[PATCH 6.12 124/337] sched/deadline: Use revised wakeup rule only for running dl_server

6.12-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Gabriele Monaco <[email protected]>

[ Upstream commit 1842bf97af109f5ebf830175c9725bf81ebb78b1 ]

Commit 14a857056466 ("sched/deadline: Use revised wakeup rule for
dl_server") applies the revised wakeup rule to any server, as a result
servers that are not running (dl_defer_running == 0) and start with a
deadline overflow get enqueued and can boost tasks as if they were
running, invalidating the defer rule and the documented state model.

Apply the revised wakeup rule only for deferrable servers that are
marked as running.

Fixes: 14a857056466 ("sched/deadline: Use revised wakeup rule for dl_server")
Signed-off-by: Gabriele Monaco <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Acked-by: Juri Lelli <[email protected]>
Tested-by: Andrea Righi <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Sasha Levin <[email protected]>
---
 kernel/sched/deadline.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index cb8eff0ebd228..f5c64d1a019d5 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -1079,7 +1079,8 @@ static void update_dl_entity(struct sched_dl_entity *dl_se)
 	if (dl_time_before(dl_se->deadline, rq_clock(rq)) ||
 	    dl_entity_overflow(dl_se, rq_clock(rq))) {
 
-		if (unlikely((!dl_is_implicit(dl_se) || dl_se->dl_defer) &&
+		if (unlikely((!dl_is_implicit(dl_se) ||
+			      (dl_se->dl_defer && dl_se->dl_defer_running)) &&
 			     !dl_time_before(dl_se->deadline, rq_clock(rq)) &&
 			     !is_dl_boosted(dl_se))) {
 			update_dl_revised_wakeup(dl_se, rq);
-- 
2.53.0