[dpdk-dev] [PATCH] net/tap: fix Rx miss the packets

[Donald_Lee at trendmicro.com]

From: Donald Lee <donald_lee at trendmicro.com>



After pmd_rx_burst be triggered, it doesn't retrieve all the frames.

It may leave some pending frames there.



Signed-off-by: Donald Lee <donald_lee at trendmicro.com>

---

drivers/net/tap/rte_eth_tap.c | 7 ++++++-

drivers/net/tap/rte_eth_tap.h | 1 +

2 files changed, 7 insertions(+), 1 deletion(-)



diff --git a/drivers/net/tap/rte_eth_tap.c b/drivers/net/tap/rte_eth_tap.c

index 3841842f0..e2785e011 100644

--- a/drivers/net/tap/rte_eth_tap.c

+++ b/drivers/net/tap/rte_eth_tap.c

@@ -353,10 +353,11 @@ pmd_rx_burst(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)

               unsigned long num_rx_bytes = 0;

               uint32_t trigger = tap_trigger;



-              if (trigger == rxq->trigger_seen)

+             if (trigger == rxq->trigger_seen && !rxq->keep_trigger)

                               return 0;

               if (trigger)

                               rxq->trigger_seen = trigger;

+             rxq->keep_trigger = 0;

               process_private = rte_eth_devices[rxq->in_port].process_private;

               rte_compiler_barrier();

               for (num_rx = 0; num_rx < nb_pkts; ) {

@@ -431,6 +432,9 @@ pmd_rx_burst(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)

                               bufs[num_rx++] = mbuf;

                               num_rx_bytes += mbuf->pkt_len;

               }

+             /* may have pending packets, keep trigger */

+             if (num_rx == nb_pkts)

+                             rxq->keep_trigger = 1;

end:

               rxq->stats.ipackets += num_rx;

               rxq->stats.ibytes += num_rx_bytes;

@@ -1352,6 +1356,7 @@ tap_rx_queue_setup(struct rte_eth_dev *dev,



                rxq->mp = mp;

               rxq->trigger_seen = 1; /* force initial burst */

+             rxq->keep_trigger = 0;

               rxq->in_port = dev->data->port_id;

               rxq->queue_id = rx_queue_id;

               rxq->nb_rx_desc = nb_desc;

diff --git a/drivers/net/tap/rte_eth_tap.h b/drivers/net/tap/rte_eth_tap.h

index 8d6d53dc0..842e8c0b7 100644

--- a/drivers/net/tap/rte_eth_tap.h

+++ b/drivers/net/tap/rte_eth_tap.h

@@ -45,6 +45,7 @@ struct pkt_stats {

struct rx_queue {

               struct rte_mempool *mp;         /* Mempool for RX packets */

               uint32_t trigger_seen;          /* Last seen Rx trigger value */

+             uint16_t keep_trigger;          /* Keep trigger state */

               uint16_t in_port;               /* Port ID */

               uint16_t queue_id;                         /* queue ID*/

               struct pkt_stats stats;         /* Stats for this RX queue */

--

2.19.1