From 08842c43d0165b0ed78907fd8cc92ce17d857913 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 7 Mar 2024 22:00:16 +0000 Subject: udp: no longer touch sk->sk_refcnt in early demux After commits ca065d0cf80f ("udp: no longer use SLAB_DESTROY_BY_RCU") and 7ae215d23c12 ("bpf: Don't refcount LISTEN sockets in sk_assign()") UDP early demux no longer need to grab a refcount on the UDP socket. This save two atomic operations per incoming packet for connected sockets. Signed-off-by: Eric Dumazet Cc: Martin KaFai Lau Cc: Joe Stringer Cc: Alexei Starovoitov Cc: Willem de Bruijn Cc: Kuniyuki Iwashima Acked-by: Paolo Abeni Signed-off-by: David S. Miller --- net/ipv4/udp.c | 5 +++-- net/ipv6/udp.c | 5 +++-- 2 files changed, 6 insertions(+), 4 deletions(-) (limited to 'net') diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 43ec4812b60ea..661d0e0d273f6 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -2568,11 +2568,12 @@ int udp_v4_early_demux(struct sk_buff *skb) uh->source, iph->saddr, dif, sdif); } - if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt)) + if (!sk) return 0; skb->sk = sk; - skb->destructor = sock_efree; + DEBUG_NET_WARN_ON_ONCE(sk_is_refcounted(sk)); + skb->destructor = sock_pfree; dst = rcu_dereference(sk->sk_rx_dst); if (dst) diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index 80ad8f436b179..7c1e6469d091d 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -1098,11 +1098,12 @@ void udp_v6_early_demux(struct sk_buff *skb) else return; - if (!sk || !refcount_inc_not_zero(&sk->sk_refcnt)) + if (!sk) return; skb->sk = sk; - skb->destructor = sock_efree; + DEBUG_NET_WARN_ON_ONCE(sk_is_refcounted(sk)); + skb->destructor = sock_pfree; dst = rcu_dereference(sk->sk_rx_dst); if (dst) -- cgit 1.2.3-korg