
{
+ sched_core_cpu_starting(cpu);
sched_rq_cpu_starting(cpu);
sched_tick_start(cpu);
return 0;
struct task_struct *g, *p;
int cpu = cpu_of(rq);
- lockdep_assert_held(&rq->lock);
+ lockdep_assert_rq_held(rq);
printk("%sCPU%d enqueued tasks (%u total):\n", loglvl, cpu, rq->nr_running);
for_each_process_thread(g, p) {
calc_load_migrate(rq);
update_max_interval();
hrtick_clear(rq);
+ sched_core_cpu_dying(cpu);
return 0;
}
#endif
/* Move init over to a non-isolated CPU */
if (set_cpus_allowed_ptr(current, housekeeping_cpumask(HK_FLAG_DOMAIN)) < 0)
BUG();
+ current->flags &= ~PF_NO_SETAFFINITY;
sched_init_granularity();
init_sched_rt_class();
struct rq *rq;
rq = cpu_rq(i);
- raw_spin_lock_init(&rq->lock);
+ raw_spin_lock_init(&rq->__lock);
rq->nr_running = 0;
rq->calc_load_active = 0;
rq->calc_load_update = jiffies + LOAD_FREQ;
rq->online = 0;
rq->idle_stamp = 0;
rq->avg_idle = 2*sysctl_sched_migration_cost;
+ rq->wake_stamp = jiffies;
+ rq->wake_avg_idle = rq->avg_idle;
rq->max_idle_balance_cost = sysctl_sched_migration_cost;
INIT_LIST_HEAD(&rq->cfs_tasks);
#endif /* CONFIG_SMP */
hrtick_rq_init(rq);
atomic_set(&rq->nr_iowait, 0);
+
+#ifdef CONFIG_SCHED_CORE
+ rq->core = rq;
+ rq->core_pick = NULL;
+ rq->core_enabled = 0;
+ rq->core_tree = RB_ROOT;
+ rq->core_forceidle = false;
+
+ rq->core_cookie = 0UL;
+#endif
}
set_load_weight(&init_task, false);
#endif
init_sched_fair_class();
- init_schedstats();
-
psi_init();
init_uclamp();
void __might_sleep(const char *file, int line, int preempt_offset)
{
+ unsigned int state = get_current_state();
/*
* Blocking primitives will set (and therefore destroy) current->state,
* since we will exit with TASK_RUNNING make sure we enter with it,
* otherwise we will destroy state.
*/
- WARN_ONCE(current->state != TASK_RUNNING && current->task_state_change,
+ WARN_ONCE(state != TASK_RUNNING && current->task_state_change,
"do not call blocking ops when !TASK_RUNNING; "
- "state=%lx set at [<%p>] %pS\n",
- current->state,
+ "state=%x set at [<%p>] %pS\n", state,
(void *)current->task_state_change,
(void *)current->task_state_change);
#ifdef CONFIG_UCLAMP_TASK_GROUP
/* Propagate the effective uclamp value for the new group */
+ mutex_lock(&uclamp_mutex);
+ rcu_read_lock();
cpu_util_update_eff(css);
+ rcu_read_unlock();
+ mutex_unlock(&uclamp_mutex);
#endif
return 0;
* has happened. This would lead to problems with PELT, due to
* move wanting to detach+attach while we're not attached yet.
*/
- if (task->state == TASK_NEW)
+ if (READ_ONCE(task->__state) == TASK_NEW)
ret = -EINVAL;
raw_spin_unlock_irq(&task->pi_lock);
enum uclamp_id clamp_id;
unsigned int clamps;
+ lockdep_assert_held(&uclamp_mutex);
+ SCHED_WARN_ON(!rcu_read_lock_held());
+
css_for_each_descendant_pre(css, top_css) {
uc_parent = css_tg(css)->parent
? css_tg(css)->parent->uclamp : NULL;
}
/* Immediately update descendants RUNNABLE tasks */
- uclamp_update_active_tasks(css, clamps);
+ uclamp_update_active_tasks(css);
}
}
static int __cfs_schedulable(struct task_group *tg, u64 period, u64 runtime);
-static int tg_set_cfs_bandwidth(struct task_group *tg, u64 period, u64 quota)
+static int tg_set_cfs_bandwidth(struct task_group *tg, u64 period, u64 quota,
+ u64 burst)
{
int i, ret = 0, runtime_enabled, runtime_was_enabled;
struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth;
if (quota != RUNTIME_INF && quota > max_cfs_runtime)
return -EINVAL;
+ if (quota != RUNTIME_INF && (burst > quota ||
+ burst + quota > max_cfs_runtime))
+ return -EINVAL;
+
/*
* Prevent race between setting of cfs_rq->runtime_enabled and
* unthrottle_offline_cfs_rqs().
raw_spin_lock_irq(&cfs_b->lock);
cfs_b->period = ns_to_ktime(period);
cfs_b->quota = quota;
+ cfs_b->burst = burst;
__refill_cfs_bandwidth_runtime(cfs_b);
static int tg_set_cfs_quota(struct task_group *tg, long cfs_quota_us)
{
- u64 quota, period;
+ u64 quota, period, burst;
period = ktime_to_ns(tg->cfs_bandwidth.period);
+ burst = tg->cfs_bandwidth.burst;
if (cfs_quota_us < 0)
quota = RUNTIME_INF;
else if ((u64)cfs_quota_us <= U64_MAX / NSEC_PER_USEC)
else
return -EINVAL;
- return tg_set_cfs_bandwidth(tg, period, quota);
+ return tg_set_cfs_bandwidth(tg, period, quota, burst);
}
static long tg_get_cfs_quota(struct task_group *tg)
static int tg_set_cfs_period(struct task_group *tg, long cfs_period_us)
{
- u64 quota, period;
+ u64 quota, period, burst;
if ((u64)cfs_period_us > U64_MAX / NSEC_PER_USEC)
return -EINVAL;
period = (u64)cfs_period_us * NSEC_PER_USEC;
quota = tg->cfs_bandwidth.quota;
+ burst = tg->cfs_bandwidth.burst;
- return tg_set_cfs_bandwidth(tg, period, quota);
+ return tg_set_cfs_bandwidth(tg, period, quota, burst);
}
static long tg_get_cfs_period(struct task_group *tg)
return cfs_period_us;
}
+static int tg_set_cfs_burst(struct task_group *tg, long cfs_burst_us)
+{
+ u64 quota, period, burst;
+
+ if ((u64)cfs_burst_us > U64_MAX / NSEC_PER_USEC)
+ return -EINVAL;
+
+ burst = (u64)cfs_burst_us * NSEC_PER_USEC;
+ period = ktime_to_ns(tg->cfs_bandwidth.period);
+ quota = tg->cfs_bandwidth.quota;
+
+ return tg_set_cfs_bandwidth(tg, period, quota, burst);
+}
+
+static long tg_get_cfs_burst(struct task_group *tg)
+{
+ u64 burst_us;
+
+ burst_us = tg->cfs_bandwidth.burst;
+ do_div(burst_us, NSEC_PER_USEC);
+
+ return burst_us;
+}
+
static s64 cpu_cfs_quota_read_s64(struct cgroup_subsys_state *css,
struct cftype *cft)
{
return tg_set_cfs_period(css_tg(css), cfs_period_us);
}
+static u64 cpu_cfs_burst_read_u64(struct cgroup_subsys_state *css,
+ struct cftype *cft)
+{
+ return tg_get_cfs_burst(css_tg(css));
+}
+
+static int cpu_cfs_burst_write_u64(struct cgroup_subsys_state *css,
+ struct cftype *cftype, u64 cfs_burst_us)
+{
+ return tg_set_cfs_burst(css_tg(css), cfs_burst_us);
+}
+
struct cfs_schedulable_data {
struct task_group *tg;
u64 period, quota;
.read_u64 = cpu_cfs_period_read_u64,
.write_u64 = cpu_cfs_period_write_u64,
},
+ {
+ .name = "cfs_burst_us",
+ .read_u64 = cpu_cfs_burst_read_u64,
+ .write_u64 = cpu_cfs_burst_write_u64,
+ },
{
.name = "stat",
.seq_show = cpu_cfs_stat_show,
{
struct task_group *tg = css_tg(of_css(of));
u64 period = tg_get_cfs_period(tg);
+ u64 burst = tg_get_cfs_burst(tg);
u64 quota;
int ret;
ret = cpu_period_quota_parse(buf, &period, "a);
if (!ret)
- ret = tg_set_cfs_bandwidth(tg, period, quota);
+ ret = tg_set_cfs_bandwidth(tg, period, quota, burst);
return ret ?: nbytes;
}
#endif
.seq_show = cpu_max_show,
.write = cpu_max_write,
},
+ {
+ .name = "max.burst",
+ .flags = CFTYPE_NOT_ON_ROOT,
+ .read_u64 = cpu_cfs_burst_read_u64,
+ .write_u64 = cpu_cfs_burst_write_u64,
+ },
#endif
#ifdef CONFIG_UCLAMP_TASK_GROUP
{
projects / linux-2.6-microblaze.git / blobdiff