net/bonding: do not drop LACPDUs on slaves Tx failure

In message (http://dpdk.org/ml/archives/dev/2017-November/081557.html)
it was noted that under congestion that the LACPDUs are dropped under
load.

This patch changes the drop logic to re-enqueue the LACPDU to the slaves
control message queue. This will allow resend attempts to be made in
subsequent tx_burst() calls on the bonded device.

Signed-off-by: Declan Doherty <declan.doherty@intel.com>

diff --git a/drivers/net/bonding/rte_eth_bond_pmd.c b/drivers/net/bonding/rte_eth_bond_pmd.c
index c0a2e83..0ce65d6 100644 (file)
--- a/drivers/net/bonding/rte_eth_bond_pmd.c
+++ b/drivers/net/bonding/rte_eth_bond_pmd.c
@@ -1229,12 +1229,10 @@ bond_ethdev_tx_burst_8023ad(void *queue, struct rte_mbuf **bufs,
        uint8_t distributing_count;
 
        uint16_t num_tx_slave, num_tx_total = 0, num_tx_fail_total = 0;
-       uint16_t i, j, op_slave_idx;
-       const uint16_t buffs_size = nb_pkts + BOND_MODE_8023AX_SLAVE_TX_PKTS + 1;
+       uint16_t i, op_slave_idx;
 
        /* Allocate additional packets in case 8023AD mode. */
-       struct rte_mbuf *slave_bufs[RTE_MAX_ETHPORTS][buffs_size];
-       void *slow_pkts[BOND_MODE_8023AX_SLAVE_TX_PKTS] = { NULL };
+       struct rte_mbuf *slave_bufs[RTE_MAX_ETHPORTS][nb_pkts];
 
        /* Total amount of packets in slave_bufs */
        uint16_t slave_nb_pkts[RTE_MAX_ETHPORTS] = { 0 };
@@ -1256,14 +1254,6 @@ bond_ethdev_tx_burst_8023ad(void *queue, struct rte_mbuf **bufs,
        for (i = 0; i < num_of_slaves; i++) {
                struct port *port = &mode_8023ad_ports[slaves[i]];
 
-               slave_slow_nb_pkts[i] = rte_ring_dequeue_burst(port->tx_ring,
-                               slow_pkts, BOND_MODE_8023AX_SLAVE_TX_PKTS,
-                               NULL);
-               slave_nb_pkts[i] = slave_slow_nb_pkts[i];
-
-               for (j = 0; j < slave_slow_nb_pkts[i]; j++)
-                       slave_bufs[i][j] = slow_pkts[j];
-
                if (ACTOR_STATE(port, DISTRIBUTING))
                        distributing_offsets[distributing_count++] = i;
        }
@@ -1305,6 +1295,27 @@ bond_ethdev_tx_burst_8023ad(void *queue, struct rte_mbuf **bufs,
                }
        }
 
+       /* Check for LACP control packets and send if available */
+       for (i = 0; i < num_of_slaves; i++) {
+               struct port *port = &mode_8023ad_ports[slaves[i]];
+               struct rte_mbuf *ctrl_pkt = NULL;
+
+               int pkt_avail = rte_ring_dequeue(port->tx_ring,
+                               (void **)&ctrl_pkt);
+
+               if (unlikely(pkt_avail == 0)) {
+                       num_tx_slave = rte_eth_tx_burst(slaves[i],
+                                       bd_tx_q->queue_id, &ctrl_pkt, 1);
+
+                       /*
+                        * re-enqueue LAG control plane packets to buffering
+                        * ring if transmission fails so the packet isn't lost.
+                        */
+                       if (num_tx_slave != nb_pkts)
+                               rte_ring_enqueue(port->tx_ring, ctrl_pkt);
+               }
+       }
+
        return num_tx_total;
 }