return rq;
}
-#include "sched_stats.h"
-
/*
- * Adding/removing a task to/from a priority array:
+ * resched_task - mark a task 'to be rescheduled now'.
+ *
+ * On UP this means the setting of the need_resched flag, on SMP it
+ * might also involve a cross-CPU call to trigger the scheduler on
+ * the target CPU.
*/
-static void dequeue_task(struct task_struct *p, struct prio_array *array)
-{
- array->nr_active--;
- list_del(&p->run_list);
- if (list_empty(array->queue + p->prio))
- __clear_bit(p->prio, array->bitmap);
-}
+#ifdef CONFIG_SMP
-static void enqueue_task(struct task_struct *p, struct prio_array *array)
-{
- sched_info_queued(p);
- list_add_tail(&p->run_list, array->queue + p->prio);
- __set_bit(p->prio, array->bitmap);
- array->nr_active++;
- p->array = array;
-}
+#ifndef tsk_is_polling
+#define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG)
+#endif
-/*
- * Put task to the end of the run list without the overhead of dequeue
- * followed by enqueue.
- */
-static void requeue_task(struct task_struct *p, struct prio_array *array)
+static void resched_task(struct task_struct *p)
{
- list_move_tail(&p->run_list, array->queue + p->prio);
-}
+ int cpu;
-static inline void
-enqueue_task_head(struct task_struct *p, struct prio_array *array)
-{
- list_add(&p->run_list, array->queue + p->prio);
- __set_bit(p->prio, array->bitmap);
- array->nr_active++;
- p->array = array;
-}
+ assert_spin_locked(&task_rq(p)->lock);
-/*
- * __normal_prio - return the priority that is based on the static
- * priority but is modified by bonuses/penalties.
- *
- * We scale the actual sleep average [0 .... MAX_SLEEP_AVG]
- * into the -5 ... 0 ... +5 bonus/penalty range.
- *
- * We use 25% of the full 0...39 priority range so that:
- *
- * 1) nice +19 interactive tasks do not preempt nice 0 CPU hogs.
- * 2) nice -20 CPU hogs do not get preempted by nice 0 tasks.
- *
- * Both properties are important to certain workloads.
- */
+ if (unlikely(test_tsk_thread_flag(p, TIF_NEED_RESCHED)))
+ return;
-static inline int __normal_prio(struct task_struct *p)
-{
- int bonus, prio;
+ set_tsk_thread_flag(p, TIF_NEED_RESCHED);
- bonus = CURRENT_BONUS(p) - MAX_BONUS / 2;
+ cpu = task_cpu(p);
+ if (cpu == smp_processor_id())
+ return;
- prio = p->static_prio - bonus;
- if (prio < MAX_RT_PRIO)
- prio = MAX_RT_PRIO;
- if (prio > MAX_PRIO-1)
- prio = MAX_PRIO-1;
- return prio;
+ /* NEED_RESCHED must be visible before we test polling */
+ smp_mb();
+ if (!tsk_is_polling(p))
+ smp_send_reschedule(cpu);
+}
+
+static void resched_cpu(int cpu)
+{
+ struct rq *rq = cpu_rq(cpu);
+ unsigned long flags;
+
+ if (!spin_trylock_irqsave(&rq->lock, flags))
+ return;
+ resched_task(cpu_curr(cpu));
+ spin_unlock_irqrestore(&rq->lock, flags);
+}
+#else
+static inline void resched_task(struct task_struct *p)
+{
+ assert_spin_locked(&task_rq(p)->lock);
+ set_tsk_need_resched(p);
}
+#endif
+
+#include "sched_stats.h"
/*
* To aid in avoiding the subversion of "niceness" due to uneven distribution
dec_raw_weighted_load(rq, p);
}
+/*
+ * Adding/removing a task to/from a priority array:
+ */
+static void dequeue_task(struct task_struct *p, struct prio_array *array)
+{
+ array->nr_active--;
+ list_del(&p->run_list);
+ if (list_empty(array->queue + p->prio))
+ __clear_bit(p->prio, array->bitmap);
+}
+
+static void enqueue_task(struct task_struct *p, struct prio_array *array)
+{
+ sched_info_queued(p);
+ list_add_tail(&p->run_list, array->queue + p->prio);
+ __set_bit(p->prio, array->bitmap);
+ array->nr_active++;
+ p->array = array;
+}
+
+/*
+ * Put task to the end of the run list without the overhead of dequeue
+ * followed by enqueue.
+ */
+static void requeue_task(struct task_struct *p, struct prio_array *array)
+{
+ list_move_tail(&p->run_list, array->queue + p->prio);
+}
+
+static inline void
+enqueue_task_head(struct task_struct *p, struct prio_array *array)
+{
+ list_add(&p->run_list, array->queue + p->prio);
+ __set_bit(p->prio, array->bitmap);
+ array->nr_active++;
+ p->array = array;
+}
+
+/*
+ * __normal_prio - return the priority that is based on the static
+ * priority but is modified by bonuses/penalties.
+ *
+ * We scale the actual sleep average [0 .... MAX_SLEEP_AVG]
+ * into the -5 ... 0 ... +5 bonus/penalty range.
+ *
+ * We use 25% of the full 0...39 priority range so that:
+ *
+ * 1) nice +19 interactive tasks do not preempt nice 0 CPU hogs.
+ * 2) nice -20 CPU hogs do not get preempted by nice 0 tasks.
+ *
+ * Both properties are important to certain workloads.
+ */
+
+static inline int __normal_prio(struct task_struct *p)
+{
+ int bonus, prio;
+
+ bonus = CURRENT_BONUS(p) - MAX_BONUS / 2;
+
+ prio = p->static_prio - bonus;
+ if (prio < MAX_RT_PRIO)
+ prio = MAX_RT_PRIO;
+ if (prio > MAX_PRIO-1)
+ prio = MAX_PRIO-1;
+ return prio;
+}
+
/*
* Calculate the expected normal priority: i.e. priority
* without taking RT-inheritance into account. Might be
p->array = NULL;
}
-/*
- * resched_task - mark a task 'to be rescheduled now'.
- *
- * On UP this means the setting of the need_resched flag, on SMP it
- * might also involve a cross-CPU call to trigger the scheduler on
- * the target CPU.
- */
-#ifdef CONFIG_SMP
-
-#ifndef tsk_is_polling
-#define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG)
-#endif
-
-static void resched_task(struct task_struct *p)
-{
- int cpu;
-
- assert_spin_locked(&task_rq(p)->lock);
-
- if (unlikely(test_tsk_thread_flag(p, TIF_NEED_RESCHED)))
- return;
-
- set_tsk_thread_flag(p, TIF_NEED_RESCHED);
-
- cpu = task_cpu(p);
- if (cpu == smp_processor_id())
- return;
-
- /* NEED_RESCHED must be visible before we test polling */
- smp_mb();
- if (!tsk_is_polling(p))
- smp_send_reschedule(cpu);
-}
-
-static void resched_cpu(int cpu)
-{
- struct rq *rq = cpu_rq(cpu);
- unsigned long flags;
-
- if (!spin_trylock_irqsave(&rq->lock, flags))
- return;
- resched_task(cpu_curr(cpu));
- spin_unlock_irqrestore(&rq->lock, flags);
-}
-#else
-static inline void resched_task(struct task_struct *p)
-{
- assert_spin_locked(&task_rq(p)->lock);
- set_tsk_need_resched(p);
-}
-#endif
-
/**
* task_curr - is this task currently executing on a CPU?
* @p: the task in question.
projects / linux-2.6 / blobdiff