examples/packet_ordering/main.c

/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright(c) 2010-2016 Intel Corporation
 */

#include <signal.h>
#include <getopt.h>

#include <rte_eal.h>
#include <rte_common.h>
#include <rte_errno.h>
#include <rte_ethdev.h>
#include <rte_lcore.h>
#include <rte_malloc.h>
#include <rte_mbuf.h>
#include <rte_mempool.h>
#include <rte_ring.h>
#include <rte_reorder.h>

#define RX_DESC_PER_QUEUE 1024
#define TX_DESC_PER_QUEUE 1024

#define MAX_PKTS_BURST 32
#define REORDER_BUFFER_SIZE 8192
#define MBUF_PER_POOL 65535
#define MBUF_POOL_CACHE_SIZE 250

#define RING_SIZE 16384

/* Macros for printing using RTE_LOG */
#define RTE_LOGTYPE_REORDERAPP          RTE_LOGTYPE_USER1

unsigned int portmask;
unsigned int disable_reorder;
unsigned int insight_worker;
volatile uint8_t quit_signal;

static struct rte_mempool *mbuf_pool;

static struct rte_eth_conf port_conf_default;

struct worker_thread_args {
    struct rte_ring *ring_in;
    struct rte_ring *ring_out;
};

struct send_thread_args {
    struct rte_ring *ring_in;
    struct rte_reorder_buffer *buffer;
};

volatile struct app_stats {
    struct {
        uint64_t rx_pkts;
        uint64_t enqueue_pkts;
        uint64_t enqueue_failed_pkts;
    } rx __rte_cache_aligned;

    struct {
        uint64_t dequeue_pkts;
        uint64_t enqueue_pkts;
        uint64_t enqueue_failed_pkts;
    } wkr __rte_cache_aligned;

    struct {
        uint64_t dequeue_pkts;
        /* Too early pkts transmitted directly w/o reordering */
        uint64_t early_pkts_txtd_woro;
        /* Too early pkts failed from direct transmit */
        uint64_t early_pkts_tx_failed_woro;
        uint64_t ro_tx_pkts;
        uint64_t ro_tx_failed_pkts;
    } tx __rte_cache_aligned;
} app_stats;

/* per worker lcore stats */
struct wkr_stats_per {
        uint64_t deq_pkts;
        uint64_t enq_pkts;
        uint64_t enq_failed_pkts;
} __rte_cache_aligned;

static struct wkr_stats_per wkr_stats[RTE_MAX_LCORE] = { {0} };
static unsigned int
get_last_lcore_id(void)
{
    int i;

    for (i = RTE_MAX_LCORE - 1; i >= 0; i--)
        if (rte_lcore_is_enabled(i))
            return i;
    return 0;
}

static unsigned int
get_previous_lcore_id(unsigned int id)
{
    int i;

    for (i = id - 1; i >= 0; i--)
        if (rte_lcore_is_enabled(i))
            return i;
    return id;
}

static inline void
pktmbuf_free_bulk(struct rte_mbuf *mbuf_table[], unsigned n)
{
    unsigned int i;

    for (i = 0; i < n; i++)
        rte_pktmbuf_free(mbuf_table[i]);
}

/* display usage */
static void
print_usage(const char *prgname)
{
    printf("%s [EAL options] -- -p PORTMASK\n"
            "  -p PORTMASK: hexadecimal bitmask of ports to configure\n",
            prgname);
}

static int
parse_portmask(const char *portmask)
{
    unsigned long pm;
    char *end = NULL;

    /* parse hexadecimal string */
    pm = strtoul(portmask, &end, 16);
    if ((portmask[0] == '\0') || (end == NULL) || (*end != '\0'))
        return -1;

    if (pm == 0)
        return -1;

    return pm;
}

/* Parse the argument given in the command line of the application */
static int
parse_args(int argc, char **argv)
{
    int opt;
    int option_index;
    char **argvopt;
    char *prgname = argv[0];
    static struct option lgopts[] = {
        {"disable-reorder", 0, 0, 0},
        {"insight-worker", 0, 0, 0},
        {NULL, 0, 0, 0}
    };

    argvopt = argv;

    while ((opt = getopt_long(argc, argvopt, "p:",
                    lgopts, &option_index)) != EOF) {
        switch (opt) {
        /* portmask */
        case 'p':
            portmask = parse_portmask(optarg);
            if (portmask == 0) {
                printf("invalid portmask\n");
                print_usage(prgname);
                return -1;
            }
            break;
        /* long options */
        case 0:
            if (!strcmp(lgopts[option_index].name, "disable-reorder")) {
                printf("reorder disabled\n");
                disable_reorder = 1;
            }
            if (!strcmp(lgopts[option_index].name,
                        "insight-worker")) {
                printf("print all worker statistics\n");
                insight_worker = 1;
            }
            break;
        default:
            print_usage(prgname);
            return -1;
        }
    }
    if (optind <= 1) {
        print_usage(prgname);
        return -1;
    }

    argv[optind-1] = prgname;
    optind = 1; /* reset getopt lib */
    return 0;
}

/*
 * Tx buffer error callback
 */
static void
flush_tx_error_callback(struct rte_mbuf **unsent, uint16_t count,
        void *userdata __rte_unused) {

    /* free the mbufs which failed from transmit */
    app_stats.tx.ro_tx_failed_pkts += count;
    RTE_LOG_DP(DEBUG, REORDERAPP, "%s:Packet loss with tx_burst\n", __func__);
    pktmbuf_free_bulk(unsent, count);

}

static inline int
free_tx_buffers(struct rte_eth_dev_tx_buffer *tx_buffer[]) {
    uint16_t port_id;

    /* initialize buffers for all ports */
    RTE_ETH_FOREACH_DEV(port_id) {
        /* skip ports that are not enabled */
        if ((portmask & (1 << port_id)) == 0)
            continue;

        rte_free(tx_buffer[port_id]);
    }
    return 0;
}

static inline int
configure_tx_buffers(struct rte_eth_dev_tx_buffer *tx_buffer[])
{
    uint16_t port_id;
    int ret;

    /* initialize buffers for all ports */
    RTE_ETH_FOREACH_DEV(port_id) {
        /* skip ports that are not enabled */
        if ((portmask & (1 << port_id)) == 0)
            continue;

        /* Initialize TX buffers */
        tx_buffer[port_id] = rte_zmalloc_socket("tx_buffer",
                RTE_ETH_TX_BUFFER_SIZE(MAX_PKTS_BURST), 0,
                rte_eth_dev_socket_id(port_id));
        if (tx_buffer[port_id] == NULL)
            rte_exit(EXIT_FAILURE, "Cannot allocate buffer for tx on port %u\n",
                 port_id);

        rte_eth_tx_buffer_init(tx_buffer[port_id], MAX_PKTS_BURST);

        ret = rte_eth_tx_buffer_set_err_callback(tx_buffer[port_id],
                flush_tx_error_callback, NULL);
        if (ret < 0)
            rte_exit(EXIT_FAILURE,
            "Cannot set error callback for tx buffer on port %u\n",
                 port_id);
    }
    return 0;
}

static inline int
configure_eth_port(uint16_t port_id)
{
    struct rte_ether_addr addr;
    const uint16_t rxRings = 1, txRings = 1;
    int ret;
    uint16_t q;
    uint16_t nb_rxd = RX_DESC_PER_QUEUE;
    uint16_t nb_txd = TX_DESC_PER_QUEUE;
    struct rte_eth_dev_info dev_info;
    struct rte_eth_txconf txconf;
    struct rte_eth_conf port_conf = port_conf_default;

    if (!rte_eth_dev_is_valid_port(port_id))
        return -1;

    ret = rte_eth_dev_info_get(port_id, &dev_info);
    if (ret != 0) {
        printf("Error during getting device (port %u) info: %s\n",
                port_id, strerror(-ret));
        return ret;
    }

    if (dev_info.tx_offload_capa & DEV_TX_OFFLOAD_MBUF_FAST_FREE)
        port_conf.txmode.offloads |=
            DEV_TX_OFFLOAD_MBUF_FAST_FREE;
    ret = rte_eth_dev_configure(port_id, rxRings, txRings, &port_conf_default);
    if (ret != 0)
        return ret;

    ret = rte_eth_dev_adjust_nb_rx_tx_desc(port_id, &nb_rxd, &nb_txd);
    if (ret != 0)
        return ret;

    for (q = 0; q < rxRings; q++) {
        ret = rte_eth_rx_queue_setup(port_id, q, nb_rxd,
                rte_eth_dev_socket_id(port_id), NULL,
                mbuf_pool);
        if (ret < 0)
            return ret;
    }

    txconf = dev_info.default_txconf;
    txconf.offloads = port_conf.txmode.offloads;
    for (q = 0; q < txRings; q++) {
        ret = rte_eth_tx_queue_setup(port_id, q, nb_txd,
                rte_eth_dev_socket_id(port_id), &txconf);
        if (ret < 0)
            return ret;
    }

    ret = rte_eth_dev_start(port_id);
    if (ret < 0)
        return ret;

    ret = rte_eth_macaddr_get(port_id, &addr);
    if (ret != 0) {
        printf("Failed to get MAC address (port %u): %s\n",
                port_id, rte_strerror(-ret));
        return ret;
    }

    printf("Port %u MAC: %02"PRIx8" %02"PRIx8" %02"PRIx8
            " %02"PRIx8" %02"PRIx8" %02"PRIx8"\n",
            port_id,
            addr.addr_bytes[0], addr.addr_bytes[1],
            addr.addr_bytes[2], addr.addr_bytes[3],
            addr.addr_bytes[4], addr.addr_bytes[5]);

    ret = rte_eth_promiscuous_enable(port_id);
    if (ret != 0)
        return ret;

    return 0;
}

static void
print_stats(void)
{
    uint16_t i;
    struct rte_eth_stats eth_stats;
    unsigned int lcore_id, last_lcore_id, master_lcore_id, end_w_lcore_id;

    last_lcore_id   = get_last_lcore_id();
    master_lcore_id = rte_get_master_lcore();
    end_w_lcore_id  = get_previous_lcore_id(last_lcore_id);

    printf("\nRX thread stats:\n");
    printf(" - Pkts rxd:                %"PRIu64"\n",
                        app_stats.rx.rx_pkts);
    printf(" - Pkts enqd to workers ring:       %"PRIu64"\n",
                        app_stats.rx.enqueue_pkts);

    for (lcore_id = 0; lcore_id <= end_w_lcore_id; lcore_id++) {
        if (insight_worker
            && rte_lcore_is_enabled(lcore_id)
            && lcore_id != master_lcore_id) {
            printf("\nWorker thread stats on core [%u]:\n",
                    lcore_id);
            printf(" - Pkts deqd from workers ring:     %"PRIu64"\n",
                    wkr_stats[lcore_id].deq_pkts);
            printf(" - Pkts enqd to tx ring:        %"PRIu64"\n",
                    wkr_stats[lcore_id].enq_pkts);
            printf(" - Pkts enq to tx failed:       %"PRIu64"\n",
                    wkr_stats[lcore_id].enq_failed_pkts);
        }

        app_stats.wkr.dequeue_pkts += wkr_stats[lcore_id].deq_pkts;
        app_stats.wkr.enqueue_pkts += wkr_stats[lcore_id].enq_pkts;
        app_stats.wkr.enqueue_failed_pkts +=
            wkr_stats[lcore_id].enq_failed_pkts;
    }

    printf("\nWorker thread stats:\n");
    printf(" - Pkts deqd from workers ring:     %"PRIu64"\n",
                        app_stats.wkr.dequeue_pkts);
    printf(" - Pkts enqd to tx ring:        %"PRIu64"\n",
                        app_stats.wkr.enqueue_pkts);
    printf(" - Pkts enq to tx failed:       %"PRIu64"\n",
                        app_stats.wkr.enqueue_failed_pkts);

    printf("\nTX stats:\n");
    printf(" - Pkts deqd from tx ring:      %"PRIu64"\n",
                        app_stats.tx.dequeue_pkts);
    printf(" - Ro Pkts transmitted:         %"PRIu64"\n",
                        app_stats.tx.ro_tx_pkts);
    printf(" - Ro Pkts tx failed:           %"PRIu64"\n",
                        app_stats.tx.ro_tx_failed_pkts);
    printf(" - Pkts transmitted w/o reorder:    %"PRIu64"\n",
                        app_stats.tx.early_pkts_txtd_woro);
    printf(" - Pkts tx failed w/o reorder:      %"PRIu64"\n",
                        app_stats.tx.early_pkts_tx_failed_woro);

    RTE_ETH_FOREACH_DEV(i) {
        rte_eth_stats_get(i, &eth_stats);
        printf("\nPort %u stats:\n", i);
        printf(" - Pkts in:   %"PRIu64"\n", eth_stats.ipackets);
        printf(" - Pkts out:  %"PRIu64"\n", eth_stats.opackets);
        printf(" - In Errs:   %"PRIu64"\n", eth_stats.ierrors);
        printf(" - Out Errs:  %"PRIu64"\n", eth_stats.oerrors);
        printf(" - Mbuf Errs: %"PRIu64"\n", eth_stats.rx_nombuf);
    }
}

static void
int_handler(int sig_num)
{
    printf("Exiting on signal %d\n", sig_num);
    quit_signal = 1;
}

static int
rx_thread(struct rte_ring *ring_out)
{
    uint32_t seqn = 0;
    uint16_t i, ret = 0;
    uint16_t nb_rx_pkts;
    uint16_t port_id;
    struct rte_mbuf *pkts[MAX_PKTS_BURST];

    RTE_LOG(INFO, REORDERAPP, "%s() started on lcore %u\n", __func__,
                            rte_lcore_id());

    while (!quit_signal) {

        RTE_ETH_FOREACH_DEV(port_id) {
            if ((portmask & (1 << port_id)) != 0) {

                /* receive packets */
                nb_rx_pkts = rte_eth_rx_burst(port_id, 0,
                                pkts, MAX_PKTS_BURST);
                if (nb_rx_pkts == 0) {
                    RTE_LOG_DP(DEBUG, REORDERAPP,
                    "%s():Received zero packets\n", __func__);
                    continue;
                }
                app_stats.rx.rx_pkts += nb_rx_pkts;

                /* mark sequence number */
                for (i = 0; i < nb_rx_pkts; )
                    pkts[i++]->seqn = seqn++;

                /* enqueue to rx_to_workers ring */
                ret = rte_ring_enqueue_burst(ring_out,
                        (void *)pkts, nb_rx_pkts, NULL);
                app_stats.rx.enqueue_pkts += ret;
                if (unlikely(ret < nb_rx_pkts)) {
                    app_stats.rx.enqueue_failed_pkts +=
                                    (nb_rx_pkts-ret);
                    pktmbuf_free_bulk(&pkts[ret], nb_rx_pkts - ret);
                }
            }
        }
    }
    return 0;
}

static int
worker_thread(void *args_ptr)
{
    const uint16_t nb_ports = rte_eth_dev_count_avail();
    uint16_t i, ret = 0;
    uint16_t burst_size = 0;
    struct worker_thread_args *args;
    struct rte_mbuf *burst_buffer[MAX_PKTS_BURST] = { NULL };
    struct rte_ring *ring_in, *ring_out;
    const unsigned xor_val = (nb_ports > 1);
    unsigned int core_id = rte_lcore_id();

    args = (struct worker_thread_args *) args_ptr;
    ring_in  = args->ring_in;
    ring_out = args->ring_out;

    RTE_LOG(INFO, REORDERAPP, "%s() started on lcore %u\n", __func__,
                            core_id);

    while (!quit_signal) {

        /* dequeue the mbufs from rx_to_workers ring */
        burst_size = rte_ring_dequeue_burst(ring_in,
                (void *)burst_buffer, MAX_PKTS_BURST, NULL);
        if (unlikely(burst_size == 0))
            continue;

        wkr_stats[core_id].deq_pkts += burst_size;

        /* just do some operation on mbuf */
        for (i = 0; i < burst_size;)
            burst_buffer[i++]->port ^= xor_val;

        /* enqueue the modified mbufs to workers_to_tx ring */
        ret = rte_ring_enqueue_burst(ring_out, (void *)burst_buffer,
                burst_size, NULL);
        wkr_stats[core_id].enq_pkts += ret;
        if (unlikely(ret < burst_size)) {
            /* Return the mbufs to their respective pool, dropping packets */
            wkr_stats[core_id].enq_failed_pkts += burst_size - ret;
            pktmbuf_free_bulk(&burst_buffer[ret], burst_size - ret);
        }
    }
    return 0;
}

static int
send_thread(struct send_thread_args *args)
{
    int ret;
    unsigned int i, dret;
    uint16_t nb_dq_mbufs;
    uint8_t outp;
    unsigned sent;
    struct rte_mbuf *mbufs[MAX_PKTS_BURST];
    struct rte_mbuf *rombufs[MAX_PKTS_BURST] = {NULL};
    static struct rte_eth_dev_tx_buffer *tx_buffer[RTE_MAX_ETHPORTS];

    RTE_LOG(INFO, REORDERAPP, "%s() started on lcore %u\n", __func__, rte_lcore_id());

    configure_tx_buffers(tx_buffer);

    while (!quit_signal) {

        /* deque the mbufs from workers_to_tx ring */
        nb_dq_mbufs = rte_ring_dequeue_burst(args->ring_in,
                (void *)mbufs, MAX_PKTS_BURST, NULL);

        if (unlikely(nb_dq_mbufs == 0))
            continue;

        app_stats.tx.dequeue_pkts += nb_dq_mbufs;

        for (i = 0; i < nb_dq_mbufs; i++) {
            /* send dequeued mbufs for reordering */
            ret = rte_reorder_insert(args->buffer, mbufs[i]);

            if (ret == -1 && rte_errno == ERANGE) {
                /* Too early pkts should be transmitted out directly */
                RTE_LOG_DP(DEBUG, REORDERAPP,
                        "%s():Cannot reorder early packet "
                        "direct enqueuing to TX\n", __func__);
                outp = mbufs[i]->port;
                if ((portmask & (1 << outp)) == 0) {
                    rte_pktmbuf_free(mbufs[i]);
                    continue;
                }
                if (rte_eth_tx_burst(outp, 0, (void *)mbufs[i], 1) != 1) {
                    rte_pktmbuf_free(mbufs[i]);
                    app_stats.tx.early_pkts_tx_failed_woro++;
                } else
                    app_stats.tx.early_pkts_txtd_woro++;
            } else if (ret == -1 && rte_errno == ENOSPC) {
                rte_pktmbuf_free(mbufs[i]);
            }
        }

        /*
         * drain MAX_PKTS_BURST of reordered
         * mbufs for transmit
         */
        dret = rte_reorder_drain(args->buffer, rombufs, MAX_PKTS_BURST);
        for (i = 0; i < dret; i++) {

            struct rte_eth_dev_tx_buffer *outbuf;
            uint8_t outp1;

            outp1 = rombufs[i]->port;
            /* skip ports that are not enabled */
            if ((portmask & (1 << outp1)) == 0) {
                rte_pktmbuf_free(rombufs[i]);
                continue;
            }

            outbuf = tx_buffer[outp1];
            sent = rte_eth_tx_buffer(outp1, 0, outbuf, rombufs[i]);
            if (sent)
                app_stats.tx.ro_tx_pkts += sent;
        }
    }

    free_tx_buffers(tx_buffer);

    return 0;
}

static int
tx_thread(struct rte_ring *ring_in)
{
    uint32_t i, dqnum;
    uint8_t outp;
    unsigned sent;
    struct rte_mbuf *mbufs[MAX_PKTS_BURST];
    struct rte_eth_dev_tx_buffer *outbuf;
    static struct rte_eth_dev_tx_buffer *tx_buffer[RTE_MAX_ETHPORTS];

    RTE_LOG(INFO, REORDERAPP, "%s() started on lcore %u\n", __func__,
                            rte_lcore_id());

    configure_tx_buffers(tx_buffer);

    while (!quit_signal) {

        /* deque the mbufs from workers_to_tx ring */
        dqnum = rte_ring_dequeue_burst(ring_in,
                (void *)mbufs, MAX_PKTS_BURST, NULL);

        if (unlikely(dqnum == 0))
            continue;

        app_stats.tx.dequeue_pkts += dqnum;

        for (i = 0; i < dqnum; i++) {
            outp = mbufs[i]->port;
            /* skip ports that are not enabled */
            if ((portmask & (1 << outp)) == 0) {
                rte_pktmbuf_free(mbufs[i]);
                continue;
            }

            outbuf = tx_buffer[outp];
            sent = rte_eth_tx_buffer(outp, 0, outbuf, mbufs[i]);
            if (sent)
                app_stats.tx.ro_tx_pkts += sent;
        }
    }

    return 0;
}

int
main(int argc, char **argv)
{
    int ret;
    unsigned nb_ports;
    unsigned int lcore_id, last_lcore_id, master_lcore_id;
    uint16_t port_id;
    uint16_t nb_ports_available;
    struct worker_thread_args worker_args = {NULL, NULL};
    struct send_thread_args send_args = {NULL, NULL};
    struct rte_ring *rx_to_workers;
    struct rte_ring *workers_to_tx;

    /* catch ctrl-c so we can print on exit */
    signal(SIGINT, int_handler);

    /* Initialize EAL */
    ret = rte_eal_init(argc, argv);
    if (ret < 0)
        return -1;

    argc -= ret;
    argv += ret;

    /* Parse the application specific arguments */
    ret = parse_args(argc, argv);
    if (ret < 0)
        return -1;

    /* Check if we have enought cores */
    if (rte_lcore_count() < 3)
        rte_exit(EXIT_FAILURE, "Error, This application needs at "
                "least 3 logical cores to run:\n"
                "1 lcore for packet RX\n"
                "1 lcore for packet TX\n"
                "and at least 1 lcore for worker threads\n");

    nb_ports = rte_eth_dev_count_avail();
    if (nb_ports == 0)
        rte_exit(EXIT_FAILURE, "Error: no ethernet ports detected\n");
    if (nb_ports != 1 && (nb_ports & 1))
        rte_exit(EXIT_FAILURE, "Error: number of ports must be even, except "
                "when using a single port\n");

    mbuf_pool = rte_pktmbuf_pool_create("mbuf_pool", MBUF_PER_POOL,
            MBUF_POOL_CACHE_SIZE, 0, RTE_MBUF_DEFAULT_BUF_SIZE,
            rte_socket_id());
    if (mbuf_pool == NULL)
        rte_exit(EXIT_FAILURE, "%s\n", rte_strerror(rte_errno));

    nb_ports_available = nb_ports;

    /* initialize all ports */
    RTE_ETH_FOREACH_DEV(port_id) {
        /* skip ports that are not enabled */
        if ((portmask & (1 << port_id)) == 0) {
            printf("\nSkipping disabled port %d\n", port_id);
            nb_ports_available--;
            continue;
        }
        /* init port */
        printf("Initializing port %u... done\n", port_id);

        if (configure_eth_port(port_id) != 0)
            rte_exit(EXIT_FAILURE, "Cannot initialize port %"PRIu8"\n",
                    port_id);
    }

    if (!nb_ports_available) {
        rte_exit(EXIT_FAILURE,
            "All available ports are disabled. Please set portmask.\n");
    }

    /* Create rings for inter core communication */
    rx_to_workers = rte_ring_create("rx_to_workers", RING_SIZE, rte_socket_id(),
            RING_F_SP_ENQ);
    if (rx_to_workers == NULL)
        rte_exit(EXIT_FAILURE, "%s\n", rte_strerror(rte_errno));

    workers_to_tx = rte_ring_create("workers_to_tx", RING_SIZE, rte_socket_id(),
            RING_F_SC_DEQ);
    if (workers_to_tx == NULL)
        rte_exit(EXIT_FAILURE, "%s\n", rte_strerror(rte_errno));

    if (!disable_reorder) {
        send_args.buffer = rte_reorder_create("PKT_RO", rte_socket_id(),
                REORDER_BUFFER_SIZE);
        if (send_args.buffer == NULL)
            rte_exit(EXIT_FAILURE, "%s\n", rte_strerror(rte_errno));
    }

    last_lcore_id   = get_last_lcore_id();
    master_lcore_id = rte_get_master_lcore();

    worker_args.ring_in  = rx_to_workers;
    worker_args.ring_out = workers_to_tx;

    /* Start worker_thread() on all the available slave cores but the last 1 */
    for (lcore_id = 0; lcore_id <= get_previous_lcore_id(last_lcore_id); lcore_id++)
        if (rte_lcore_is_enabled(lcore_id) && lcore_id != master_lcore_id)
            rte_eal_remote_launch(worker_thread, (void *)&worker_args,
                    lcore_id);

    if (disable_reorder) {
        /* Start tx_thread() on the last slave core */
        rte_eal_remote_launch((lcore_function_t *)tx_thread, workers_to_tx,
                last_lcore_id);
    } else {
        send_args.ring_in = workers_to_tx;
        /* Start send_thread() on the last slave core */
        rte_eal_remote_launch((lcore_function_t *)send_thread,
                (void *)&send_args, last_lcore_id);
    }

    /* Start rx_thread() on the master core */
    rx_thread(rx_to_workers);

    RTE_LCORE_FOREACH_SLAVE(lcore_id) {
        if (rte_eal_wait_lcore(lcore_id) < 0)
            return -1;
    }

    print_stats();
    return 0;
}