perf-time-to-tsc.c

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// SPDX-License-Identifier: GPL-2.0
#include <errno.h>
#include <inttypes.h>
#include <stdio.h>
#include <unistd.h>
#include <linux/types.h>
#include <sys/prctl.h>

#include "parse-events.h"
#include "evlist.h"
#include "evsel.h"
#include "thread_map.h"
#include "cpumap.h"
#include "tsc.h"
#include "tests/tests.h"

#include "arch-tests.h"

#define CHECK__(x) {                \
    while ((x) < 0) {           \
        pr_debug(#x " failed!\n");  \
        goto out_err;           \
    }                   \
}

#define CHECK_NOT_NULL__(x) {           \
    while ((x) == NULL) {           \
        pr_debug(#x " failed!\n");  \
        goto out_err;           \
    }                   \
}

int test__perf_time_to_tsc(struct test *test __maybe_unused, int subtest __maybe_unused)
{
    struct record_opts opts = {
        .mmap_pages      = UINT_MAX,
        .user_freq       = UINT_MAX,
        .user_interval       = ULLONG_MAX,
        .target          = {
            .uses_mmap   = true,
        },
        .sample_time         = true,
    };
    struct thread_map *threads = NULL;
    struct cpu_map *cpus = NULL;
    struct perf_evlist *evlist = NULL;
    struct perf_evsel *evsel = NULL;
    int err = -1, ret, i;
    const char *comm1, *comm2;
    struct perf_tsc_conversion tc;
    struct perf_event_mmap_page *pc;
    union perf_event *event;
    u64 test_tsc, comm1_tsc, comm2_tsc;
    u64 test_time, comm1_time = 0, comm2_time = 0;
    struct perf_mmap *md;

    threads = thread_map__new(-1, getpid(), UINT_MAX);
    CHECK_NOT_NULL__(threads);

    cpus = cpu_map__new(NULL);
    CHECK_NOT_NULL__(cpus);

    evlist = perf_evlist__new();
    CHECK_NOT_NULL__(evlist);

    perf_evlist__set_maps(evlist, cpus, threads);

    CHECK__(parse_events(evlist, "cycles:u", NULL));

    perf_evlist__config(evlist, &opts, NULL);

    evsel = perf_evlist__first(evlist);

    evsel->attr.comm = 1;
    evsel->attr.disabled = 1;
    evsel->attr.enable_on_exec = 0;

    CHECK__(perf_evlist__open(evlist));

    CHECK__(perf_evlist__mmap(evlist, UINT_MAX));

    pc = evlist->mmap[0].base;
    ret = perf_read_tsc_conversion(pc, &tc);
    if (ret) {
        if (ret == -EOPNOTSUPP) {
            fprintf(stderr, " (not supported)");
            return 0;
        }
        goto out_err;
    }

    perf_evlist__enable(evlist);

    comm1 = "Test COMM 1";
    CHECK__(prctl(PR_SET_NAME, (unsigned long)comm1, 0, 0, 0));

    test_tsc = rdtsc();

    comm2 = "Test COMM 2";
    CHECK__(prctl(PR_SET_NAME, (unsigned long)comm2, 0, 0, 0));

    perf_evlist__disable(evlist);

    for (i = 0; i < evlist->nr_mmaps; i++) {
        md = &evlist->mmap[i];
        if (perf_mmap__read_init(md) < 0)
            continue;

        while ((event = perf_mmap__read_event(md)) != NULL) {
            struct perf_sample sample;

            if (event->header.type != PERF_RECORD_COMM ||
                (pid_t)event->comm.pid != getpid() ||
                (pid_t)event->comm.tid != getpid())
                goto next_event;

            if (strcmp(event->comm.comm, comm1) == 0) {
                CHECK__(perf_evsel__parse_sample(evsel, event,
                                 &sample));
                comm1_time = sample.time;
            }
            if (strcmp(event->comm.comm, comm2) == 0) {
                CHECK__(perf_evsel__parse_sample(evsel, event,
                                 &sample));
                comm2_time = sample.time;
            }
next_event:
            perf_mmap__consume(md);
        }
        perf_mmap__read_done(md);
    }

    if (!comm1_time || !comm2_time)
        goto out_err;

    test_time = tsc_to_perf_time(test_tsc, &tc);
    comm1_tsc = perf_time_to_tsc(comm1_time, &tc);
    comm2_tsc = perf_time_to_tsc(comm2_time, &tc);

    pr_debug("1st event perf time %"PRIu64" tsc %"PRIu64"\n",
         comm1_time, comm1_tsc);
    pr_debug("rdtsc          time %"PRIu64" tsc %"PRIu64"\n",
         test_time, test_tsc);
    pr_debug("2nd event perf time %"PRIu64" tsc %"PRIu64"\n",
         comm2_time, comm2_tsc);

    if (test_time <= comm1_time ||
        test_time >= comm2_time)
        goto out_err;

    if (test_tsc <= comm1_tsc ||
        test_tsc >= comm2_tsc)
        goto out_err;

    err = 0;

out_err:
    perf_evlist__delete(evlist);
    return err;
}