examples/load_balancer/runtime.c

/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright(c) 2010-2014 Intel Corporation
 */

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <inttypes.h>
#include <sys/types.h>
#include <string.h>
#include <sys/queue.h>
#include <stdarg.h>
#include <errno.h>
#include <getopt.h>

#include <rte_common.h>
#include <rte_byteorder.h>
#include <rte_log.h>
#include <rte_memory.h>
#include <rte_memcpy.h>
#include <rte_eal.h>
#include <rte_launch.h>
#include <rte_atomic.h>
#include <rte_cycles.h>
#include <rte_prefetch.h>
#include <rte_lcore.h>
#include <rte_per_lcore.h>
#include <rte_branch_prediction.h>
#include <rte_interrupts.h>
#include <rte_random.h>
#include <rte_debug.h>
#include <rte_ether.h>
#include <rte_ethdev.h>
#include <rte_ring.h>
#include <rte_mempool.h>
#include <rte_mbuf.h>
#include <rte_ip.h>
#include <rte_tcp.h>
#include <rte_lpm.h>

#include "main.h"

#ifndef APP_LCORE_IO_FLUSH
#define APP_LCORE_IO_FLUSH           1000000
#endif

#ifndef APP_LCORE_WORKER_FLUSH
#define APP_LCORE_WORKER_FLUSH       1000000
#endif

#ifndef APP_STATS
#define APP_STATS                    1000000
#endif

#define APP_IO_RX_DROP_ALL_PACKETS   0
#define APP_WORKER_DROP_ALL_PACKETS  0
#define APP_IO_TX_DROP_ALL_PACKETS   0

#ifndef APP_IO_RX_PREFETCH_ENABLE
#define APP_IO_RX_PREFETCH_ENABLE    1
#endif

#ifndef APP_WORKER_PREFETCH_ENABLE
#define APP_WORKER_PREFETCH_ENABLE   1
#endif

#ifndef APP_IO_TX_PREFETCH_ENABLE
#define APP_IO_TX_PREFETCH_ENABLE    1
#endif

#if APP_IO_RX_PREFETCH_ENABLE
#define APP_IO_RX_PREFETCH0(p)       rte_prefetch0(p)
#define APP_IO_RX_PREFETCH1(p)       rte_prefetch1(p)
#else
#define APP_IO_RX_PREFETCH0(p)
#define APP_IO_RX_PREFETCH1(p)
#endif

#if APP_WORKER_PREFETCH_ENABLE
#define APP_WORKER_PREFETCH0(p)      rte_prefetch0(p)
#define APP_WORKER_PREFETCH1(p)      rte_prefetch1(p)
#else
#define APP_WORKER_PREFETCH0(p)
#define APP_WORKER_PREFETCH1(p)
#endif

#if APP_IO_TX_PREFETCH_ENABLE
#define APP_IO_TX_PREFETCH0(p)       rte_prefetch0(p)
#define APP_IO_TX_PREFETCH1(p)       rte_prefetch1(p)
#else
#define APP_IO_TX_PREFETCH0(p)
#define APP_IO_TX_PREFETCH1(p)
#endif

static inline void
app_lcore_io_rx_buffer_to_send (
    struct app_lcore_params_io *lp,
    uint32_t worker,
    struct rte_mbuf *mbuf,
    uint32_t bsz)
{
    uint32_t pos;
    int ret;

    pos = lp->rx.mbuf_out[worker].n_mbufs;
    lp->rx.mbuf_out[worker].array[pos ++] = mbuf;
    if (likely(pos < bsz)) {
        lp->rx.mbuf_out[worker].n_mbufs = pos;
        return;
    }

    ret = rte_ring_sp_enqueue_bulk(
        lp->rx.rings[worker],
        (void **) lp->rx.mbuf_out[worker].array,
        bsz,
        NULL);

    if (unlikely(ret == 0)) {
        uint32_t k;
        for (k = 0; k < bsz; k ++) {
            struct rte_mbuf *m = lp->rx.mbuf_out[worker].array[k];
            rte_pktmbuf_free(m);
        }
    }

    lp->rx.mbuf_out[worker].n_mbufs = 0;
    lp->rx.mbuf_out_flush[worker] = 0;

#if APP_STATS
    lp->rx.rings_iters[worker] ++;
    if (likely(ret == 0)) {
        lp->rx.rings_count[worker] ++;
    }
    if (unlikely(lp->rx.rings_iters[worker] == APP_STATS)) {
        unsigned lcore = rte_lcore_id();

        printf("\tI/O RX %u out (worker %u): enq success rate = %.2f\n",
            lcore,
            (unsigned)worker,
            ((double) lp->rx.rings_count[worker]) / ((double) lp->rx.rings_iters[worker]));
        lp->rx.rings_iters[worker] = 0;
        lp->rx.rings_count[worker] = 0;
    }
#endif
}

static inline void
app_lcore_io_rx(
    struct app_lcore_params_io *lp,
    uint32_t n_workers,
    uint32_t bsz_rd,
    uint32_t bsz_wr,
    uint8_t pos_lb)
{
    struct rte_mbuf *mbuf_1_0, *mbuf_1_1, *mbuf_2_0, *mbuf_2_1;
    uint8_t *data_1_0, *data_1_1 = NULL;
    uint32_t i;

    for (i = 0; i < lp->rx.n_nic_queues; i ++) {
        uint16_t port = lp->rx.nic_queues[i].port;
        uint8_t queue = lp->rx.nic_queues[i].queue;
        uint32_t n_mbufs, j;

        n_mbufs = rte_eth_rx_burst(
            port,
            queue,
            lp->rx.mbuf_in.array,
            (uint16_t) bsz_rd);

        if (unlikely(n_mbufs == 0)) {
            continue;
        }

#if APP_STATS
        lp->rx.nic_queues_iters[i] ++;
        lp->rx.nic_queues_count[i] += n_mbufs;
        if (unlikely(lp->rx.nic_queues_iters[i] == APP_STATS)) {
            struct rte_eth_stats stats;
            unsigned lcore = rte_lcore_id();

            rte_eth_stats_get(port, &stats);

            printf("I/O RX %u in (NIC port %u): NIC drop ratio = %.2f avg burst size = %.2f\n",
                lcore,
                port,
                (double) stats.imissed / (double) (stats.imissed + stats.ipackets),
                ((double) lp->rx.nic_queues_count[i]) / ((double) lp->rx.nic_queues_iters[i]));
            lp->rx.nic_queues_iters[i] = 0;
            lp->rx.nic_queues_count[i] = 0;
        }
#endif

#if APP_IO_RX_DROP_ALL_PACKETS
        for (j = 0; j < n_mbufs; j ++) {
            struct rte_mbuf *pkt = lp->rx.mbuf_in.array[j];
            rte_pktmbuf_free(pkt);
        }

        continue;
#endif

        mbuf_1_0 = lp->rx.mbuf_in.array[0];
        mbuf_1_1 = lp->rx.mbuf_in.array[1];
        data_1_0 = rte_pktmbuf_mtod(mbuf_1_0, uint8_t *);
        if (likely(n_mbufs > 1)) {
            data_1_1 = rte_pktmbuf_mtod(mbuf_1_1, uint8_t *);
        }

        mbuf_2_0 = lp->rx.mbuf_in.array[2];
        mbuf_2_1 = lp->rx.mbuf_in.array[3];
        APP_IO_RX_PREFETCH0(mbuf_2_0);
        APP_IO_RX_PREFETCH0(mbuf_2_1);

        for (j = 0; j + 3 < n_mbufs; j += 2) {
            struct rte_mbuf *mbuf_0_0, *mbuf_0_1;
            uint8_t *data_0_0, *data_0_1;
            uint32_t worker_0, worker_1;

            mbuf_0_0 = mbuf_1_0;
            mbuf_0_1 = mbuf_1_1;
            data_0_0 = data_1_0;
            data_0_1 = data_1_1;

            mbuf_1_0 = mbuf_2_0;
            mbuf_1_1 = mbuf_2_1;
            data_1_0 = rte_pktmbuf_mtod(mbuf_2_0, uint8_t *);
            data_1_1 = rte_pktmbuf_mtod(mbuf_2_1, uint8_t *);
            APP_IO_RX_PREFETCH0(data_1_0);
            APP_IO_RX_PREFETCH0(data_1_1);

            mbuf_2_0 = lp->rx.mbuf_in.array[j+4];
            mbuf_2_1 = lp->rx.mbuf_in.array[j+5];
            APP_IO_RX_PREFETCH0(mbuf_2_0);
            APP_IO_RX_PREFETCH0(mbuf_2_1);

            worker_0 = data_0_0[pos_lb] & (n_workers - 1);
            worker_1 = data_0_1[pos_lb] & (n_workers - 1);

            app_lcore_io_rx_buffer_to_send(lp, worker_0, mbuf_0_0, bsz_wr);
            app_lcore_io_rx_buffer_to_send(lp, worker_1, mbuf_0_1, bsz_wr);
        }

        /* Handle the last 1, 2 (when n_mbufs is even) or 3 (when n_mbufs is odd) packets  */
        for ( ; j < n_mbufs; j += 1) {
            struct rte_mbuf *mbuf;
            uint8_t *data;
            uint32_t worker;

            mbuf = mbuf_1_0;
            mbuf_1_0 = mbuf_1_1;
            mbuf_1_1 = mbuf_2_0;
            mbuf_2_0 = mbuf_2_1;

            data = rte_pktmbuf_mtod(mbuf, uint8_t *);

            APP_IO_RX_PREFETCH0(mbuf_1_0);

            worker = data[pos_lb] & (n_workers - 1);

            app_lcore_io_rx_buffer_to_send(lp, worker, mbuf, bsz_wr);
        }
    }
}

static inline void
app_lcore_io_rx_flush(struct app_lcore_params_io *lp, uint32_t n_workers)
{
    uint32_t worker;

    for (worker = 0; worker < n_workers; worker ++) {
        int ret;

        if (likely((lp->rx.mbuf_out_flush[worker] == 0) ||
                   (lp->rx.mbuf_out[worker].n_mbufs == 0))) {
            lp->rx.mbuf_out_flush[worker] = 1;
            continue;
        }

        ret = rte_ring_sp_enqueue_bulk(
            lp->rx.rings[worker],
            (void **) lp->rx.mbuf_out[worker].array,
            lp->rx.mbuf_out[worker].n_mbufs,
            NULL);

        if (unlikely(ret == 0)) {
            uint32_t k;
            for (k = 0; k < lp->rx.mbuf_out[worker].n_mbufs; k ++) {
                struct rte_mbuf *pkt_to_free = lp->rx.mbuf_out[worker].array[k];
                rte_pktmbuf_free(pkt_to_free);
            }
        }

        lp->rx.mbuf_out[worker].n_mbufs = 0;
        lp->rx.mbuf_out_flush[worker] = 1;
    }
}

static inline void
app_lcore_io_tx(
    struct app_lcore_params_io *lp,
    uint32_t n_workers,
    uint32_t bsz_rd,
    uint32_t bsz_wr)
{
    uint32_t worker;

    for (worker = 0; worker < n_workers; worker ++) {
        uint32_t i;

        for (i = 0; i < lp->tx.n_nic_ports; i ++) {
            uint16_t port = lp->tx.nic_ports[i];
            struct rte_ring *ring = lp->tx.rings[port][worker];
            uint32_t n_mbufs, n_pkts;
            int ret;

            n_mbufs = lp->tx.mbuf_out[port].n_mbufs;
            ret = rte_ring_sc_dequeue_bulk(
                ring,
                (void **) &lp->tx.mbuf_out[port].array[n_mbufs],
                bsz_rd,
                NULL);

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

            n_mbufs += bsz_rd;

#if APP_IO_TX_DROP_ALL_PACKETS
            {
                uint32_t j;
                APP_IO_TX_PREFETCH0(lp->tx.mbuf_out[port].array[0]);
                APP_IO_TX_PREFETCH0(lp->tx.mbuf_out[port].array[1]);

                for (j = 0; j < n_mbufs; j ++) {
                    if (likely(j < n_mbufs - 2)) {
                        APP_IO_TX_PREFETCH0(lp->tx.mbuf_out[port].array[j + 2]);
                    }

                    rte_pktmbuf_free(lp->tx.mbuf_out[port].array[j]);
                }

                lp->tx.mbuf_out[port].n_mbufs = 0;

                continue;
            }
#endif

            if (unlikely(n_mbufs < bsz_wr)) {
                lp->tx.mbuf_out[port].n_mbufs = n_mbufs;
                continue;
            }

            n_pkts = rte_eth_tx_burst(
                port,
                0,
                lp->tx.mbuf_out[port].array,
                (uint16_t) n_mbufs);

#if APP_STATS
            lp->tx.nic_ports_iters[port] ++;
            lp->tx.nic_ports_count[port] += n_pkts;
            if (unlikely(lp->tx.nic_ports_iters[port] == APP_STATS)) {
                unsigned lcore = rte_lcore_id();

                printf("\t\t\tI/O TX %u out (port %u): avg burst size = %.2f\n",
                    lcore,
                    port,
                    ((double) lp->tx.nic_ports_count[port]) / ((double) lp->tx.nic_ports_iters[port]));
                lp->tx.nic_ports_iters[port] = 0;
                lp->tx.nic_ports_count[port] = 0;
            }
#endif

            if (unlikely(n_pkts < n_mbufs)) {
                uint32_t k;
                for (k = n_pkts; k < n_mbufs; k ++) {
                    struct rte_mbuf *pkt_to_free = lp->tx.mbuf_out[port].array[k];
                    rte_pktmbuf_free(pkt_to_free);
                }
            }
            lp->tx.mbuf_out[port].n_mbufs = 0;
            lp->tx.mbuf_out_flush[port] = 0;
        }
    }
}

static inline void
app_lcore_io_tx_flush(struct app_lcore_params_io *lp)
{
    uint16_t port;
    uint32_t i;

    for (i = 0; i < lp->tx.n_nic_ports; i++) {
        uint32_t n_pkts;

        port = lp->tx.nic_ports[i];
        if (likely((lp->tx.mbuf_out_flush[port] == 0) ||
                   (lp->tx.mbuf_out[port].n_mbufs == 0))) {
            lp->tx.mbuf_out_flush[port] = 1;
            continue;
        }

        n_pkts = rte_eth_tx_burst(
            port,
            0,
            lp->tx.mbuf_out[port].array,
            (uint16_t) lp->tx.mbuf_out[port].n_mbufs);

        if (unlikely(n_pkts < lp->tx.mbuf_out[port].n_mbufs)) {
            uint32_t k;
            for (k = n_pkts; k < lp->tx.mbuf_out[port].n_mbufs; k ++) {
                struct rte_mbuf *pkt_to_free = lp->tx.mbuf_out[port].array[k];
                rte_pktmbuf_free(pkt_to_free);
            }
        }

        lp->tx.mbuf_out[port].n_mbufs = 0;
        lp->tx.mbuf_out_flush[port] = 1;
    }
}

static void
app_lcore_main_loop_io(void)
{
    uint32_t lcore = rte_lcore_id();
    struct app_lcore_params_io *lp = &app.lcore_params[lcore].io;
    uint32_t n_workers = app_get_lcores_worker();
    uint64_t i = 0;

    uint32_t bsz_rx_rd = app.burst_size_io_rx_read;
    uint32_t bsz_rx_wr = app.burst_size_io_rx_write;
    uint32_t bsz_tx_rd = app.burst_size_io_tx_read;
    uint32_t bsz_tx_wr = app.burst_size_io_tx_write;

    uint8_t pos_lb = app.pos_lb;

    for ( ; ; ) {
        if (APP_LCORE_IO_FLUSH && (unlikely(i == APP_LCORE_IO_FLUSH))) {
            if (likely(lp->rx.n_nic_queues > 0)) {
                app_lcore_io_rx_flush(lp, n_workers);
            }

            if (likely(lp->tx.n_nic_ports > 0)) {
                app_lcore_io_tx_flush(lp);
            }

            i = 0;
        }

        if (likely(lp->rx.n_nic_queues > 0)) {
            app_lcore_io_rx(lp, n_workers, bsz_rx_rd, bsz_rx_wr, pos_lb);
        }

        if (likely(lp->tx.n_nic_ports > 0)) {
            app_lcore_io_tx(lp, n_workers, bsz_tx_rd, bsz_tx_wr);
        }

        i ++;
    }
}

static inline void
app_lcore_worker(
    struct app_lcore_params_worker *lp,
    uint32_t bsz_rd,
    uint32_t bsz_wr)
{
    uint32_t i;

    for (i = 0; i < lp->n_rings_in; i ++) {
        struct rte_ring *ring_in = lp->rings_in[i];
        uint32_t j;
        int ret;

        ret = rte_ring_sc_dequeue_bulk(
            ring_in,
            (void **) lp->mbuf_in.array,
            bsz_rd,
            NULL);

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

#if APP_WORKER_DROP_ALL_PACKETS
        for (j = 0; j < bsz_rd; j ++) {
            struct rte_mbuf *pkt = lp->mbuf_in.array[j];
            rte_pktmbuf_free(pkt);
        }

        continue;
#endif

        APP_WORKER_PREFETCH1(rte_pktmbuf_mtod(lp->mbuf_in.array[0], unsigned char *));
        APP_WORKER_PREFETCH0(lp->mbuf_in.array[1]);

        for (j = 0; j < bsz_rd; j ++) {
            struct rte_mbuf *pkt;
            struct rte_ipv4_hdr *ipv4_hdr;
            uint32_t ipv4_dst, pos;
            uint32_t port;

            if (likely(j < bsz_rd - 1)) {
                APP_WORKER_PREFETCH1(rte_pktmbuf_mtod(lp->mbuf_in.array[j+1], unsigned char *));
            }
            if (likely(j < bsz_rd - 2)) {
                APP_WORKER_PREFETCH0(lp->mbuf_in.array[j+2]);
            }

            pkt = lp->mbuf_in.array[j];
            ipv4_hdr = rte_pktmbuf_mtod_offset(
                pkt, struct rte_ipv4_hdr *,
                sizeof(struct rte_ether_hdr));
            ipv4_dst = rte_be_to_cpu_32(ipv4_hdr->dst_addr);

            if (unlikely(rte_lpm_lookup(lp->lpm_table, ipv4_dst, &port) != 0)) {
                port = pkt->port;
            }

            pos = lp->mbuf_out[port].n_mbufs;

            lp->mbuf_out[port].array[pos ++] = pkt;
            if (likely(pos < bsz_wr)) {
                lp->mbuf_out[port].n_mbufs = pos;
                continue;
            }

            ret = rte_ring_sp_enqueue_bulk(
                lp->rings_out[port],
                (void **) lp->mbuf_out[port].array,
                bsz_wr,
                NULL);

#if APP_STATS
            lp->rings_out_iters[port] ++;
            if (ret > 0) {
                lp->rings_out_count[port] += 1;
            }
            if (lp->rings_out_iters[port] == APP_STATS){
                printf("\t\tWorker %u out (NIC port %u): enq success rate = %.2f\n",
                    (unsigned) lp->worker_id,
                    port,
                    ((double) lp->rings_out_count[port]) / ((double) lp->rings_out_iters[port]));
                lp->rings_out_iters[port] = 0;
                lp->rings_out_count[port] = 0;
            }
#endif

            if (unlikely(ret == 0)) {
                uint32_t k;
                for (k = 0; k < bsz_wr; k ++) {
                    struct rte_mbuf *pkt_to_free = lp->mbuf_out[port].array[k];
                    rte_pktmbuf_free(pkt_to_free);
                }
            }

            lp->mbuf_out[port].n_mbufs = 0;
            lp->mbuf_out_flush[port] = 0;
        }
    }
}

static inline void
app_lcore_worker_flush(struct app_lcore_params_worker *lp)
{
    uint32_t port;

    for (port = 0; port < APP_MAX_NIC_PORTS; port ++) {
        int ret;

        if (unlikely(lp->rings_out[port] == NULL)) {
            continue;
        }

        if (likely((lp->mbuf_out_flush[port] == 0) ||
                   (lp->mbuf_out[port].n_mbufs == 0))) {
            lp->mbuf_out_flush[port] = 1;
            continue;
        }

        ret = rte_ring_sp_enqueue_bulk(
            lp->rings_out[port],
            (void **) lp->mbuf_out[port].array,
            lp->mbuf_out[port].n_mbufs,
            NULL);

        if (unlikely(ret == 0)) {
            uint32_t k;
            for (k = 0; k < lp->mbuf_out[port].n_mbufs; k ++) {
                struct rte_mbuf *pkt_to_free = lp->mbuf_out[port].array[k];
                rte_pktmbuf_free(pkt_to_free);
            }
        }

        lp->mbuf_out[port].n_mbufs = 0;
        lp->mbuf_out_flush[port] = 1;
    }
}

static void
app_lcore_main_loop_worker(void) {
    uint32_t lcore = rte_lcore_id();
    struct app_lcore_params_worker *lp = &app.lcore_params[lcore].worker;
    uint64_t i = 0;

    uint32_t bsz_rd = app.burst_size_worker_read;
    uint32_t bsz_wr = app.burst_size_worker_write;

    for ( ; ; ) {
        if (APP_LCORE_WORKER_FLUSH && (unlikely(i == APP_LCORE_WORKER_FLUSH))) {
            app_lcore_worker_flush(lp);
            i = 0;
        }

        app_lcore_worker(lp, bsz_rd, bsz_wr);

        i ++;
    }
}

int
app_lcore_main_loop(__attribute__((unused)) void *arg)
{
    struct app_lcore_params *lp;
    unsigned lcore;

    lcore = rte_lcore_id();
    lp = &app.lcore_params[lcore];

    if (lp->type == e_APP_LCORE_IO) {
        printf("Logical core %u (I/O) main loop.\n", lcore);
        app_lcore_main_loop_io();
    }

    if (lp->type == e_APP_LCORE_WORKER) {
        printf("Logical core %u (worker %u) main loop.\n",
            lcore,
            (unsigned) lp->worker.worker_id);
        app_lcore_main_loop_worker();
    }

    return 0;
}