perf/tests/perf-time-to-tsc.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 #include <errno.h>
0003 #include <inttypes.h>
0004 #include <limits.h>
0005 #include <stdbool.h>
0006 #include <stdio.h>
0007 #include <unistd.h>
0008 #include <linux/types.h>
0009 #include <sys/prctl.h>
0010 #include <perf/cpumap.h>
0011 #include <perf/evlist.h>
0012 #include <perf/mmap.h>
0013
0014 #include "debug.h"
0015 #include "parse-events.h"
0016 #include "evlist.h"
0017 #include "evsel.h"
0018 #include "thread_map.h"
0019 #include "record.h"
0020 #include "tsc.h"
0021 #include "mmap.h"
0022 #include "tests.h"
0023
0024 /*
0025  * Except x86_64/i386 and Arm64, other archs don't support TSC in perf.  Just
0026  * enable the test for x86_64/i386 and Arm64 archs.
0027  */
0028 #if defined(__x86_64__) || defined(__i386__) || defined(__aarch64__)
0029 #define TSC_IS_SUPPORTED 1
0030 #else
0031 #define TSC_IS_SUPPORTED 0
0032 #endif
0033
0034 #define CHECK__(x) {                \
0035     while ((x) < 0) {           \
0036         pr_debug(#x " failed!\n");  \
0037         goto out_err;           \
0038     }                   \
0039 }
0040
0041 #define CHECK_NOT_NULL__(x) {           \
0042     while ((x) == NULL) {           \
0043         pr_debug(#x " failed!\n");  \
0044         goto out_err;           \
0045     }                   \
0046 }
0047
0048 static int test__tsc_is_supported(struct test_suite *test __maybe_unused,
0049                   int subtest __maybe_unused)
0050 {
0051     if (!TSC_IS_SUPPORTED) {
0052         pr_debug("Test not supported on this architecture\n");
0053         return TEST_SKIP;
0054     }
0055
0056     return TEST_OK;
0057 }
0058
0059 /**
0060  * test__perf_time_to_tsc - test converting perf time to TSC.
0061  *
0062  * This function implements a test that checks that the conversion of perf time
0063  * to and from TSC is consistent with the order of events.  If the test passes
0064  * %0 is returned, otherwise %-1 is returned.  If TSC conversion is not
0065  * supported then the test passes but " (not supported)" is printed.
0066  */
0067 static int test__perf_time_to_tsc(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
0068 {
0069     struct record_opts opts = {
0070         .mmap_pages      = UINT_MAX,
0071         .user_freq       = UINT_MAX,
0072         .user_interval       = ULLONG_MAX,
0073         .target          = {
0074             .uses_mmap   = true,
0075         },
0076         .sample_time         = true,
0077     };
0078     struct perf_thread_map *threads = NULL;
0079     struct perf_cpu_map *cpus = NULL;
0080     struct evlist *evlist = NULL;
0081     struct evsel *evsel = NULL;
0082     int err = TEST_FAIL, ret, i;
0083     const char *comm1, *comm2;
0084     struct perf_tsc_conversion tc;
0085     struct perf_event_mmap_page *pc;
0086     union perf_event *event;
0087     u64 test_tsc, comm1_tsc, comm2_tsc;
0088     u64 test_time, comm1_time = 0, comm2_time = 0;
0089     struct mmap *md;
0090
0091
0092     threads = thread_map__new(-1, getpid(), UINT_MAX);
0093     CHECK_NOT_NULL__(threads);
0094
0095     cpus = perf_cpu_map__new(NULL);
0096     CHECK_NOT_NULL__(cpus);
0097
0098     evlist = evlist__new();
0099     CHECK_NOT_NULL__(evlist);
0100
0101     perf_evlist__set_maps(&evlist->core, cpus, threads);
0102
0103     CHECK__(parse_event(evlist, "cycles:u"));
0104
0105     evlist__config(evlist, &opts, NULL);
0106
0107     /* For hybrid "cycles:u", it creates two events */
0108     evlist__for_each_entry(evlist, evsel) {
0109         evsel->core.attr.comm = 1;
0110         evsel->core.attr.disabled = 1;
0111         evsel->core.attr.enable_on_exec = 0;
0112     }
0113
0114     ret = evlist__open(evlist);
0115     if (ret < 0) {
0116         if (ret == -ENOENT)
0117             err = TEST_SKIP;
0118         else
0119             pr_debug("evlist__open() failed\n");
0120         goto out_err;
0121     }
0122
0123     CHECK__(evlist__mmap(evlist, UINT_MAX));
0124
0125     pc = evlist->mmap[0].core.base;
0126     ret = perf_read_tsc_conversion(pc, &tc);
0127     if (ret) {
0128         if (ret == -EOPNOTSUPP) {
0129             pr_debug("perf_read_tsc_conversion is not supported in current kernel\n");
0130             err = TEST_SKIP;
0131         }
0132         goto out_err;
0133     }
0134
0135     evlist__enable(evlist);
0136
0137     comm1 = "Test COMM 1";
0138     CHECK__(prctl(PR_SET_NAME, (unsigned long)comm1, 0, 0, 0));
0139
0140     test_tsc = rdtsc();
0141
0142     comm2 = "Test COMM 2";
0143     CHECK__(prctl(PR_SET_NAME, (unsigned long)comm2, 0, 0, 0));
0144
0145     evlist__disable(evlist);
0146
0147     for (i = 0; i < evlist->core.nr_mmaps; i++) {
0148         md = &evlist->mmap[i];
0149         if (perf_mmap__read_init(&md->core) < 0)
0150             continue;
0151
0152         while ((event = perf_mmap__read_event(&md->core)) != NULL) {
0153             struct perf_sample sample;
0154
0155             if (event->header.type != PERF_RECORD_COMM ||
0156                 (pid_t)event->comm.pid != getpid() ||
0157                 (pid_t)event->comm.tid != getpid())
0158                 goto next_event;
0159
0160             if (strcmp(event->comm.comm, comm1) == 0) {
0161                 CHECK_NOT_NULL__(evsel = evlist__event2evsel(evlist, event));
0162                 CHECK__(evsel__parse_sample(evsel, event, &sample));
0163                 comm1_time = sample.time;
0164             }
0165             if (strcmp(event->comm.comm, comm2) == 0) {
0166                 CHECK_NOT_NULL__(evsel = evlist__event2evsel(evlist, event));
0167                 CHECK__(evsel__parse_sample(evsel, event, &sample));
0168                 comm2_time = sample.time;
0169             }
0170 next_event:
0171             perf_mmap__consume(&md->core);
0172         }
0173         perf_mmap__read_done(&md->core);
0174     }
0175
0176     if (!comm1_time || !comm2_time)
0177         goto out_err;
0178
0179     test_time = tsc_to_perf_time(test_tsc, &tc);
0180     comm1_tsc = perf_time_to_tsc(comm1_time, &tc);
0181     comm2_tsc = perf_time_to_tsc(comm2_time, &tc);
0182
0183     pr_debug("1st event perf time %"PRIu64" tsc %"PRIu64"\n",
0184          comm1_time, comm1_tsc);
0185     pr_debug("rdtsc          time %"PRIu64" tsc %"PRIu64"\n",
0186          test_time, test_tsc);
0187     pr_debug("2nd event perf time %"PRIu64" tsc %"PRIu64"\n",
0188          comm2_time, comm2_tsc);
0189
0190     if (test_time <= comm1_time ||
0191         test_time >= comm2_time)
0192         goto out_err;
0193
0194     if (test_tsc <= comm1_tsc ||
0195         test_tsc >= comm2_tsc)
0196         goto out_err;
0197
0198     err = TEST_OK;
0199
0200 out_err:
0201     evlist__delete(evlist);
0202     perf_cpu_map__put(cpus);
0203     perf_thread_map__put(threads);
0204     return err;
0205 }
0206
0207 static struct test_case time_to_tsc_tests[] = {
0208     TEST_CASE_REASON("TSC support", tsc_is_supported,
0209              "This architecture does not support"),
0210     TEST_CASE_REASON("Perf time to TSC", perf_time_to_tsc,
0211              "perf_read_tsc_conversion is not supported"),
0212     { .name = NULL, }
0213 };
0214
0215 struct test_suite suite__perf_time_to_tsc = {
0216     .desc = "Convert perf time to TSC",
0217     .test_cases = time_to_tsc_tests,
0218 };