1 files changed, 84 insertions, 65 deletions

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index ec1a286684a5..a814b3c88029 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -333,9 +333,12 @@ static inline struct rq *__task_rq_lock(struct task_struct *p)
 	for (;;) {
 		rq = task_rq(p);
 		raw_spin_lock(&rq->lock);
-		if (likely(rq == task_rq(p)))
+		if (likely(rq == task_rq(p) && !task_on_rq_migrating(p)))
 			return rq;
 		raw_spin_unlock(&rq->lock);
+
+		while (unlikely(task_on_rq_migrating(p)))
+			cpu_relax();
 	}
 }
 
@@ -352,10 +355,13 @@ static struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags)
 		raw_spin_lock_irqsave(&p->pi_lock, *flags);
 		rq = task_rq(p);
 		raw_spin_lock(&rq->lock);
-		if (likely(rq == task_rq(p)))
+		if (likely(rq == task_rq(p) && !task_on_rq_migrating(p)))
 			return rq;
 		raw_spin_unlock(&rq->lock);
 		raw_spin_unlock_irqrestore(&p->pi_lock, *flags);
+
+		while (unlikely(task_on_rq_migrating(p)))
+			cpu_relax();
 	}
 }
 
@@ -449,7 +455,15 @@ static void __hrtick_start(void *arg)
 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);
+	ktime_t time;
+	s64 delta;
+
+	/*
+	 * Don't schedule slices shorter than 10000ns, that just
+	 * doesn't make sense and can cause timer DoS.
+	 */
+	delta = max_t(s64, delay, 10000LL);
+	time = ktime_add_ns(timer->base->get_time(), delta);
 
 	hrtimer_set_expires(timer, time);
 
@@ -1043,7 +1057,7 @@ void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags)
 	 * 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))
+	if (task_on_rq_queued(rq->curr) && test_tsk_need_resched(rq->curr))
 		rq->skip_clock_update = 1;
 }
 
@@ -1088,7 +1102,7 @@ void set_task_cpu(struct task_struct *p, unsigned int new_cpu)
 
 static void __migrate_swap_task(struct task_struct *p, int cpu)
 {
-	if (p->on_rq) {
+	if (task_on_rq_queued(p)) {
 		struct rq *src_rq, *dst_rq;
 
 		src_rq = task_rq(p);
@@ -1214,7 +1228,7 @@ static int migration_cpu_stop(void *data);
 unsigned long wait_task_inactive(struct task_struct *p, long match_state)
 {
 	unsigned long flags;
-	int running, on_rq;
+	int running, queued;
 	unsigned long ncsw;
 	struct rq *rq;
 
@@ -1252,7 +1266,7 @@ unsigned long wait_task_inactive(struct task_struct *p, long match_state)
 		rq = task_rq_lock(p, &flags);
 		trace_sched_wait_task(p);
 		running = task_running(rq, p);
-		on_rq = p->on_rq;
+		queued = task_on_rq_queued(p);
 		ncsw = 0;
 		if (!match_state || p->state == match_state)
 			ncsw = p->nvcsw | LONG_MIN; /* sets MSB */
@@ -1284,7 +1298,7 @@ unsigned long wait_task_inactive(struct task_struct *p, long match_state)
 		 * running right now), it's preempted, and we should
 		 * yield - it could be a while.
 		 */
-		if (unlikely(on_rq)) {
+		if (unlikely(queued)) {
 			ktime_t to = ktime_set(0, NSEC_PER_SEC/HZ);
 
 			set_current_state(TASK_UNINTERRUPTIBLE);
@@ -1478,7 +1492,7 @@ ttwu_stat(struct task_struct *p, int cpu, int wake_flags)
 static void ttwu_activate(struct rq *rq, struct task_struct *p, int en_flags)
 {
 	activate_task(rq, p, en_flags);
-	p->on_rq = 1;
+	p->on_rq = TASK_ON_RQ_QUEUED;
 
 	/* if a worker is waking up, notify workqueue */
 	if (p->flags & PF_WQ_WORKER)
@@ -1537,7 +1551,7 @@ static int ttwu_remote(struct task_struct *p, int wake_flags)
 	int ret = 0;
 
 	rq = __task_rq_lock(p);
-	if (p->on_rq) {
+	if (task_on_rq_queued(p)) {
 		/* check_preempt_curr() may use rq clock */
 		update_rq_clock(rq);
 		ttwu_do_wakeup(rq, p, wake_flags);
@@ -1742,7 +1756,7 @@ static void try_to_wake_up_local(struct task_struct *p)
 	if (!(p->state & TASK_NORMAL))
 		goto out;
 
-	if (!p->on_rq)
+	if (!task_on_rq_queued(p))
 		ttwu_activate(rq, p, ENQUEUE_WAKEUP);
 
 	ttwu_do_wakeup(rq, p, 0);
@@ -2095,7 +2109,7 @@ void wake_up_new_task(struct task_struct *p)
 	init_task_runnable_average(p);
 	rq = __task_rq_lock(p);
 	activate_task(rq, p, 0);
-	p->on_rq = 1;
+	p->on_rq = TASK_ON_RQ_QUEUED;
 	trace_sched_wakeup_new(p, true);
 	check_preempt_curr(rq, p, WF_FORK);
 #ifdef CONFIG_SMP
@@ -2451,7 +2465,7 @@ static u64 do_task_delta_exec(struct task_struct *p, struct rq *rq)
 	 * project cycles that may never be accounted to this
 	 * thread, breaking clock_gettime().
 	 */
-	if (task_current(rq, p) && p->on_rq) {
+	if (task_current(rq, p) && task_on_rq_queued(p)) {
 		update_rq_clock(rq);
 		ns = rq_clock_task(rq) - p->se.exec_start;
 		if ((s64)ns < 0)
@@ -2497,7 +2511,7 @@ unsigned long long task_sched_runtime(struct task_struct *p)
 	 * If we see ->on_cpu without ->on_rq, the task is leaving, and has
 	 * been accounted, so we're correct here as well.
 	 */
-	if (!p->on_cpu || !p->on_rq)
+	if (!p->on_cpu || !task_on_rq_queued(p))
 		return p->se.sum_exec_runtime;
 #endif
 
@@ -2801,7 +2815,7 @@ need_resched:
 		switch_count = &prev->nvcsw;
 	}
 
-	if (prev->on_rq || rq->skip_clock_update < 0)
+	if (task_on_rq_queued(prev) || rq->skip_clock_update < 0)
 		update_rq_clock(rq);
 
 	next = pick_next_task(rq, prev);
@@ -2966,7 +2980,7 @@ EXPORT_SYMBOL(default_wake_function);
  */
 void rt_mutex_setprio(struct task_struct *p, int prio)
 {
-	int oldprio, on_rq, running, enqueue_flag = 0;
+	int oldprio, queued, running, enqueue_flag = 0;
 	struct rq *rq;
 	const struct sched_class *prev_class;
 
@@ -2995,9 +3009,9 @@ void rt_mutex_setprio(struct task_struct *p, int prio)
 	trace_sched_pi_setprio(p, prio);
 	oldprio = p->prio;
 	prev_class = p->sched_class;
-	on_rq = p->on_rq;
+	queued = task_on_rq_queued(p);
 	running = task_current(rq, p);
-	if (on_rq)
+	if (queued)
 		dequeue_task(rq, p, 0);
 	if (running)
 		p->sched_class->put_prev_task(rq, p);
@@ -3037,7 +3051,7 @@ void rt_mutex_setprio(struct task_struct *p, int prio)
 
 	if (running)
 		p->sched_class->set_curr_task(rq);
-	if (on_rq)
+	if (queued)
 		enqueue_task(rq, p, enqueue_flag);
 
 	check_class_changed(rq, p, prev_class, oldprio);
@@ -3048,7 +3062,7 @@ out_unlock:
 
 void set_user_nice(struct task_struct *p, long nice)
 {
-	int old_prio, delta, on_rq;
+	int old_prio, delta, queued;
 	unsigned long flags;
 	struct rq *rq;
 
@@ -3069,8 +3083,8 @@ void set_user_nice(struct task_struct *p, long nice)
 		p->static_prio = NICE_TO_PRIO(nice);
 		goto out_unlock;
 	}
-	on_rq = p->on_rq;
-	if (on_rq)
+	queued = task_on_rq_queued(p);
+	if (queued)
 		dequeue_task(rq, p, 0);
 
 	p->static_prio = NICE_TO_PRIO(nice);
@@ -3079,7 +3093,7 @@ void set_user_nice(struct task_struct *p, long nice)
 	p->prio = effective_prio(p);
 	delta = p->prio - old_prio;
 
-	if (on_rq) {
+	if (queued) {
 		enqueue_task(rq, p, 0);
 		/*
 		 * If the task increased its priority or is running and
@@ -3351,7 +3365,7 @@ static int __sched_setscheduler(struct task_struct *p,
 {
 	int newprio = dl_policy(attr->sched_policy) ? MAX_DL_PRIO - 1 :
 		      MAX_RT_PRIO - 1 - attr->sched_priority;
-	int retval, oldprio, oldpolicy = -1, on_rq, running;
+	int retval, oldprio, oldpolicy = -1, queued, running;
 	int policy = attr->sched_policy;
 	unsigned long flags;
 	const struct sched_class *prev_class;
@@ -3548,9 +3562,9 @@ change:
 		return 0;
 	}
 
-	on_rq = p->on_rq;
+	queued = task_on_rq_queued(p);
 	running = task_current(rq, p);
-	if (on_rq)
+	if (queued)
 		dequeue_task(rq, p, 0);
 	if (running)
 		p->sched_class->put_prev_task(rq, p);
@@ -3560,7 +3574,7 @@ change:
 
 	if (running)
 		p->sched_class->set_curr_task(rq);
-	if (on_rq) {
+	if (queued) {
 		/*
 		 * We enqueue to tail when the priority of a task is
 		 * increased (user space view).
@@ -4512,7 +4526,7 @@ void show_state_filter(unsigned long state_filter)
 		"  task                        PC stack   pid father\n");
 #endif
 	rcu_read_lock();
-	do_each_thread(g, p) {
+	for_each_process_thread(g, p) {
 		/*
 		 * reset the NMI-timeout, listing all files on a slow
 		 * console might take a lot of time:
@@ -4520,7 +4534,7 @@ void show_state_filter(unsigned long state_filter)
 		touch_nmi_watchdog();
 		if (!state_filter || (p->state & state_filter))
 			sched_show_task(p);
-	} while_each_thread(g, p);
+	}
 
 	touch_all_softlockup_watchdogs();
 
@@ -4575,7 +4589,7 @@ void init_idle(struct task_struct *idle, int cpu)
 	rcu_read_unlock();
 
 	rq->curr = rq->idle = idle;
-	idle->on_rq = 1;
+	idle->on_rq = TASK_ON_RQ_QUEUED;
 #if defined(CONFIG_SMP)
 	idle->on_cpu = 1;
 #endif
@@ -4652,7 +4666,7 @@ int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
 		goto out;
 
 	dest_cpu = cpumask_any_and(cpu_active_mask, new_mask);
-	if (p->on_rq) {
+	if (task_on_rq_queued(p)) {
 		struct migration_arg arg = { p, dest_cpu };
 		/* Need help from migration thread: drop lock and wait. */
 		task_rq_unlock(rq, p, &flags);
@@ -4680,20 +4694,20 @@ EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr);
  */
 static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu)
 {
-	struct rq *rq_dest, *rq_src;
+	struct rq *rq;
 	int ret = 0;
 
 	if (unlikely(!cpu_active(dest_cpu)))
 		return ret;
 
-	rq_src = cpu_rq(src_cpu);
-	rq_dest = cpu_rq(dest_cpu);
+	rq = cpu_rq(src_cpu);
 
 	raw_spin_lock(&p->pi_lock);
-	double_rq_lock(rq_src, rq_dest);
+	raw_spin_lock(&rq->lock);
 	/* 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;
@@ -4702,16 +4716,23 @@ static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu)
 	 * 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);
+	if (task_on_rq_queued(p)) {
+		dequeue_task(rq, p, 0);
+		p->on_rq = TASK_ON_RQ_MIGRATING;
 		set_task_cpu(p, dest_cpu);
-		enqueue_task(rq_dest, p, 0);
-		check_preempt_curr(rq_dest, p, 0);
+		raw_spin_unlock(&rq->lock);
+
+		rq = cpu_rq(dest_cpu);
+		raw_spin_lock(&rq->lock);
+		BUG_ON(task_rq(p) != rq);
+		p->on_rq = TASK_ON_RQ_QUEUED;
+		enqueue_task(rq, p, 0);
+		check_preempt_curr(rq, p, 0);
 	}
 done:
 	ret = 1;
 fail:
-	double_rq_unlock(rq_src, rq_dest);
+	raw_spin_unlock(&rq->lock);
 	raw_spin_unlock(&p->pi_lock);
 	return ret;
 }
@@ -4743,13 +4764,13 @@ void sched_setnuma(struct task_struct *p, int nid)
 {
 	struct rq *rq;
 	unsigned long flags;
-	bool on_rq, running;
+	bool queued, running;
 
 	rq = task_rq_lock(p, &flags);
-	on_rq = p->on_rq;
+	queued = task_on_rq_queued(p);
 	running = task_current(rq, p);
 
-	if (on_rq)
+	if (queued)
 		dequeue_task(rq, p, 0);
 	if (running)
 		p->sched_class->put_prev_task(rq, p);
@@ -4758,7 +4779,7 @@ void sched_setnuma(struct task_struct *p, int nid)
 
 	if (running)
 		p->sched_class->set_curr_task(rq);
-	if (on_rq)
+	if (queued)
 		enqueue_task(rq, p, 0);
 	task_rq_unlock(rq, p, &flags);
 }
@@ -5746,7 +5767,7 @@ build_overlap_sched_groups(struct sched_domain *sd, int cpu)
 	const struct cpumask *span = sched_domain_span(sd);
 	struct cpumask *covered = sched_domains_tmpmask;
 	struct sd_data *sdd = sd->private;
-	struct sched_domain *child;
+	struct sched_domain *sibling;
 	int i;
 
 	cpumask_clear(covered);
@@ -5757,10 +5778,10 @@ build_overlap_sched_groups(struct sched_domain *sd, int cpu)
 		if (cpumask_test_cpu(i, covered))
 			continue;
 
-		child = *per_cpu_ptr(sdd->sd, i);
+		sibling = *per_cpu_ptr(sdd->sd, i);
 
 		/* See the comment near build_group_mask(). */
-		if (!cpumask_test_cpu(i, sched_domain_span(child)))
+		if (!cpumask_test_cpu(i, sched_domain_span(sibling)))
 			continue;
 
 		sg = kzalloc_node(sizeof(struct sched_group) + cpumask_size(),
@@ -5770,10 +5791,9 @@ build_overlap_sched_groups(struct sched_domain *sd, int cpu)
 			goto fail;
 
 		sg_span = sched_group_cpus(sg);
-		if (child->child) {
-			child = child->child;
-			cpumask_copy(sg_span, sched_domain_span(child));
-		} else
+		if (sibling->child)
+			cpumask_copy(sg_span, sched_domain_span(sibling->child));
+		else
 			cpumask_set_cpu(i, sg_span);
 
 		cpumask_or(covered, covered, sg_span);
@@ -7124,13 +7144,13 @@ static void normalize_task(struct rq *rq, struct task_struct *p)
 		.sched_policy = SCHED_NORMAL,
 	};
 	int old_prio = p->prio;
-	int on_rq;
+	int queued;
 
-	on_rq = p->on_rq;
-	if (on_rq)
+	queued = task_on_rq_queued(p);
+	if (queued)
 		dequeue_task(rq, p, 0);
 	__setscheduler(rq, p, &attr);
-	if (on_rq) {
+	if (queued) {
 		enqueue_task(rq, p, 0);
 		resched_curr(rq);
 	}
@@ -7145,7 +7165,7 @@ void normalize_rt_tasks(void)
 	struct rq *rq;
 
 	read_lock_irqsave(&tasklist_lock, flags);
-	do_each_thread(g, p) {
+	for_each_process_thread(g, p) {
 		/*
 		 * Only normalize user tasks:
 		 */
@@ -7176,8 +7196,7 @@ void normalize_rt_tasks(void)
 
 		__task_rq_unlock(rq);
 		raw_spin_unlock(&p->pi_lock);
-	} while_each_thread(g, p);
-
+	}
 	read_unlock_irqrestore(&tasklist_lock, flags);
 }
 
@@ -7318,16 +7337,16 @@ void sched_offline_group(struct task_group *tg)
 void sched_move_task(struct task_struct *tsk)
 {
 	struct task_group *tg;
-	int on_rq, running;
+	int queued, running;
 	unsigned long flags;
 	struct rq *rq;
 
 	rq = task_rq_lock(tsk, &flags);
 
 	running = task_current(rq, tsk);
-	on_rq = tsk->on_rq;
+	queued = task_on_rq_queued(tsk);
 
-	if (on_rq)
+	if (queued)
 		dequeue_task(rq, tsk, 0);
 	if (unlikely(running))
 		tsk->sched_class->put_prev_task(rq, tsk);
@@ -7340,14 +7359,14 @@ void sched_move_task(struct task_struct *tsk)
 
 #ifdef CONFIG_FAIR_GROUP_SCHED
 	if (tsk->sched_class->task_move_group)
-		tsk->sched_class->task_move_group(tsk, on_rq);
+		tsk->sched_class->task_move_group(tsk, queued);
 	else
 #endif
 		set_task_rq(tsk, task_cpu(tsk));
 
 	if (unlikely(running))
 		tsk->sched_class->set_curr_task(rq);
-	if (on_rq)
+	if (queued)
 		enqueue_task(rq, tsk, 0);
 
 	task_rq_unlock(rq, tsk, &flags);
@@ -7365,10 +7384,10 @@ static inline int tg_has_rt_tasks(struct task_group *tg)
 {
 	struct task_struct *g, *p;
 
-	do_each_thread(g, p) {
+	for_each_process_thread(g, p) {
 		if (rt_task(p) && task_rq(p)->rt.tg == tg)
 			return 1;
-	} while_each_thread(g, p);
+	}
 
 	return 0;
 }