diff options
Diffstat (limited to 'kernel/sched.c')
| -rw-r--r-- | kernel/sched.c | 26 |
1 files changed, 21 insertions, 5 deletions
diff --git a/kernel/sched.c b/kernel/sched.c index b4dab63c6dbd..0ec84f57695d 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -1941,6 +1941,7 @@ int can_migrate_task(task_t *p, runqueue_t *rq, int this_cpu, return 1; } +#define rq_best_prio(rq) min((rq)->curr->prio, (rq)->best_expired_prio) /* * move_tasks tries to move up to max_nr_move tasks and max_load_move weighted * load from busiest to this_rq, as part of a balancing operation within @@ -1955,7 +1956,9 @@ static int move_tasks(runqueue_t *this_rq, int this_cpu, runqueue_t *busiest, { prio_array_t *array, *dst_array; struct list_head *head, *curr; - int idx, pulled = 0, pinned = 0, this_min_prio; + int idx, pulled = 0, pinned = 0, this_best_prio, busiest_best_prio; + int busiest_best_prio_seen; + int skip_for_load; /* skip the task based on weighted load issues */ long rem_load_move; task_t *tmp; @@ -1964,7 +1967,16 @@ static int move_tasks(runqueue_t *this_rq, int this_cpu, runqueue_t *busiest, rem_load_move = max_load_move; pinned = 1; - this_min_prio = this_rq->curr->prio; + this_best_prio = rq_best_prio(this_rq); + busiest_best_prio = rq_best_prio(busiest); + /* + * 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==busiest_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. + */ + busiest_best_prio_seen = busiest_best_prio == busiest->curr->prio; /* * We first consider expired tasks. Those will likely not be @@ -2009,8 +2021,12 @@ skip_queue: * skip a task if it will be the highest priority task (i.e. smallest * prio value) on its new queue regardless of its load weight */ - if ((idx >= this_min_prio && tmp->load_weight > rem_load_move) || + skip_for_load = tmp->load_weight > rem_load_move; + if (skip_for_load && idx < this_best_prio) + skip_for_load = !busiest_best_prio_seen && idx == busiest_best_prio; + if (skip_for_load || !can_migrate_task(tmp, busiest, this_cpu, sd, idle, &pinned)) { + busiest_best_prio_seen |= idx == busiest_best_prio; if (curr != head) goto skip_queue; idx++; @@ -2031,8 +2047,8 @@ skip_queue: * and the prescribed amount of weighted load. */ if (pulled < max_nr_move && rem_load_move > 0) { - if (idx < this_min_prio) - this_min_prio = idx; + if (idx < this_best_prio) + this_best_prio = idx; if (curr != head) goto skip_queue; idx++; |