5 files changed, 37 insertions, 73 deletions

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index d1555185c054..e9866f86f304 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -881,6 +881,33 @@ void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags)
 }
 
 #ifdef CONFIG_SMP
+
+static inline bool is_per_cpu_kthread(struct task_struct *p)
+{
+	if (!(p->flags & PF_KTHREAD))
+		return false;
+
+	if (p->nr_cpus_allowed != 1)
+		return false;
+
+	return true;
+}
+
+/*
+ * Per-CPU kthreads are allowed to run on !actie && online CPUs, see
+ * __set_cpus_allowed_ptr() and select_fallback_rq().
+ */
+static inline bool is_cpu_allowed(struct task_struct *p, int cpu)
+{
+	if (!cpumask_test_cpu(cpu, &p->cpus_allowed))
+		return false;
+
+	if (is_per_cpu_kthread(p))
+		return cpu_online(cpu);
+
+	return cpu_active(cpu);
+}
+
 /*
  * This is how migration works:
  *
@@ -938,16 +965,8 @@ struct migration_arg {
 static struct rq *__migrate_task(struct rq *rq, struct rq_flags *rf,
 				 struct task_struct *p, int dest_cpu)
 {
-	if (p->flags & PF_KTHREAD) {
-		if (unlikely(!cpu_online(dest_cpu)))
-			return rq;
-	} else {
-		if (unlikely(!cpu_active(dest_cpu)))
-			return rq;
-	}
-
 	/* Affinity changed (again). */
-	if (!cpumask_test_cpu(dest_cpu, &p->cpus_allowed))
+	if (!is_cpu_allowed(p, dest_cpu))
 		return rq;
 
 	update_rq_clock(rq);
@@ -1476,10 +1495,9 @@ static int select_fallback_rq(int cpu, struct task_struct *p)
 	for (;;) {
 		/* Any allowed, online CPU? */
 		for_each_cpu(dest_cpu, &p->cpus_allowed) {
-			if (!(p->flags & PF_KTHREAD) && !cpu_active(dest_cpu))
-				continue;
-			if (!cpu_online(dest_cpu))
+			if (!is_cpu_allowed(p, dest_cpu))
 				continue;
+
 			goto out;
 		}
 
@@ -1542,8 +1560,7 @@ int select_task_rq(struct task_struct *p, int cpu, int sd_flags, int wake_flags)
 	 * [ this allows ->select_task() to simply return task_cpu(p) and
 	 *   not worry about this generic constraint ]
 	 */
-	if (unlikely(!cpumask_test_cpu(cpu, &p->cpus_allowed) ||
-		     !cpu_online(cpu)))
+	if (unlikely(!is_cpu_allowed(p, cpu)))
 		cpu = select_fallback_rq(task_cpu(p), p);
 
 	return cpu;
@@ -5005,20 +5022,6 @@ int __cond_resched_lock(spinlock_t *lock)
 }
 EXPORT_SYMBOL(__cond_resched_lock);
 
-int __sched __cond_resched_softirq(void)
-{
-	BUG_ON(!in_softirq());
-
-	if (should_resched(SOFTIRQ_DISABLE_OFFSET)) {
-		local_bh_enable();
-		preempt_schedule_common();
-		local_bh_disable();
-		return 1;
-	}
-	return 0;
-}
-EXPORT_SYMBOL(__cond_resched_softirq);
-
 /**
  * yield - yield the current processor to other threads.
  *
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index 1356afd1eeb6..fbfc3f1d368a 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -1259,6 +1259,9 @@ static enum hrtimer_restart inactive_task_timer(struct hrtimer *timer)
 
 	rq = task_rq_lock(p, &rf);
 
+	sched_clock_tick();
+	update_rq_clock(rq);
+
 	if (!dl_task(p) || p->state == TASK_DEAD) {
 		struct dl_bw *dl_b = dl_bw_of(task_cpu(p));
 
@@ -1278,9 +1281,6 @@ static enum hrtimer_restart inactive_task_timer(struct hrtimer *timer)
 	if (dl_se->dl_non_contending == 0)
 		goto unlock;
 
-	sched_clock_tick();
-	update_rq_clock(rq);
-
 	sub_running_bw(dl_se, &rq->dl);
 	dl_se->dl_non_contending = 0;
 unlock:
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index 15b10e210a6b..e593b4118578 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -823,35 +823,9 @@ static const struct seq_operations sched_debug_sops = {
 	.show		= sched_debug_show,
 };
 
-static int sched_debug_release(struct inode *inode, struct file *file)
-{
-	seq_release(inode, file);
-
-	return 0;
-}
-
-static int sched_debug_open(struct inode *inode, struct file *filp)
-{
-	int ret = 0;
-
-	ret = seq_open(filp, &sched_debug_sops);
-
-	return ret;
-}
-
-static const struct file_operations sched_debug_fops = {
-	.open		= sched_debug_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= sched_debug_release,
-};
-
 static int __init init_sched_debug_procfs(void)
 {
-	struct proc_dir_entry *pe;
-
-	pe = proc_create("sched_debug", 0444, NULL, &sched_debug_fops);
-	if (!pe)
+	if (!proc_create_seq("sched_debug", 0444, NULL, &sched_debug_sops))
 		return -ENOMEM;
 	return 0;
 }
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 67702b4d9ac7..6601baf2361c 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -983,7 +983,7 @@ static inline void rq_clock_skip_update(struct rq *rq)
 }
 
 /*
- * See rt task throttoling, which is the only time a skip
+ * See rt task throttling, which is the only time a skip
  * request is cancelled.
  */
 static inline void rq_clock_cancel_skipupdate(struct rq *rq)
diff --git a/kernel/sched/stats.c b/kernel/sched/stats.c
index ab112cbfd7c8..750fb3c67eed 100644
--- a/kernel/sched/stats.c
+++ b/kernel/sched/stats.c
@@ -120,22 +120,9 @@ static const struct seq_operations schedstat_sops = {
 	.show  = show_schedstat,
 };
 
-static int schedstat_open(struct inode *inode, struct file *file)
-{
-	return seq_open(file, &schedstat_sops);
-}
-
-static const struct file_operations proc_schedstat_operations = {
-	.open    = schedstat_open,
-	.read    = seq_read,
-	.llseek  = seq_lseek,
-	.release = seq_release,
-};
-
 static int __init proc_schedstat_init(void)
 {
-	proc_create("schedstat", 0, NULL, &proc_schedstat_operations);
-
+	proc_create_seq("schedstat", 0, NULL, &schedstat_sops);
 	return 0;
 }
 subsys_initcall(proc_schedstat_init);