topology.c

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// SPDX-License-Identifier: GPL-2.0
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include "tests.h"
#include "util.h"
#include "session.h"
#include "evlist.h"
#include "debug.h"

#define TEMPL "/tmp/perf-test-XXXXXX"
#define DATA_SIZE   10

static int get_temp(char *path)
{
    int fd;

    strcpy(path, TEMPL);

    fd = mkstemp(path);
    if (fd < 0) {
        perror("mkstemp failed");
        return -1;
    }

    close(fd);
    return 0;
}

static int session_write_header(char *path)
{
    struct perf_session *session;
    struct perf_data data = {
        .file      = {
            .path = path,
        },
        .mode      = PERF_DATA_MODE_WRITE,
    };

    session = perf_session__new(&data, false, NULL);
    TEST_ASSERT_VAL("can't get session", session);

    session->evlist = perf_evlist__new_default();
    TEST_ASSERT_VAL("can't get evlist", session->evlist);

    perf_header__set_feat(&session->header, HEADER_CPU_TOPOLOGY);
    perf_header__set_feat(&session->header, HEADER_NRCPUS);

    session->header.data_size += DATA_SIZE;

    TEST_ASSERT_VAL("failed to write header",
            !perf_session__write_header(session, session->evlist, data.file.fd, true));

    perf_session__delete(session);

    return 0;
}

static int check_cpu_topology(char *path, struct cpu_map *map)
{
    struct perf_session *session;
    struct perf_data data = {
        .file      = {
            .path = path,
        },
        .mode      = PERF_DATA_MODE_READ,
    };
    int i;

    session = perf_session__new(&data, false, NULL);
    TEST_ASSERT_VAL("can't get session", session);

    /* On platforms with large numbers of CPUs process_cpu_topology()
     * might issue an error while reading the perf.data file section
     * HEADER_CPU_TOPOLOGY and the cpu_topology_map pointed to by member
     * cpu is a NULL pointer.
     * Example: On s390
     *   CPU 0 is on core_id 0 and physical_package_id 6
     *   CPU 1 is on core_id 1 and physical_package_id 3
     *
     *   Core_id and physical_package_id are platform and architecture
     *   dependend and might have higher numbers than the CPU id.
     *   This actually depends on the configuration.
     *
     *  In this case process_cpu_topology() prints error message:
     *  "socket_id number is too big. You may need to upgrade the
     *  perf tool."
     *
     *  This is the reason why this test might be skipped.
     */
    if (!session->header.env.cpu)
        return TEST_SKIP;

    for (i = 0; i < session->header.env.nr_cpus_avail; i++) {
        if (!cpu_map__has(map, i))
            continue;
        pr_debug("CPU %d, core %d, socket %d\n", i,
             session->header.env.cpu[i].core_id,
             session->header.env.cpu[i].socket_id);
    }

    for (i = 0; i < map->nr; i++) {
        TEST_ASSERT_VAL("Core ID doesn't match",
            (session->header.env.cpu[map->map[i]].core_id == (cpu_map__get_core(map, i, NULL) & 0xffff)));

        TEST_ASSERT_VAL("Socket ID doesn't match",
            (session->header.env.cpu[map->map[i]].socket_id == cpu_map__get_socket(map, i, NULL)));
    }

    perf_session__delete(session);

    return 0;
}

int test__session_topology(struct test *test __maybe_unused, int subtest __maybe_unused)
{
    char path[PATH_MAX];
    struct cpu_map *map;
    int ret = TEST_FAIL;

    TEST_ASSERT_VAL("can't get templ file", !get_temp(path));

    pr_debug("templ file: %s\n", path);

    if (session_write_header(path))
        goto free_path;

    map = cpu_map__new(NULL);
    if (map == NULL) {
        pr_debug("failed to get system cpumap\n");
        goto free_path;
    }

    ret = check_cpu_topology(path, map);
    cpu_map__put(map);

free_path:
    unlink(path);
    return ret;
}