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

   1 #include <stdio.h>
   2 #include <unistd.h>
   3 #include <linux/types.h>
   4 #include <sys/prctl.h>
   5
   6 #include "parse-events.h"
   7 #include "evlist.h"
   8 #include "evsel.h"
   9 #include "thread_map.h"
  10 #include "cpumap.h"
  11 #include "tests.h"
  12
  13 #include "../arch/x86/util/tsc.h"
  14
  15 #define CHECK__(x) {                            \
  16         while ((x) < 0) {                       \
  17                 pr_debug(#x " failed!\n");      \
  18                 goto out_err;                   \
  19         }                                       \
  20 }
  21
  22 #define CHECK_NOT_NULL__(x) {                   \
  23         while ((x) == NULL) {                   \
  24                 pr_debug(#x " failed!\n");      \
  25                 goto out_err;                   \
  26         }                                       \
  27 }
  28
  29 static u64 rdtsc(void)
  30 {
  31         unsigned int low, high;
  32
  33         asm volatile("rdtsc" : "=a" (low), "=d" (high));
  34
  35         return low | ((u64)high) << 32;
  36 }
  37
  38 /**
  39  * test__perf_time_to_tsc - test converting perf time to TSC.
  40  *
  41  * This function implements a test that checks that the conversion of perf time
  42  * to and from TSC is consistent with the order of events.  If the test passes
  43  * %0 is returned, otherwise %-1 is returned.  If TSC conversion is not
  44  * supported then then the test passes but " (not supported)" is printed.
  45  */
  46 int test__perf_time_to_tsc(void)
  47 {
  48         struct record_opts opts = {
  49                 .mmap_pages          = UINT_MAX,
  50                 .user_freq           = UINT_MAX,
  51                 .user_interval       = ULLONG_MAX,
  52                 .freq                = 4000,
  53                 .target              = {
  54                         .uses_mmap   = true,
  55                 },
  56                 .sample_time         = true,
  57         };
  58         struct thread_map *threads = NULL;
  59         struct cpu_map *cpus = NULL;
  60         struct perf_evlist *evlist = NULL;
  61         struct perf_evsel *evsel = NULL;
  62         int err = -1, ret, i;
  63         const char *comm1, *comm2;
  64         struct perf_tsc_conversion tc;
  65         struct perf_event_mmap_page *pc;
  66         union perf_event *event;
  67         u64 test_tsc, comm1_tsc, comm2_tsc;
  68         u64 test_time, comm1_time = 0, comm2_time = 0;
  69
  70         threads = thread_map__new(-1, getpid(), UINT_MAX);
  71         CHECK_NOT_NULL__(threads);
  72
  73         cpus = cpu_map__new(NULL);
  74         CHECK_NOT_NULL__(cpus);
  75
  76         evlist = perf_evlist__new();
  77         CHECK_NOT_NULL__(evlist);
  78
  79         perf_evlist__set_maps(evlist, cpus, threads);
  80
  81         CHECK__(parse_events(evlist, "cycles:u"));
  82
  83         perf_evlist__config(evlist, &opts);
  84
  85         evsel = perf_evlist__first(evlist);
  86
  87         evsel->attr.comm = 1;
  88         evsel->attr.disabled = 1;
  89         evsel->attr.enable_on_exec = 0;
  90
  91         CHECK__(perf_evlist__open(evlist));
  92
  93         CHECK__(perf_evlist__mmap(evlist, UINT_MAX, false));
  94
  95         pc = evlist->mmap[0].base;
  96         ret = perf_read_tsc_conversion(pc, &tc);
  97         if (ret) {
  98                 if (ret == -EOPNOTSUPP) {
  99                         fprintf(stderr, " (not supported)");
 100                         return 0;
 101                 }
 102                 goto out_err;
 103         }
 104
 105         perf_evlist__enable(evlist);
 106
 107         comm1 = "Test COMM 1";
 108         CHECK__(prctl(PR_SET_NAME, (unsigned long)comm1, 0, 0, 0));
 109
 110         test_tsc = rdtsc();
 111
 112         comm2 = "Test COMM 2";
 113         CHECK__(prctl(PR_SET_NAME, (unsigned long)comm2, 0, 0, 0));
 114
 115         perf_evlist__disable(evlist);
 116
 117         for (i = 0; i < evlist->nr_mmaps; i++) {
 118                 while ((event = perf_evlist__mmap_read(evlist, i)) != NULL) {
 119                         struct perf_sample sample;
 120
 121                         if (event->header.type != PERF_RECORD_COMM ||
 122                             (pid_t)event->comm.pid != getpid() ||
 123                             (pid_t)event->comm.tid != getpid())
 124                                 goto next_event;
 125
 126                         if (strcmp(event->comm.comm, comm1) == 0) {
 127                                 CHECK__(perf_evsel__parse_sample(evsel, event,
 128                                                                  &sample));
 129                                 comm1_time = sample.time;
 130                         }
 131                         if (strcmp(event->comm.comm, comm2) == 0) {
 132                                 CHECK__(perf_evsel__parse_sample(evsel, event,
 133                                                                  &sample));
 134                                 comm2_time = sample.time;
 135                         }
 136 next_event:
 137                         perf_evlist__mmap_consume(evlist, i);
 138                 }
 139         }
 140
 141         if (!comm1_time || !comm2_time)
 142                 goto out_err;
 143
 144         test_time = tsc_to_perf_time(test_tsc, &tc);
 145         comm1_tsc = perf_time_to_tsc(comm1_time, &tc);
 146         comm2_tsc = perf_time_to_tsc(comm2_time, &tc);
 147
 148         pr_debug("1st event perf time %"PRIu64" tsc %"PRIu64"\n",
 149                  comm1_time, comm1_tsc);
 150         pr_debug("rdtsc          time %"PRIu64" tsc %"PRIu64"\n",
 151                  test_time, test_tsc);
 152         pr_debug("2nd event perf time %"PRIu64" tsc %"PRIu64"\n",
 153                  comm2_time, comm2_tsc);
 154
 155         if (test_time <= comm1_time ||
 156             test_time >= comm2_time)
 157                 goto out_err;
 158
 159         if (test_tsc <= comm1_tsc ||
 160             test_tsc >= comm2_tsc)
 161                 goto out_err;
 162
 163         err = 0;
 164
 165 out_err:
 166         if (evlist) {
 167                 perf_evlist__disable(evlist);
 168                 perf_evlist__delete(evlist);
 169         }
 170
 171         return err;
 172 }