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

JIRA: https://issues.redhat.com/browse/RHEL-111810

commit c50784e
Author: Tejun Heo <tj@kernel.org>
Date:   Fri Jun 13 13:23:07 2025 -1000

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

    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: Phil Auld <pauld@redhat.com>

Author: auldp

kernel/sched/ext.c

@@ -4205,12 +4205,12 @@ 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(sch, cgroup_set_weight))
-			SCX_CALL_OP(sch, SCX_KF_UNLOCKED, cgroup_set_weight, NULL,
-				    tg_cgrp(tg), weight);
-		tg->scx_weight = weight;
-	}
+	if (scx_cgroup_enabled && SCX_HAS_OP(sch, cgroup_set_weight) &&
+	    tg->scx_weight != weight)
+		SCX_CALL_OP(sch, SCX_KF_UNLOCKED, cgroup_set_weight, NULL,
+			    tg_cgrp(tg), weight);
+
+	tg->scx_weight = weight;
 
 	percpu_up_read(&scx_cgroup_rwsem);
 }