Hi ,
>
> In some vendors the RX and TX configuration must be the same, therefore
> the MTU size need to be equal to max_rx_pkt_len.
> The MTU is the largest size packet in bytes that can be sent on the
> network, therefore before changing this parameter, the NIC could not
> receive packets larger than 1500 bytes, which is the default MTU size.
> In addition, scatter-gather need to be enabled in order to receive
> frames bigger than mbuf size.
>
> Cc: sta...@dpdk.org
>
> Signed-off-by: Noa Ezra <n...@mellanox.com>
> ---
> examples/ip_fragmentation/main.c | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
> diff --git a/examples/ip_fragmentation/main.c
> b/examples/ip_fragmentation/main.c
> index 17a877d..d294f5f 100644
> --- a/examples/ip_fragmentation/main.c
> +++ b/examples/ip_fragmentation/main.c
> @@ -141,6 +141,7 @@ struct lcore_queue_conf {
> .max_rx_pkt_len = JUMBO_FRAME_MAX_SIZE,
> .split_hdr_size = 0,
> .offloads = (DEV_RX_OFFLOAD_CHECKSUM |
> + DEV_RX_OFFLOAD_SCATTER |
> DEV_RX_OFFLOAD_JUMBO_FRAME),
> },
> .txmode = {
> @@ -892,6 +893,16 @@ struct rte_lpm6_config lpm6_config = {
> dev_info.max_rx_pktlen,
> local_port_conf.rxmode.max_rx_pkt_len);
>
> + /* set the mtu to the maximum received packet size */
> + ret = rte_eth_dev_set_mtu(portid,
> + local_port_conf.rxmode.max_rx_pkt_len);
> + if (ret < 0) {
> + printf("\n");
> + rte_exit(EXIT_FAILURE, "Set MTU failed: "
> + "err=%d, port=%d\n",
> + ret, portid);
> + }
> +
It probably doesn't matter for that particular case, but
shouldn't set_mtu() be done after dev_configure()?
To avoid situation when max_rx_pkt_len will be set by set_mtu()
and then overwritten by dev_configure().
Konstantin
> /* get the lcore_id for this port */
> while (rte_lcore_is_enabled(rx_lcore_id) == 0 ||
> qconf->n_rx_queue == (unsigned)rx_queue_per_lcore) {
> --
> 1.8.3.1
