sched_ext: Make scx_group_set_weight() always update tg->scx.weight

[ Upstream commit c50784e ]

Otherwise, tg->scx.weight can go out of sync while scx_cgroup is not enabled
and ops.cgroup_init() may be called with a stale weight value.

Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: 8195136 ("sched_ext: Add cgroup support")
Cc: stable@vger.kernel.org # v6.12+
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: Sasha Levin

kernel/sched/ext.c

@@ -4074,12 +4074,12 @@ void scx_group_set_weight(struct task_group *tg, unsigned long weight)
 {
 	percpu_down_read(&scx_cgroup_rwsem);
 
-	if (scx_cgroup_enabled && tg->scx_weight != weight) {
-		if (SCX_HAS_OP(cgroup_set_weight))
-			SCX_CALL_OP(SCX_KF_UNLOCKED, cgroup_set_weight, NULL,
-				    tg_cgrp(tg), weight);
-		tg->scx_weight = weight;
-	}
+	if (scx_cgroup_enabled && SCX_HAS_OP(cgroup_set_weight) &&
+	    tg->scx_weight != weight)
+		SCX_CALL_OP(SCX_KF_UNLOCKED, cgroup_set_weight, NULL,
+			    tg_cgrp(tg), weight);
+
+	tg->scx_weight = weight;
 
 	percpu_up_read(&scx_cgroup_rwsem);
 }