[RFC -v7 PATCH 1/7] sched: check the right ->nr_running inyield_task_fair

From: Rik van Riel
Date: Wed Jan 26 2011 - 17:27:07 EST

With CONFIG_FAIR_GROUP_SCHED, each task_group has its own cfs_rq.
Yielding to a task from another cfs_rq may be worthwhile, since
a process calling yield typically cannot use the CPU right now.

Therefor, we want to check the per-cpu nr_running, not the
cgroup local one.

Signed-off-by: Rik van Riel <riel@xxxxxxxxxx>
kernel/sched_fair.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index c62ebae..7b338ac 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -1304,7 +1304,7 @@ static void yield_task_fair(struct rq *rq)
* Are we the only task in the tree?
- if (unlikely(cfs_rq->nr_running == 1))
+ if (unlikely(rq->nr_running == 1))

clear_buddies(cfs_rq, se);
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