A new helper is introduced to calculate xskmap memory usage.
The xfsmap memory usage can be dynamically changed when we add or remove
a xsk_map_node. Hence we need to track the count of xsk_map_node to get
its memory usage.
The result as follows,
- before
10: xskmap name count_map flags 0x0
key 4B value 4B max_entries 65536 memlock 524288B
- after
10: xskmap name count_map flags 0x0 <<< no elements case
key 4B value 4B max_entries 65536 memlock 524608B
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20230305124615.12358-17-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
b4fd0d672b