[PATCH sched_ext/for-6.11] sched_ext: Reverting @p->sched_class if @p->disallow is set

[Zhangqiao (2012 lab)]

From: Zhang Qiao <zhangqiao22@xxxxxxxxxx>

when ops.init_task() sets @p->disallow, @p->policy was
reverted to @SCHED_NORMAL, but @p->sched_class was not,
so reverting p->sched_class to fair_sched_classs now.

Signed-off-by: Zhang Qiao <zhangqiao22@xxxxxxxxxx>
---
 kernel/sched/ext.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c
index ae9ec8f..fb83edd 100644
--- a/kernel/sched/ext.c
+++ b/kernel/sched/ext.c
@@ -3220,13 +3220,14 @@ static int scx_ops_init_task(struct task_struct *p, struct task_group *tg, bool
 
 		/*
 		 * We're either in fork or load path and @p->policy will be
-		 * applied right after. Reverting @p->policy here and rejecting
-		 * %SCHED_EXT transitions from scx_check_setscheduler()
+		 * applied right after. Reverting @p->policy and @p->sched_class
+		 * here and rejecting %SCHED_EXT transitions from scx_check_setscheduler()
 		 * guarantees that if ops.init_task() sets @p->disallow, @p can
 		 * never be in SCX.
 		 */
 		if (p->policy == SCHED_EXT) {
 			p->policy = SCHED_NORMAL;
+			p->sched_class = &fair_sched_class;
 			atomic_long_inc(&scx_nr_rejected);
 		}
 
-- 
2.45.2.windows.1