6.12-stable review patch. If anyone has any objections, please let me know.
------------------
From: Vincent Guittot <vincent.guittot@xxxxxxxxxx>
[ Upstream commit c1f43c342e1f2e32f0620bf2e972e2a9ea0a1e60 ]
We can't stop the tick of a rq if there are at least 2 tasks enqueued in
the whole hierarchy and not only at the root cfs rq.
rq->cfs.nr_running tracks the number of sched_entity at one level
whereas rq->cfs.h_nr_running tracks all queued tasks in the
hierarchy.
Fixes: 11cc374f4643b ("sched_ext: Simplify scx_can_stop_tick() invocation in sched_can_stop_tick()")
Signed-off-by: Vincent Guittot <vincent.guittot@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@xxxxxxx>
Link: https://lore.kernel.org/r/20241202174606.4074512-2-vincent.guittot@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
kernel/sched/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 6cc12777bb11..d07dc87787df 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -1300,7 +1300,7 @@ bool sched_can_stop_tick(struct rq *rq)
if (scx_enabled() && !scx_can_stop_tick(rq))
return false;
- if (rq->cfs.nr_running > 1)
+ if (rq->cfs.h_nr_running > 1)
return false;
/*
--
2.39.5
