From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AD9587494; Thu, 19 Jun 2025 15:09:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750345746; cv=none; b=Y5jmhYS/9dimMXwc2iQRZMLukjU1QPeaEIy39V31UXO2DPmWLFcVmvbk7qXGacV3eAo+b5zdP3qU1GOZI5AaX42FVriiR10FF48mDYcBXuCij5stiGwttDwxXP1evGwV6gJFLLpVXeZELiENfi9A7jRj/5TUHaHhkv3LshBGrC8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750345746; c=relaxed/simple; bh=0CL1Z+OfZHqKzBgIZXUGehFGRPGbCXxgysN3GeqYBwM=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=DJEp2xbY8siMwKa+VUqPoQ+b4tHYD8xPKeyamKKFkLNELfTofYDM2ya5KlJG1+hQm5kdKSCkxeusj46Rac1nlppjw9tEzlwH0GmBzXDGcPmiaPc4Y5ny8Spp/b6tTnWNRXN0Q63J6KAuEjOKCDCiY7qL55gS9kyIrAxhgwm5Sr8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=gIxPYLQq; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="gIxPYLQq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 95D59C4CEEA; Thu, 19 Jun 2025 15:09:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1750345746; bh=0CL1Z+OfZHqKzBgIZXUGehFGRPGbCXxgysN3GeqYBwM=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=gIxPYLQqQRi2LEP1eIp+IV7e49SS5nJonA15ARRP2UVf1x+UHpKBWIA54Siz9jQYi yDFRxQR6dFoAACDbrG0RzDBxRROsA5MQjMDI7LMuu8tID+mkgzltl/ToWODYAu7yq/ +CgilN0hh9WygaZS6v3QAXLW3WdpaiU0YI25eoyXFZdAiquCfJefXPKFk0ntUqTwlP KcNGR1tjBKOJYJHvKsBXafe1Fvg9eQ/m0nB20xkqY6EaSkso35dtt3OFI49g2Wwj1w Ll2oPP2gsDjiSpliLRlQfQIHrOwCUMX3DQT/+rIGwAqXyhIlzRZi2gYRnqFkKqiV3y HOKCGTrxYzHQQ== Date: Thu, 19 Jun 2025 08:09:04 -0700 From: Jakub Kicinski To: Jason Xing Cc: davem@davemloft.net, edumazet@google.com, pabeni@redhat.com, bjorn@kernel.org, magnus.karlsson@intel.com, maciej.fijalkowski@intel.com, jonathan.lemon@gmail.com, sdf@fomichev.me, ast@kernel.org, daniel@iogearbox.net, hawk@kernel.org, john.fastabend@gmail.com, joe@dama.to, willemdebruijn.kernel@gmail.com, bpf@vger.kernel.org, netdev@vger.kernel.org, Jason Xing Subject: Re: [PATCH net-next v3] net: xsk: introduce XDP_MAX_TX_BUDGET set/getsockopt Message-ID: <20250619080904.0a70574c@kernel.org> In-Reply-To: <20250619090440.65509-1-kerneljasonxing@gmail.com> References: <20250619090440.65509-1-kerneljasonxing@gmail.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit 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