Hi,
> -----Original Message-----
> From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Jean-Mickael Guerin
> Sent: Thursday, December 04, 2014 2:26 PM
> To: dev at dpdk.org
> Subject: [dpdk-dev] [PATCH 2/2] ixgbe: don't override mbuf buffer length
>
> The template mbuf_initializer is hard coded with a buflen which
> might have been set differently by the application at the time of
> mbuf pool creation.
>
> Switch to a mbuf allocation, to fetch the correct default values.
> There is no performance impact because this is not a data-plane API.
>
> Signed-off-by: Jean-Mickael Guerin <jean-mickael.guerin at 6wind.com>
> Acked-by: David Marchand <david.marchand at 6wind.com>
> Fixes: 0ff3324da2 ("ixgbe: rework vector pmd following mbuf changes")
> ---
> lib/librte_pmd_ixgbe/ixgbe_rxtx_vec.c | 19 ++++++++++++-------
> 1 file changed, 12 insertions(+), 7 deletions(-)
>
> diff --git a/lib/librte_pmd_ixgbe/ixgbe_rxtx_vec.c
> b/lib/librte_pmd_ixgbe/ixgbe_rxtx_vec.c
> index c1b5a78..f7b02f5 100644
> --- a/lib/librte_pmd_ixgbe/ixgbe_rxtx_vec.c
> +++ b/lib/librte_pmd_ixgbe/ixgbe_rxtx_vec.c
> @@ -732,17 +732,22 @@ static struct ixgbe_txq_ops vec_txq_ops = {
> int
> ixgbe_rxq_vec_setup(struct igb_rx_queue *rxq)
> {
> - struct rte_mbuf mb_def = { .buf_addr = 0 }; /* zeroed mbuf */
> + struct rte_mbuf *mb_def;
>
> - mb_def.nb_segs = 1;
> - mb_def.data_off = RTE_PKTMBUF_HEADROOM;
> - mb_def.buf_len = rxq->mb_pool->elt_size - sizeof(struct rte_mbuf);
> - mb_def.port = rxq->port_id;
> - rte_mbuf_refcnt_set(&mb_def, 1);
> + mb_def = rte_pktmbuf_alloc(rxq->mb_pool);
Could you explain to me, what is an advantage of using dynamic allocation vs
local struct here?
I don't see any.
Plus if rte_pktmbuf_alloc() would fail, we'll leave our rx queue not configured
properly.
As I can see ixgbe_dev_rx_queue_setup() doesn't check the return value of >
ixgbe_rxq_vec_setup()
(as it is just not supposed to fail).
So ixgbe_dev_rx_queue_setup() will return OK for unconfigured RX queue.
> + if (mb_def == NULL) {
> + PMD_INIT_LOG(ERR, "ixgbe_rxq_vec_setup: could not allocate one
> mbuf");
> + return -1;
> + }
> + /* nb_segs, refcnt, data_off and buf_len are already set */
> + mb_def->port = rxq->port_id;
>
> /* prevent compiler reordering: rearm_data covers previous fields */
> rte_compiler_barrier();
I don't think we need it here.
> - rxq->mbuf_initializer = *((uint64_t *)&mb_def.rearm_data);
> + rxq->mbuf_initializer = *((uint64_t *)&mb_def->rearm_data);
> +
> + rte_pktmbuf_free(mb_def);
> +
> return 0;
> }
>
> --
> 2.1.3
Somy vote - NACK for the whole series.
Konstantin
