examples/multi_process: fix resilience by enabling Rx drop

The symmetric_mp example app is set up to allow two processes to
share a NIC port, with each pulling packets from one queue. In order
to have the app continue working when one of the process dies, the
drop_en bit should be set in the NIC configuration. Without this bit
set, the NIC will stall once any queue fills. With the bit set, once
a queue fills, all subsequent packets for that queue are discarded
allowing other queues to continue operating as normal.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>

diff --git a/examples/multi_process/symmetric_mp/main.c b/examples/multi_process/symmetric_mp/main.c
index 01faae9..2fc2acf 100644 (file)
--- a/examples/multi_process/symmetric_mp/main.c
+++ b/examples/multi_process/symmetric_mp/main.c
@@ -229,6 +229,7 @@ smp_port_init(uint8_t port, struct rte_mempool *mbuf_pool, uint16_t num_queues)
                        }
        };
        const uint16_t rx_rings = num_queues, tx_rings = num_queues;
+       struct rte_eth_dev_info info;
        int retval;
        uint16_t q;
 
@@ -241,6 +242,9 @@ smp_port_init(uint8_t port, struct rte_mempool *mbuf_pool, uint16_t num_queues)
        printf("# Initialising port %u... ", (unsigned)port);
        fflush(stdout);
 
+       rte_eth_dev_info_get(port, &info);
+       info.default_rxconf.rx_drop_en = 1;
+
        retval = rte_eth_dev_configure(port, rx_rings, tx_rings, &port_conf);
        if (retval < 0)
                return retval;
@@ -248,7 +252,7 @@ smp_port_init(uint8_t port, struct rte_mempool *mbuf_pool, uint16_t num_queues)
        for (q = 0; q < rx_rings; q ++) {
                retval = rte_eth_rx_queue_setup(port, q, RX_RING_SIZE,
                                rte_eth_dev_socket_id(port),
-                               NULL,
+                               &info.default_rxconf,
                                mbuf_pool);
                if (retval < 0)
                        return retval;