tools/perf/tests/mmap-basic.c

   1 #include "evlist.h"
   2 #include "evsel.h"
   3 #include "thread_map.h"
   4 #include "cpumap.h"
   5 #include "tests.h"
   6
   7 /*
   8  * This test will generate random numbers of calls to some getpid syscalls,
   9  * then establish an mmap for a group of events that are created to monitor
  10  * the syscalls.
  11  *
  12  * It will receive the events, using mmap, use its PERF_SAMPLE_ID generated
  13  * sample.id field to map back to its respective perf_evsel instance.
  14  *
  15  * Then it checks if the number of syscalls reported as perf events by
  16  * the kernel corresponds to the number of syscalls made.
  17  */
  18 int test__basic_mmap(void)
  19 {
  20         int err = -1;
  21         union perf_event *event;
  22         struct thread_map *threads;
  23         struct cpu_map *cpus;
  24         struct perf_evlist *evlist;
  25         cpu_set_t cpu_set;
  26         const char *syscall_names[] = { "getsid", "getppid", "getpgid", };
  27         pid_t (*syscalls[])(void) = { (void *)getsid, getppid, (void*)getpgid };
  28 #define nsyscalls ARRAY_SIZE(syscall_names)
  29         unsigned int nr_events[nsyscalls],
  30                      expected_nr_events[nsyscalls], i, j;
  31         struct perf_evsel *evsels[nsyscalls], *evsel;
  32         char sbuf[STRERR_BUFSIZE];
  33
  34         threads = thread_map__new(-1, getpid(), UINT_MAX);
  35         if (threads == NULL) {
  36                 pr_debug("thread_map__new\n");
  37                 return -1;
  38         }
  39
  40         cpus = cpu_map__new(NULL);
  41         if (cpus == NULL) {
  42                 pr_debug("cpu_map__new\n");
  43                 goto out_free_threads;
  44         }
  45
  46         CPU_ZERO(&cpu_set);
  47         CPU_SET(cpus->map[0], &cpu_set);
  48         sched_setaffinity(0, sizeof(cpu_set), &cpu_set);
  49         if (sched_setaffinity(0, sizeof(cpu_set), &cpu_set) < 0) {
  50                 pr_debug("sched_setaffinity() failed on CPU %d: %s ",
  51                          cpus->map[0], strerror_r(errno, sbuf, sizeof(sbuf)));
  52                 goto out_free_cpus;
  53         }
  54
  55         evlist = perf_evlist__new();
  56         if (evlist == NULL) {
  57                 pr_debug("perf_evlist__new\n");
  58                 goto out_free_cpus;
  59         }
  60
  61         perf_evlist__set_maps(evlist, cpus, threads);
  62
  63         for (i = 0; i < nsyscalls; ++i) {
  64                 char name[64];
  65
  66                 snprintf(name, sizeof(name), "sys_enter_%s", syscall_names[i]);
  67                 evsels[i] = perf_evsel__newtp("syscalls", name);
  68                 if (evsels[i] == NULL) {
  69                         pr_debug("perf_evsel__new\n");
  70                         goto out_delete_evlist;
  71                 }
  72
  73                 evsels[i]->attr.wakeup_events = 1;
  74                 perf_evsel__set_sample_id(evsels[i], false);
  75
  76                 perf_evlist__add(evlist, evsels[i]);
  77
  78                 if (perf_evsel__open(evsels[i], cpus, threads) < 0) {
  79                         pr_debug("failed to open counter: %s, "
  80                                  "tweak /proc/sys/kernel/perf_event_paranoid?\n",
  81                                  strerror_r(errno, sbuf, sizeof(sbuf)));
  82                         goto out_delete_evlist;
  83                 }
  84
  85                 nr_events[i] = 0;
  86                 expected_nr_events[i] = 1 + rand() % 127;
  87         }
  88
  89         if (perf_evlist__mmap(evlist, 128, true) < 0) {
  90                 pr_debug("failed to mmap events: %d (%s)\n", errno,
  91                          strerror_r(errno, sbuf, sizeof(sbuf)));
  92                 goto out_delete_evlist;
  93         }
  94
  95         for (i = 0; i < nsyscalls; ++i)
  96                 for (j = 0; j < expected_nr_events[i]; ++j) {
  97                         int foo = syscalls[i]();
  98                         ++foo;
  99                 }
 100
 101         while ((event = perf_evlist__mmap_read(evlist, 0)) != NULL) {
 102                 struct perf_sample sample;
 103
 104                 if (event->header.type != PERF_RECORD_SAMPLE) {
 105                         pr_debug("unexpected %s event\n",
 106                                  perf_event__name(event->header.type));
 107                         goto out_delete_evlist;
 108                 }
 109
 110                 err = perf_evlist__parse_sample(evlist, event, &sample);
 111                 if (err) {
 112                         pr_err("Can't parse sample, err = %d\n", err);
 113                         goto out_delete_evlist;
 114                 }
 115
 116                 err = -1;
 117                 evsel = perf_evlist__id2evsel(evlist, sample.id);
 118                 if (evsel == NULL) {
 119                         pr_debug("event with id %" PRIu64
 120                                  " doesn't map to an evsel\n", sample.id);
 121                         goto out_delete_evlist;
 122                 }
 123                 nr_events[evsel->idx]++;
 124                 perf_evlist__mmap_consume(evlist, 0);
 125         }
 126
 127         err = 0;
 128         evlist__for_each(evlist, evsel) {
 129                 if (nr_events[evsel->idx] != expected_nr_events[evsel->idx]) {
 130                         pr_debug("expected %d %s events, got %d\n",
 131                                  expected_nr_events[evsel->idx],
 132                                  perf_evsel__name(evsel), nr_events[evsel->idx]);
 133                         err = -1;
 134                         goto out_delete_evlist;
 135                 }
 136         }
 137
 138 out_delete_evlist:
 139         perf_evlist__delete(evlist);
 140         cpus    = NULL;
 141         threads = NULL;
 142 out_free_cpus:
 143         cpu_map__put(cpus);
 144 out_free_threads:
 145         thread_map__put(threads);
 146         return err;
 147 }