Commit 6471658d authored Sep 16, 2025 by Eric Dumazet Committed by Paolo Abeni Sep 18, 2025

udp: use skb_attempt_defer_free()



Move skb freeing from udp recvmsg() path to the cpu
which allocated/received it, as TCP did in linux-5.17.

This increases max thoughput by 20% to 30%, depending
on number of BH producers.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250916160951.541279-11-edumazet@google.com


Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

parent 3cd04c8f

net/ipv4/udp.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -1825,6 +1825,13 @@ void skb_consume_udp(struct sock sk, struct sk_buff skb, int len)
		if (unlikely(READ_ONCE(udp_sk(sk)->peeking_with_offset)))
		sk_peek_offset_bwd(sk, len);

		if (!skb_shared(skb)) {
		if (unlikely(udp_skb_has_head_state(skb)))
		skb_release_head_state(skb);
		skb_attempt_defer_free(skb);
		return;
		}

		if (!skb_unref(skb))
		return;