Re: [syzbot] [kernel?] WARNING in enqueue_dl_entity

[Hillf Danton]

On Fri, 22 Nov 2024 14:48:23 -0800
> syzbot has found a reproducer for the following issue on:
> 
> HEAD commit:    28eb75e178d3 Merge tag 'drm-next-2024-11-21' of https://gi..
> git tree:       upstream
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1016fec0580000

#syz test upstream master

--- x/kernel/sched/fair.c
+++ y/kernel/sched/fair.c
@@ -7151,8 +7151,11 @@ static int dequeue_entities(struct rq *r
 			idle_h_nr_running = h_nr_running;
 
 		/* end evaluation on encountering a throttled cfs_rq */
-		if (cfs_rq_throttled(cfs_rq))
+		if (cfs_rq_throttled(cfs_rq)) {
+			if (rq_h_nr_running && !rq->cfs.h_nr_running)
+				dl_server_stop(&rq->fair_server);
 			return 0;
+		}
 	}
 
 	sub_nr_running(rq, h_nr_running);
--