examples/rxtx_callbacks/main.c

/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright(c) 2010-2015 Intel Corporation
 */

#include <stdint.h>
#include <inttypes.h>
#include <getopt.h>
#include <rte_eal.h>
#include <rte_ethdev.h>
#include <rte_cycles.h>
#include <rte_lcore.h>
#include <rte_mbuf.h>

#define RX_RING_SIZE 1024
#define TX_RING_SIZE 1024

#define NUM_MBUFS 8191
#define MBUF_CACHE_SIZE 250
#define BURST_SIZE 32

static const char usage[] =
    "%s EAL_ARGS -- [-t]\n";

static const struct rte_eth_conf port_conf_default = {
    .rxmode = {
        .max_rx_pkt_len = RTE_ETHER_MAX_LEN,
    },
};

static struct {
    uint64_t total_cycles;
    uint64_t total_queue_cycles;
    uint64_t total_pkts;
} latency_numbers;

int hw_timestamping;

#define TICKS_PER_CYCLE_SHIFT 16
static uint64_t ticks_per_cycle_mult;

static uint16_t
add_timestamps(uint16_t port __rte_unused, uint16_t qidx __rte_unused,
        struct rte_mbuf **pkts, uint16_t nb_pkts,
        uint16_t max_pkts __rte_unused, void *_ __rte_unused)
{
    unsigned i;
    uint64_t now = rte_rdtsc();

    for (i = 0; i < nb_pkts; i++)
        pkts[i]->udata64 = now;
    return nb_pkts;
}

static uint16_t
calc_latency(uint16_t port, uint16_t qidx __rte_unused,
        struct rte_mbuf **pkts, uint16_t nb_pkts, void *_ __rte_unused)
{
    uint64_t cycles = 0;
    uint64_t queue_ticks = 0;
    uint64_t now = rte_rdtsc();
    uint64_t ticks;
    unsigned i;

    if (hw_timestamping)
        rte_eth_read_clock(port, &ticks);

    for (i = 0; i < nb_pkts; i++) {
        cycles += now - pkts[i]->udata64;
        if (hw_timestamping)
            queue_ticks += ticks - pkts[i]->timestamp;
    }

    latency_numbers.total_cycles += cycles;
    if (hw_timestamping)
        latency_numbers.total_queue_cycles += (queue_ticks
            * ticks_per_cycle_mult) >> TICKS_PER_CYCLE_SHIFT;

    latency_numbers.total_pkts += nb_pkts;

    if (latency_numbers.total_pkts > (100 * 1000 * 1000ULL)) {
        printf("Latency = %"PRIu64" cycles\n",
        latency_numbers.total_cycles / latency_numbers.total_pkts);
        if (hw_timestamping) {
            printf("Latency from HW = %"PRIu64" cycles\n",
               latency_numbers.total_queue_cycles
               / latency_numbers.total_pkts);
        }
        latency_numbers.total_cycles = 0;
        latency_numbers.total_queue_cycles = 0;
        latency_numbers.total_pkts = 0;
    }
    return nb_pkts;
}

/*
 * Initialises a given port using global settings and with the rx buffers
 * coming from the mbuf_pool passed as parameter
 */
static inline int
port_init(uint16_t port, struct rte_mempool *mbuf_pool)
{
    struct rte_eth_conf port_conf = port_conf_default;
    const uint16_t rx_rings = 1, tx_rings = 1;
    uint16_t nb_rxd = RX_RING_SIZE;
    uint16_t nb_txd = TX_RING_SIZE;
    int retval;
    uint16_t q;
    struct rte_eth_dev_info dev_info;
    struct rte_eth_rxconf rxconf;
    struct rte_eth_txconf txconf;

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

    rte_eth_dev_info_get(port, &dev_info);
    if (dev_info.tx_offload_capa & DEV_TX_OFFLOAD_MBUF_FAST_FREE)
        port_conf.txmode.offloads |=
            DEV_TX_OFFLOAD_MBUF_FAST_FREE;

    retval = rte_eth_dev_configure(port, rx_rings, tx_rings, &port_conf);
    if (retval != 0)
        return retval;

    retval = rte_eth_dev_adjust_nb_rx_tx_desc(port, &nb_rxd, &nb_txd);
    if (retval != 0)
        return retval;

    rxconf = dev_info.default_rxconf;

    if (hw_timestamping) {
        if (!(dev_info.rx_offload_capa & DEV_RX_OFFLOAD_TIMESTAMP)) {
            printf("\nERROR: Port %u does not support hardware timestamping\n"
                    , port);
            return -1;
        }
        rxconf.offloads |= DEV_RX_OFFLOAD_TIMESTAMP;
    }

    for (q = 0; q < rx_rings; q++) {
        retval = rte_eth_rx_queue_setup(port, q, nb_rxd,
            rte_eth_dev_socket_id(port), &rxconf, mbuf_pool);
        if (retval < 0)
            return retval;
    }

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

    retval  = rte_eth_dev_start(port);
    if (retval < 0)
        return retval;

    if (hw_timestamping && ticks_per_cycle_mult  == 0) {
        uint64_t cycles_base = rte_rdtsc();
        uint64_t ticks_base;
        retval = rte_eth_read_clock(port, &ticks_base);
        if (retval != 0)
            return retval;
        rte_delay_ms(100);
        uint64_t cycles = rte_rdtsc();
        uint64_t ticks;
        rte_eth_read_clock(port, &ticks);
        uint64_t c_freq = cycles - cycles_base;
        uint64_t t_freq = ticks - ticks_base;
        double freq_mult = (double)c_freq / t_freq;
        printf("TSC Freq ~= %" PRIu64
                "\nHW Freq ~= %" PRIu64
                "\nRatio : %f\n",
                c_freq * 10, t_freq * 10, freq_mult);
        /* TSC will be faster than internal ticks so freq_mult is > 0
         * We convert the multiplication to an integer shift & mult
         */
        ticks_per_cycle_mult = (1 << TICKS_PER_CYCLE_SHIFT) / freq_mult;
    }

    struct rte_ether_addr addr;

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

    rte_eth_promiscuous_enable(port);
    rte_eth_add_rx_callback(port, 0, add_timestamps, NULL);
    rte_eth_add_tx_callback(port, 0, calc_latency, NULL);

    return 0;
}

/*
 * Main thread that does the work, reading from INPUT_PORT
 * and writing to OUTPUT_PORT
 */
static  __attribute__((noreturn)) void
lcore_main(void)
{
    uint16_t port;

    RTE_ETH_FOREACH_DEV(port)
        if (rte_eth_dev_socket_id(port) > 0 &&
                rte_eth_dev_socket_id(port) !=
                        (int)rte_socket_id())
            printf("WARNING, port %u is on remote NUMA node to "
                    "polling thread.\n\tPerformance will "
                    "not be optimal.\n", port);

    printf("\nCore %u forwarding packets. [Ctrl+C to quit]\n",
            rte_lcore_id());
    for (;;) {
        RTE_ETH_FOREACH_DEV(port) {
            struct rte_mbuf *bufs[BURST_SIZE];
            const uint16_t nb_rx = rte_eth_rx_burst(port, 0,
                    bufs, BURST_SIZE);
            if (unlikely(nb_rx == 0))
                continue;
            const uint16_t nb_tx = rte_eth_tx_burst(port ^ 1, 0,
                    bufs, nb_rx);
            if (unlikely(nb_tx < nb_rx)) {
                uint16_t buf;

                for (buf = nb_tx; buf < nb_rx; buf++)
                    rte_pktmbuf_free(bufs[buf]);
            }
        }
    }
}

/* Main function, does initialisation and calls the per-lcore functions */
int
main(int argc, char *argv[])
{
    struct rte_mempool *mbuf_pool;
    uint16_t nb_ports;
    uint16_t portid;
    struct option lgopts[] = {
        { NULL,  0, 0, 0 }
    };
    int opt, option_index;


    /* init EAL */
    int ret = rte_eal_init(argc, argv);

    if (ret < 0)
        rte_exit(EXIT_FAILURE, "Error with EAL initialization\n");
    argc -= ret;
    argv += ret;

    while ((opt = getopt_long(argc, argv, "t", lgopts, &option_index))
            != EOF)
        switch (opt) {
        case 't':
            hw_timestamping = 1;
            break;
        default:
            printf(usage, argv[0]);
            return -1;
        }
    optind = 1; /* reset getopt lib */

    nb_ports = rte_eth_dev_count_avail();
    if (nb_ports < 2 || (nb_ports & 1))
        rte_exit(EXIT_FAILURE, "Error: number of ports must be even\n");

    mbuf_pool = rte_pktmbuf_pool_create("MBUF_POOL",
        NUM_MBUFS * nb_ports, MBUF_CACHE_SIZE, 0,
        RTE_MBUF_DEFAULT_BUF_SIZE, rte_socket_id());
    if (mbuf_pool == NULL)
        rte_exit(EXIT_FAILURE, "Cannot create mbuf pool\n");

    /* initialize all ports */
    RTE_ETH_FOREACH_DEV(portid)
        if (port_init(portid, mbuf_pool) != 0)
            rte_exit(EXIT_FAILURE, "Cannot init port %"PRIu8"\n",
                    portid);

    if (rte_lcore_count() > 1)
        printf("\nWARNING: Too much enabled lcores - "
            "App uses only 1 lcore\n");

    /* call lcore_main on master core only */
    lcore_main();
    return 0;
}