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-rw-r--r--kernel/sched_fair.c84
1 files changed, 53 insertions, 31 deletions
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 30ae9c2a2861..5c208e090ae4 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -707,6 +707,8 @@ static inline struct sched_entity *parent_entity(struct sched_entity *se)
return se->parent;
}
+#define GROUP_IMBALANCE_PCT 20
+
#else /* CONFIG_FAIR_GROUP_SCHED */
#define for_each_sched_entity(se) \
@@ -967,25 +969,6 @@ static struct task_struct *load_balance_next_fair(void *arg)
return __load_balance_iterator(cfs_rq, cfs_rq->rb_load_balance_curr);
}
-#ifdef CONFIG_FAIR_GROUP_SCHED
-static int cfs_rq_best_prio(struct cfs_rq *cfs_rq)
-{
- struct sched_entity *curr;
- struct task_struct *p;
-
- if (!cfs_rq->nr_running)
- return MAX_PRIO;
-
- curr = cfs_rq->curr;
- if (!curr)
- curr = __pick_next_entity(cfs_rq);
-
- p = task_of(curr);
-
- return p->prio;
-}
-#endif
-
static unsigned long
load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,
unsigned long max_load_move,
@@ -995,28 +978,45 @@ load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,
struct cfs_rq *busy_cfs_rq;
long rem_load_move = max_load_move;
struct rq_iterator cfs_rq_iterator;
+ unsigned long load_moved;
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) {
#ifdef CONFIG_FAIR_GROUP_SCHED
- struct cfs_rq *this_cfs_rq;
- long imbalance;
- unsigned long maxload;
+ struct cfs_rq *this_cfs_rq = busy_cfs_rq->tg->cfs_rq[this_cpu];
+ unsigned long maxload, task_load, group_weight;
+ unsigned long thisload, per_task_load;
+ struct sched_entity *se = busy_cfs_rq->tg->se[busiest->cpu];
- this_cfs_rq = cpu_cfs_rq(busy_cfs_rq, this_cpu);
+ task_load = busy_cfs_rq->load.weight;
+ group_weight = se->load.weight;
- imbalance = busy_cfs_rq->load.weight - this_cfs_rq->load.weight;
- /* Don't pull if this_cfs_rq has more load than busy_cfs_rq */
- if (imbalance <= 0)
+ /*
+ * 'group_weight' is contributed by tasks of total weight
+ * 'task_load'. To move 'rem_load_move' worth of weight only,
+ * we need to move a maximum task load of:
+ *
+ * maxload = (remload / group_weight) * task_load;
+ */
+ maxload = (rem_load_move * task_load) / group_weight;
+
+ if (!maxload || !task_load)
continue;
- /* Don't pull more than imbalance/2 */
- imbalance /= 2;
- maxload = min(rem_load_move, imbalance);
+ per_task_load = task_load / busy_cfs_rq->nr_running;
+ /*
+ * balance_tasks will try to forcibly move atleast one task if
+ * possible (because of SCHED_LOAD_SCALE_FUZZ). Avoid that if
+ * maxload is less than GROUP_IMBALANCE_FUZZ% the per_task_load.
+ */
+ if (100 * maxload < GROUP_IMBALANCE_PCT * per_task_load)
+ continue;
- *this_best_prio = cfs_rq_best_prio(this_cfs_rq);
+ /* Disable priority-based load balance */
+ *this_best_prio = 0;
+ thisload = this_cfs_rq->load.weight;
#else
# define maxload rem_load_move
#endif
@@ -1025,11 +1025,33 @@ load_balance_fair(struct rq *this_rq, int this_cpu, struct rq *busiest,
* load_balance_[start|next]_fair iterators
*/
cfs_rq_iterator.arg = busy_cfs_rq;
- rem_load_move -= balance_tasks(this_rq, this_cpu, busiest,
+ load_moved = balance_tasks(this_rq, this_cpu, busiest,
maxload, sd, idle, all_pinned,
this_best_prio,
&cfs_rq_iterator);
+#ifdef CONFIG_FAIR_GROUP_SCHED
+ /*
+ * load_moved holds the task load that was moved. The
+ * effective (group) weight moved would be:
+ * load_moved_eff = load_moved/task_load * group_weight;
+ */
+ load_moved = (group_weight * load_moved) / task_load;
+
+ /* Adjust shares on both cpus to reflect load_moved */
+ group_weight -= load_moved;
+ set_se_shares(se, group_weight);
+
+ se = busy_cfs_rq->tg->se[this_cpu];
+ if (!thisload)
+ group_weight = load_moved;
+ else
+ group_weight = se->load.weight + load_moved;
+ set_se_shares(se, group_weight);
+#endif
+
+ rem_load_move -= load_moved;
+
if (rem_load_move <= 0)
break;
}