Commit 563bc216 authored by Tianchen Ding's avatar Tianchen Ding Committed by Peter Zijlstra
Browse files

sched/eevdf: Force propagating min_slice of cfs_rq when {en,de}queue tasks 



When a task is enqueued and its parent cgroup se is already on_rq, this
parent cgroup se will not be enqueued again, and hence the root->min_slice
leaves unchanged. The same issue happens when a task is dequeued and its
parent cgroup se has other runnable entities, and the parent cgroup se
will not be dequeued.

Force propagating min_slice when se doesn't need to be enqueued or
dequeued. Ensure the se hierarchy always get the latest min_slice.

Fixes: aef6987d ("sched/eevdf: Propagate min_slice up the cgroup hierarchy")
Signed-off-by: default avatarTianchen Ding <dtcccc@linux.alibaba.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20250211063659.7180-1-dtcccc@linux.alibaba.com
parent b9f2b29b

kernel/sched/fair.c

+4 −0
Original line number Diff line number Diff line
@@ -7002,6 +7002,8 @@ enqueue_task_fair(struct rq *rq, struct task_struct *p, int flags) 
		update_cfs_group(se);



		se->slice = slice;

		if (se != cfs_rq->curr)

			min_vruntime_cb_propagate(&se->run_node, NULL);

		slice = cfs_rq_min_slice(cfs_rq);



		cfs_rq->h_nr_runnable += h_nr_runnable;
@@ -7131,6 +7133,8 @@ static int dequeue_entities(struct rq *rq, struct sched_entity *se, int flags) 
		update_cfs_group(se);



		se->slice = slice;

		if (se != cfs_rq->curr)

			min_vruntime_cb_propagate(&se->run_node, NULL);

		slice = cfs_rq_min_slice(cfs_rq);



		cfs_rq->h_nr_runnable -= h_nr_runnable;