[PATCH tip] [PATCH]sched/fair: Fix endless loop in idle_balance()

From: Kirill Tkhai
Date: Thu Mar 06 2014 - 10:16:33 EST



This patch must go on top of the series:

[tip 1/2] sched/fair: Push down check for high priority class task into idle_balance()
[tip 2/2] sched/core: Fix endless loop in pick_next_task()

Check for fair tasks number to decide, that we've pulled a task.
rq's nr_running may contain throttled RT tasks.

Signed-off-by: Kirill Tkhai <ktkhai@xxxxxxxxxxxxx>
CC: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CC: Ingo Molnar <mingo@xxxxxxxxxx>

Peter, this finaly fixes problem with RT throttling.
Should I send all three patches as one series?
---
kernel/sched/fair.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 10db4a8..f1eedae 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -6710,7 +6710,7 @@ static int idle_balance(struct rq *this_rq)
* While browsing the domains, we released the rq lock.
* A task could have be enqueued in the meantime
*/
- if (this_rq->nr_running && !pulled_task) {
+ if (this_rq->cfs.h_nr_running && !pulled_task) {
pulled_task = 1;
goto out;
}



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/