[Patch bpf-next] sock_map: include sk_psock memory overhead too

Cong Wang
2023-03-26T22:16:38Z

From: Cong Wang <cong.wang@bytedance.com>

When a socket is added to a sockmap, sk_psock is allocated too as its
sk_user_data, therefore it should be consider as an overhead of sockmap
memory usage.

Before this patch:

1: sockmap flags 0x0
key 4B value 4B max_entries 2 memlock 656B
pids echo-sockmap(549)

After this patch:

9: sockmap flags 0x0
key 4B value 4B max_entries 2 memlock 1824B
pids echo-sockmap(568)

Fixes: 73d2c61919e9 ("bpf, net: sock_map memory usage")
Cc: Yafang Shao <laoar.shao@gmail.com>
Cc: Jakub Sitnicki <jakub@cloudflare.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
---
net/core/sock_map.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/net/core/sock_map.c b/net/core/sock_map.c
index 7c189c2e2fbf..22197e565ece 100644
--- a/net/core/sock_map.c
+++ b/net/core/sock_map.c
@@ -799,9 +799,17 @@ static void sock_map_fini_seq_private(void *priv_data)

static u64 sock_map_mem_usage(const struct bpf_map *map)
{
+ struct bpf_stab *stab = container_of(map, struct bpf_stab, map);
u64 usage = sizeof(struct bpf_stab);
+ int i;

usage += (u64)map->max_entries * sizeof(struct sock *);
+
+ for (i = 0; i < stab->map.max_entries; i++) {
+ if (stab->sks[i])
+ usage += sizeof(struct sk_psock);
+ }
+
return usage;
}

@@ -1412,7 +1420,7 @@ static u64 sock_hash_mem_usage(const struct bpf_map *map)
u64 usage = sizeof(*htab);

usage += htab->buckets_num * sizeof(struct bpf_shtab_bucket);
- usage += atomic_read(&htab->count) * (u64)htab->elem_size;
+ usage += atomic_read(&htab->count) * ((u64)htab->elem_size + sizeof(struct sk_psock));
return usage;
}

--
2.34.1