[PATCH bpf-next v4 02/18] bpf: lpm_trie memory usage

Yafang Shao
2023-03-05T12:46:28Z

trie_mem_usage() is introduced to calculate the lpm_trie memory usage.
Some small memory allocations are ignored. The inner node is also
ignored.

The result as follows,

- before
10: lpm_trie flags 0x1
key 8B value 8B max_entries 65536 memlock 1048576B

- after
10: lpm_trie flags 0x1
key 8B value 8B max_entries 65536 memlock 2291536B

Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
---
kernel/bpf/lpm_trie.c | 11 +++++++++++
1 file changed, 11 insertions(+)

diff --git a/kernel/bpf/lpm_trie.c b/kernel/bpf/lpm_trie.c
index d833496..dc23f2a 100644
--- a/kernel/bpf/lpm_trie.c
+++ b/kernel/bpf/lpm_trie.c
@@ -720,6 +720,16 @@ static int trie_check_btf(const struct bpf_map *map,
-EINVAL : 0;
}

+static u64 trie_mem_usage(const struct bpf_map *map)
+{
+ struct lpm_trie *trie = container_of(map, struct lpm_trie, map);
+ u64 elem_size;
+
+ elem_size = sizeof(struct lpm_trie_node) + trie->data_size +
+ trie->map.value_size;
+ return elem_size * READ_ONCE(trie->n_entries);
+}
+
BTF_ID_LIST_SINGLE(trie_map_btf_ids, struct, lpm_trie)
const struct bpf_map_ops trie_map_ops = {
.map_meta_equal = bpf_map_meta_equal,
@@ -733,5 +743,6 @@ static int trie_check_btf(const struct bpf_map *map,
.map_update_batch = generic_map_update_batch,
.map_delete_batch = generic_map_delete_batch,
.map_check_btf = trie_check_btf,
+ .map_mem_usage = trie_mem_usage,
.map_btf_id = &trie_map_btf_ids[0],
};
--
1.8.3.1