SQL priority modifier has no effect

[lance6716]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

mysql> select LOW_PRIORITY * from test.t;
+---+------+
| c | c2   |
+---+------+
| 1 |    1 |
| 2 |    2 |
+---+------+
2 rows in set (0.00 sec)

mysql> select * from test.t;
+---+------+
| c | c2   |
+---+------+
| 1 |    1 |
| 2 |    2 |
+---+------+
2 rows in set (0.00 sec)

then check grafana

2. What did you expect to see? (Required)

see priorities of two levels: medium and low

3. What did you see instead (Required)

there's no low label

4. What is your TiDB version? (Required)

[nolouch]

I think this priority is different from the priority shown in the metrics of resource control.

[lance6716]

How can I verify the SQL priority really take effect? I'm try to fix https://github.com/pingcap/tidb/issues/49602

also cc @overvenus