sched_ext: Allow dequeue_task_scx to fail

Since dequeue_task() allowed to fail, there is a compile error:

kernel/sched/ext.c:3630:19: error: initialization of ‘bool (*)(struct rq*, struct task_struct *, int)’ {aka ‘_Bool (*)(struct rq *, struct task_struct *, int)’} from incompatible pointer type ‘void (*)(struct rq*, struct task_struct *, int)’
  3630 |  .dequeue_task  = dequeue_task_scx,
       |                   ^~~~~~~~~~~~~~~~

Allow dequeue_task_scx to fail too.

Fixes: 863ccdb ("sched: Allow sched_class::dequeue_task() to fail")
Signed-off-by: Yipeng Zou <[email protected]>
Signed-off-by: Tejun Heo <[email protected]>

Author: Yipeng Zou

kernel/sched/ext.c

@@ -2033,11 +2033,11 @@ static void ops_dequeue(struct task_struct *p, u64 deq_flags)
 	}
 }
 
-static void dequeue_task_scx(struct rq *rq, struct task_struct *p, int deq_flags)
+static bool dequeue_task_scx(struct rq *rq, struct task_struct *p, int deq_flags)
 {
 	if (!(p->scx.flags & SCX_TASK_QUEUED)) {
 		WARN_ON_ONCE(task_runnable(p));
-		return;
+		return true;
 	}
 
 	ops_dequeue(p, deq_flags);
@@ -2072,6 +2072,7 @@ static void dequeue_task_scx(struct rq *rq, struct task_struct *p, int deq_flags
 	sub_nr_running(rq, 1);
 
 	dispatch_dequeue(rq, p);
+	return true;
 }
 
 static void yield_task_scx(struct rq *rq)