Re: [PATCH net-next v3] net: xsk: introduce XDP_MAX_TX_BUDGET set/getsockopt

[Jakub Kicinski <kuba@kernel.org>]

On Thu, 19 Jun 2025 17:04:40 +0800 Jason Xing wrote:
> @@ -424,7 +421,9 @@ bool xsk_tx_peek_desc(struct xsk_buff_pool *pool, struct xdp_desc *desc)
>  	rcu_read_lock();
>  again:
>  	list_for_each_entry_rcu(xs, &pool->xsk_tx_list, tx_list) {
> -		if (xs->tx_budget_spent >= MAX_PER_SOCKET_BUDGET) {
> +		int max_budget = READ_ONCE(xs->max_tx_budget);
> +
> +		if (xs->tx_budget_spent >= max_budget) {
>  			budget_exhausted = true;
>  			continue;
>  		}
> @@ -779,7 +778,7 @@ static struct sk_buff *xsk_build_skb(struct xdp_sock *xs,
>  static int __xsk_generic_xmit(struct sock *sk)
>  {
>  	struct xdp_sock *xs = xdp_sk(sk);
> -	u32 max_batch = TX_BATCH_SIZE;
> +	u32 max_budget = READ_ONCE(xs->max_tx_budget);

Hm, maybe a question to Stan / Willem & other XSK experts but are these
two max values / code paths really related? Question 2 -- is generic
XSK a legit optimization target, legit enough to add uAPI?

Jason, I think some additions to Documentation/ and quantification of
the benefits would be needed as well.
-- 
pw-bot: cr