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

[Cong Wang <xiyou.wangcong@gmail.com>]

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