Merge branch 'linus' into sched/urgent, to pick up fixes and updates

Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 35 insertions, 25 deletions

diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index aad49451584e..86b77987435e 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -3,12 +3,8 @@
  * Real-Time Scheduling Class (mapped to the SCHED_FIFO and SCHED_RR
  * policies)
  */
-
 #include "sched.h"
 
-#include <linux/slab.h>
-#include <linux/irq_work.h>
-
 int sched_rr_timeslice = RR_TIMESLICE;
 int sysctl_sched_rr_timeslice = (MSEC_PER_SEC / HZ) * RR_TIMESLICE;
 
@@ -359,7 +355,7 @@ static DEFINE_PER_CPU(struct callback_head, rt_pull_head);
 static void push_rt_tasks(struct rq *);
 static void pull_rt_task(struct rq *);
 
-static inline void queue_push_tasks(struct rq *rq)
+static inline void rt_queue_push_tasks(struct rq *rq)
 {
 	if (!has_pushable_tasks(rq))
 		return;
@@ -367,7 +363,7 @@ static inline void queue_push_tasks(struct rq *rq)
 	queue_balance_callback(rq, &per_cpu(rt_push_head, rq->cpu), push_rt_tasks);
 }
 
-static inline void queue_pull_task(struct rq *rq)
+static inline void rt_queue_pull_task(struct rq *rq)
 {
 	queue_balance_callback(rq, &per_cpu(rt_pull_head, rq->cpu), pull_rt_task);
 }
@@ -425,7 +421,7 @@ static inline void pull_rt_task(struct rq *this_rq)
 {
 }
 
-static inline void queue_push_tasks(struct rq *rq)
+static inline void rt_queue_push_tasks(struct rq *rq)
 {
 }
 #endif /* CONFIG_SMP */
@@ -961,9 +957,6 @@ static void update_curr_rt(struct rq *rq)
 	if (unlikely((s64)delta_exec <= 0))
 		return;
 
-	/* Kick cpufreq (see the comment in kernel/sched/sched.h). */
-	cpufreq_update_util(rq, SCHED_CPUFREQ_RT);
-
 	schedstat_set(curr->se.statistics.exec_max,
 		      max(curr->se.statistics.exec_max, delta_exec));
 
@@ -1005,6 +998,9 @@ dequeue_top_rt_rq(struct rt_rq *rt_rq)
 
 	sub_nr_running(rq, rt_rq->rt_nr_running);
 	rt_rq->rt_queued = 0;
+
+	/* Kick cpufreq (see the comment in kernel/sched/sched.h). */
+	cpufreq_update_util(rq, 0);
 }
 
 static void
@@ -1021,6 +1017,9 @@ enqueue_top_rt_rq(struct rt_rq *rt_rq)
 
 	add_nr_running(rq, rt_rq->rt_nr_running);
 	rt_rq->rt_queued = 1;
+
+	/* Kick cpufreq (see the comment in kernel/sched/sched.h). */
+	cpufreq_update_util(rq, 0);
 }
 
 #if defined CONFIG_SMP
@@ -1453,9 +1452,9 @@ static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p)
 		return;
 
 	/*
-	 * There appears to be other cpus that can accept
-	 * current and none to run 'p', so lets reschedule
-	 * to try and push current away:
+	 * There appear to be other CPUs that can accept
+	 * the current task but none can run 'p', so lets reschedule
+	 * to try and push the current task away:
 	 */
 	requeue_task_rt(rq, p, 1);
 	resched_curr(rq);
@@ -1569,7 +1568,7 @@ pick_next_task_rt(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
 	/* The running task is never eligible for pushing */
 	dequeue_pushable_task(rq, p);
 
-	queue_push_tasks(rq);
+	rt_queue_push_tasks(rq);
 
 	return p;
 }
@@ -1596,12 +1595,13 @@ static int pick_rt_task(struct rq *rq, struct task_struct *p, int cpu)
 	if (!task_running(rq, p) &&
 	    cpumask_test_cpu(cpu, &p->cpus_allowed))
 		return 1;
+
 	return 0;
 }
 
 /*
  * Return the highest pushable rq's task, which is suitable to be executed
- * on the cpu, NULL otherwise
+ * on the CPU, NULL otherwise
  */
 static struct task_struct *pick_highest_pushable_task(struct rq *rq, int cpu)
 {
@@ -1639,11 +1639,11 @@ static int find_lowest_rq(struct task_struct *task)
 		return -1; /* No targets found */
 
 	/*
-	 * At this point we have built a mask of cpus representing the
+	 * At this point we have built a mask of CPUs representing the
 	 * lowest priority tasks in the system.  Now we want to elect
 	 * the best one based on our affinity and topology.
 	 *
-	 * We prioritize the last cpu that the task executed on since
+	 * We prioritize the last CPU that the task executed on since
 	 * it is most likely cache-hot in that location.
 	 */
 	if (cpumask_test_cpu(cpu, lowest_mask))
@@ -1651,7 +1651,7 @@ static int find_lowest_rq(struct task_struct *task)
 
 	/*
 	 * Otherwise, we consult the sched_domains span maps to figure
-	 * out which cpu is logically closest to our hot cache data.
+	 * out which CPU is logically closest to our hot cache data.
 	 */
 	if (!cpumask_test_cpu(this_cpu, lowest_mask))
 		this_cpu = -1; /* Skip this_cpu opt if not among lowest */
@@ -1692,6 +1692,7 @@ static int find_lowest_rq(struct task_struct *task)
 	cpu = cpumask_any(lowest_mask);
 	if (cpu < nr_cpu_ids)
 		return cpu;
+
 	return -1;
 }
 
@@ -1827,7 +1828,7 @@ retry:
 			 * The task hasn't migrated, and is still the next
 			 * eligible task, but we failed to find a run-queue
 			 * to push it to.  Do not retry in this case, since
-			 * other cpus will pull from us when ready.
+			 * other CPUs will pull from us when ready.
 			 */
 			goto out;
 		}
@@ -1919,7 +1920,7 @@ static int rto_next_cpu(struct root_domain *rd)
 	 * rt_next_cpu() will simply return the first CPU found in
 	 * the rto_mask.
 	 *
-	 * If rto_next_cpu() is called with rto_cpu is a valid cpu, it
+	 * If rto_next_cpu() is called with rto_cpu is a valid CPU, it
 	 * will return the next CPU found in the rto_mask.
 	 *
 	 * If there are no more CPUs left in the rto_mask, then a check is made
@@ -1980,7 +1981,7 @@ static void tell_cpu_to_push(struct rq *rq)
 	raw_spin_lock(&rq->rd->rto_lock);
 
 	/*
-	 * The rto_cpu is updated under the lock, if it has a valid cpu
+	 * The rto_cpu is updated under the lock, if it has a valid CPU
 	 * then the IPI is still running and will continue due to the
 	 * update to loop_next, and nothing needs to be done here.
 	 * Otherwise it is finishing up and an ipi needs to be sent.
@@ -2105,7 +2106,7 @@ static void pull_rt_task(struct rq *this_rq)
 
 			/*
 			 * There's a chance that p is higher in priority
-			 * than what's currently running on its cpu.
+			 * than what's currently running on its CPU.
 			 * This is just that p is wakeing up and hasn't
 			 * had a chance to schedule. We only pull
 			 * p if it is lower in priority than the
@@ -2187,7 +2188,7 @@ static void switched_from_rt(struct rq *rq, struct task_struct *p)
 	if (!task_on_rq_queued(p) || rq->rt.rt_nr_running)
 		return;
 
-	queue_pull_task(rq);
+	rt_queue_pull_task(rq);
 }
 
 void __init init_sched_rt_class(void)
@@ -2218,7 +2219,7 @@ static void switched_to_rt(struct rq *rq, struct task_struct *p)
 	if (task_on_rq_queued(p) && rq->curr != p) {
 #ifdef CONFIG_SMP
 		if (p->nr_cpus_allowed > 1 && rq->rt.overloaded)
-			queue_push_tasks(rq);
+			rt_queue_push_tasks(rq);
 #endif /* CONFIG_SMP */
 		if (p->prio < rq->curr->prio && cpu_online(cpu_of(rq)))
 			resched_curr(rq);
@@ -2242,7 +2243,7 @@ prio_changed_rt(struct rq *rq, struct task_struct *p, int oldprio)
 		 * may need to pull tasks to this runqueue.
 		 */
 		if (oldprio < p->prio)
-			queue_pull_task(rq);
+			rt_queue_pull_task(rq);
 
 		/*
 		 * If there's a higher priority task waiting to run
@@ -2292,6 +2293,14 @@ static void watchdog(struct rq *rq, struct task_struct *p)
 static inline void watchdog(struct rq *rq, struct task_struct *p) { }
 #endif
 
+/*
+ * scheduler tick hitting a task of our scheduling class.
+ *
+ * NOTE: This function can be called remotely by the tick offload that
+ * goes along full dynticks. Therefore no local assumption can be made
+ * and everything must be accessed through the @rq and @curr passed in
+ * parameters.
+ */
 static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued)
 {
 	struct sched_rt_entity *rt_se = &p->rt;
@@ -2685,6 +2694,7 @@ int sched_rr_handler(struct ctl_table *table, int write,
 			msecs_to_jiffies(sysctl_sched_rr_timeslice);
 	}
 	mutex_unlock(&mutex);
+
 	return ret;
 }