This check doesn't do what's required by rte_eth_tx_burst: "When the number of previously sent packets reached the "minimum transmit packets to free" threshold"
This can cause problems when txq->tx_free_thresh + [number of elements in the pool] < txq->nb_tx_desc. Signed-off-by: Zoltan Kiss <zoltan.kiss at linaro.org> --- drivers/net/ixgbe/ixgbe_rxtx.c | 4 ++-- drivers/net/ixgbe/ixgbe_rxtx_vec.c | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/net/ixgbe/ixgbe_rxtx.c b/drivers/net/ixgbe/ixgbe_rxtx.c index 4f9ab22..b70ed8c 100644 --- a/drivers/net/ixgbe/ixgbe_rxtx.c +++ b/drivers/net/ixgbe/ixgbe_rxtx.c @@ -250,10 +250,10 @@ tx_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, /* * Begin scanning the H/W ring for done descriptors when the - * number of available descriptors drops below tx_free_thresh. For + * number of in flight descriptors reaches tx_free_thresh. For * each done descriptor, free the associated buffer. */ - if (txq->nb_tx_free < txq->tx_free_thresh) + if ((txq->nb_tx_desc - txq->nb_tx_free) > txq->tx_free_thresh) ixgbe_tx_free_bufs(txq); /* Only use descriptors that are available */ diff --git a/drivers/net/ixgbe/ixgbe_rxtx_vec.c b/drivers/net/ixgbe/ixgbe_rxtx_vec.c index abd10f6..f91c698 100644 --- a/drivers/net/ixgbe/ixgbe_rxtx_vec.c +++ b/drivers/net/ixgbe/ixgbe_rxtx_vec.c @@ -598,7 +598,7 @@ ixgbe_xmit_pkts_vec(void *tx_queue, struct rte_mbuf **tx_pkts, if (unlikely(nb_pkts > RTE_IXGBE_VPMD_TX_BURST)) nb_pkts = RTE_IXGBE_VPMD_TX_BURST; - if (txq->nb_tx_free < txq->tx_free_thresh) + if ((txq->nb_tx_desc - txq->nb_tx_free) > txq->tx_free_thresh) ixgbe_tx_free_bufs(txq); nb_commit = nb_pkts = (uint16_t)RTE_MIN(txq->nb_tx_free, nb_pkts); -- 1.9.1