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 #include <linux/err.h>
   7
   8 /*
   9  * This test will generate random numbers of calls to some getpid syscalls,
  10  * then establish an mmap for a group of events that are created to monitor
  11  * the syscalls.
  12  *
  13  * It will receive the events, using mmap, use its PERF_SAMPLE_ID generated
  14  * sample.id field to map back to its respective perf_evsel instance.
  15  *
  16  * Then it checks if the number of syscalls reported as perf events by
  17  * the kernel corresponds to the number of syscalls made.
  18  */
  19 int test__basic_mmap(void)
  20 {
  21         int err = -1;
  22         union perf_event *event;
  23         struct thread_map *threads;
  24         struct cpu_map *cpus;
  25         struct perf_evlist *evlist;
  26         cpu_set_t cpu_set;
  27         const char *syscall_names[] = { "getsid", "getppid", "getpgid", };
  28         pid_t (*syscalls[])(void) = { (void *)getsid, getppid, (void*)getpgid };
  29 #define nsyscalls ARRAY_SIZE(syscall_names)
  30         unsigned int nr_events[nsyscalls],
  31                      expected_nr_events[nsyscalls], i, j;
  32         struct perf_evsel *evsels[nsyscalls], *evsel;
  33         char sbuf[STRERR_BUFSIZE];
  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_r(errno, sbuf, sizeof(sbuf)));
  53                 goto out_free_cpus;
  54         }
  55
  56         evlist = perf_evlist__new();
  57         if (evlist == NULL) {
  58                 pr_debug("perf_evlist__new\n");
  59                 goto out_free_cpus;
  60         }
  61
  62         perf_evlist__set_maps(evlist, cpus, threads);
  63
  64         for (i = 0; i < nsyscalls; ++i) {
  65                 char name[64];
  66
  67                 snprintf(name, sizeof(name), "sys_enter_%s", syscall_names[i]);
  68                 evsels[i] = perf_evsel__newtp("syscalls", name);
  69                 if (IS_ERR(evsels[i])) {
  70                         pr_debug("perf_evsel__new\n");
  71                         goto out_delete_evlist;
  72                 }
  73
  74                 evsels[i]->attr.wakeup_events = 1;
  75                 perf_evsel__set_sample_id(evsels[i], false);
  76
  77                 perf_evlist__add(evlist, evsels[i]);
  78
  79                 if (perf_evsel__open(evsels[i], cpus, threads) < 0) {
  80                         pr_debug("failed to open counter: %s, "
  81                                  "tweak /proc/sys/kernel/perf_event_paranoid?\n",
  82                                  strerror_r(errno, sbuf, sizeof(sbuf)));
  83                         goto out_delete_evlist;
  84                 }
  85
  86                 nr_events[i] = 0;
  87                 expected_nr_events[i] = 1 + rand() % 127;
  88         }
  89
  90         if (perf_evlist__mmap(evlist, 128, true) < 0) {
  91                 pr_debug("failed to mmap events: %d (%s)\n", errno,
  92                          strerror_r(errno, sbuf, sizeof(sbuf)));
  93                 goto out_delete_evlist;
  94         }
  95
  96         for (i = 0; i < nsyscalls; ++i)
  97                 for (j = 0; j < expected_nr_events[i]; ++j) {
  98                         int foo = syscalls[i]();
  99                         ++foo;
 100                 }
 101
 102         while ((event = perf_evlist__mmap_read(evlist, 0)) != NULL) {
 103                 struct perf_sample sample;
 104
 105                 if (event->header.type != PERF_RECORD_SAMPLE) {
 106                         pr_debug("unexpected %s event\n",
 107                                  perf_event__name(event->header.type));
 108                         goto out_delete_evlist;
 109                 }
 110
 111                 err = perf_evlist__parse_sample(evlist, event, &sample);
 112                 if (err) {
 113                         pr_err("Can't parse sample, err = %d\n", err);
 114                         goto out_delete_evlist;
 115                 }
 116
 117                 err = -1;
 118                 evsel = perf_evlist__id2evsel(evlist, sample.id);
 119                 if (evsel == NULL) {
 120                         pr_debug("event with id %" PRIu64
 121                                  " doesn't map to an evsel\n", sample.id);
 122                         goto out_delete_evlist;
 123                 }
 124                 nr_events[evsel->idx]++;
 125                 perf_evlist__mmap_consume(evlist, 0);
 126         }
 127
 128         err = 0;
 129         evlist__for_each(evlist, evsel) {
 130                 if (nr_events[evsel->idx] != expected_nr_events[evsel->idx]) {
 131                         pr_debug("expected %d %s events, got %d\n",
 132                                  expected_nr_events[evsel->idx],
 133                                  perf_evsel__name(evsel), nr_events[evsel->idx]);
 134                         err = -1;
 135                         goto out_delete_evlist;
 136                 }
 137         }
 138
 139 out_delete_evlist:
 140         perf_evlist__delete(evlist);
 141         cpus    = NULL;
 142         threads = NULL;
 143 out_free_cpus:
 144         cpu_map__put(cpus);
 145 out_free_threads:
 146         thread_map__put(threads);
 147         return err;
 148 }