root/tools/perf/tests/event-times.c
// SPDX-License-Identifier: GPL-2.0
#include <linux/compiler.h>
#include <linux/string.h>
#include <errno.h>
#include <inttypes.h>
#include <string.h>
#include <sys/wait.h>
#include <perf/cpumap.h>
#include "tests.h"
#include "evlist.h"
#include "evsel.h"
#include "debug.h"
#include "parse-events.h"
#include "thread_map.h"
#include "target.h"

static int attach__enable_on_exec(struct evlist *evlist)
{
        struct evsel *evsel = evlist__last(evlist);
        struct target target = {};
        const char *argv[] = { "true", NULL, };
        char sbuf[STRERR_BUFSIZE];
        int err;

        pr_debug("attaching to spawned child, enable on exec\n");

        err = evlist__create_maps(evlist, &target);
        if (err < 0) {
                pr_debug("Not enough memory to create thread/cpu maps\n");
                return err;
        }

        err = evlist__prepare_workload(evlist, &target, argv, false, NULL);
        if (err < 0) {
                pr_debug("Couldn't run the workload!\n");
                return err;
        }

        evsel->core.attr.enable_on_exec = 1;

        err = evlist__open(evlist);
        if (err < 0) {
                pr_debug("perf_evlist__open: %s\n",
                         str_error_r(errno, sbuf, sizeof(sbuf)));
                return err;
        }

        return evlist__start_workload(evlist) == 1 ? TEST_OK : TEST_FAIL;
}

static int detach__enable_on_exec(struct evlist *evlist)
{
        waitpid(evlist->workload.pid, NULL, 0);
        return 0;
}

static int attach__current_disabled(struct evlist *evlist)
{
        struct evsel *evsel = evlist__last(evlist);
        struct perf_thread_map *threads;
        int err;

        pr_debug("attaching to current thread as disabled\n");

        threads = thread_map__new_by_tid(getpid());
        if (threads == NULL) {
                pr_debug("thread_map__new\n");
                return -1;
        }

        evsel->core.attr.disabled = 1;

        err = evsel__open_per_thread(evsel, threads);
        if (err) {
                pr_debug("Failed to open event cpu-clock:u\n");
                return err;
        }

        perf_thread_map__put(threads);
        return evsel__enable(evsel) == 0 ? TEST_OK : TEST_FAIL;
}

static int attach__current_enabled(struct evlist *evlist)
{
        struct evsel *evsel = evlist__last(evlist);
        struct perf_thread_map *threads;
        int err;

        pr_debug("attaching to current thread as enabled\n");

        threads = thread_map__new_by_tid(getpid());
        if (threads == NULL) {
                pr_debug("failed to call thread_map__new\n");
                return -1;
        }

        err = evsel__open_per_thread(evsel, threads);

        perf_thread_map__put(threads);
        return err == 0 ? TEST_OK : TEST_FAIL;
}

static int detach__disable(struct evlist *evlist)
{
        struct evsel *evsel = evlist__last(evlist);

        return evsel__enable(evsel);
}

static int attach__cpu_disabled(struct evlist *evlist)
{
        struct evsel *evsel = evlist__last(evlist);
        struct perf_cpu_map *cpus;
        int err;

        pr_debug("attaching to CPU 0 as enabled\n");

        cpus = perf_cpu_map__new("0");
        if (cpus == NULL) {
                pr_debug("failed to call perf_cpu_map__new\n");
                return -1;
        }

        evsel->core.attr.disabled = 1;

        err = evsel__open_per_cpu(evsel, cpus, -1);
        perf_cpu_map__put(cpus);
        if (err) {
                if (err == -EACCES)
                        return TEST_SKIP;

                pr_debug("Failed to open event cpu-clock:u\n");
                return err;
        }

        return evsel__enable(evsel);
}

static int attach__cpu_enabled(struct evlist *evlist)
{
        struct evsel *evsel = evlist__last(evlist);
        struct perf_cpu_map *cpus;
        int err;

        pr_debug("attaching to CPU 0 as enabled\n");

        cpus = perf_cpu_map__new("0");
        if (cpus == NULL) {
                pr_debug("failed to call perf_cpu_map__new\n");
                return -1;
        }

        err = evsel__open_per_cpu(evsel, cpus, -1);
        perf_cpu_map__put(cpus);
        if (err == -EACCES)
                return TEST_SKIP;

        return err ? TEST_FAIL : TEST_OK;
}

static int test_times(int (attach)(struct evlist *),
                      int (detach)(struct evlist *))
{
        struct perf_counts_values count;
        struct evlist *evlist = NULL;
        struct evsel *evsel;
        int err = -1, i;

        evlist = evlist__new();
        if (!evlist) {
                pr_debug("failed to create event list\n");
                goto out_err;
        }

        err = parse_event(evlist, "cpu-clock:u");
        if (err) {
                pr_debug("failed to parse event cpu-clock:u\n");
                goto out_err;
        }

        evsel = evlist__last(evlist);
        evsel->core.attr.read_format |=
                PERF_FORMAT_TOTAL_TIME_ENABLED |
                PERF_FORMAT_TOTAL_TIME_RUNNING;

        err = attach(evlist);
        if (err == TEST_SKIP) {
                pr_debug("  SKIP  : not enough rights\n");
                evlist__delete(evlist);
                return err;
        }

        TEST_ASSERT_VAL("failed to attach", !err);

        for (i = 0; i < 100000000; i++) { }

        TEST_ASSERT_VAL("failed to detach", !detach(evlist));

        perf_evsel__read(&evsel->core, 0, 0, &count);

        err = !(count.ena == count.run);

        pr_debug("  %s: ena %" PRIu64", run %" PRIu64"\n",
                 !err ? "OK    " : "FAILED",
                 count.ena, count.run);

out_err:
        evlist__delete(evlist);
        return !err ? TEST_OK : TEST_FAIL;
}

/*
 * This test creates software event 'cpu-clock'
 * attaches it in several ways (explained below)
 * and checks that enabled and running times
 * match.
 */
static int test__event_times(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
{
        int err, ret = 0;

#define _T(attach, detach)                      \
        err = test_times(attach, detach);       \
        if (err && (ret == TEST_OK || ret == TEST_SKIP))        \
                ret = err;

        /* attach on newly spawned process after exec */
        _T(attach__enable_on_exec,   detach__enable_on_exec)
        /* attach on current process as enabled */
        _T(attach__current_enabled,  detach__disable)
        /* attach on current process as disabled */
        _T(attach__current_disabled, detach__disable)
        /* attach on cpu as disabled */
        _T(attach__cpu_disabled,     detach__disable)
        /* attach on cpu as enabled */
        _T(attach__cpu_enabled,      detach__disable)

#undef _T
        return ret;
}

DEFINE_SUITE("Event times", event_times);