- * Load-balancing iterator. Note: while the runqueue stays locked
- * during the whole iteration, the current task might be
- * dequeued so the iterator has to be dequeue-safe. Here we
- * achieve that by always pre-iterating before returning
- * the current task:
- */
-static struct task_struct *
-__load_balance_iterator(struct cfs_rq *cfs_rq, struct list_head *next)
-{
- struct task_struct *p = NULL;
- struct sched_entity *se;
-
- if (next == &cfs_rq->tasks)
- return NULL;
-
- se = list_entry(next, struct sched_entity, group_node);
- p = task_of(se);
- cfs_rq->balance_iterator = next->next;
-
- return p;
-}
-
-static struct task_struct *load_balance_start_fair(void *arg)
-{
- struct cfs_rq *cfs_rq = arg;
-
- return __load_balance_iterator(cfs_rq, cfs_rq->tasks.next);
-}
-
-static struct task_struct *load_balance_next_fair(void *arg)
-{
- struct cfs_rq *cfs_rq = arg;
-
- return __load_balance_iterator(cfs_rq, cfs_rq->balance_iterator);
-}
-
-/*
- * runqueue iterator, to support SMP load-balancing between different
- * scheduling classes, without having to expose their internal data
- * structures to the load-balancing proper:
- */
-struct rq_iterator {
- void *arg;
- struct task_struct *(*start)(void *);
- struct task_struct *(*next)(void *);
-};
-
-static unsigned long
-balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest,
- unsigned long max_load_move, struct sched_domain *sd,
- enum cpu_idle_type idle, int *all_pinned,
- int *this_best_prio, struct cfs_rq *busiest_cfs_rq);
-
-
-#ifdef CONFIG_FAIR_GROUP_SCHED
-static unsigned long
-load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,
- unsigned long max_load_move,
- struct sched_domain *sd, enum cpu_idle_type idle,
- int *all_pinned, int *this_best_prio)
-{
- long rem_load_move = max_load_move;
- int busiest_cpu = cpu_of(busiest);
- struct task_group *tg;
-
- rcu_read_lock();
- update_h_load(busiest_cpu);
-
- list_for_each_entry_rcu(tg, &task_groups, list) {
- struct cfs_rq *busiest_cfs_rq = tg->cfs_rq[busiest_cpu];
- unsigned long busiest_h_load = busiest_cfs_rq->h_load;
- unsigned long busiest_weight = busiest_cfs_rq->load.weight;
- u64 rem_load, moved_load;
-
- /*
- * empty group
- */
- if (!busiest_cfs_rq->task_weight)
- continue;
-
- rem_load = (u64)rem_load_move * busiest_weight;
- rem_load = div_u64(rem_load, busiest_h_load + 1);
-
- moved_load = balance_tasks(this_rq, this_cpu, busiest,
- rem_load, sd, idle, all_pinned, this_best_prio,
- busiest_cfs_rq);
-
- if (!moved_load)
- continue;
-
- moved_load *= busiest_h_load;
- moved_load = div_u64(moved_load, busiest_weight + 1);
-
- rem_load_move -= moved_load;
- if (rem_load_move < 0)
- break;
- }
- rcu_read_unlock();
-
- return max_load_move - rem_load_move;
-}
-#else
-static unsigned long
-load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,
- unsigned long max_load_move,
- struct sched_domain *sd, enum cpu_idle_type idle,
- int *all_pinned, int *this_best_prio)
-{
- return balance_tasks(this_rq, this_cpu, busiest,
- max_load_move, sd, idle, all_pinned,
- this_best_prio, &busiest->cfs);
-}
-#endif
-
-static int
-iter_move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest,
- struct sched_domain *sd, enum cpu_idle_type idle,
- struct rq_iterator *iterator);
-
-/*
- * move_one_task tries to move exactly one task from busiest to this_rq, as
- * part of active balancing operations within "domain".
- * Returns 1 if successful and 0 otherwise.
- *
- * Called with both runqueues locked.
- */
-static int
-move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest,
- struct sched_domain *sd, enum cpu_idle_type idle)
-{
- struct cfs_rq *busy_cfs_rq;
- struct rq_iterator cfs_rq_iterator;
-
- cfs_rq_iterator.start = load_balance_start_fair;
- cfs_rq_iterator.next = load_balance_next_fair;
-
- for_each_leaf_cfs_rq(busiest, busy_cfs_rq) {
- /*
- * pass busy_cfs_rq argument into
- * load_balance_[start|next]_fair iterators
- */
- cfs_rq_iterator.arg = busy_cfs_rq;
- if (iter_move_one_task(this_rq, this_cpu, busiest, sd, idle,
- &cfs_rq_iterator))
- return 1;
- }
-
- return 0;
-}
-
-/*