Re: [dpdk-dev] [PATCH v3 2/3] ethdev: Add rxtx callback support

[Thomas Monjalon <thomas.monjalon@6wind.com>]

2015-02-18 17:42, John McNamara:
> From: Richardson, Bruce <bruce.richardson@intel.com>
> 
> Add in support for inline processing of packets inside the RX or
> TX call. For an RX callback, what happens is that we get a set of
> packets from the NIC and then pass them to a callback function, if
> configured, to allow additional processing to be done on them, e.g.
> filling in more mbuf fields, before passing back to the application.
> On TX, the packets are similarly post-processed before being handed
> to the NIC for transmission.
> 
> Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
> Signed-off-by: John McNamara <john.mcnamara@intel.com>
[...]
> @@ -2393,7 +2447,18 @@ rte_eth_rx_burst(uint8_t port_id, uint16_t queue_id,
>  	struct rte_eth_dev *dev;
>  
>  	dev = &rte_eth_devices[port_id];
> -	return (*dev->rx_pkt_burst)(dev->data->rx_queues[queue_id], rx_pkts, nb_pkts);
> +	nb_pkts = (*dev->rx_pkt_burst)(dev->data->rx_queues[queue_id], rx_pkts,
> +			nb_pkts);
> +	struct rte_eth_rxtx_callback *cb = dev->post_rx_burst_cbs[queue_id];
> +
> +	if (unlikely(cb != NULL)) {
> +		do {
> +			nb_pkts = cb->fn(port_id, queue_id, rx_pkts, nb_pkts,
> +					cb->param);
> +			cb = cb->next;
> +		} while (cb != NULL);
> +	}

Excuse me, it wasn't very clear for me but I thought from the following email
that the consensus was to use a compile-time option:
	http://dpdk.org/ml/archives/dev/2015-February/013450.html