Commit faf7b4ae authored by Eric Dumazet's avatar Eric Dumazet Committed by Paolo Abeni
Browse files

udp: update sk_rmem_alloc before busylock acquisition 



Avoid piling too many producers on the busylock
by updating sk_rmem_alloc before busylock acquisition.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Reviewed-by: default avatarDavid Ahern <dsahern@kernel.org>
Reviewed-by: default avatarKuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: default avatarWillem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250916160951.541279-7-edumazet@google.com


Reviewed-by: default avatarJakub Kicinski <kuba@kernel.org>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent 9aaec660

net/ipv4/udp.c

+5 −2
Original line number Diff line number Diff line
@@ -1753,13 +1753,16 @@ int __udp_enqueue_schedule_skb(struct sock *sk, struct sk_buff *skb) 
	if (rmem > (rcvbuf >> 1)) {

		skb_condense(skb);

		size = skb->truesize;

		rmem = atomic_add_return(size, &sk->sk_rmem_alloc);

		if (rmem > rcvbuf)

			goto uncharge_drop;

		busy = busylock_acquire(sk);

	} else {

		atomic_add(size, &sk->sk_rmem_alloc);

	}



	udp_set_dev_scratch(skb);



	atomic_add(size, &sk->sk_rmem_alloc);



	spin_lock(&list->lock);

	err = udp_rmem_schedule(sk, size);

	if (err) {