examples/service_cores/main.c

/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright(c) 2017 Intel Corporation
 */

#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <stdint.h>
#include <errno.h>
#include <sys/queue.h>

#include <rte_memory.h>
#include <rte_launch.h>
#include <rte_eal.h>
#include <rte_debug.h>
#include <rte_cycles.h>

/* allow application scheduling of the services */
#include <rte_service.h>

/* Allow application registration of its own services. An application does not
 * have to register services, but it can be useful if it wishes to run a
 * function on a core that is otherwise in use as a service core. In this
 * example, all services are dummy services registered by the sample app itself.
 */
#include <rte_service_component.h>

#define PROFILE_CORES_MAX 8
#define PROFILE_SERVICE_PER_CORE 5

/* dummy function to do "work" */
static int32_t service_func(void *args)
{
    RTE_SET_USED(args);
    rte_delay_us(2000);
    return 0;
}

static struct rte_service_spec services[] = {
    {"service_1", service_func, NULL, 0, 0},
    {"service_2", service_func, NULL, 0, 0},
    {"service_3", service_func, NULL, 0, 0},
    {"service_4", service_func, NULL, 0, 0},
    {"service_5", service_func, NULL, 0, 0},
};
#define NUM_SERVICES RTE_DIM(services)

/* this struct holds the mapping of a particular core to all services */
struct profile_for_core {
    uint32_t mapped_services[PROFILE_SERVICE_PER_CORE];
};

/* struct that can be applied as the service core mapping. Items in this
 * struct will be passed to the ordinary rte_service_* APIs to configure the
 * service cores at runtime, based on the requirements.
 *
 * These profiles can be considered a "configuration" for the service cores,
 * where switching profile just changes the number of cores and the mappings
 * for each of them. As a result, the core requirements and performance of the
 * application scales.
 */
struct profile {
    char name[64];
    uint32_t num_cores;
    struct profile_for_core cores[PROFILE_CORES_MAX];
};

static struct profile profiles[] = {
    /* profile 0: high performance */
    {
        .name = "High Performance",
        .num_cores = 5,
        .cores[0] = {.mapped_services = {1, 0, 0, 0, 0} },
        .cores[1] = {.mapped_services = {0, 1, 0, 0, 0} },
        .cores[2] = {.mapped_services = {0, 0, 1, 0, 0} },
        .cores[3] = {.mapped_services = {0, 0, 0, 1, 0} },
        .cores[4] = {.mapped_services = {0, 0, 0, 0, 1} },
    },
    /* profile 1: mid performance with single service priority */
    {
        .name = "Mid-High Performance",
        .num_cores = 3,
        .cores[0] = {.mapped_services = {1, 1, 0, 0, 0} },
        .cores[1] = {.mapped_services = {0, 0, 1, 1, 0} },
        .cores[2] = {.mapped_services = {0, 0, 0, 0, 1} },
        .cores[3] = {.mapped_services = {0, 0, 0, 0, 0} },
        .cores[4] = {.mapped_services = {0, 0, 0, 0, 0} },
    },
    /* profile 2: mid performance with single service priority */
    {
        .name = "Mid-Low Performance",
        .num_cores = 2,
        .cores[0] = {.mapped_services = {1, 1, 1, 0, 0} },
        .cores[1] = {.mapped_services = {1, 1, 0, 1, 1} },
        .cores[2] = {.mapped_services = {0, 0, 0, 0, 0} },
        .cores[3] = {.mapped_services = {0, 0, 0, 0, 0} },
        .cores[4] = {.mapped_services = {0, 0, 0, 0, 0} },
    },
    /* profile 3: scale down performance on single core */
    {
        .name = "Scale down performance",
        .num_cores = 1,
        .cores[0] = {.mapped_services = {1, 1, 1, 1, 1} },
        .cores[1] = {.mapped_services = {0, 0, 0, 0, 0} },
        .cores[2] = {.mapped_services = {0, 0, 0, 0, 0} },
        .cores[3] = {.mapped_services = {0, 0, 0, 0, 0} },
        .cores[4] = {.mapped_services = {0, 0, 0, 0, 0} },
    },
};
#define NUM_PROFILES RTE_DIM(profiles)

static void
apply_profile(int profile_id)
{
    uint32_t i;
    uint32_t s;
    int ret;
    struct profile *p = &profiles[profile_id];
    const uint8_t core_off = 1;

    if (p->num_cores > rte_lcore_count() - 1) {
        printf("insufficent cores to run (%s)",
            p->name);
        return;
    }

    for (i = 0; i < p->num_cores; i++) {
        uint32_t core = i + core_off;
        ret = rte_service_lcore_add(core);
        if (ret && ret != -EALREADY)
            printf("core %d added ret %d\n", core, ret);

        ret = rte_service_lcore_start(core);
        if (ret && ret != -EALREADY)
            printf("core %d start ret %d\n", core, ret);

        for (s = 0; s < NUM_SERVICES; s++) {
            if (rte_service_map_lcore_set(s, core,
                    p->cores[i].mapped_services[s]))
                printf("failed to map lcore %d\n", core);
        }
    }

    for ( ; i < PROFILE_CORES_MAX; i++) {
        uint32_t core = i + core_off;
        for (s = 0; s < NUM_SERVICES; s++) {
            ret = rte_service_map_lcore_set(s, core, 0);
            if (ret && ret != -EINVAL) {
                printf("%s %d: map lcore set = %d\n", __func__,
                        __LINE__, ret);
            }
        }
        ret = rte_service_lcore_stop(core);
        if (ret && ret != -EALREADY) {
            printf("%s %d: lcore stop = %d\n", __func__,
                    __LINE__, ret);
        }
        ret = rte_service_lcore_del(core);
        if (ret && ret != -EINVAL) {
            printf("%s %d: lcore del = %d\n", __func__,
                    __LINE__, ret);
        }
    }
}

int
main(int argc, char **argv)
{
    int ret;

    ret = rte_eal_init(argc, argv);
    if (ret < 0)
        rte_panic("Cannot init EAL\n");

    uint32_t i;
    for (i = 0; i < NUM_SERVICES; i++) {
        services[i].callback_userdata = 0;
        uint32_t id;
        ret = rte_service_component_register(&services[i], &id);
        if (ret)
            rte_exit(-1, "service register() failed");

        /* set the service itself to be ready to run. In the case of
         * ethdev, eventdev etc PMDs, this will be set when the
         * appropriate configure or setup function is called.
         */
        rte_service_component_runstate_set(id, 1);

        /* Collect statistics for the service */
        rte_service_set_stats_enable(id, 1);

        /* the application sets the service to be active. Note that the
         * previous component_runstate_set() is the PMD indicating
         * ready, while this function is the application setting the
         * service to run. Applications can choose to not run a service
         * by setting runstate to 0 at any time.
         */
        ret = rte_service_runstate_set(id, 1);
        if (ret)
            return -ENOEXEC;
    }

    i = 0;
    while (1) {
        const char clr[] = { 27, '[', '2', 'J', '\0' };
        const char topLeft[] = { 27, '[', '1', ';', '1', 'H', '\0' };
        printf("%s%s", clr, topLeft);

        apply_profile(i);
        printf("\n==> Profile: %s\n\n", profiles[i].name);

        sleep(1);
        rte_service_dump(stdout, UINT32_MAX);

        sleep(5);
        rte_service_dump(stdout, UINT32_MAX);

        i++;
        if (i >= NUM_PROFILES)
            i = 0;
    }

    /* clean up the EAL */
    rte_eal_cleanup();

    return 0;
}