sw-clock.c 3.2 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149
  1. // SPDX-License-Identifier: GPL-2.0
  2. #include <errno.h>
  3. #include <inttypes.h>
  4. #include <unistd.h>
  5. #include <stdlib.h>
  6. #include <signal.h>
  7. #include <sys/mman.h>
  8. #include <linux/string.h>
  9. #include "tests.h"
  10. #include "util/debug.h"
  11. #include "util/evsel.h"
  12. #include "util/evlist.h"
  13. #include "util/cpumap.h"
  14. #include "util/mmap.h"
  15. #include "util/thread_map.h"
  16. #include <perf/evlist.h>
  17. #include <perf/mmap.h>
  18. #define NR_LOOPS 10000000
  19. /*
  20. * This test will open software clock events (cpu-clock, task-clock)
  21. * then check their frequency -> period conversion has no artifact of
  22. * setting period to 1 forcefully.
  23. */
  24. static int __test__sw_clock_freq(enum perf_sw_ids clock_id)
  25. {
  26. int i, err = -1;
  27. volatile int tmp = 0;
  28. u64 total_periods = 0;
  29. int nr_samples = 0;
  30. char sbuf[STRERR_BUFSIZE];
  31. union perf_event *event;
  32. struct evsel *evsel;
  33. struct evlist *evlist;
  34. struct perf_event_attr attr = {
  35. .type = PERF_TYPE_SOFTWARE,
  36. .config = clock_id,
  37. .sample_type = PERF_SAMPLE_PERIOD,
  38. .exclude_kernel = 1,
  39. .disabled = 1,
  40. .freq = 1,
  41. };
  42. struct perf_cpu_map *cpus;
  43. struct perf_thread_map *threads;
  44. struct mmap *md;
  45. attr.sample_freq = 500;
  46. evlist = evlist__new();
  47. if (evlist == NULL) {
  48. pr_debug("evlist__new\n");
  49. return -1;
  50. }
  51. evsel = evsel__new(&attr);
  52. if (evsel == NULL) {
  53. pr_debug("evsel__new\n");
  54. goto out_delete_evlist;
  55. }
  56. evlist__add(evlist, evsel);
  57. cpus = perf_cpu_map__dummy_new();
  58. threads = thread_map__new_by_tid(getpid());
  59. if (!cpus || !threads) {
  60. err = -ENOMEM;
  61. pr_debug("Not enough memory to create thread/cpu maps\n");
  62. goto out_free_maps;
  63. }
  64. perf_evlist__set_maps(&evlist->core, cpus, threads);
  65. cpus = NULL;
  66. threads = NULL;
  67. if (evlist__open(evlist)) {
  68. const char *knob = "/proc/sys/kernel/perf_event_max_sample_rate";
  69. err = -errno;
  70. pr_debug("Couldn't open evlist: %s\nHint: check %s, using %" PRIu64 " in this test.\n",
  71. str_error_r(errno, sbuf, sizeof(sbuf)),
  72. knob, (u64)attr.sample_freq);
  73. goto out_delete_evlist;
  74. }
  75. err = evlist__mmap(evlist, 128);
  76. if (err < 0) {
  77. pr_debug("failed to mmap event: %d (%s)\n", errno,
  78. str_error_r(errno, sbuf, sizeof(sbuf)));
  79. goto out_delete_evlist;
  80. }
  81. evlist__enable(evlist);
  82. /* collect samples */
  83. for (i = 0; i < NR_LOOPS; i++)
  84. tmp++;
  85. evlist__disable(evlist);
  86. md = &evlist->mmap[0];
  87. if (perf_mmap__read_init(&md->core) < 0)
  88. goto out_init;
  89. while ((event = perf_mmap__read_event(&md->core)) != NULL) {
  90. struct perf_sample sample;
  91. if (event->header.type != PERF_RECORD_SAMPLE)
  92. goto next_event;
  93. err = perf_evlist__parse_sample(evlist, event, &sample);
  94. if (err < 0) {
  95. pr_debug("Error during parse sample\n");
  96. goto out_delete_evlist;
  97. }
  98. total_periods += sample.period;
  99. nr_samples++;
  100. next_event:
  101. perf_mmap__consume(&md->core);
  102. }
  103. perf_mmap__read_done(&md->core);
  104. out_init:
  105. if ((u64) nr_samples == total_periods) {
  106. pr_debug("All (%d) samples have period value of 1!\n",
  107. nr_samples);
  108. err = -1;
  109. }
  110. out_free_maps:
  111. perf_cpu_map__put(cpus);
  112. perf_thread_map__put(threads);
  113. out_delete_evlist:
  114. evlist__delete(evlist);
  115. return err;
  116. }
  117. int test__sw_clock_freq(struct test *test __maybe_unused, int subtest __maybe_unused)
  118. {
  119. int ret;
  120. ret = __test__sw_clock_freq(PERF_COUNT_SW_CPU_CLOCK);
  121. if (!ret)
  122. ret = __test__sw_clock_freq(PERF_COUNT_SW_TASK_CLOCK);
  123. return ret;
  124. }