X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=kernel%2Fsched_rt.c;h=8abd752a0ebd9fa9d9bb8f9c61100923d5df17ac;hb=e87cb5db0dc357473ac71801051954ddd6ff604f;hp=1192a2741b996e924e7a0b21c087d3b70215a4dd;hpb=99e1221d1a1edac316f7f8116c781f75733b1159;p=linux-2.6 diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c index 1192a2741b..8abd752a0e 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -7,7 +7,7 @@ * Update the current task's runtime statistics. Skip current tasks that * are not in our scheduling class. */ -static inline void update_curr_rt(struct rq *rq, u64 now) +static void update_curr_rt(struct rq *rq) { struct task_struct *curr = rq->curr; u64 delta_exec; @@ -15,18 +15,17 @@ static inline void update_curr_rt(struct rq *rq, u64 now) if (!task_has_rt_policy(curr)) return; - delta_exec = now - curr->se.exec_start; + delta_exec = rq->clock - curr->se.exec_start; if (unlikely((s64)delta_exec < 0)) delta_exec = 0; - if (unlikely(delta_exec > curr->se.exec_max)) - curr->se.exec_max = delta_exec; + + schedstat_set(curr->se.exec_max, max(curr->se.exec_max, delta_exec)); curr->se.sum_exec_runtime += delta_exec; - curr->se.exec_start = now; + curr->se.exec_start = rq->clock; } -static void -enqueue_task_rt(struct rq *rq, struct task_struct *p, int wakeup, u64 now) +static void enqueue_task_rt(struct rq *rq, struct task_struct *p, int wakeup) { struct rt_prio_array *array = &rq->rt.active; @@ -37,12 +36,11 @@ enqueue_task_rt(struct rq *rq, struct task_struct *p, int wakeup, u64 now) /* * Adding/removing a task to/from a priority array: */ -static void -dequeue_task_rt(struct rq *rq, struct task_struct *p, int sleep, u64 now) +static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int sleep) { struct rt_prio_array *array = &rq->rt.active; - update_curr_rt(rq, now); + update_curr_rt(rq); list_del(&p->run_list); if (list_empty(array->queue + p->prio)) @@ -61,9 +59,9 @@ static void requeue_task_rt(struct rq *rq, struct task_struct *p) } static void -yield_task_rt(struct rq *rq, struct task_struct *p) +yield_task_rt(struct rq *rq) { - requeue_task_rt(rq, p); + requeue_task_rt(rq, rq->curr); } /* @@ -75,7 +73,7 @@ static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p) resched_task(rq->curr); } -static struct task_struct *pick_next_task_rt(struct rq *rq, u64 now) +static struct task_struct *pick_next_task_rt(struct rq *rq) { struct rt_prio_array *array = &rq->rt.active; struct task_struct *next; @@ -89,17 +87,18 @@ static struct task_struct *pick_next_task_rt(struct rq *rq, u64 now) queue = array->queue + idx; next = list_entry(queue->next, struct task_struct, run_list); - next->se.exec_start = now; + next->se.exec_start = rq->clock; return next; } -static void put_prev_task_rt(struct rq *rq, struct task_struct *p, u64 now) +static void put_prev_task_rt(struct rq *rq, struct task_struct *p) { - update_curr_rt(rq, now); + update_curr_rt(rq); p->se.exec_start = 0; } +#ifdef CONFIG_SMP /* * Load-balancing iterator. Note: while the runqueue stays locked * during the whole iteration, the current task might be @@ -172,29 +171,14 @@ static struct task_struct *load_balance_next_rt(void *arg) return p; } -static int +static unsigned long load_balance_rt(struct rq *this_rq, int this_cpu, struct rq *busiest, - unsigned long max_nr_move, unsigned long max_load_move, - struct sched_domain *sd, enum cpu_idle_type idle, - int *all_pinned, unsigned long *load_moved) + unsigned long max_load_move, + struct sched_domain *sd, enum cpu_idle_type idle, + int *all_pinned, int *this_best_prio) { - int this_best_prio, best_prio, best_prio_seen = 0; - int nr_moved; struct rq_iterator rt_rq_iterator; - best_prio = sched_find_first_bit(busiest->rt.active.bitmap); - this_best_prio = sched_find_first_bit(this_rq->rt.active.bitmap); - - /* - * Enable handling of the case where there is more than one task - * with the best priority. If the current running task is one - * of those with prio==best_prio we know it won't be moved - * and therefore it's safe to override the skip (based on load) - * of any task we find with that prio. - */ - if (busiest->curr->prio == best_prio) - best_prio_seen = 1; - rt_rq_iterator.start = load_balance_start_rt; rt_rq_iterator.next = load_balance_next_rt; /* pass 'busiest' rq argument into @@ -202,13 +186,24 @@ load_balance_rt(struct rq *this_rq, int this_cpu, struct rq *busiest, */ rt_rq_iterator.arg = busiest; - nr_moved = balance_tasks(this_rq, this_cpu, busiest, max_nr_move, - max_load_move, sd, idle, all_pinned, load_moved, - this_best_prio, best_prio, best_prio_seen, - &rt_rq_iterator); + return balance_tasks(this_rq, this_cpu, busiest, max_load_move, sd, + idle, all_pinned, this_best_prio, &rt_rq_iterator); +} - return nr_moved; +static int +move_one_task_rt(struct rq *this_rq, int this_cpu, struct rq *busiest, + struct sched_domain *sd, enum cpu_idle_type idle) +{ + struct rq_iterator rt_rq_iterator; + + rt_rq_iterator.start = load_balance_start_rt; + rt_rq_iterator.next = load_balance_next_rt; + rt_rq_iterator.arg = busiest; + + return iter_move_one_task(this_rq, this_cpu, busiest, sd, idle, + &rt_rq_iterator); } +#endif static void task_tick_rt(struct rq *rq, struct task_struct *p) { @@ -222,23 +217,27 @@ static void task_tick_rt(struct rq *rq, struct task_struct *p) if (--p->time_slice) return; - p->time_slice = static_prio_timeslice(p->static_prio); - set_tsk_need_resched(p); + p->time_slice = DEF_TIMESLICE; - /* put it at the end of the queue: */ - requeue_task_rt(rq, p); + /* + * Requeue to the end of queue if we are not the only element + * on the queue: + */ + if (p->run_list.prev != p->run_list.next) { + requeue_task_rt(rq, p); + set_tsk_need_resched(p); + } } -/* - * No parent/child timeslice management necessary for RT tasks, - * just activate them: - */ -static void task_new_rt(struct rq *rq, struct task_struct *p) +static void set_curr_task_rt(struct rq *rq) { - activate_task(rq, p, 1); + struct task_struct *p = rq->curr; + + p->se.exec_start = rq->clock; } -static struct sched_class rt_sched_class __read_mostly = { +const struct sched_class rt_sched_class = { + .next = &fair_sched_class, .enqueue_task = enqueue_task_rt, .dequeue_task = dequeue_task_rt, .yield_task = yield_task_rt, @@ -248,8 +247,11 @@ static struct sched_class rt_sched_class __read_mostly = { .pick_next_task = pick_next_task_rt, .put_prev_task = put_prev_task_rt, +#ifdef CONFIG_SMP .load_balance = load_balance_rt, + .move_one_task = move_one_task_rt, +#endif + .set_curr_task = set_curr_task_rt, .task_tick = task_tick_rt, - .task_new = task_new_rt, };