Message-ID: <a4602b15-25b1-c388-73b4-1f97f6f0e555@gmail.com>
Date:   Mon, 29 Nov 2021 19:36:46 -0700
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Subject: Re: [PATCH v2 net-next 01/26] rtnetlink: introduce generic XDP
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To:     Alexander Lobakin <alexandr.lobakin@intel.com>,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>
Cc:     Jesse Brandeburg <jesse.brandeburg@intel.com>,
        Michal Swiatkowski <michal.swiatkowski@linux.intel.com>,
        Maciej Fijalkowski <maciej.fijalkowski@intel.com>,
        Jonathan Corbet <corbet@lwn.net>,
        Shay Agroskin <shayagr@amazon.com>,
        Arthur Kiyanovski <akiyano@amazon.com>,
        David Arinzon <darinzon@amazon.com>,
        Noam Dagan <ndagan@amazon.com>,
        Saeed Bishara <saeedb@amazon.com>,
        Ioana Ciornei <ioana.ciornei@nxp.com>,
        Claudiu Manoil <claudiu.manoil@nxp.com>,
        Tony Nguyen <anthony.l.nguyen@intel.com>,
        Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
        Marcin Wojtas <mw@semihalf.com>,
        Russell King <linux@armlinux.org.uk>,
        Saeed Mahameed <saeedm@nvidia.com>,
        Leon Romanovsky <leon@kernel.org>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Jesper Dangaard Brouer <hawk@kernel.org>,
        =?UTF-8?Q?Toke_H=c3=b8iland-J=c3=b8rgensen?= <toke@redhat.com>,
        John Fastabend <john.fastabend@gmail.com>,
        Edward Cree <ecree.xilinx@gmail.com>,
        Martin Habets <habetsm.xilinx@gmail.com>,
        "Michael S. Tsirkin" <mst@redhat.com>,
        Jason Wang <jasowang@redhat.com>,
        Andrii Nakryiko <andrii@kernel.org>,
        Martin KaFai Lau <kafai@fb.com>,
        Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
        KP Singh <kpsingh@kernel.org>,
        Lorenzo Bianconi <lorenzo@kernel.org>,
        Yajun Deng <yajun.deng@linux.dev>,
        Sergey Ryazanov <ryazanov.s.a@gmail.com>,
        David Ahern <dsahern@kernel.org>,
        Andrei Vagin <avagin@gmail.com>,
        Johannes Berg <johannes.berg@intel.com>,
        Vladimir Oltean <vladimir.oltean@nxp.com>,
        Cong Wang <cong.wang@bytedance.com>, netdev@vger.kernel.org,
        linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-rdma@vger.kernel.org, bpf@vger.kernel.org,
        virtualization@lists.linux-foundation.org
References: <20211123163955.154512-1-alexandr.lobakin@intel.com>
 <20211123163955.154512-2-alexandr.lobakin@intel.com>
From:   David Ahern <dsahern@gmail.com>
In-Reply-To: <20211123163955.154512-2-alexandr.lobakin@intel.com>
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Precedence: bulk

On 11/23/21 9:39 AM, Alexander Lobakin wrote:
> +static bool rtnl_get_xdp_stats_xdpxsk(struct sk_buff *skb, u32 ch,
> +				      const void *attr_data)
> +{
> +	const struct ifla_xdp_stats *xstats = attr_data;
> +
> +	xstats += ch;
> +
> +	if (nla_put_u64_64bit(skb, IFLA_XDP_XSTATS_PACKETS, xstats->packets,
> +			      IFLA_XDP_XSTATS_UNSPEC) ||
> +	    nla_put_u64_64bit(skb, IFLA_XDP_XSTATS_BYTES, xstats->bytes,
> +			      IFLA_XDP_XSTATS_UNSPEC) ||
> +	    nla_put_u64_64bit(skb, IFLA_XDP_XSTATS_ERRORS, xstats->errors,
> +			      IFLA_XDP_XSTATS_UNSPEC) ||
> +	    nla_put_u64_64bit(skb, IFLA_XDP_XSTATS_ABORTED, xstats->aborted,
> +			      IFLA_XDP_XSTATS_UNSPEC) ||
> +	    nla_put_u64_64bit(skb, IFLA_XDP_XSTATS_DROP, xstats->drop,
> +			      IFLA_XDP_XSTATS_UNSPEC) ||
> +	    nla_put_u64_64bit(skb, IFLA_XDP_XSTATS_INVALID, xstats->invalid,
> +			      IFLA_XDP_XSTATS_UNSPEC) ||
> +	    nla_put_u64_64bit(skb, IFLA_XDP_XSTATS_PASS, xstats->pass,
> +			      IFLA_XDP_XSTATS_UNSPEC) ||
> +	    nla_put_u64_64bit(skb, IFLA_XDP_XSTATS_REDIRECT, xstats->redirect,
> +			      IFLA_XDP_XSTATS_UNSPEC) ||
> +	    nla_put_u64_64bit(skb, IFLA_XDP_XSTATS_REDIRECT_ERRORS,
> +			      xstats->redirect_errors,
> +			      IFLA_XDP_XSTATS_UNSPEC) ||
> +	    nla_put_u64_64bit(skb, IFLA_XDP_XSTATS_TX, xstats->tx,
> +			      IFLA_XDP_XSTATS_UNSPEC) ||
> +	    nla_put_u64_64bit(skb, IFLA_XDP_XSTATS_TX_ERRORS,
> +			      xstats->tx_errors, IFLA_XDP_XSTATS_UNSPEC) ||
> +	    nla_put_u64_64bit(skb, IFLA_XDP_XSTATS_XMIT_PACKETS,
> +			      xstats->xmit_packets, IFLA_XDP_XSTATS_UNSPEC) ||
> +	    nla_put_u64_64bit(skb, IFLA_XDP_XSTATS_XMIT_BYTES,
> +			      xstats->xmit_bytes, IFLA_XDP_XSTATS_UNSPEC) ||
> +	    nla_put_u64_64bit(skb, IFLA_XDP_XSTATS_XMIT_ERRORS,
> +			      xstats->xmit_errors, IFLA_XDP_XSTATS_UNSPEC) ||
> +	    nla_put_u64_64bit(skb, IFLA_XDP_XSTATS_XMIT_FULL,
> +			      xstats->xmit_full, IFLA_XDP_XSTATS_UNSPEC))
> +		return false;
> +
> +	return true;
> +}
> +

Another thought on this patch: with individual attributes you could save
some overhead by not sending 0 counters to userspace. e.g., define a
helper that does:

static inline int nla_put_u64_if_set(struct sk_buff *skb, int attrtype,
                                     u64 value, int padattr)
{
	if (value)
		return nla_put_u64_64bit(skb, attrtype, value, padattr);

	return 0;
}