6.12-stable review patch. If anyone has any objections, please let me know.
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From: Vincent Guittot vincent.guittot@linaro.org
[ 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@linaro.org Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Reviewed-by: Dietmar Eggemann dietmar.eggemann@arm.com Link: https://lore.kernel.org/r/20241202174606.4074512-2-vincent.guittot@linaro.or... Signed-off-by: Sasha Levin sashal@kernel.org --- 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;
/*