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Diffstat (limited to 'kernel/sched/rt.c')
-rw-r--r--kernel/sched/rt.c60
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;
}