Commit message: sched: Fix information leak in sys_sched_getattr()

We're copying the on-stack structure to userspace, but forgot to give
the right number of bytes to copy. This allows the calling process to
obtain up to PAGE_SIZE bytes from the stack (and possibly adjacent
kernel memory).

This fix copies only as much as we actually have on the stack
(attr->size defaults to the size of the struct) and leaves the rest of
the userspace-provided buffer untouched.

Found using kmemcheck + trinity.

Fixes: d50dde5a10f30 ("sched: Add new scheduler syscalls to support an extended scheduling parameters ABI")
Cc: Dario Faggioli <raistlin@linux.it>
Cc: Juri Lelli <juri.lelli@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1392585857-10725-1-git-send-email-vegard.nossum@oracle.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
CVE: CVE-2014-9903
CWE: CWE-200
Vulnerability description: The sched_read_attr function in kernel/sched/core.c in the Linux kernel 3.14-rc before 3.14-rc4 uses an incorrect size, which allows local users to obtain sensitive information from kernel stack memory via a crafted sched_getattr system call.

Project: linux
File: core.c

SYSCALL_DEFINE2(sched_setattr, pid_t, pid, struct sched_attr __user *, uattr)
{
	struct sched_attr attr;
	struct task_struct *p;
	int retval;

	if (!uattr || pid < 0)
		return -EINVAL;

	if (sched_copy_attr(uattr, &attr))
		return -EFAULT;

	rcu_read_lock();
	retval = -ESRCH;
	p = find_process_by_pid(pid);
	if (p != NULL)
		retval = sched_setattr(p, &attr);
	rcu_read_unlock();

	return retval;
}

Project: linux
File: core.c

SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param)
{
	struct sched_param lp;
	struct task_struct *p;
	int retval;

	if (!param || pid < 0)
		return -EINVAL;

	rcu_read_lock();
	p = find_process_by_pid(pid);
	retval = -ESRCH;
	if (!p)
		goto out_unlock;

	retval = security_task_getscheduler(p);
	if (retval)
		goto out_unlock;

	if (task_has_dl_policy(p)) {
		retval = -EINVAL;
		goto out_unlock;
	}
	lp.sched_priority = p->rt_priority;
	rcu_read_unlock();

	/*
	 * This one might sleep, we cannot do it with a spinlock held ...
	 */
	retval = copy_to_user(param, &lp, sizeof(*param)) ? -EFAULT : 0;

	return retval;

out_unlock:
	rcu_read_unlock();
	return retval;
}

Project: linux
File: core.c

SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid,
		struct timespec __user *, interval)
{
	struct task_struct *p;
	unsigned int time_slice;
	unsigned long flags;
	struct rq *rq;
	int retval;
	struct timespec t;

	if (pid < 0)
		return -EINVAL;

	retval = -ESRCH;
	rcu_read_lock();
	p = find_process_by_pid(pid);
	if (!p)
		goto out_unlock;

	retval = security_task_getscheduler(p);
	if (retval)
		goto out_unlock;

	rq = task_rq_lock(p, &flags);
	time_slice = 0;
	if (p->sched_class->get_rr_interval)
		time_slice = p->sched_class->get_rr_interval(rq, p);
	task_rq_unlock(rq, p, &flags);

	rcu_read_unlock();
	jiffies_to_timespec(time_slice, &t);
	retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0;
	return retval;

out_unlock:
	rcu_read_unlock();
	return retval;
}

Project: linux
File: core.c

SYSCALL_DEFINE3(sched_getattr, pid_t, pid, struct sched_attr __user *, uattr,
		unsigned int, size)
{
	struct sched_attr attr = {
		.size = sizeof(struct sched_attr),
	};
	struct task_struct *p;
	int retval;

	if (!uattr || pid < 0 || size > PAGE_SIZE ||
	    size < SCHED_ATTR_SIZE_VER0)
		return -EINVAL;

	rcu_read_lock();
	p = find_process_by_pid(pid);
	retval = -ESRCH;
	if (!p)
		goto out_unlock;

	retval = security_task_getscheduler(p);
	if (retval)
		goto out_unlock;

	attr.sched_policy = p->policy;
	if (p->sched_reset_on_fork)
		attr.sched_flags |= SCHED_FLAG_RESET_ON_FORK;
	if (task_has_dl_policy(p))
		__getparam_dl(p, &attr);
	else if (task_has_rt_policy(p))
		attr.sched_priority = p->rt_priority;
	else
		attr.sched_nice = TASK_NICE(p);

	rcu_read_unlock();

	retval = sched_read_attr(uattr, &attr, size);
	return retval;

out_unlock:
	rcu_read_unlock();
	return retval;
}

Project: linux
File: core.c

__checkparam_dl(const struct sched_attr *attr)
{
	return attr && attr->sched_deadline != 0 &&
		(attr->sched_period == 0 ||
		(s64)(attr->sched_period   - attr->sched_deadline) >= 0) &&
		(s64)(attr->sched_deadline - attr->sched_runtime ) >= 0  &&
		attr->sched_runtime >= (2 << (DL_SCALE - 1));
}

Project: linux
File: core.c

void __dl_add(struct dl_bw *dl_b, u64 tsk_bw)
{
	dl_b->total_bw += tsk_bw;
}

Project: linux
File: core.c

void __dl_clear(struct dl_bw *dl_b, u64 tsk_bw)
{
	dl_b->total_bw -= tsk_bw;
}

Project: linux
File: core.c

bool __dl_overflow(struct dl_bw *dl_b, int cpus, u64 old_bw, u64 new_bw)
{
	return dl_b->bw != -1 &&
	       dl_b->bw * cpus < dl_b->total_bw - old_bw + new_bw;
}

Project: linux
File: core.c

void __might_sleep(const char *file, int line, int preempt_offset)
{
	static unsigned long prev_jiffy;	/* ratelimiting */

	rcu_sleep_check(); /* WARN_ON_ONCE() by default, no rate limit reqd. */
	if ((preempt_count_equals(preempt_offset) && !irqs_disabled()) ||
	    system_state != SYSTEM_RUNNING || oops_in_progress)
		return;
	if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy)
		return;
	prev_jiffy = jiffies;

	printk(KERN_ERR
		"BUG: sleeping function called from invalid context at %s:%d\n",
			file, line);
	printk(KERN_ERR
		"in_atomic(): %d, irqs_disabled(): %d, pid: %d, name: %s\n",
			in_atomic(), irqs_disabled(),
			current->pid, current->comm);

	debug_show_held_locks(current);
	if (irqs_disabled())
		print_irqtrace_events(current);
	dump_stack();
}

Project: linux
File: core.c

static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu)
{
	struct rq *rq_dest, *rq_src;
	int ret = 0;

	if (unlikely(!cpu_active(dest_cpu)))
		return ret;

	rq_src = cpu_rq(src_cpu);
	rq_dest = cpu_rq(dest_cpu);

	raw_spin_lock(&p->pi_lock);
	double_rq_lock(rq_src, rq_dest);
	/* Already moved. */
	if (task_cpu(p) != src_cpu)
		goto done;
	/* Affinity changed (again). */
	if (!cpumask_test_cpu(dest_cpu, tsk_cpus_allowed(p)))
		goto fail;

	/*
	 * If we're not on a rq, the next wake-up will ensure we're
	 * placed properly.
	 */
	if (p->on_rq) {
		dequeue_task(rq_src, p, 0);
		set_task_cpu(p, dest_cpu);
		enqueue_task(rq_dest, p, 0);
		check_preempt_curr(rq_dest, p, 0);
	}
done:
	ret = 1;
fail:
	double_rq_unlock(rq_src, rq_dest);
	raw_spin_unlock(&p->pi_lock);
	return ret;
}

Project: linux
File: core.c

static void __sched_fork(unsigned long clone_flags, struct task_struct *p)
{
	p->on_rq			= 0;

	p->se.on_rq			= 0;
	p->se.exec_start		= 0;
	p->se.sum_exec_runtime		= 0;
	p->se.prev_sum_exec_runtime	= 0;
	p->se.nr_migrations		= 0;
	p->se.vruntime			= 0;
	INIT_LIST_HEAD(&p->se.group_node);

#ifdef CONFIG_SCHEDSTATS
	memset(&p->se.statistics, 0, sizeof(p->se.statistics));
#endif

	RB_CLEAR_NODE(&p->dl.rb_node);
	hrtimer_init(&p->dl.dl_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
	p->dl.dl_runtime = p->dl.runtime = 0;
	p->dl.dl_deadline = p->dl.deadline = 0;
	p->dl.dl_period = 0;
	p->dl.flags = 0;

	INIT_LIST_HEAD(&p->rt.run_list);

#ifdef CONFIG_PREEMPT_NOTIFIERS
	INIT_HLIST_HEAD(&p->preempt_notifiers);
#endif

#ifdef CONFIG_NUMA_BALANCING
	if (p->mm && atomic_read(&p->mm->mm_users) == 1) {
		p->mm->numa_next_scan = jiffies + msecs_to_jiffies(sysctl_numa_balancing_scan_delay);
		p->mm->numa_scan_seq = 0;
	}

	if (clone_flags & CLONE_VM)
		p->numa_preferred_nid = current->numa_preferred_nid;
	else
		p->numa_preferred_nid = -1;

	p->node_stamp = 0ULL;
	p->numa_scan_seq = p->mm ? p->mm->numa_scan_seq : 0;
	p->numa_scan_period = sysctl_numa_balancing_scan_delay;
	p->numa_work.next = &p->numa_work;
	p->numa_faults = NULL;
	p->numa_faults_buffer = NULL;

	INIT_LIST_HEAD(&p->numa_entry);
	p->numa_group = NULL;
#endif /* CONFIG_NUMA_BALANCING */
}

Project: linux
File: core.c

static int __sched_setscheduler(struct task_struct *p,
				const struct sched_attr *attr,
				bool user)
{
	int retval, oldprio, oldpolicy = -1, on_rq, running;
	int policy = attr->sched_policy;
	unsigned long flags;
	const struct sched_class *prev_class;
	struct rq *rq;
	int reset_on_fork;

	/* may grab non-irq protected spin_locks */
	BUG_ON(in_interrupt());
recheck:
	/* double check policy once rq lock held */
	if (policy < 0) {
		reset_on_fork = p->sched_reset_on_fork;
		policy = oldpolicy = p->policy;
	} else {
		reset_on_fork = !!(attr->sched_flags & SCHED_FLAG_RESET_ON_FORK);

		if (policy != SCHED_DEADLINE &&
				policy != SCHED_FIFO && policy != SCHED_RR &&
				policy != SCHED_NORMAL && policy != SCHED_BATCH &&
				policy != SCHED_IDLE)
			return -EINVAL;
	}

	if (attr->sched_flags & ~(SCHED_FLAG_RESET_ON_FORK))
		return -EINVAL;

	/*
	 * Valid priorities for SCHED_FIFO and SCHED_RR are
	 * 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL,
	 * SCHED_BATCH and SCHED_IDLE is 0.
	 */
	if ((p->mm && attr->sched_priority > MAX_USER_RT_PRIO-1) ||
	    (!p->mm && attr->sched_priority > MAX_RT_PRIO-1))
		return -EINVAL;
	if ((dl_policy(policy) && !__checkparam_dl(attr)) ||
	    (rt_policy(policy) != (attr->sched_priority != 0)))
		return -EINVAL;

	/*
	 * Allow unprivileged RT tasks to decrease priority:
	 */
	if (user && !capable(CAP_SYS_NICE)) {
		if (fair_policy(policy)) {
			if (attr->sched_nice < TASK_NICE(p) &&
			    !can_nice(p, attr->sched_nice))
				return -EPERM;
		}

		if (rt_policy(policy)) {
			unsigned long rlim_rtprio =
					task_rlimit(p, RLIMIT_RTPRIO);

			/* can't set/change the rt policy */
			if (policy != p->policy && !rlim_rtprio)
				return -EPERM;

			/* can't increase priority */
			if (attr->sched_priority > p->rt_priority &&
			    attr->sched_priority > rlim_rtprio)
				return -EPERM;
		}

		/*
		 * Treat SCHED_IDLE as nice 20. Only allow a switch to
		 * SCHED_NORMAL if the RLIMIT_NICE would normally permit it.
		 */
		if (p->policy == SCHED_IDLE && policy != SCHED_IDLE) {
			if (!can_nice(p, TASK_NICE(p)))
				return -EPERM;
		}

		/* can't change other user's priorities */
		if (!check_same_owner(p))
			return -EPERM;

		/* Normal users shall not reset the sched_reset_on_fork flag */
		if (p->sched_reset_on_fork && !reset_on_fork)
			return -EPERM;
	}

	if (user) {
		retval = security_task_setscheduler(p);
		if (retval)
			return retval;
	}

	/*
	 * make sure no PI-waiters arrive (or leave) while we are
	 * changing the priority of the task:
	 *
	 * To be able to change p->policy safely, the appropriate
	 * runqueue lock must be held.
	 */
	rq = task_rq_lock(p, &flags);

	/*
	 * Changing the policy of the stop threads its a very bad idea
	 */
	if (p == rq->stop) {
		task_rq_unlock(rq, p, &flags);
		return -EINVAL;
	}

	/*
	 * If not changing anything there's no need to proceed further:
	 */
	if (unlikely(policy == p->policy)) {
		if (fair_policy(policy) && attr->sched_nice != TASK_NICE(p))
			goto change;
		if (rt_policy(policy) && attr->sched_priority != p->rt_priority)
			goto change;
		if (dl_policy(policy))
			goto change;

		task_rq_unlock(rq, p, &flags);
		return 0;
	}
change:

	if (user) {
#ifdef CONFIG_RT_GROUP_SCHED
		/*
		 * Do not allow realtime tasks into groups that have no runtime
		 * assigned.
		 */
		if (rt_bandwidth_enabled() && rt_policy(policy) &&
				task_group(p)->rt_bandwidth.rt_runtime == 0 &&
				!task_group_is_autogroup(task_group(p))) {
			task_rq_unlock(rq, p, &flags);
			return -EPERM;
		}
#endif
#ifdef CONFIG_SMP
		if (dl_bandwidth_enabled() && dl_policy(policy)) {
			cpumask_t *span = rq->rd->span;

			/*
			 * Don't allow tasks with an affinity mask smaller than
			 * the entire root_domain to become SCHED_DEADLINE. We
			 * will also fail if there's no bandwidth available.
			 */
			if (!cpumask_subset(span, &p->cpus_allowed) ||
			    rq->rd->dl_bw.bw == 0) {
				task_rq_unlock(rq, p, &flags);
				return -EPERM;
			}
		}
#endif
	}

	/* recheck policy now with rq lock held */
	if (unlikely(oldpolicy != -1 && oldpolicy != p->policy)) {
		policy = oldpolicy = -1;
		task_rq_unlock(rq, p, &flags);
		goto recheck;
	}

	/*
	 * If setscheduling to SCHED_DEADLINE (or changing the parameters
	 * of a SCHED_DEADLINE task) we need to check if enough bandwidth
	 * is available.
	 */
	if ((dl_policy(policy) || dl_task(p)) && dl_overflow(p, policy, attr)) {
		task_rq_unlock(rq, p, &flags);
		return -EBUSY;
	}

	on_rq = p->on_rq;
	running = task_current(rq, p);
	if (on_rq)
		dequeue_task(rq, p, 0);
	if (running)
		p->sched_class->put_prev_task(rq, p);

	p->sched_reset_on_fork = reset_on_fork;

	oldprio = p->prio;
	prev_class = p->sched_class;
	__setscheduler(rq, p, attr);

	if (running)
		p->sched_class->set_curr_task(rq);
	if (on_rq)
		enqueue_task(rq, p, 0);

	check_class_changed(rq, p, prev_class, oldprio);
	task_rq_unlock(rq, p, &flags);

	rt_mutex_adjust_pi(p);

	return 0;
}

Project: linux
File: core.c

static void __sched __schedule(void)
{
	struct task_struct *prev, *next;
	unsigned long *switch_count;
	struct rq *rq;
	int cpu;

need_resched:
	preempt_disable();
	cpu = smp_processor_id();
	rq = cpu_rq(cpu);
	rcu_note_context_switch(cpu);
	prev = rq->curr;

	schedule_debug(prev);

	if (sched_feat(HRTICK))
		hrtick_clear(rq);

	/*
	 * Make sure that signal_pending_state()->signal_pending() below
	 * can't be reordered with __set_current_state(TASK_INTERRUPTIBLE)
	 * done by the caller to avoid the race with signal_wake_up().
	 */
	smp_mb__before_spinlock();
	raw_spin_lock_irq(&rq->lock);

	switch_count = &prev->nivcsw;
	if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) {
		if (unlikely(signal_pending_state(prev->state, prev))) {
			prev->state = TASK_RUNNING;
		} else {
			deactivate_task(rq, prev, DEQUEUE_SLEEP);
			prev->on_rq = 0;

			/*
			 * If a worker went to sleep, notify and ask workqueue
			 * whether it wants to wake up a task to maintain
			 * concurrency.
			 */
			if (prev->flags & PF_WQ_WORKER) {
				struct task_struct *to_wakeup;

				to_wakeup = wq_worker_sleeping(prev, cpu);
				if (to_wakeup)
					try_to_wake_up_local(to_wakeup);
			}
		}
		switch_count = &prev->nvcsw;
	}

	pre_schedule(rq, prev);

	if (unlikely(!rq->nr_running))
		idle_balance(cpu, rq);

	put_prev_task(rq, prev);
	next = pick_next_task(rq);
	clear_tsk_need_resched(prev);
	clear_preempt_need_resched();
	rq->skip_clock_update = 0;

	if (likely(prev != next)) {
		rq->nr_switches++;
		rq->curr = next;
		++*switch_count;

		context_switch(rq, prev, next); /* unlocks the rq */
		/*
		 * The context switch have flipped the stack from under us
		 * and restored the local variables which were saved when
		 * this task called schedule() in the past. prev == current
		 * is still correct, but it can be moved to another cpu/rq.
		 */
		cpu = smp_processor_id();
		rq = cpu_rq(cpu);
	} else
		raw_spin_unlock_irq(&rq->lock);

	post_schedule(rq);

	sched_preempt_enable_no_resched();
	if (need_resched())
		goto need_resched;
}

Project: linux
File: core.c

static noinline void __schedule_bug(struct task_struct *prev)
{
	if (oops_in_progress)
		return;

	printk(KERN_ERR "BUG: scheduling while atomic: %s/%d/0x%08x\n",
		prev->comm, prev->pid, preempt_count());

	debug_show_held_locks(prev);
	print_modules();
	if (irqs_disabled())
		print_irqtrace_events(prev);
	dump_stack();
	add_taint(TAINT_WARN, LOCKDEP_STILL_OK);
}

Project: linux
File: core.c

static int __sdt_alloc(const struct cpumask *cpu_map)
{
	struct sched_domain_topology_level *tl;
	int j;

	for_each_sd_topology(tl) {
		struct sd_data *sdd = &tl->data;

		sdd->sd = alloc_percpu(struct sched_domain *);
		if (!sdd->sd)
			return -ENOMEM;

		sdd->sg = alloc_percpu(struct sched_group *);
		if (!sdd->sg)
			return -ENOMEM;

		sdd->sgp = alloc_percpu(struct sched_group_power *);
		if (!sdd->sgp)
			return -ENOMEM;

		for_each_cpu(j, cpu_map) {
			struct sched_domain *sd;
			struct sched_group *sg;
			struct sched_group_power *sgp;

		       	sd = kzalloc_node(sizeof(struct sched_domain) + cpumask_size(),
					GFP_KERNEL, cpu_to_node(j));
			if (!sd)
				return -ENOMEM;

			*per_cpu_ptr(sdd->sd, j) = sd;

			sg = kzalloc_node(sizeof(struct sched_group) + cpumask_size(),
					GFP_KERNEL, cpu_to_node(j));
			if (!sg)
				return -ENOMEM;

			sg->next = sg;

			*per_cpu_ptr(sdd->sg, j) = sg;

			sgp = kzalloc_node(sizeof(struct sched_group_power) + cpumask_size(),
					GFP_KERNEL, cpu_to_node(j));
			if (!sgp)
				return -ENOMEM;

			*per_cpu_ptr(sdd->sgp, j) = sgp;
		}
	}

	return 0;
}

Project: linux
File: core.c

static void __sdt_free(const struct cpumask *cpu_map)
{
	struct sched_domain_topology_level *tl;
	int j;

	for_each_sd_topology(tl) {
		struct sd_data *sdd = &tl->data;

		for_each_cpu(j, cpu_map) {
			struct sched_domain *sd;

			if (sdd->sd) {
				sd = *per_cpu_ptr(sdd->sd, j);
				if (sd && (sd->flags & SD_OVERLAP))
					free_sched_groups(sd->groups, 0);
				kfree(*per_cpu_ptr(sdd->sd, j));
			}

			if (sdd->sg)
				kfree(*per_cpu_ptr(sdd->sg, j));
			if (sdd->sgp)
				kfree(*per_cpu_ptr(sdd->sgp, j));
		}
		free_percpu(sdd->sd);
		sdd->sd = NULL;
		free_percpu(sdd->sg);
		sdd->sg = NULL;
		free_percpu(sdd->sgp);
		sdd->sgp = NULL;
	}
}

Project: linux
File: core.c

__setparam_dl(struct task_struct *p, const struct sched_attr *attr)
{
	struct sched_dl_entity *dl_se = &p->dl;

	init_dl_task_timer(dl_se);
	dl_se->dl_runtime = attr->sched_runtime;
	dl_se->dl_deadline = attr->sched_deadline;
	dl_se->dl_period = attr->sched_period ?: dl_se->dl_deadline;
	dl_se->flags = attr->sched_flags;
	dl_se->dl_bw = to_ratio(dl_se->dl_period, dl_se->dl_runtime);
	dl_se->dl_throttled = 0;
	dl_se->dl_new = 1;
}

Project: linux
File: core.c

static void __setscheduler(struct rq *rq, struct task_struct *p,
			   const struct sched_attr *attr)
{
	int policy = attr->sched_policy;

	if (policy == -1) /* setparam */
		policy = p->policy;

	p->policy = policy;

	if (dl_policy(policy))
		__setparam_dl(p, attr);
	else if (fair_policy(policy))
		p->static_prio = NICE_TO_PRIO(attr->sched_nice);

	/*
	 * __sched_setscheduler() ensures attr->sched_priority == 0 when
	 * !rt_policy. Always setting this ensures that things like
	 * getparam()/getattr() don't report silly values for !rt tasks.
	 */
	p->rt_priority = attr->sched_priority;

	p->normal_prio = normal_prio(p);
	p->prio = rt_mutex_getprio(p);

	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;

	set_load_weight(p);
}

Project: linux
File: core.c

static int _sched_setscheduler(struct task_struct *p, int policy,
			       const struct sched_param *param, bool check)
{
	struct sched_attr attr = {
		.sched_policy   = policy,
		.sched_priority = param->sched_priority,
		.sched_nice	= PRIO_TO_NICE(p->static_prio),
	};

	/*
	 * Fixup the legacy SCHED_RESET_ON_FORK hack
	 */
	if (policy & SCHED_RESET_ON_FORK) {
		attr.sched_flags |= SCHED_FLAG_RESET_ON_FORK;
		policy &= ~SCHED_RESET_ON_FORK;
		attr.sched_policy = policy;
	}

	return __sched_setscheduler(p, &attr, check);
}

Project: linux
File: core.c

int __weak arch_sd_sibling_asym_packing(void)
{
       return 0*SD_ASYM_PACKING;
}

Project: linux
File: core.c

build_overlap_sched_groups(struct sched_domain *sd, int cpu)
{
	struct sched_group *first = NULL, *last = NULL, *groups = NULL, *sg;
	const struct cpumask *span = sched_domain_span(sd);
	struct cpumask *covered = sched_domains_tmpmask;
	struct sd_data *sdd = sd->private;
	struct sched_domain *child;
	int i;

	cpumask_clear(covered);

	for_each_cpu(i, span) {
		struct cpumask *sg_span;

		if (cpumask_test_cpu(i, covered))
			continue;

		child = *per_cpu_ptr(sdd->sd, i);

		/* See the comment near build_group_mask(). */
		if (!cpumask_test_cpu(i, sched_domain_span(child)))
			continue;

		sg = kzalloc_node(sizeof(struct sched_group) + cpumask_size(),
				GFP_KERNEL, cpu_to_node(cpu));

		if (!sg)
			goto fail;

		sg_span = sched_group_cpus(sg);
		if (child->child) {
			child = child->child;
			cpumask_copy(sg_span, sched_domain_span(child));
		} else
			cpumask_set_cpu(i, sg_span);

		cpumask_or(covered, covered, sg_span);

		sg->sgp = *per_cpu_ptr(sdd->sgp, i);
		if (atomic_inc_return(&sg->sgp->ref) == 1)
			build_group_mask(sd, sg);

		/*
		 * Initialize sgp->power such that even if we mess up the
		 * domains and no possible iteration will get us here, we won't
		 * die on a /0 trap.
		 */
		sg->sgp->power = SCHED_POWER_SCALE * cpumask_weight(sg_span);
		sg->sgp->power_orig = sg->sgp->power;

		/*
		 * Make sure the first group of this domain contains the
		 * canonical balance cpu. Otherwise the sched_domain iteration
		 * breaks. See update_sg_lb_stats().
		 */
		if ((!groups && cpumask_test_cpu(cpu, sg_span)) ||
		    group_balance_cpu(sg) == cpu)
			groups = sg;

		if (!first)
			first = sg;
		if (last)
			last->next = sg;
		last = sg;
		last->next = first;
	}
	sd->groups = groups;

	return 0;

fail:
	free_sched_groups(first, 0);

	return -ENOMEM;
}

Project: linux
File: core.c

struct sched_domain *build_sched_domain(struct sched_domain_topology_level *tl,
		const struct cpumask *cpu_map, struct sched_domain_attr *attr,
		struct sched_domain *child, int cpu)
{
	struct sched_domain *sd = tl->init(tl, cpu);
	if (!sd)
		return child;

	cpumask_and(sched_domain_span(sd), cpu_map, tl->mask(cpu));
	if (child) {
		sd->level = child->level + 1;
		sched_domain_level_max = max(sched_domain_level_max, sd->level);
		child->parent = sd;
		sd->child = child;
	}
	set_domain_attribute(sd, attr);

	return sd;
}

Project: linux
File: core.c

build_sched_groups(struct sched_domain *sd, int cpu)
{
	struct sched_group *first = NULL, *last = NULL;
	struct sd_data *sdd = sd->private;
	const struct cpumask *span = sched_domain_span(sd);
	struct cpumask *covered;
	int i;

	get_group(cpu, sdd, &sd->groups);
	atomic_inc(&sd->groups->ref);

	if (cpu != cpumask_first(span))
		return 0;

	lockdep_assert_held(&sched_domains_mutex);
	covered = sched_domains_tmpmask;

	cpumask_clear(covered);

	for_each_cpu(i, span) {
		struct sched_group *sg;
		int group, j;

		if (cpumask_test_cpu(i, covered))
			continue;

		group = get_group(i, sdd, &sg);
		cpumask_clear(sched_group_cpus(sg));
		sg->sgp->power = 0;
		cpumask_setall(sched_group_mask(sg));

		for_each_cpu(j, span) {
			if (get_group(j, sdd, NULL) != group)
				continue;

			cpumask_set_cpu(j, covered);
			cpumask_set_cpu(j, sched_group_cpus(sg));
		}

		if (!first)
			first = sg;
		if (last)
			last->next = sg;
		last = sg;
	}
	last->next = first;

	return 0;
}

Project: linux
File: core.c

void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags)
{
	const struct sched_class *class;

	if (p->sched_class == rq->curr->sched_class) {
		rq->curr->sched_class->check_preempt_curr(rq, p, flags);
	} else {
		for_each_class(class) {
			if (class == rq->curr->sched_class)
				break;
			if (class == p->sched_class) {
				resched_task(rq->curr);
				break;
			}
		}
	}

	/*
	 * A queue event has occurred, and we're going to schedule.  In
	 * this case, we can save a useless back to back clock update.
	 */
	if (rq->curr->on_rq && test_tsk_need_resched(rq->curr))
		rq->skip_clock_update = 1;
}

Project: linux
File: core.c

static void claim_allocations(int cpu, struct sched_domain *sd)
{
	struct sd_data *sdd = sd->private;

	WARN_ON_ONCE(*per_cpu_ptr(sdd->sd, cpu) != sd);
	*per_cpu_ptr(sdd->sd, cpu) = NULL;

	if (atomic_read(&(*per_cpu_ptr(sdd->sg, cpu))->ref))
		*per_cpu_ptr(sdd->sg, cpu) = NULL;

	if (atomic_read(&(*per_cpu_ptr(sdd->sgp, cpu))->ref))
		*per_cpu_ptr(sdd->sgp, cpu) = NULL;
}

Project: linux
File: core.c

context_switch(struct rq *rq, struct task_struct *prev,
	       struct task_struct *next)
{
	struct mm_struct *mm, *oldmm;

	prepare_task_switch(rq, prev, next);

	mm = next->mm;
	oldmm = prev->active_mm;
	/*
	 * For paravirt, this is coupled with an exit in switch_to to
	 * combine the page table reload and the switch backend into
	 * one hypercall.
	 */
	arch_start_context_switch(prev);

	if (!mm) {
		next->active_mm = oldmm;
		atomic_inc(&oldmm->mm_count);
		enter_lazy_tlb(oldmm, next);
	} else
		switch_mm(oldmm, mm, next);

	if (!prev->mm) {
		prev->active_mm = NULL;
		rq->prev_mm = oldmm;
	}
	/*
	 * Since the runqueue lock will be released by the next
	 * task (which is an invalid locking op but in the case
	 * of the scheduler it's an obvious special-case), so we
	 * do an early lockdep release here:
	 */
#ifndef __ARCH_WANT_UNLOCKED_CTXSW
	spin_release(&rq->lock.dep_map, 1, _THIS_IP_);
#endif

	context_tracking_task_switch(prev, next);
	/* Here we just switch the register state and the stack. */
	switch_to(prev, next, prev);

	barrier();
	/*
	 * this_rq must be evaluated again because prev may have moved
	 * CPUs since it called schedule(), thus the 'rq' on its stack
	 * frame will be invalid.
	 */
	finish_task_switch(this_rq(), prev);
}

Project: linux
File: core.c

static void cpu_cgroup_attach(struct cgroup_subsys_state *css,
			      struct cgroup_taskset *tset)
{
	struct task_struct *task;

	cgroup_taskset_for_each(task, css, tset)
		sched_move_task(task);
}

Project: linux
File: core.c

static int cpu_cgroup_can_attach(struct cgroup_subsys_state *css,
				 struct cgroup_taskset *tset)
{
	struct task_struct *task;

	cgroup_taskset_for_each(task, css, tset) {
#ifdef CONFIG_RT_GROUP_SCHED
		if (!sched_rt_can_attach(css_tg(css), task))
			return -EINVAL;
#else
		/* We don't support RT-tasks being in separate groups */
		if (task->sched_class != &fair_sched_class)
			return -EINVAL;
#endif
	}
	return 0;
}

Project: linux
File: core.c

cpu_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
{
	struct task_group *parent = css_tg(parent_css);
	struct task_group *tg;

	if (!parent) {
		/* This is early initialization for the top cgroup */
		return &root_task_group.css;
	}

	tg = sched_create_group(parent);
	if (IS_ERR(tg))
		return ERR_PTR(-ENOMEM);

	return &tg->css;
}

Project: linux
File: core.c

static void cpu_cgroup_css_free(struct cgroup_subsys_state *css)
{
	struct task_group *tg = css_tg(css);

	sched_destroy_group(tg);
}

Project: linux
File: core.c

static void cpu_cgroup_css_offline(struct cgroup_subsys_state *css)
{
	struct task_group *tg = css_tg(css);

	sched_offline_group(tg);
}

Project: linux
File: core.c

static int cpu_cgroup_css_online(struct cgroup_subsys_state *css)
{
	struct task_group *tg = css_tg(css);
	struct task_group *parent = css_tg(css_parent(css));

	if (parent)
		sched_online_group(tg, parent);
	return 0;
}

Project: linux
File: core.c

static void cpu_cgroup_exit(struct cgroup_subsys_state *css,
			    struct cgroup_subsys_state *old_css,
			    struct task_struct *task)
{
	/*
	 * cgroup_exit() is called in the copy_process() failure path.
	 * Ignore this case since the task hasn't ran yet, this avoids
	 * trying to poke a half freed task state from generic code.
	 */
	if (!(task->flags & PF_EXITING))
		return;

	sched_move_task(task);
}

Project: linux
File: core.c

static int cpuset_cpu_active(struct notifier_block *nfb, unsigned long action,
			     void *hcpu)
{
	switch (action) {
	case CPU_ONLINE_FROZEN:
	case CPU_DOWN_FAILED_FROZEN:

		/*
		 * num_cpus_frozen tracks how many CPUs are involved in suspend
		 * resume sequence. As long as this is not the last online
		 * operation in the resume sequence, just build a single sched
		 * domain, ignoring cpusets.
		 */
		num_cpus_frozen--;
		if (likely(num_cpus_frozen)) {
			partition_sched_domains(1, NULL, NULL);
			break;
		}

		/*
		 * This is the last CPU online operation. So fall through and
		 * restore the original sched domains by considering the
		 * cpuset configurations.
		 */

	case CPU_ONLINE:
	case CPU_DOWN_FAILED:
		cpuset_update_active_cpus(true);
		break;
	default:
		return NOTIFY_DONE;
	}
	return NOTIFY_OK;
}

Project: linux
File: core.c

static int cpuset_cpu_inactive(struct notifier_block *nfb, unsigned long action,
			       void *hcpu)
{
	switch (action) {
	case CPU_DOWN_PREPARE:
		cpuset_update_active_cpus(false);
		break;
	case CPU_DOWN_PREPARE_FROZEN:
		num_cpus_frozen++;
		partition_sched_domains(1, NULL, NULL);
		break;
	default:
		return NOTIFY_DONE;
	}
	return NOTIFY_OK;
}

Project: linux
File: core.c

static void dequeue_task(struct rq *rq, struct task_struct *p, int flags)
{
	update_rq_clock(rq);
	sched_info_dequeued(rq, p);
	p->sched_class->dequeue_task(rq, p, flags);
}

Project: linux
File: core.c

static inline int dl_bw_cpus(int i)
{
	struct root_domain *rd = cpu_rq(i)->rd;
	int cpus = 0;

	for_each_cpu_and(i, rd->span, cpu_active_mask)
		cpus++;

	return cpus;
}

Project: linux
File: core.c

inline struct dl_bw *dl_bw_of(int i)
{
	return &cpu_rq(i)->rd->dl_bw;
}

Project: linux
File: core.c

static int dl_overflow(struct task_struct *p, int policy,
		       const struct sched_attr *attr)
{

	struct dl_bw *dl_b = dl_bw_of(task_cpu(p));
	u64 period = attr->sched_period ?: attr->sched_deadline;
	u64 runtime = attr->sched_runtime;
	u64 new_bw = dl_policy(policy) ? to_ratio(period, runtime) : 0;
	int cpus, err = -1;

	if (new_bw == p->dl.dl_bw)
		return 0;

	/*
	 * Either if a task, enters, leave, or stays -deadline but changes
	 * its parameters, we may need to update accordingly the total
	 * allocated bandwidth of the container.
	 */
	raw_spin_lock(&dl_b->lock);
	cpus = dl_bw_cpus(task_cpu(p));
	if (dl_policy(policy) && !task_has_dl_policy(p) &&
	    !__dl_overflow(dl_b, cpus, 0, new_bw)) {
		__dl_add(dl_b, new_bw);
		err = 0;
	} else if (dl_policy(policy) && task_has_dl_policy(p) &&
		   !__dl_overflow(dl_b, cpus, p->dl.dl_bw, new_bw)) {
		__dl_clear(dl_b, p->dl.dl_bw);
		__dl_add(dl_b, new_bw);
		err = 0;
	} else if (!dl_policy(policy) && task_has_dl_policy(p)) {
		__dl_clear(dl_b, p->dl.dl_bw);
		err = 0;
	}
	raw_spin_unlock(&dl_b->lock);

	return err;
}

Project: linux
File: core.c

static u64 do_task_delta_exec(struct task_struct *p, struct rq *rq)
{
	u64 ns = 0;

	if (task_current(rq, p)) {
		update_rq_clock(rq);
		ns = rq_clock_task(rq) - p->se.exec_start;
		if ((s64)ns < 0)
			ns = 0;
	}

	return ns;
}

Project: linux
File: core.c

static void enqueue_task(struct rq *rq, struct task_struct *p, int flags)
{
	update_rq_clock(rq);
	sched_info_queued(rq, p);
	p->sched_class->enqueue_task(rq, p, flags);
}

Project: linux
File: core.c

static bool find_numa_distance(int distance)
{
	int i;

	if (distance == node_distance(0, 0))
		return true;

	for (i = 0; i < sched_domains_numa_levels; i++) {
		if (sched_domains_numa_distance[i] == distance)
			return true;
	}

	return false;
}

Project: linux
File: core.c

static void fire_sched_in_preempt_notifiers(struct task_struct *curr)
{
	struct preempt_notifier *notifier;

	hlist_for_each_entry(notifier, &curr->preempt_notifiers, link)
		notifier->ops->sched_in(notifier, raw_smp_processor_id());
}

Project: linux
File: core.c

fire_sched_out_preempt_notifiers(struct task_struct *curr,
				 struct task_struct *next)
{
	struct preempt_notifier *notifier;

	hlist_for_each_entry(notifier, &curr->preempt_notifiers, link)
		notifier->ops->sched_out(notifier, next);
}

Project: linux
File: core.c

static void free_sched_groups(struct sched_group *sg, int free_sgp)
{
	struct sched_group *tmp, *first;

	if (!sg)
		return;

	first = sg;
	do {
		tmp = sg->next;

		if (free_sgp && atomic_dec_and_test(&sg->sgp->ref))
			kfree(sg->sgp);

		kfree(sg);
		sg = tmp;
	} while (sg != first);
}

Project: linux
File: core.c

static int get_group(int cpu, struct sd_data *sdd, struct sched_group **sg)
{
	struct sched_domain *sd = *per_cpu_ptr(sdd->sd, cpu);
	struct sched_domain *child = sd->child;

	if (child)
		cpu = cpumask_first(sched_domain_span(child));

	if (sg) {
		*sg = *per_cpu_ptr(sdd->sg, cpu);
		(*sg)->sgp = *per_cpu_ptr(sdd->sgp, cpu);
		atomic_set(&(*sg)->sgp->ref, 1); /* for claim_allocations */
	}

	return cpu;
}

Project: linux
File: core.c

void hrtick_start(struct rq *rq, u64 delay)
{
	struct hrtimer *timer = &rq->hrtick_timer;
	ktime_t time = ktime_add_ns(timer->base->get_time(), delay);

	hrtimer_set_expires(timer, time);

	if (rq == this_rq()) {
		__hrtick_restart(rq);
	} else if (!rq->hrtick_csd_pending) {
		__smp_call_function_single(cpu_of(rq), &rq->hrtick_csd, 0);
		rq->hrtick_csd_pending = 1;
	}
}

Project: linux
File: core.c

void hrtick_start(struct rq *rq, u64 delay)
{
	__hrtimer_start_range_ns(&rq->hrtick_timer, ns_to_ktime(delay), 0,
			HRTIMER_MODE_REL_PINNED, 0);
}

Project: linux
File: core.c

void init_idle(struct task_struct *idle, int cpu)
{
	struct rq *rq = cpu_rq(cpu);
	unsigned long flags;

	raw_spin_lock_irqsave(&rq->lock, flags);

	__sched_fork(0, idle);
	idle->state = TASK_RUNNING;
	idle->se.exec_start = sched_clock();

	do_set_cpus_allowed(idle, cpumask_of(cpu));
	/*
	 * We're having a chicken and egg problem, even though we are
	 * holding rq->lock, the cpu isn't yet set to this cpu so the
	 * lockdep check in task_group() will fail.
	 *
	 * Similar case to sched_fork(). / Alternatively we could
	 * use task_rq_lock() here and obtain the other rq->lock.
	 *
	 * Silence PROVE_RCU
	 */
	rcu_read_lock();
	__set_task_cpu(idle, cpu);
	rcu_read_unlock();

	rq->curr = rq->idle = idle;
#if defined(CONFIG_SMP)
	idle->on_cpu = 1;
#endif
	raw_spin_unlock_irqrestore(&rq->lock, flags);

	/* Set the preempt count _outside_ the spinlocks! */
	init_idle_preempt_count(idle, cpu);

	/*
	 * The idle tasks have their own, simple scheduling class:
	 */
	idle->sched_class = &idle_sched_class;
	ftrace_graph_init_idle_task(idle, cpu);
	vtime_init_idle(idle, cpu);
#if defined(CONFIG_SMP)
	sprintf(idle->comm, "%s/%d", INIT_TASK_COMM, cpu);
#endif
}

Project: linux
File: core.c

static int init_rootdomain(struct root_domain *rd)
{
	memset(rd, 0, sizeof(*rd));

	if (!alloc_cpumask_var(&rd->span, GFP_KERNEL))
		goto out;
	if (!alloc_cpumask_var(&rd->online, GFP_KERNEL))
		goto free_span;
	if (!alloc_cpumask_var(&rd->dlo_mask, GFP_KERNEL))
		goto free_online;
	if (!alloc_cpumask_var(&rd->rto_mask, GFP_KERNEL))
		goto free_dlo_mask;

	init_dl_bw(&rd->dl_bw);
	if (cpudl_init(&rd->cpudl) != 0)
		goto free_dlo_mask;

	if (cpupri_init(&rd->cpupri) != 0)
		goto free_rto_mask;
	return 0;

free_rto_mask:
	free_cpumask_var(rd->rto_mask);
free_dlo_mask:
	free_cpumask_var(rd->dlo_mask);
free_online:
	free_cpumask_var(rd->online);
free_span:
	free_cpumask_var(rd->span);
out:
	return -ENOMEM;
}

Project: linux
File: core.c

static void init_sched_groups_power(int cpu, struct sched_domain *sd)
{
	struct sched_group *sg = sd->groups;

	WARN_ON(!sg);

	do {
		sg->group_weight = cpumask_weight(sched_group_cpus(sg));
		sg = sg->next;
	} while (sg != sd->groups);

	if (cpu != group_balance_cpu(sg))
		return;

	update_group_power(sd, cpu);
	atomic_set(&sg->sgp->nr_busy_cpus, sg->group_weight);
}

Project: linux
File: core.c

static void migrate_tasks(unsigned int dead_cpu)
{
	struct rq *rq = cpu_rq(dead_cpu);
	struct task_struct *next, *stop = rq->stop;
	int dest_cpu;

	/*
	 * Fudge the rq selection such that the below task selection loop
	 * doesn't get stuck on the currently eligible stop task.
	 *
	 * We're currently inside stop_machine() and the rq is either stuck
	 * in the stop_machine_cpu_stop() loop, or we're executing this code,
	 * either way we should never end up calling schedule() until we're
	 * done here.
	 */
	rq->stop = NULL;

	/*
	 * put_prev_task() and pick_next_task() sched
	 * class method both need to have an up-to-date
	 * value of rq->clock[_task]
	 */
	update_rq_clock(rq);

	for ( ; ; ) {
		/*
		 * There's this thread running, bail when that's the only
		 * remaining thread.
		 */
		if (rq->nr_running == 1)
			break;

		next = pick_next_task(rq);
		BUG_ON(!next);
		next->sched_class->put_prev_task(rq, next);

		/* Find suitable destination for @next, with force if needed. */
		dest_cpu = select_fallback_rq(dead_cpu, next);
		raw_spin_unlock(&rq->lock);

		__migrate_task(next, dead_cpu, dest_cpu);

		raw_spin_lock(&rq->lock);
	}

	rq->stop = stop;
}

Project: linux
File: core.c

migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
{
	int cpu = (long)hcpu;
	unsigned long flags;
	struct rq *rq = cpu_rq(cpu);

	switch (action & ~CPU_TASKS_FROZEN) {

	case CPU_UP_PREPARE:
		rq->calc_load_update = calc_load_update;
		break;

	case CPU_ONLINE:
		/* Update our root-domain */
		raw_spin_lock_irqsave(&rq->lock, flags);
		if (rq->rd) {
			BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span));

			set_rq_online(rq);
		}
		raw_spin_unlock_irqrestore(&rq->lock, flags);
		break;

#ifdef CONFIG_HOTPLUG_CPU
	case CPU_DYING:
		sched_ttwu_pending();
		/* Update our root-domain */
		raw_spin_lock_irqsave(&rq->lock, flags);
		if (rq->rd) {
			BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span));
			set_rq_offline(rq);
		}
		migrate_tasks(cpu);
		BUG_ON(rq->nr_running != 1); /* the migration thread */
		raw_spin_unlock_irqrestore(&rq->lock, flags);
		break;

	case CPU_DEAD:
		calc_load_migrate(rq);
		break;
#endif
	}

	update_max_interval();

	return NOTIFY_OK;
}

Project: linux
File: core.c

void normalize_rt_tasks(void)
{
	struct task_struct *g, *p;
	unsigned long flags;
	struct rq *rq;

	read_lock_irqsave(&tasklist_lock, flags);
	do_each_thread(g, p) {
		/*
		 * Only normalize user tasks:
		 */
		if (!p->mm)
			continue;

		p->se.exec_start		= 0;
#ifdef CONFIG_SCHEDSTATS
		p->se.statistics.wait_start	= 0;
		p->se.statistics.sleep_start	= 0;
		p->se.statistics.block_start	= 0;
#endif

		if (!dl_task(p) && !rt_task(p)) {
			/*
			 * Renice negative nice level userspace
			 * tasks back to 0:
			 */
			if (TASK_NICE(p) < 0 && p->mm)
				set_user_nice(p, 0);
			continue;
		}

		raw_spin_lock(&p->pi_lock);
		rq = __task_rq_lock(p);

		normalize_task(rq, p);

		__task_rq_unlock(rq);
		raw_spin_unlock(&p->pi_lock);
	} while_each_thread(g, p);

	read_unlock_irqrestore(&tasklist_lock, flags);
}

Project: linux
File: core.c

static void normalize_task(struct rq *rq, struct task_struct *p)
{
	const struct sched_class *prev_class = p->sched_class;
	struct sched_attr attr = {
		.sched_policy = SCHED_NORMAL,
	};
	int old_prio = p->prio;
	int on_rq;

	on_rq = p->on_rq;
	if (on_rq)
		dequeue_task(rq, p, 0);
	__setscheduler(rq, p, &attr);
	if (on_rq) {
		enqueue_task(rq, p, 0);
		resched_task(rq->curr);
	}

	check_class_changed(rq, p, prev_class, old_prio);
}

Project: linux
File: core.c

void __kprobes preempt_count_sub(int val)
{
#ifdef CONFIG_DEBUG_PREEMPT
	/*
	 * Underflow?
	 */
	if (DEBUG_LOCKS_WARN_ON(val > preempt_count()))
		return;
	/*
	 * Is the spinlock portion underflowing?
	 */
	if (DEBUG_LOCKS_WARN_ON((val < PREEMPT_MASK) &&
			!(preempt_count() & PREEMPT_MASK)))
		return;
#endif

	if (preempt_count() == val)
		trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1));
	__preempt_count_sub(val);
}

Project: linux
File: core.c

asmlinkage void __sched notrace preempt_schedule(void)
{
	/*
	 * If there is a non-zero preempt_count or interrupts are disabled,
	 * we do not want to preempt the current task. Just return..
	 */
	if (likely(!preemptible()))
		return;

	do {
		__preempt_count_add(PREEMPT_ACTIVE);
		__schedule();
		__preempt_count_sub(PREEMPT_ACTIVE);

		/*
		 * Check again in case we missed a preemption opportunity
		 * between schedule and now.
		 */
		barrier();
	} while (need_resched());
}

Project: linux
File: core.c

asmlinkage void __sched preempt_schedule_irq(void)
{
	enum ctx_state prev_state;

	/* Catch callers which need to be fixed */
	BUG_ON(preempt_count() || !irqs_disabled());

	prev_state = exception_enter();

	do {
		__preempt_count_add(PREEMPT_ACTIVE);
		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();
	} while (need_resched());

	exception_exit(prev_state);
}

Project: linux
File: core.c

prepare_task_switch(struct rq *rq, struct task_struct *prev,
		    struct task_struct *next)
{
	trace_sched_switch(prev, next);
	sched_info_switch(rq, prev, next);
	perf_event_task_sched_out(prev, next);
	fire_sched_out_preempt_notifiers(prev, next);
	prepare_lock_switch(rq, next);
	prepare_arch_switch(next);
}

Project: linux
File: core.c

void resched_task(struct task_struct *p)
{
	int cpu;

	lockdep_assert_held(&task_rq(p)->lock);

	if (test_tsk_need_resched(p))
		return;

	set_tsk_need_resched(p);

	cpu = task_cpu(p);
	if (cpu == smp_processor_id()) {
		set_preempt_need_resched();
		return;
	}

	/* NEED_RESCHED must be visible before we test polling */
	smp_mb();
	if (!tsk_is_polling(p))
		smp_send_reschedule(cpu);
}

Project: linux
File: core.c

void rt_mutex_setprio(struct task_struct *p, int prio)
{
	int oldprio, on_rq, running, enqueue_flag = 0;
	struct rq *rq;
	const struct sched_class *prev_class;

	BUG_ON(prio > MAX_PRIO);

	rq = __task_rq_lock(p);

	/*
	 * Idle task boosting is a nono in general. There is one
	 * exception, when PREEMPT_RT and NOHZ is active:
	 *
	 * The idle task calls get_next_timer_interrupt() and holds
	 * the timer wheel base->lock on the CPU and another CPU wants
	 * to access the timer (probably to cancel it). We can safely
	 * ignore the boosting request, as the idle CPU runs this code
	 * with interrupts disabled and will complete the lock
	 * protected section without being interrupted. So there is no
	 * real need to boost.
	 */
	if (unlikely(p == rq->idle)) {
		WARN_ON(p != rq->curr);
		WARN_ON(p->pi_blocked_on);
		goto out_unlock;
	}

	trace_sched_pi_setprio(p, prio);
	p->pi_top_task = rt_mutex_get_top_task(p);
	oldprio = p->prio;
	prev_class = p->sched_class;
	on_rq = p->on_rq;
	running = task_current(rq, p);
	if (on_rq)
		dequeue_task(rq, p, 0);
	if (running)
		p->sched_class->put_prev_task(rq, p);

	/*
	 * Boosting condition are:
	 * 1. -rt task is running and holds mutex A
	 *      --> -dl task blocks on mutex A
	 *
	 * 2. -dl task is running and holds mutex A
	 *      --> -dl task blocks on mutex A and could preempt the
	 *          running task
	 */
	if (dl_prio(prio)) {
		if (!dl_prio(p->normal_prio) || (p->pi_top_task &&
			dl_entity_preempt(&p->pi_top_task->dl, &p->dl))) {
			p->dl.dl_boosted = 1;
			p->dl.dl_throttled = 0;
			enqueue_flag = ENQUEUE_REPLENISH;
		} else
			p->dl.dl_boosted = 0;
		p->sched_class = &dl_sched_class;
	} else if (rt_prio(prio)) {
		if (dl_prio(oldprio))
			p->dl.dl_boosted = 0;
		if (oldprio < prio)
			enqueue_flag = ENQUEUE_HEAD;
		p->sched_class = &rt_sched_class;
	} else {
		if (dl_prio(oldprio))
			p->dl.dl_boosted = 0;
		p->sched_class = &fair_sched_class;
	}

	p->prio = prio;

	if (running)
		p->sched_class->set_curr_task(rq);
	if (on_rq)
		enqueue_task(rq, p, enqueue_flag);

	check_class_changed(rq, p, prev_class, oldprio);
out_unlock:
	__task_rq_unlock(rq);
}

Project: linux
File: core.c

bool sched_can_stop_tick(void)
{
       struct rq *rq;

       rq = this_rq();

       /* Make sure rq->nr_running update is visible after the IPI */
       smp_rmb();

       /* More than one running task need preemption */
       if (rq->nr_running > 1)
               return false;

       return true;
}

Project: linux
File: core.c

static int sched_copy_attr(struct sched_attr __user *uattr,
			   struct sched_attr *attr)
{
	u32 size;
	int ret;

	if (!access_ok(VERIFY_WRITE, uattr, SCHED_ATTR_SIZE_VER0))
		return -EFAULT;

	/*
	 * zero the full structure, so that a short copy will be nice.
	 */
	memset(attr, 0, sizeof(*attr));

	ret = get_user(size, &uattr->size);
	if (ret)
		return ret;

	if (size > PAGE_SIZE)	/* silly large */
		goto err_size;

	if (!size)		/* abi compat */
		size = SCHED_ATTR_SIZE_VER0;

	if (size < SCHED_ATTR_SIZE_VER0)
		goto err_size;

	/*
	 * If we're handed a bigger struct than we know of,
	 * ensure all the unknown bits are 0 - i.e. new
	 * user-space does not rely on any kernel feature
	 * extensions we dont know about yet.
	 */
	if (size > sizeof(*attr)) {
		unsigned char __user *addr;
		unsigned char __user *end;
		unsigned char val;

		addr = (void __user *)uattr + sizeof(*attr);
		end  = (void __user *)uattr + size;

		for (; addr < end; addr++) {
			ret = get_user(val, addr);
			if (ret)
				return ret;
			if (val)
				goto err_size;
		}
		size = sizeof(*attr);
	}

	ret = copy_from_user(attr, uattr, size);
	if (ret)
		return -EFAULT;

	/*
	 * XXX: do we want to be lenient like existing syscalls; or do we want
	 * to be strict and return an error on out-of-bounds values?
	 */
	attr->sched_nice = clamp(attr->sched_nice, -20, 19);

out:
	return ret;

err_size:
	put_user(sizeof(*attr), &uattr->size);
	ret = -E2BIG;
	goto out;
}

Project: linux
File: core.c

static int sched_cpu_active(struct notifier_block *nfb,
				      unsigned long action, void *hcpu)
{
	switch (action & ~CPU_TASKS_FROZEN) {
	case CPU_STARTING:
	case CPU_DOWN_FAILED:
		set_cpu_active((long)hcpu, true);
		return NOTIFY_OK;
	default:
		return NOTIFY_DONE;
	}
}

Project: linux
File: core.c

static int sched_cpu_inactive(struct notifier_block *nfb,
					unsigned long action, void *hcpu)
{
	unsigned long flags;
	long cpu = (long)hcpu;

	switch (action & ~CPU_TASKS_FROZEN) {
	case CPU_DOWN_PREPARE:
		set_cpu_active(cpu, false);

		/* explicitly allow suspend */
		if (!(action & CPU_TASKS_FROZEN)) {
			struct dl_bw *dl_b = dl_bw_of(cpu);
			bool overflow;
			int cpus;

			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);

			if (overflow)
				return notifier_from_errno(-EBUSY);
		}
		return NOTIFY_OK;
	}

	return NOTIFY_DONE;
}

Project: linux
File: core.c

struct task_group *sched_create_group(struct task_group *parent)
{
	struct task_group *tg;

	tg = kzalloc(sizeof(*tg), GFP_KERNEL);
	if (!tg)
		return ERR_PTR(-ENOMEM);

	if (!alloc_fair_sched_group(tg, parent))
		goto err;

	if (!alloc_rt_sched_group(tg, parent))
		goto err;

	return tg;

err:
	free_sched_group(tg);
	return ERR_PTR(-ENOMEM);
}

Project: linux
File: core.c

void sched_destroy_group(struct task_group *tg)
{
	/* wait for possible concurrent references to cfs_rqs complete */
	call_rcu(&tg->rcu, free_sched_group_rcu);
}

Project: linux
File: core.c

static void sched_dl_do_global(void)
{
	u64 new_bw = -1;
	int cpu;
	unsigned long flags;

	def_dl_bandwidth.dl_period = global_rt_period();
	def_dl_bandwidth.dl_runtime = global_rt_runtime();

	if (global_rt_runtime() != RUNTIME_INF)
		new_bw = to_ratio(global_rt_period(), global_rt_runtime());

	/*
	 * FIXME: As above...
	 */
	for_each_possible_cpu(cpu) {
		struct dl_bw *dl_b = dl_bw_of(cpu);

		raw_spin_lock_irqsave(&dl_b->lock, flags);
		dl_b->bw = new_bw;
		raw_spin_unlock_irqrestore(&dl_b->lock, flags);
	}
}

Project: linux
File: core.c

static int sched_dl_global_constraints(void)
{
	u64 runtime = global_rt_runtime();
	u64 period = global_rt_period();
	u64 new_bw = to_ratio(period, runtime);
	int cpu, ret = 0;
	unsigned long flags;

	/*
	 * Here we want to check the bandwidth not being set to some
	 * value smaller than the currently allocated bandwidth in
	 * any of the root_domains.
	 *
	 * FIXME: Cycling on all the CPUs is overdoing, but simpler than
	 * cycling on root_domains... Discussion on different/better
	 * solutions is welcome!
	 */
	for_each_possible_cpu(cpu) {
		struct dl_bw *dl_b = dl_bw_of(cpu);

		raw_spin_lock_irqsave(&dl_b->lock, flags);
		if (new_bw < dl_b->total_bw)
			ret = -EBUSY;
		raw_spin_unlock_irqrestore(&dl_b->lock, flags);

		if (ret)
			break;
	}

	return ret;
}

Project: linux
File: core.c

static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level,
				  struct cpumask *groupmask)
{
	struct sched_group *group = sd->groups;
	char str[256];

	cpulist_scnprintf(str, sizeof(str), sched_domain_span(sd));
	cpumask_clear(groupmask);

	printk(KERN_DEBUG "%*s domain %d: ", level, "", level);

	if (!(sd->flags & SD_LOAD_BALANCE)) {
		printk("does not load-balance\n");
		if (sd->parent)
			printk(KERN_ERR "ERROR: !SD_LOAD_BALANCE domain"
					" has parent");
		return -1;
	}

	printk(KERN_CONT "span %s level %s\n", str, sd->name);

	if (!cpumask_test_cpu(cpu, sched_domain_span(sd))) {
		printk(KERN_ERR "ERROR: domain->span does not contain "
				"CPU%d\n", cpu);
	}
	if (!cpumask_test_cpu(cpu, sched_group_cpus(group))) {
		printk(KERN_ERR "ERROR: domain->groups does not contain"
				" CPU%d\n", cpu);
	}

	printk(KERN_DEBUG "%*s groups:", level + 1, "");
	do {
		if (!group) {
			printk("\n");
			printk(KERN_ERR "ERROR: group is NULL\n");
			break;
		}

		/*
		 * Even though we initialize ->power to something semi-sane,
		 * we leave power_orig unset. This allows us to detect if
		 * domain iteration is still funny without causing /0 traps.
		 */
		if (!group->sgp->power_orig) {
			printk(KERN_CONT "\n");
			printk(KERN_ERR "ERROR: domain->cpu_power not "
					"set\n");
			break;
		}

		if (!cpumask_weight(sched_group_cpus(group))) {
			printk(KERN_CONT "\n");
			printk(KERN_ERR "ERROR: empty group\n");
			break;
		}

		if (!(sd->flags & SD_OVERLAP) &&
		    cpumask_intersects(groupmask, sched_group_cpus(group))) {
			printk(KERN_CONT "\n");
			printk(KERN_ERR "ERROR: repeated CPUs\n");
			break;
		}

		cpumask_or(groupmask, groupmask, sched_group_cpus(group));

		cpulist_scnprintf(str, sizeof(str), sched_group_cpus(group));

		printk(KERN_CONT " %s", str);
		if (group->sgp->power != SCHED_POWER_SCALE) {
			printk(KERN_CONT " (cpu_power = %d)",
				group->sgp->power);
		}

		group = group->next;
	} while (group != sd->groups);
	printk(KERN_CONT "\n");

	if (!cpumask_equal(sched_domain_span(sd), groupmask))
		printk(KERN_ERR "ERROR: groups don't span domain->span\n");

	if (sd->parent &&
	    !cpumask_subset(groupmask, sched_domain_span(sd->parent)))
		printk(KERN_ERR "ERROR: parent span is not a superset "
			"of domain->span\n");
	return 0;
}

Project: linux
File: core.c

static void sched_domains_numa_masks_clear(int cpu)
{
	int i, j;
	for (i = 0; i < sched_domains_numa_levels; i++) {
		for (j = 0; j < nr_node_ids; j++)
			cpumask_clear_cpu(cpu, sched_domains_numa_masks[i][j]);
	}
}

Project: linux
File: core.c

static void sched_domains_numa_masks_set(int cpu)
{
	int i, j;
	int node = cpu_to_node(cpu);

	for (i = 0; i < sched_domains_numa_levels; i++) {
		for (j = 0; j < nr_node_ids; j++) {
			if (node_distance(j, node) <= sched_domains_numa_distance[i])
				cpumask_set_cpu(cpu, sched_domains_numa_masks[i][j]);
		}
	}
}

Project: linux
File: core.c

static int sched_domains_numa_masks_update(struct notifier_block *nfb,
					   unsigned long action,
					   void *hcpu)
{
	int cpu = (long)hcpu;

	switch (action & ~CPU_TASKS_FROZEN) {
	case CPU_ONLINE:
		sched_domains_numa_masks_set(cpu);
		break;

	case CPU_DEAD:
		sched_domains_numa_masks_clear(cpu);
		break;

	default:
		return NOTIFY_DONE;
	}

	return NOTIFY_OK;
}

Project: linux
File: core.c

static int sched_domains_numa_masks_update(struct notifier_block *nfb,
					   unsigned long action,
					   void *hcpu)
{
	return 0;
}

Project: linux
File: core.c

static void sched_feat_enable(int i)
{
	if (!static_key_enabled(&sched_feat_keys[i]))
		static_key_slow_inc(&sched_feat_keys[i]);
}

Project: linux
File: core.c

static void sched_feat_enable(int i) { };

Project: linux
File: core.c

static int sched_feat_set(char *cmp)
{
	int i;
	int neg = 0;

	if (strncmp(cmp, "NO_", 3) == 0) {
		neg = 1;
		cmp += 3;
	}

	for (i = 0; i < __SCHED_FEAT_NR; i++) {
		if (strcmp(cmp, sched_feat_names[i]) == 0) {
			if (neg) {
				sysctl_sched_features &= ~(1UL << i);
				sched_feat_disable(i);
			} else {
				sysctl_sched_features |= (1UL << i);
				sched_feat_enable(i);
			}
			break;
		}
	}

	return i;
}

Project: linux
File: core.c

static int sched_feat_show(struct seq_file *m, void *v)
{
	int i;

	for (i = 0; i < __SCHED_FEAT_NR; i++) {
		if (!(sysctl_sched_features & (1UL << i)))
			seq_puts(m, "NO_");
		seq_printf(m, "%s ", sched_feat_names[i]);
	}
	seq_puts(m, "\n");

	return 0;
}

Project: linux
File: core.c

sched_feat_write(struct file *filp, const char __user *ubuf,
		size_t cnt, loff_t *ppos)
{
	char buf[64];
	char *cmp;
	int i;

	if (cnt > 63)
		cnt = 63;

	if (copy_from_user(&buf, ubuf, cnt))
		return -EFAULT;

	buf[cnt] = 0;
	cmp = strstrip(buf);

	i = sched_feat_set(cmp);
	if (i == __SCHED_FEAT_NR)
		return -EINVAL;

	*ppos += cnt;

	return cnt;
}

Project: linux
File: core.c

int sched_fork(unsigned long clone_flags, struct task_struct *p)
{
	unsigned long flags;
	int cpu = get_cpu();

	__sched_fork(clone_flags, p);
	/*
	 * We mark the process as running here. This guarantees that
	 * 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_RUNNING;

	/*
	 * Make sure we do not leak PI boosting priority to the child.
	 */
	p->prio = current->normal_prio;

	/*
	 * Revert to default priority/policy on fork if requested.
	 */
	if (unlikely(p->sched_reset_on_fork)) {
		if (task_has_dl_policy(p) || task_has_rt_policy(p)) {
			p->policy = SCHED_NORMAL;
			p->static_prio = NICE_TO_PRIO(0);
			p->rt_priority = 0;
		} else if (PRIO_TO_NICE(p->static_prio) < 0)
			p->static_prio = NICE_TO_PRIO(0);

		p->prio = p->normal_prio = __normal_prio(p);
		set_load_weight(p);

		/*
		 * We don't need the reset flag anymore after the fork. It has
		 * fulfilled its duty:
		 */
		p->sched_reset_on_fork = 0;
	}

	if (dl_prio(p->prio)) {
		put_cpu();
		return -EAGAIN;
	} else if (rt_prio(p->prio)) {
		p->sched_class = &rt_sched_class;
	} else {
		p->sched_class = &fair_sched_class;
	}

	if (p->sched_class->task_fork)
		p->sched_class->task_fork(p);

	/*
	 * The child is not yet in the pid-hash so no cgroup attach races,
	 * and the cgroup is pinned to this child due to cgroup_fork()
	 * is ran before sched_fork().
	 *
	 * Silence PROVE_RCU.
	 */
	raw_spin_lock_irqsave(&p->pi_lock, flags);
	set_task_cpu(p, cpu);
	raw_spin_unlock_irqrestore(&p->pi_lock, flags);

#if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT)
	if (likely(sched_info_on()))
		memset(&p->sched_info, 0, sizeof(p->sched_info));
#endif
#if defined(CONFIG_SMP)
	p->on_cpu = 0;
#endif
	init_task_preempt_count(p);
#ifdef CONFIG_SMP
	plist_node_init(&p->pushable_tasks, MAX_PRIO);
	RB_CLEAR_NODE(&p->pushable_dl_tasks);
#endif

	put_cpu();
	return 0;
}

Project: linux
File: core.c

static int sched_group_set_rt_period(struct task_group *tg, long rt_period_us)
{
	u64 rt_runtime, rt_period;

	rt_period = (u64)rt_period_us * NSEC_PER_USEC;
	rt_runtime = tg->rt_bandwidth.rt_runtime;

	if (rt_period == 0)
		return -EINVAL;

	return tg_set_rt_bandwidth(tg, rt_period, rt_runtime);
}

Project: linux
File: core.c

void __init sched_init(void)
{
	int i, j;
	unsigned long alloc_size = 0, ptr;

#ifdef CONFIG_FAIR_GROUP_SCHED
	alloc_size += 2 * nr_cpu_ids * sizeof(void **);
#endif
#ifdef CONFIG_RT_GROUP_SCHED
	alloc_size += 2 * nr_cpu_ids * sizeof(void **);
#endif
#ifdef CONFIG_CPUMASK_OFFSTACK
	alloc_size += num_possible_cpus() * cpumask_size();
#endif
	if (alloc_size) {
		ptr = (unsigned long)kzalloc(alloc_size, GFP_NOWAIT);

#ifdef CONFIG_FAIR_GROUP_SCHED
		root_task_group.se = (struct sched_entity **)ptr;
		ptr += nr_cpu_ids * sizeof(void **);

		root_task_group.cfs_rq = (struct cfs_rq **)ptr;
		ptr += nr_cpu_ids * sizeof(void **);

#endif /* CONFIG_FAIR_GROUP_SCHED */
#ifdef CONFIG_RT_GROUP_SCHED
		root_task_group.rt_se = (struct sched_rt_entity **)ptr;
		ptr += nr_cpu_ids * sizeof(void **);

		root_task_group.rt_rq = (struct rt_rq **)ptr;
		ptr += nr_cpu_ids * sizeof(void **);

#endif /* CONFIG_RT_GROUP_SCHED */
#ifdef CONFIG_CPUMASK_OFFSTACK
		for_each_possible_cpu(i) {
			per_cpu(load_balance_mask, i) = (void *)ptr;
			ptr += cpumask_size();
		}
#endif /* CONFIG_CPUMASK_OFFSTACK */
	}

	init_rt_bandwidth(&def_rt_bandwidth,
			global_rt_period(), global_rt_runtime());
	init_dl_bandwidth(&def_dl_bandwidth,
			global_rt_period(), global_rt_runtime());

#ifdef CONFIG_SMP
	init_defrootdomain();
#endif

#ifdef CONFIG_RT_GROUP_SCHED
	init_rt_bandwidth(&root_task_group.rt_bandwidth,
			global_rt_period(), global_rt_runtime());
#endif /* CONFIG_RT_GROUP_SCHED */

#ifdef CONFIG_CGROUP_SCHED
	list_add(&root_task_group.list, &task_groups);
	INIT_LIST_HEAD(&root_task_group.children);
	INIT_LIST_HEAD(&root_task_group.siblings);
	autogroup_init(&init_task);

#endif /* CONFIG_CGROUP_SCHED */

	for_each_possible_cpu(i) {
		struct rq *rq;

		rq = cpu_rq(i);
		raw_spin_lock_init(&rq->lock);
		rq->nr_running = 0;
		rq->calc_load_active = 0;
		rq->calc_load_update = jiffies + LOAD_FREQ;
		init_cfs_rq(&rq->cfs);
		init_rt_rq(&rq->rt, rq);
		init_dl_rq(&rq->dl, rq);
#ifdef CONFIG_FAIR_GROUP_SCHED
		root_task_group.shares = ROOT_TASK_GROUP_LOAD;
		INIT_LIST_HEAD(&rq->leaf_cfs_rq_list);
		/*
		 * How much cpu bandwidth does root_task_group get?
		 *
		 * In case of task-groups formed thr' the cgroup filesystem, it
		 * gets 100% of the cpu resources in the system. This overall
		 * system cpu resource is divided among the tasks of
		 * root_task_group and its child task-groups in a fair manner,
		 * based on each entity's (task or task-group's) weight
		 * (se->load.weight).
		 *
		 * In other words, if root_task_group has 10 tasks of weight
		 * 1024) and two child groups A0 and A1 (of weight 1024 each),
		 * then A0's share of the cpu resource is:
		 *
		 *	A0's bandwidth = 1024 / (10*1024 + 1024 + 1024) = 8.33%
		 *
		 * We achieve this by letting root_task_group's tasks sit
		 * directly in rq->cfs (i.e root_task_group->se[] = NULL).
		 */
		init_cfs_bandwidth(&root_task_group.cfs_bandwidth);
		init_tg_cfs_entry(&root_task_group, &rq->cfs, NULL, i, NULL);
#endif /* CONFIG_FAIR_GROUP_SCHED */

		rq->rt.rt_runtime = def_rt_bandwidth.rt_runtime;
#ifdef CONFIG_RT_GROUP_SCHED
		INIT_LIST_HEAD(&rq->leaf_rt_rq_list);
		init_tg_rt_entry(&root_task_group, &rq->rt, NULL, i, NULL);
#endif

		for (j = 0; j < CPU_LOAD_IDX_MAX; j++)
			rq->cpu_load[j] = 0;

		rq->last_load_update_tick = jiffies;

#ifdef CONFIG_SMP
		rq->sd = NULL;
		rq->rd = NULL;
		rq->cpu_power = SCHED_POWER_SCALE;
		rq->post_schedule = 0;
		rq->active_balance = 0;
		rq->next_balance = jiffies;
		rq->push_cpu = 0;
		rq->cpu = i;
		rq->online = 0;
		rq->idle_stamp = 0;
		rq->avg_idle = 2*sysctl_sched_migration_cost;
		rq->max_idle_balance_cost = sysctl_sched_migration_cost;

		INIT_LIST_HEAD(&rq->cfs_tasks);

		rq_attach_root(rq, &def_root_domain);
#ifdef CONFIG_NO_HZ_COMMON
		rq->nohz_flags = 0;
#endif
#ifdef CONFIG_NO_HZ_FULL
		rq->last_sched_tick = 0;
#endif
#endif
		init_rq_hrtick(rq);
		atomic_set(&rq->nr_iowait, 0);
	}

	set_load_weight(&init_task);

#ifdef CONFIG_PREEMPT_NOTIFIERS
	INIT_HLIST_HEAD(&init_task.preempt_notifiers);
#endif

	/*
	 * The boot idle thread does lazy MMU switching as well:
	 */
	atomic_inc(&init_mm.mm_count);
	enter_lazy_tlb(&init_mm, current);

	/*
	 * Make us the idle thread. Technically, schedule() should not be
	 * called from this thread, however somewhere below it might be,
	 * but because we are the idle thread, we just pick up running again
	 * when this runqueue becomes "idle".
	 */
	init_idle(current, smp_processor_id());

	calc_load_update = jiffies + LOAD_FREQ;

	/*
	 * During early bootup we pretend to be a normal task:
	 */
	current->sched_class = &fair_sched_class;

#ifdef CONFIG_SMP
	zalloc_cpumask_var(&sched_domains_tmpmask, GFP_NOWAIT);
	/* May be allocated at isolcpus cmdline parse time */
	if (cpu_isolated_map == NULL)
		zalloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT);
	idle_thread_set_boot_cpu();
#endif
	init_sched_fair_class();

	scheduler_running = 1;
}

Project: linux
File: core.c

static void sched_init_numa(void)
{
	int next_distance, curr_distance = node_distance(0, 0);
	struct sched_domain_topology_level *tl;
	int level = 0;
	int i, j, k;

	sched_domains_numa_distance = kzalloc(sizeof(int) * nr_node_ids, GFP_KERNEL);
	if (!sched_domains_numa_distance)
		return;

	/*
	 * O(nr_nodes^2) deduplicating selection sort -- in order to find the
	 * unique distances in the node_distance() table.
	 *
	 * Assumes node_distance(0,j) includes all distances in
	 * node_distance(i,j) in order to avoid cubic time.
	 */
	next_distance = curr_distance;
	for (i = 0; i < nr_node_ids; i++) {
		for (j = 0; j < nr_node_ids; j++) {
			for (k = 0; k < nr_node_ids; k++) {
				int distance = node_distance(i, k);

				if (distance > curr_distance &&
				    (distance < next_distance ||
				     next_distance == curr_distance))
					next_distance = distance;

				/*
				 * While not a strong assumption it would be nice to know
				 * about cases where if node A is connected to B, B is not
				 * equally connected to A.
				 */
				if (sched_debug() && node_distance(k, i) != distance)
					sched_numa_warn("Node-distance not symmetric");

				if (sched_debug() && i && !find_numa_distance(distance))
					sched_numa_warn("Node-0 not representative");
			}
			if (next_distance != curr_distance) {
				sched_domains_numa_distance[level++] = next_distance;
				sched_domains_numa_levels = level;
				curr_distance = next_distance;
			} else break;
		}

		/*
		 * In case of sched_debug() we verify the above assumption.
		 */
		if (!sched_debug())
			break;
	}
	/*
	 * 'level' contains the number of unique distances, excluding the
	 * identity distance node_distance(i,i).
	 *
	 * The sched_domains_numa_distance[] array includes the actual distance
	 * numbers.
	 */

	/*
	 * Here, we should temporarily reset sched_domains_numa_levels to 0.
	 * If it fails to allocate memory for array sched_domains_numa_masks[][],
	 * the array will contain less then 'level' members. This could be
	 * dangerous when we use it to iterate array sched_domains_numa_masks[][]
	 * in other functions.
	 *
	 * We reset it to 'level' at the end of this function.
	 */
	sched_domains_numa_levels = 0;

	sched_domains_numa_masks = kzalloc(sizeof(void *) * level, GFP_KERNEL);
	if (!sched_domains_numa_masks)
		return;

	/*
	 * Now for each level, construct a mask per node which contains all
	 * cpus of nodes that are that many hops away from us.
	 */
	for (i = 0; i < level; i++) {
		sched_domains_numa_masks[i] =
			kzalloc(nr_node_ids * sizeof(void *), GFP_KERNEL);
		if (!sched_domains_numa_masks[i])
			return;

		for (j = 0; j < nr_node_ids; j++) {
			struct cpumask *mask = kzalloc(cpumask_size(), GFP_KERNEL);
			if (!mask)
				return;

			sched_domains_numa_masks[i][j] = mask;

			for (k = 0; k < nr_node_ids; k++) {
				if (node_distance(j, k) > sched_domains_numa_distance[i])
					continue;

				cpumask_or(mask, mask, cpumask_of_node(k));
			}
		}
	}

	tl = kzalloc((ARRAY_SIZE(default_topology) + level) *
			sizeof(struct sched_domain_topology_level), GFP_KERNEL);
	if (!tl)
		return;

	/*
	 * Copy the default topology bits..
	 */
	for (i = 0; default_topology[i].init; i++)
		tl[i] = default_topology[i];

	/*
	 * .. and append 'j' levels of NUMA goodness.
	 */
	for (j = 0; j < level; i++, j++) {
		tl[i] = (struct sched_domain_topology_level){
			.init = sd_numa_init,
			.mask = sd_numa_mask,
			.flags = SDTL_OVERLAP,
			.numa_level = j,
		};
	}

	sched_domain_topology = tl;

	sched_domains_numa_levels = level;
}

Project: linux
File: core.c

void __init sched_init_smp(void)
{
	cpumask_var_t non_isolated_cpus;

	alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL);
	alloc_cpumask_var(&fallback_doms, GFP_KERNEL);

	sched_init_numa();

	/*
	 * There's no userspace yet to cause hotplug operations; hence all the
	 * cpu masks are stable and all blatant races in the below code cannot
	 * happen.
	 */
	mutex_lock(&sched_domains_mutex);
	init_sched_domains(cpu_active_mask);
	cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map);
	if (cpumask_empty(non_isolated_cpus))
		cpumask_set_cpu(smp_processor_id(), non_isolated_cpus);
	mutex_unlock(&sched_domains_mutex);

	hotcpu_notifier(sched_domains_numa_masks_update, CPU_PRI_SCHED_ACTIVE);
	hotcpu_notifier(cpuset_cpu_active, CPU_PRI_CPUSET_ACTIVE);
	hotcpu_notifier(cpuset_cpu_inactive, CPU_PRI_CPUSET_INACTIVE);

	init_hrtick();

	/* Move init over to a non-isolated CPU */
	if (set_cpus_allowed_ptr(current, non_isolated_cpus) < 0)
		BUG();
	sched_init_granularity();
	free_cpumask_var(non_isolated_cpus);

	init_sched_rt_class();
	init_sched_dl_class();
}

Project: linux
File: core.c

void sched_move_task(struct task_struct *tsk)
{
	struct task_group *tg;
	int on_rq, running;
	unsigned long flags;
	struct rq *rq;

	rq = task_rq_lock(tsk, &flags);

	running = task_current(rq, tsk);
	on_rq = tsk->on_rq;

	if (on_rq)
		dequeue_task(rq, tsk, 0);
	if (unlikely(running))
		tsk->sched_class->put_prev_task(rq, tsk);

	tg = container_of(task_css_check(tsk, cpu_cgroup_subsys_id,
				lockdep_is_held(&tsk->sighand->siglock)),
			  struct task_group, css);
	tg = autogroup_task_group(tsk, tg);
	tsk->sched_task_group = tg;

#ifdef CONFIG_FAIR_GROUP_SCHED
	if (tsk->sched_class->task_move_group)
		tsk->sched_class->task_move_group(tsk, on_rq);
	else
#endif
		set_task_rq(tsk, task_cpu(tsk));

	if (unlikely(running))
		tsk->sched_class->set_curr_task(rq);
	if (on_rq)
		enqueue_task(rq, tsk, 0);

	task_rq_unlock(rq, tsk, &flags);
}

Project: linux
File: core.c

void sched_offline_group(struct task_group *tg)
{
	unsigned long flags;
	int i;

	/* end participation in shares distribution */
	for_each_possible_cpu(i)
		unregister_fair_sched_group(tg, i);

	spin_lock_irqsave(&task_group_lock, flags);
	list_del_rcu(&tg->list);
	list_del_rcu(&tg->siblings);
	spin_unlock_irqrestore(&task_group_lock, flags);
}

Project: linux
File: core.c

static int sched_rt_global_constraints(void)
{
	unsigned long flags;
	int i, ret = 0;

	raw_spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags);
	for_each_possible_cpu(i) {
		struct rt_rq *rt_rq = &cpu_rq(i)->rt;

		raw_spin_lock(&rt_rq->rt_runtime_lock);
		rt_rq->rt_runtime = global_rt_runtime();
		raw_spin_unlock(&rt_rq->rt_runtime_lock);
	}
	raw_spin_unlock_irqrestore(&def_rt_bandwidth.rt_runtime_lock, flags);

	return ret;
}

Project: linux
File: core.c

int sched_rt_handler(struct ctl_table *table, int write,
		void __user *buffer, size_t *lenp,
		loff_t *ppos)
{
	int old_period, old_runtime;
	static DEFINE_MUTEX(mutex);
	int ret;

	mutex_lock(&mutex);
	old_period = sysctl_sched_rt_period;
	old_runtime = sysctl_sched_rt_runtime;

	ret = proc_dointvec(table, write, buffer, lenp, ppos);

	if (!ret && write) {
		ret = sched_rt_global_validate();
		if (ret)
			goto undo;

		ret = sched_rt_global_constraints();
		if (ret)
			goto undo;

		ret = sched_dl_global_constraints();
		if (ret)
			goto undo;

		sched_rt_do_global();
		sched_dl_do_global();
	}
	if (0) {
undo:
		sysctl_sched_rt_period = old_period;
		sysctl_sched_rt_runtime = old_runtime;
	}
	mutex_unlock(&mutex);

	return ret;
}

Project: linux
File: core.c

void sched_setnuma(struct task_struct *p, int nid)
{
	struct rq *rq;
	unsigned long flags;
	bool on_rq, running;

	rq = task_rq_lock(p, &flags);
	on_rq = p->on_rq;
	running = task_current(rq, p);

	if (on_rq)
		dequeue_task(rq, p, 0);
	if (running)
		p->sched_class->put_prev_task(rq, p);

	p->numa_preferred_nid = nid;

	if (running)
		p->sched_class->set_curr_task(rq);
	if (on_rq)
		enqueue_task(rq, p, 0);
	task_rq_unlock(rq, p, &flags);
}

Project: linux
File: core.c

void sched_show_task(struct task_struct *p)
{
	unsigned long free = 0;
	int ppid;
	unsigned state;

	state = p->state ? __ffs(p->state) + 1 : 0;
	printk(KERN_INFO "%-15.15s %c", p->comm,
		state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?');
#if BITS_PER_LONG == 32
	if (state == TASK_RUNNING)
		printk(KERN_CONT " running  ");
	else
		printk(KERN_CONT " %08lx ", thread_saved_pc(p));
#else
	if (state == TASK_RUNNING)
		printk(KERN_CONT "  running task    ");
	else
		printk(KERN_CONT " %016lx ", thread_saved_pc(p));
#endif
#ifdef CONFIG_DEBUG_STACK_USAGE
	free = stack_not_used(p);
#endif
	rcu_read_lock();
	ppid = task_pid_nr(rcu_dereference(p->real_parent));
	rcu_read_unlock();
	printk(KERN_CONT "%5lu %5d %6d 0x%08lx\n", free,
		task_pid_nr(p), ppid,
		(unsigned long)task_thread_info(p)->flags);

	print_worker_info(KERN_INFO, p);
	show_stack(p, NULL);
}

Project: linux
File: core.c

static void sched_ttwu_pending(void)
{
	struct rq *rq = this_rq();
	struct llist_node *llist = llist_del_all(&rq->wake_list);
	struct task_struct *p;

	raw_spin_lock(&rq->lock);

	while (llist) {
		p = llist_entry(llist, struct task_struct, wake_entry);
		llist = llist_next(llist);
		ttwu_do_activate(rq, p, 0);
	}

	raw_spin_unlock(&rq->lock);
}

Project: linux
File: core.c

asmlinkage void __sched schedule(void)
{
	struct task_struct *tsk = current;

	sched_submit_work(tsk);
	__schedule();
}

Project: linux
File: core.c

static inline void schedule_debug(struct task_struct *prev)
{
	/*
	 * Test if we are atomic. Since do_exit() needs to call into
	 * schedule() atomically, we ignore that path. Otherwise whine
	 * if we are scheduling when we should not.
	 */
	if (unlikely(in_atomic_preempt_off() && prev->state != TASK_DEAD))
		__schedule_bug(prev);
	rcu_sleep_check();

	profile_hit(SCHED_PROFILING, __builtin_return_address(0));

	schedstat_inc(this_rq(), sched_count);
}

Project: linux
File: core.c

asmlinkage void __sched schedule_user(void)
{
	/*
	 * If we come here after a random call to set_need_resched(),
	 * or we have been woken up remotely but the IPI has not yet arrived,
	 * we haven't yet exited the RCU idle mode. Do it here manually until
	 * we find a better solution.
	 */
	user_exit();
	schedule();
	user_enter();
}

Project: linux
File: core.c

void scheduler_tick(void)
{
	int cpu = smp_processor_id();
	struct rq *rq = cpu_rq(cpu);
	struct task_struct *curr = rq->curr;

	sched_clock_tick();

	raw_spin_lock(&rq->lock);
	update_rq_clock(rq);
	curr->sched_class->task_tick(rq, curr, 0);
	update_cpu_load_active(rq);
	raw_spin_unlock(&rq->lock);

	perf_event_task_tick();

#ifdef CONFIG_SMP
	rq->idle_balance = idle_cpu(cpu);
	trigger_load_balance(rq);
#endif
	rq_last_tick_reset(rq);
}

Project: linux
File: core.c

u64 scheduler_tick_max_deferment(void)
{
	struct rq *rq = this_rq();
	unsigned long next, now = ACCESS_ONCE(jiffies);

	next = rq->last_sched_tick + HZ;

	if (time_before_eq(next, now))
		return 0;

	return jiffies_to_nsecs(next - now);
}

Project: linux
File: core.c

static struct ctl_table *sd_alloc_ctl_cpu_table(int cpu)
{
	struct ctl_table *entry, *table;
	struct sched_domain *sd;
	int domain_num = 0, i;
	char buf[32];

	for_each_domain(cpu, sd)
		domain_num++;
	entry = table = sd_alloc_ctl_entry(domain_num + 1);
	if (table == NULL)
		return NULL;

	i = 0;
	for_each_domain(cpu, sd) {
		snprintf(buf, 32, "domain%d", i);
		entry->procname = kstrdup(buf, GFP_KERNEL);
		entry->mode = 0555;
		entry->child = sd_alloc_ctl_domain_table(sd);
		entry++;
		i++;
	}
	return table;
}

Project: linux
File: core.c

sd_alloc_ctl_domain_table(struct sched_domain *sd)
{
	struct ctl_table *table = sd_alloc_ctl_entry(13);

	if (table == NULL)
		return NULL;

	set_table_entry(&table[0], "min_interval", &sd->min_interval,
		sizeof(long), 0644, proc_doulongvec_minmax, false);
	set_table_entry(&table[1], "max_interval", &sd->max_interval,
		sizeof(long), 0644, proc_doulongvec_minmax, false);
	set_table_entry(&table[2], "busy_idx", &sd->busy_idx,
		sizeof(int), 0644, proc_dointvec_minmax, true);
	set_table_entry(&table[3], "idle_idx", &sd->idle_idx,
		sizeof(int), 0644, proc_dointvec_minmax, true);
	set_table_entry(&table[4], "newidle_idx", &sd->newidle_idx,
		sizeof(int), 0644, proc_dointvec_minmax, true);
	set_table_entry(&table[5], "wake_idx", &sd->wake_idx,
		sizeof(int), 0644, proc_dointvec_minmax, true);
	set_table_entry(&table[6], "forkexec_idx", &sd->forkexec_idx,
		sizeof(int), 0644, proc_dointvec_minmax, true);
	set_table_entry(&table[7], "busy_factor", &sd->busy_factor,
		sizeof(int), 0644, proc_dointvec_minmax, false);
	set_table_entry(&table[8], "imbalance_pct", &sd->imbalance_pct,
		sizeof(int), 0644, proc_dointvec_minmax, false);
	set_table_entry(&table[9], "cache_nice_tries",
		&sd->cache_nice_tries,
		sizeof(int), 0644, proc_dointvec_minmax, false);
	set_table_entry(&table[10], "flags", &sd->flags,
		sizeof(int), 0644, proc_dointvec_minmax, false);
	set_table_entry(&table[11], "name", sd->name,
		CORENAME_MAX_SIZE, 0444, proc_dostring, false);
	/* &table[12] is terminator */

	return table;
}

Project: linux
File: core.c

static inline int sd_local_flags(int level)
{
	if (sched_domains_numa_distance[level] > RECLAIM_DISTANCE)
		return 0;

	return SD_BALANCE_EXEC | SD_BALANCE_FORK | SD_WAKE_AFFINE;
}

Project: linux
File: core.c

sd_numa_init(struct sched_domain_topology_level *tl, int cpu)
{
	struct sched_domain *sd = *per_cpu_ptr(tl->data.sd, cpu);
	int level = tl->numa_level;
	int sd_weight = cpumask_weight(
			sched_domains_numa_masks[level][cpu_to_node(cpu)]);

	*sd = (struct sched_domain){
		.min_interval		= sd_weight,
		.max_interval		= 2*sd_weight,
		.busy_factor		= 32,
		.imbalance_pct		= 125,
		.cache_nice_tries	= 2,
		.busy_idx		= 3,
		.idle_idx		= 2,
		.newidle_idx		= 0,
		.wake_idx		= 0,
		.forkexec_idx		= 0,

		.flags			= 1*SD_LOAD_BALANCE
					| 1*SD_BALANCE_NEWIDLE
					| 0*SD_BALANCE_EXEC
					| 0*SD_BALANCE_FORK
					| 0*SD_BALANCE_WAKE
					| 0*SD_WAKE_AFFINE
					| 0*SD_SHARE_CPUPOWER
					| 0*SD_SHARE_PKG_RESOURCES
					| 1*SD_SERIALIZE
					| 0*SD_PREFER_SIBLING
					| 1*SD_NUMA
					| sd_local_flags(level)
					,
		.last_balance		= jiffies,
		.balance_interval	= sd_weight,
	};
	SD_INIT_NAME(sd, NUMA);
	sd->private = &tl->data;

	/*
	 * Ugly hack to pass state to sd_numa_mask()...
	 */
	sched_domains_curr_level = tl->numa_level;

	return sd;
}

Project: linux
File: core.c

sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent)
{
	unsigned long cflags = sd->flags, pflags = parent->flags;

	if (sd_degenerate(parent))
		return 1;

	if (!cpumask_equal(sched_domain_span(sd), sched_domain_span(parent)))
		return 0;

	/* Flags needing groups don't count if only 1 group in parent */
	if (parent->groups == parent->groups->next) {
		pflags &= ~(SD_LOAD_BALANCE |
				SD_BALANCE_NEWIDLE |
				SD_BALANCE_FORK |
				SD_BALANCE_EXEC |
				SD_SHARE_CPUPOWER |
				SD_SHARE_PKG_RESOURCES |
				SD_PREFER_SIBLING);
		if (nr_node_ids == 1)
			pflags &= ~SD_SERIALIZE;
	}
	if (~cflags & pflags)
		return 0;

	return 1;
}

Project: linux
File: core.c

static int select_fallback_rq(int cpu, struct task_struct *p)
{
	int nid = cpu_to_node(cpu);
	const struct cpumask *nodemask = NULL;
	enum { cpuset, possible, fail } state = cpuset;
	int dest_cpu;

	/*
	 * If the node that the cpu is on has been offlined, cpu_to_node()
	 * will return -1. There is no cpu on the node, and we should
	 * select the cpu on the other node.
	 */
	if (nid != -1) {
		nodemask = cpumask_of_node(nid);

		/* Look for allowed, online CPU in same node. */
		for_each_cpu(dest_cpu, nodemask) {
			if (!cpu_online(dest_cpu))
				continue;
			if (!cpu_active(dest_cpu))
				continue;
			if (cpumask_test_cpu(dest_cpu, tsk_cpus_allowed(p)))
				return dest_cpu;
		}
	}

	for (;;) {
		/* Any allowed, online CPU? */
		for_each_cpu(dest_cpu, tsk_cpus_allowed(p)) {
			if (!cpu_online(dest_cpu))
				continue;
			if (!cpu_active(dest_cpu))
				continue;
			goto out;
		}

		switch (state) {
		case cpuset:
			/* No more Mr. Nice Guy. */
			cpuset_cpus_allowed_fallback(p);
			state = possible;
			break;

		case possible:
			do_set_cpus_allowed(p, cpu_possible_mask);
			state = fail;
			break;

		case fail:
			BUG();
			break;
		}
	}

out:
	if (state != cpuset) {
		/*
		 * Don't tell them about moving exiting tasks or
		 * kernel threads (both mm NULL), since they never
		 * leave kernel.
		 */
		if (p->mm && printk_ratelimit()) {
			printk_sched("process %d (%s) no longer affine to cpu%d\n",
					task_pid_nr(p), p->comm, cpu);
		}
	}

	return dest_cpu;
}

Project: linux
File: core.c

int select_task_rq(struct task_struct *p, int cpu, int sd_flags, int wake_flags)
{
	cpu = p->sched_class->select_task_rq(p, cpu, sd_flags, wake_flags);

	/*
	 * In order not to call set_task_cpu() on a blocking task we need
	 * to rely on ttwu() to place the task on a valid ->cpus_allowed
	 * cpu.
	 *
	 * Since this is common to all placement strategies, this lives here.
	 *
	 * [ this allows ->select_task() to simply return task_cpu(p) and
	 *   not worry about this generic constraint ]
	 */
	if (unlikely(!cpumask_test_cpu(cpu, tsk_cpus_allowed(p)) ||
		     !cpu_online(cpu)))
		cpu = select_fallback_rq(task_cpu(p), p);

	return cpu;
}

Project: linux
File: core.c

int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
{
	unsigned long flags;
	struct rq *rq;
	unsigned int dest_cpu;
	int ret = 0;

	rq = task_rq_lock(p, &flags);

	if (cpumask_equal(&p->cpus_allowed, new_mask))
		goto out;

	if (!cpumask_intersects(new_mask, cpu_active_mask)) {
		ret = -EINVAL;
		goto out;
	}

	do_set_cpus_allowed(p, new_mask);

	/* Can the task run on the task's current CPU? If so, we're done */
	if (cpumask_test_cpu(task_cpu(p), new_mask))
		goto out;

	dest_cpu = cpumask_any_and(cpu_active_mask, new_mask);
	if (p->on_rq) {
		struct migration_arg arg = { p, dest_cpu };
		/* Need help from migration thread: drop lock and wait. */
		task_rq_unlock(rq, p, &flags);
		stop_one_cpu(cpu_of(rq), migration_cpu_stop, &arg);
		tlb_migrate_finish(p->mm);
		return 0;
	}
out:
	task_rq_unlock(rq, p, &flags);

	return ret;
}

Project: linux
File: core.c

void set_numabalancing_state(bool enabled)
{
	if (enabled)
		sched_feat_set("NUMA");
	else
		sched_feat_set("NO_NUMA");
}

Project: linux
File: core.c

void set_numabalancing_state(bool enabled)
{
	numabalancing_enabled = enabled;
}

Project: linux
File: core.c

void set_user_nice(struct task_struct *p, long nice)
{
	int old_prio, delta, on_rq;
	unsigned long flags;
	struct rq *rq;

	if (TASK_NICE(p) == nice || nice < -20 || nice > 19)
		return;
	/*
	 * We have to be careful, if called from sys_setpriority(),
	 * the task might be in the middle of scheduling on another CPU.
	 */
	rq = task_rq_lock(p, &flags);
	/*
	 * The RT priorities are set via sched_setscheduler(), but we still
	 * allow the 'normal' nice value to be set - but as expected
	 * it wont have any effect on scheduling until the task is
	 * SCHED_DEADLINE, SCHED_FIFO or SCHED_RR:
	 */
	if (task_has_dl_policy(p) || task_has_rt_policy(p)) {
		p->static_prio = NICE_TO_PRIO(nice);
		goto out_unlock;
	}
	on_rq = p->on_rq;
	if (on_rq)
		dequeue_task(rq, p, 0);

	p->static_prio = NICE_TO_PRIO(nice);
	set_load_weight(p);
	old_prio = p->prio;
	p->prio = effective_prio(p);
	delta = p->prio - old_prio;

	if (on_rq) {
		enqueue_task(rq, p, 0);
		/*
		 * If the task increased its priority or is running and
		 * lowered its priority, then reschedule its CPU:
		 */
		if (delta < 0 || (delta > 0 && task_running(rq, p)))
			resched_task(rq->curr);
	}
out_unlock:
	task_rq_unlock(rq, p, &flags);
}

Project: linux
File: core.c

void show_state_filter(unsigned long state_filter)
{
	struct task_struct *g, *p;

#if BITS_PER_LONG == 32
	printk(KERN_INFO
		"  task                PC stack   pid father\n");
#else
	printk(KERN_INFO
		"  task                        PC stack   pid father\n");
#endif
	rcu_read_lock();
	do_each_thread(g, p) {
		/*
		 * reset the NMI-timeout, listing all files on a slow
		 * console might take a lot of time:
		 */
		touch_nmi_watchdog();
		if (!state_filter || (p->state & state_filter))
			sched_show_task(p);
	} while_each_thread(g, p);

	touch_all_softlockup_watchdogs();

#ifdef CONFIG_SCHED_DEBUG
	sysrq_sched_debug_show();
#endif
	rcu_read_unlock();
	/*
	 * Only show locks if all tasks are dumped:
	 */
	if (!state_filter)
		debug_show_all_locks();
}

Project: linux
File: core.c

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);
	}
}

Project: linux
File: core.c

int sysctl_numa_balancing(struct ctl_table *table, int write,
			 void __user *buffer, size_t *lenp, loff_t *ppos)
{
	struct ctl_table t;
	int err;
	int state = numabalancing_enabled;

	if (write && !capable(CAP_SYS_ADMIN))
		return -EPERM;

	t = *table;
	t.data = &state;
	err = proc_dointvec_minmax(&t, write, buffer, lenp, ppos);
	if (err < 0)
		return err;
	if (write)
		set_numabalancing_state(state);
	return err;
}

Project: linux
File: core.c

unsigned long long task_sched_runtime(struct task_struct *p)
{
	unsigned long flags;
	struct rq *rq;
	u64 ns = 0;

#if defined(CONFIG_64BIT) && defined(CONFIG_SMP)
	/*
	 * 64-bit doesn't need locks to atomically read a 64bit value.
	 * So we have a optimization chance when the task's delta_exec is 0.
	 * Reading ->on_cpu is racy, but this is ok.
	 *
	 * If we race with it leaving cpu, we'll take a lock. So we're correct.
	 * If we race with it entering cpu, unaccounted time is 0. This is
	 * indistinguishable from the read occurring a few cycles earlier.
	 */
	if (!p->on_cpu)
		return p->se.sum_exec_runtime;
#endif

	rq = task_rq_lock(p, &flags);
	ns = p->se.sum_exec_runtime + do_task_delta_exec(p, rq);
	task_rq_unlock(rq, p, &flags);

	return ns;
}

Project: linux
File: core.c

static int tg_cfs_schedulable_down(struct task_group *tg, void *data)
{
	struct cfs_schedulable_data *d = data;
	struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth;
	s64 quota = 0, parent_quota = -1;

	if (!tg->parent) {
		quota = RUNTIME_INF;
	} else {
		struct cfs_bandwidth *parent_b = &tg->parent->cfs_bandwidth;

		quota = normalize_cfs_quota(tg, d);
		parent_quota = parent_b->hierarchal_quota;

		/*
		 * ensure max(child_quota) <= parent_quota, inherit when no
		 * limit is set
		 */
		if (quota == RUNTIME_INF)
			quota = parent_quota;
		else if (parent_quota != RUNTIME_INF && quota > parent_quota)
			return -EINVAL;
	}
	cfs_b->hierarchal_quota = quota;

	return 0;
}

Project: linux
File: core.c

static inline int tg_has_rt_tasks(struct task_group *tg)
{
	struct task_struct *g, *p;

	do_each_thread(g, p) {
		if (rt_task(p) && task_rq(p)->rt.tg == tg)
			return 1;
	} while_each_thread(g, p);

	return 0;
}

Project: linux
File: core.c

static int tg_set_rt_bandwidth(struct task_group *tg,
		u64 rt_period, u64 rt_runtime)
{
	int i, err = 0;

	mutex_lock(&rt_constraints_mutex);
	read_lock(&tasklist_lock);
	err = __rt_schedulable(tg, rt_period, rt_runtime);
	if (err)
		goto unlock;

	raw_spin_lock_irq(&tg->rt_bandwidth.rt_runtime_lock);
	tg->rt_bandwidth.rt_period = ns_to_ktime(rt_period);
	tg->rt_bandwidth.rt_runtime = rt_runtime;

	for_each_possible_cpu(i) {
		struct rt_rq *rt_rq = tg->rt_rq[i];

		raw_spin_lock(&rt_rq->rt_runtime_lock);
		rt_rq->rt_runtime = rt_runtime;
		raw_spin_unlock(&rt_rq->rt_runtime_lock);
	}
	raw_spin_unlock_irq(&tg->rt_bandwidth.rt_runtime_lock);
unlock:
	read_unlock(&tasklist_lock);
	mutex_unlock(&rt_constraints_mutex);

	return err;
}

Project: linux
File: core.c

try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags)
{
	unsigned long flags;
	int cpu, success = 0;

	/*
	 * If we are going to wake up a thread waiting for CONDITION we
	 * need to ensure that CONDITION=1 done by the caller can not be
	 * reordered with p->state check below. This pairs with mb() in
	 * set_current_state() the waiting thread does.
	 */
	smp_mb__before_spinlock();
	raw_spin_lock_irqsave(&p->pi_lock, flags);
	if (!(p->state & state))
		goto out;

	success = 1; /* we're going to change ->state */
	cpu = task_cpu(p);

	if (p->on_rq && ttwu_remote(p, wake_flags))
		goto stat;

#ifdef CONFIG_SMP
	/*
	 * If the owning (remote) cpu is still in the middle of schedule() with
	 * this task as prev, wait until its done referencing the task.
	 */
	while (p->on_cpu)
		cpu_relax();
	/*
	 * Pairs with the smp_wmb() in finish_lock_switch().
	 */
	smp_rmb();

	p->sched_contributes_to_load = !!task_contributes_to_load(p);
	p->state = TASK_WAKING;

	if (p->sched_class->task_waking)
		p->sched_class->task_waking(p);

	cpu = select_task_rq(p, p->wake_cpu, SD_BALANCE_WAKE, wake_flags);
	if (task_cpu(p) != cpu) {
		wake_flags |= WF_MIGRATED;
		set_task_cpu(p, cpu);
	}
#endif /* CONFIG_SMP */

	ttwu_queue(p, cpu);
stat:
	ttwu_stat(p, cpu, wake_flags);
out:
	raw_spin_unlock_irqrestore(&p->pi_lock, flags);

	return success;
}

Project: linux
File: core.c

static void try_to_wake_up_local(struct task_struct *p)
{
	struct rq *rq = task_rq(p);

	if (WARN_ON_ONCE(rq != this_rq()) ||
	    WARN_ON_ONCE(p == current))
		return;

	lockdep_assert_held(&rq->lock);

	if (!raw_spin_trylock(&p->pi_lock)) {
		raw_spin_unlock(&rq->lock);
		raw_spin_lock(&p->pi_lock);
		raw_spin_lock(&rq->lock);
	}

	if (!(p->state & TASK_NORMAL))
		goto out;

	if (!p->on_rq)
		ttwu_activate(rq, p, ENQUEUE_WAKEUP);

	ttwu_do_wakeup(rq, p, 0);
	ttwu_stat(p, smp_processor_id(), 0);
out:
	raw_spin_unlock(&p->pi_lock);
}

Project: linux
File: core.c

static void ttwu_queue(struct task_struct *p, int cpu)
{
	struct rq *rq = cpu_rq(cpu);

#if defined(CONFIG_SMP)
	if (sched_feat(TTWU_QUEUE) && !cpus_share_cache(smp_processor_id(), cpu)) {
		sched_clock_cpu(cpu); /* sync clocks x-cpu */
		ttwu_queue_remote(p, cpu);
		return;
	}
#endif

	raw_spin_lock(&rq->lock);
	ttwu_do_activate(rq, p, 0);
	raw_spin_unlock(&rq->lock);
}

Project: linux
File: core.c

static void ttwu_queue_remote(struct task_struct *p, int cpu)
{
	if (llist_add(&p->wake_entry, &cpu_rq(cpu)->wake_list))
		smp_send_reschedule(cpu);
}

Project: linux
File: core.c

static int ttwu_remote(struct task_struct *p, int wake_flags)
{
	struct rq *rq;
	int ret = 0;

	rq = __task_rq_lock(p);
	if (p->on_rq) {
		/* check_preempt_curr() may use rq clock */
		update_rq_clock(rq);
		ttwu_do_wakeup(rq, p, wake_flags);
		ret = 1;
	}
	__task_rq_unlock(rq);

	return ret;
}

Project: linux
File: core.c

void update_rq_clock(struct rq *rq)
{
	s64 delta;

	if (rq->skip_clock_update > 0)
		return;

	delta = sched_clock_cpu(cpu_of(rq)) - rq->clock;
	rq->clock += delta;
	update_rq_clock_task(rq, delta);
}

Project: linux
File: core.c

static void update_rq_clock_task(struct rq *rq, s64 delta)
{
/*
 * In theory, the compile should just see 0 here, and optimize out the call
 * to sched_rt_avg_update. But I don't trust it...
 */
#if defined(CONFIG_IRQ_TIME_ACCOUNTING) || defined(CONFIG_PARAVIRT_TIME_ACCOUNTING)
	s64 steal = 0, irq_delta = 0;
#endif
#ifdef CONFIG_IRQ_TIME_ACCOUNTING
	irq_delta = irq_time_read(cpu_of(rq)) - rq->prev_irq_time;

	/*
	 * Since irq_time is only updated on {soft,}irq_exit, we might run into
	 * this case when a previous update_rq_clock() happened inside a
	 * {soft,}irq region.
	 *
	 * When this happens, we stop ->clock_task and only update the
	 * prev_irq_time stamp to account for the part that fit, so that a next
	 * update will consume the rest. This ensures ->clock_task is
	 * monotonic.
	 *
	 * It does however cause some slight miss-attribution of {soft,}irq
	 * time, a more accurate solution would be to update the irq_time using
	 * the current rq->clock timestamp, except that would require using
	 * atomic ops.
	 */
	if (irq_delta > delta)
		irq_delta = delta;

	rq->prev_irq_time += irq_delta;
	delta -= irq_delta;
#endif
#ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING
	if (static_key_false((&paravirt_steal_rq_enabled))) {
		u64 st;

		steal = paravirt_steal_clock(cpu_of(rq));
		steal -= rq->prev_steal_time_rq;

		if (unlikely(steal > delta))
			steal = delta;

		st = steal_ticks(steal);
		steal = st * TICK_NSEC;

		rq->prev_steal_time_rq += steal;

		delta -= steal;
	}
#endif

	rq->clock_task += delta;

#if defined(CONFIG_IRQ_TIME_ACCOUNTING) || defined(CONFIG_PARAVIRT_TIME_ACCOUNTING)
	if ((irq_delta + steal) && sched_feat(NONTASK_POWER))
		sched_rt_avg_update(rq, irq_delta + steal);
#endif
}

Project: linux
File: core.c

static bool wake_up_full_nohz_cpu(int cpu)
{
	if (tick_nohz_full_cpu(cpu)) {
		if (cpu != smp_processor_id() ||
		    tick_nohz_tick_stopped())
			smp_send_reschedule(cpu);
		return true;
	}

	return false;
}

Project: linux
File: core.c

int wake_up_process(struct task_struct *p)
{
	WARN_ON(task_is_stopped_or_traced(p));
	return try_to_wake_up(p, TASK_NORMAL, 0);
}