sched/rt: Move group schedulability check to sched_rt_global_validate()

The sched_rt_global_constraints() function is a remnant that used to set
up global RT throttling but that is no more since commit 5f6bd380c7bdb
("sched/rt: Remove default bandwidth control") and the function ended up
only doing schedulability check.
Move the check into the validation function where it fits better.
(The order of validations sched_dl_global_validate() and
sched_rt_global_validate() shouldn't matter.)

Signed-off-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260323-sched-rert_groups-v3-2-1e7d5ed6b249@suse.com

1 files changed, 8 insertions, 9 deletions

diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 893e54dab13e..e16d8f1b4aa2 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -2832,15 +2832,7 @@ long sched_group_rt_period(struct task_group *tg)
 #ifdef CONFIG_SYSCTL
 static int sched_rt_global_constraints(void)
 {
-	int ret = 0;
-	if (!rt_group_sched_enabled())
-		return ret;
-
-	mutex_lock(&rt_constraints_mutex);
-	ret = __rt_schedulable(NULL, 0, 0);
-	mutex_unlock(&rt_constraints_mutex);
-
-	return ret;
+	return 0;
 }
 #endif /* CONFIG_SYSCTL */
 
@@ -2872,6 +2864,13 @@ static int sched_rt_global_validate(void)
 			NSEC_PER_USEC > max_rt_runtime)))
 		return -EINVAL;
 
+#ifdef CONFIG_RT_GROUP_SCHED
+	if (!rt_group_sched_enabled())
+		return 0;
+
+	scoped_guard(mutex, &rt_constraints_mutex)
+		return __rt_schedulable(NULL, 0, 0);
+#endif
 	return 0;
 }