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