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-rw-r--r--kernel/sched_fair.c26
1 files changed, 16 insertions, 10 deletions
diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index a543a5b202a..b320753aa6c 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -146,8 +146,20 @@ static inline struct cfs_rq *cpu_cfs_rq(struct cfs_rq *cfs_rq, int this_cpu)
static inline void list_add_leaf_cfs_rq(struct cfs_rq *cfs_rq)
{
if (!cfs_rq->on_list) {
- list_add_rcu(&cfs_rq->leaf_cfs_rq_list,
+ /*
+ * Ensure we either appear before our parent (if already
+ * enqueued) or force our parent to appear after us when it is
+ * enqueued. The fact that we always enqueue bottom-up
+ * reduces this to two cases.
+ */
+ if (cfs_rq->tg->parent &&
+ cfs_rq->tg->parent->cfs_rq[cpu_of(rq_of(cfs_rq))]->on_list) {
+ list_add_rcu(&cfs_rq->leaf_cfs_rq_list,
+ &rq_of(cfs_rq)->leaf_cfs_rq_list);
+ } else {
+ list_add_tail_rcu(&cfs_rq->leaf_cfs_rq_list,
&rq_of(cfs_rq)->leaf_cfs_rq_list);
+ }
cfs_rq->on_list = 1;
}
@@ -2016,7 +2028,7 @@ out:
/*
* update tg->load_weight by folding this cpu's load_avg
*/
-static int tg_shares_up(struct task_group *tg, int cpu)
+static int update_shares_cpu(struct task_group *tg, int cpu)
{
struct cfs_rq *cfs_rq;
unsigned long flags;
@@ -2056,14 +2068,8 @@ static void update_shares(int cpu)
struct rq *rq = cpu_rq(cpu);
rcu_read_lock();
- for_each_leaf_cfs_rq(rq, cfs_rq) {
- struct task_group *tg = cfs_rq->tg;
-
- do {
- tg_shares_up(tg, cpu);
- tg = tg->parent;
- } while (tg);
- }
+ for_each_leaf_cfs_rq(rq, cfs_rq)
+ update_shares_cpu(cfs_rq->tg, cpu);
rcu_read_unlock();
}