where are my tmp_disk_tables

gistfile1.txt

mysql> show global status like '%tmp%';
+-------------------------+-----------+
| Variable_name           | Value     |
+-------------------------+-----------+
| Created_tmp_disk_tables | 146954844 |
| Created_tmp_files       | 812363    |
| Created_tmp_tables      | 220784074 |
+-------------------------+-----------+

mysql> show variables like '%tmp%';
+-------------------+-----------+
| Variable_name     | Value     |
+-------------------+-----------+
| max_tmp_tables    | 32        |
| slave_load_tmpdir | /tmp      |
| tmp_table_size    | 536870912 |
| tmpdir            | /tmp      |
+-------------------+-----------+
4 rows in set (0.00 sec)

mysql> SELECT @@tmpdir;
+----------+
| @@tmpdir |
+----------+
| /tmp     |
+----------+
1 row in set (0.00 sec)

/tmp# ls -lah
total 20K
drwxrwxrwt  2 root root  16K Jan 15 15:57 .
drwxr-xr-x 24 root root 4.0K Sep 26 14:12 ..