Rearrange pick_next_task_fair() a bit to avoid checking cfs_rq->nr_running twice for the case where FAIR_GROUP_SCHED is enabled and the previous task doesn't belong to the fair class.
Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- kernel/sched/fair.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index fe03efd3880a..e519f6c03fe9 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -6267,10 +6267,10 @@ pick_next_task_fair(struct rq *rq, struct task_struct *prev, struct rq_flags *rf int new_tasks;
again: -#ifdef CONFIG_FAIR_GROUP_SCHED if (!cfs_rq->nr_running) goto idle;
+#ifdef CONFIG_FAIR_GROUP_SCHED if (prev->sched_class != &fair_sched_class) goto simple;
@@ -6300,11 +6300,17 @@ pick_next_task_fair(struct rq *rq, struct task_struct *prev, struct rq_flags *rf /* * This call to check_cfs_rq_runtime() will do the * throttle and dequeue its entity in the parent(s). - * Therefore the 'simple' nr_running test will indeed + * Therefore the nr_running test will indeed * be correct. */ - if (unlikely(check_cfs_rq_runtime(cfs_rq))) + if (unlikely(check_cfs_rq_runtime(cfs_rq))) { + cfs_rq = &rq->cfs; + + if (!cfs_rq->nr_running) + goto idle; + goto simple; + } }
se = pick_next_entity(cfs_rq, curr); @@ -6344,12 +6350,8 @@ pick_next_task_fair(struct rq *rq, struct task_struct *prev, struct rq_flags *rf
return p; simple: - cfs_rq = &rq->cfs; #endif
- if (!cfs_rq->nr_running) - goto idle; - put_prev_task(rq, prev);
do {