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: 819513666966 ("sched_ext: Add cgroup support")
Cc: stable@vger.kernel.org # v6.12+

diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c
index 2c41c78be61ebbac6bfb654878e98277d04de149..33a0d8c6ff95fb0059d8f8620c4b6a6b49b622d6 100644 (file)
--- a/kernel/sched/ext.c
+++ b/kernel/sched/ext.c
@@ -4241,12 +4241,12 @@ 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);
 }