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", "getpgrp",
  27                                         "getpgid", };
  28         pid_t (*syscalls[])(void) = { (void *)getsid, getppid, getpgrp,
  29                                       (void*)getpgid };
  30 #define nsyscalls ARRAY_SIZE(syscall_names)
  31         unsigned int nr_events[nsyscalls],
  32                      expected_nr_events[nsyscalls], i, j;
  33         struct perf_evsel *evsels[nsyscalls], *evsel;
  34
  35         threads = thread_map__new(-1, getpid(), UINT_MAX);
  36         if (threads == NULL) {
  37                 pr_debug("thread_map__new\n");
  38                 return -1;
  39         }
  40
  41         cpus = cpu_map__new(NULL);
  42         if (cpus == NULL) {
  43                 pr_debug("cpu_map__new\n");
  44                 goto out_free_threads;
  45         }
  46
  47         CPU_ZERO(&cpu_set);
  48         CPU_SET(cpus->map[0], &cpu_set);
  49         sched_setaffinity(0, sizeof(cpu_set), &cpu_set);
  50         if (sched_setaffinity(0, sizeof(cpu_set), &cpu_set) < 0) {
  51                 pr_debug("sched_setaffinity() failed on CPU %d: %s ",
  52                          cpus->map[0], strerror(errno));
  53                 goto out_free_cpus;
  54         }
  55
  56         evlist = perf_evlist__new(cpus, threads);
  57         if (evlist == NULL) {
  58                 pr_debug("perf_evlist__new\n");
  59                 goto out_free_cpus;
  60         }
  61
  62         for (i = 0; i < nsyscalls; ++i) {
  63                 char name[64];
  64
  65                 snprintf(name, sizeof(name), "sys_enter_%s", syscall_names[i]);
  66                 evsels[i] = perf_evsel__newtp("syscalls", name, i);
  67                 if (evsels[i] == NULL) {
  68                         pr_debug("perf_evsel__new\n");
  69                         goto out_free_evlist;
  70                 }
  71
  72                 evsels[i]->attr.wakeup_events = 1;
  73                 perf_evsel__set_sample_id(evsels[i]);
  74
  75                 perf_evlist__add(evlist, evsels[i]);
  76
  77                 if (perf_evsel__open(evsels[i], cpus, threads) < 0) {
  78                         pr_debug("failed to open counter: %s, "
  79                                  "tweak /proc/sys/kernel/perf_event_paranoid?\n",
  80                                  strerror(errno));
  81                         goto out_close_fd;
  82                 }
  83
  84                 nr_events[i] = 0;
  85                 expected_nr_events[i] = 1 + rand() % 127;
  86         }
  87
  88         if (perf_evlist__mmap(evlist, 128, true) < 0) {
  89                 pr_debug("failed to mmap events: %d (%s)\n", errno,
  90                          strerror(errno));
  91                 goto out_close_fd;
  92         }
  93
  94         for (i = 0; i < nsyscalls; ++i)
  95                 for (j = 0; j < expected_nr_events[i]; ++j) {
  96                         int foo = syscalls[i]();
  97                         ++foo;
  98                 }
  99
 100         while ((event = perf_evlist__mmap_read(evlist, 0)) != NULL) {
 101                 struct perf_sample sample;
 102
 103                 if (event->header.type != PERF_RECORD_SAMPLE) {
 104                         pr_debug("unexpected %s event\n",
 105                                  perf_event__name(event->header.type));
 106                         goto out_munmap;
 107                 }
 108
 109                 err = perf_evlist__parse_sample(evlist, event, &sample);
 110                 if (err) {
 111                         pr_err("Can't parse sample, err = %d\n", err);
 112                         goto out_munmap;
 113                 }
 114
 115                 err = -1;
 116                 evsel = perf_evlist__id2evsel(evlist, sample.id);
 117                 if (evsel == NULL) {
 118                         pr_debug("event with id %" PRIu64
 119                                  " doesn't map to an evsel\n", sample.id);
 120                         goto out_munmap;
 121                 }
 122                 nr_events[evsel->idx]++;
 123         }
 124
 125         err = 0;
 126         list_for_each_entry(evsel, &evlist->entries, node) {
 127                 if (nr_events[evsel->idx] != expected_nr_events[evsel->idx]) {
 128                         pr_debug("expected %d %s events, got %d\n",
 129                                  expected_nr_events[evsel->idx],
 130                                  perf_evsel__name(evsel), nr_events[evsel->idx]);
 131                         err = -1;
 132                         goto out_munmap;
 133                 }
 134         }
 135
 136 out_munmap:
 137         perf_evlist__munmap(evlist);
 138 out_close_fd:
 139         for (i = 0; i < nsyscalls; ++i)
 140                 perf_evsel__close_fd(evsels[i], 1, threads->nr);
 141 out_free_evlist:
 142         perf_evlist__delete(evlist);
 143 out_free_cpus:
 144         cpu_map__delete(cpus);
 145 out_free_threads:
 146         thread_map__delete(threads);
 147         return err;
 148 }