netdev - RE: [PATCH v2 net-next] udp: use indirect call wrapper for data ready()

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Date: Tue, 18 Jul 2023 11:47:14 -0400
From: Willem de Bruijn <willemdebruijn.kernel@...il.com>
To: Paolo Abeni <pabeni@...hat.com>, 
 netdev@...r.kernel.org
Cc: Willem de Bruijn <willemdebruijn.kernel@...il.com>, 
 "David S. Miller" <davem@...emloft.net>, 
 David Ahern <dsahern@...nel.org>, 
 Eric Dumazet <edumazet@...gle.com>, 
 Jakub Kicinski <kuba@...nel.org>
Subject: RE: [PATCH v2 net-next] udp: use indirect call wrapper for data
 ready()

Paolo Abeni wrote:
> In most cases UDP sockets use the default data ready callback.
> Leverage the indirect call wrapper for such callback to avoid an
> indirect call in fastpath.
> 
> The above gives small but measurable performance gain under UDP flood.
> 
> Signed-off-by: Paolo Abeni <pabeni@...hat.com>

Reviewed-by: Willem de Bruijn <willemb@...gle.com>

> ---
> v1 -> v2:
>  - do not introduce the specific helper (Willem)

I was just about to Ack v1. Did not mean to request a respin if
no one else spoke up. But thanks for humoring me :)

> ---
>  net/ipv4/udp.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
> index 42a96b3547c9..8c3ebd95f5b9 100644
> --- a/net/ipv4/udp.c
> +++ b/net/ipv4/udp.c
> @@ -1553,7 +1553,7 @@ int __udp_enqueue_schedule_skb(struct sock *sk, struct sk_buff *skb)
>  	spin_unlock(&list->lock);
>  
>  	if (!sock_flag(sk, SOCK_DEAD))
> -		sk->sk_data_ready(sk);
> +		INDIRECT_CALL_1(sk->sk_data_ready, sock_def_readable, sk);
>  
>  	busylock_release(busy);
>  	return 0;
> -- 
> 2.41.0
>