diff options
| author | Eric Dumazet <[email protected]> | 2025-03-20 12:16:04 +0000 |
|---|---|---|
| committer | Jakub Kicinski <[email protected]> | 2025-03-25 14:37:16 +0000 |
| commit | 0de2a5c4b824da2205658ebebb99a55c43cdf60f (patch) | |
| tree | 35c86479d8dd4f78f78c63164a17f70fc9e72b3a /net/ipv4/tcp.c | |
| parent | Merge branch 'nexthop-convert-rtm_-new-del-nexthop-to-per-netns-rtnl' (diff) | |
| download | kernel-0de2a5c4b824da2205658ebebb99a55c43cdf60f.tar.gz kernel-0de2a5c4b824da2205658ebebb99a55c43cdf60f.zip | |
tcp: avoid atomic operations on sk->sk_rmem_alloc
TCP uses generic skb_set_owner_r() and sock_rfree()
for received packets, with socket lock being owned.
Switch to private versions, avoiding two atomic operations
per packet.
Signed-off-by: Eric Dumazet <[email protected]>
Reviewed-by: Neal Cardwell <[email protected]>
Reviewed-by: Kuniyuki Iwashima <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
Diffstat (limited to 'net/ipv4/tcp.c')
| -rw-r--r-- | net/ipv4/tcp.c | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 6edc441b3702..ea8de00f669d 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -1525,11 +1525,25 @@ void tcp_cleanup_rbuf(struct sock *sk, int copied) __tcp_cleanup_rbuf(sk, copied); } +/* private version of sock_rfree() avoiding one atomic_sub() */ +void tcp_sock_rfree(struct sk_buff *skb) +{ + struct sock *sk = skb->sk; + unsigned int len = skb->truesize; + + sock_owned_by_me(sk); + atomic_set(&sk->sk_rmem_alloc, + atomic_read(&sk->sk_rmem_alloc) - len); + + sk_forward_alloc_add(sk, len); + sk_mem_reclaim(sk); +} + static void tcp_eat_recv_skb(struct sock *sk, struct sk_buff *skb) { __skb_unlink(skb, &sk->sk_receive_queue); - if (likely(skb->destructor == sock_rfree)) { - sock_rfree(skb); + if (likely(skb->destructor == tcp_sock_rfree)) { + tcp_sock_rfree(skb); skb->destructor = NULL; skb->sk = NULL; return skb_attempt_defer_free(skb); |