tools/perf/tests/mmap-basic.c

   1 #include <errno.h>
   2 #include <inttypes.h>
   3 /* For the CLR_() macros */
   4 #include <pthread.h>
   5
   6 #include "evlist.h"
   7 #include "evsel.h"
   8 #include "thread_map.h"
   9 #include "cpumap.h"
  10 #include "tests.h"
  11 #include <linux/err.h>
  12 #include <linux/kernel.h>
  13
  14 /*
  15  * This test will generate random numbers of calls to some getpid syscalls,
  16  * then establish an mmap for a group of events that are created to monitor
  17  * the syscalls.
  18  *
  19  * It will receive the events, using mmap, use its PERF_SAMPLE_ID generated
  20  * sample.id field to map back to its respective perf_evsel instance.
  21  *
  22  * Then it checks if the number of syscalls reported as perf events by
  23  * the kernel corresponds to the number of syscalls made.
  24  */
  25 int test__basic_mmap(struct test *test __maybe_unused, int subtest __maybe_unused)
  26 {
  27         int err = -1;
  28         union perf_event *event;
  29         struct thread_map *threads;
  30         struct cpu_map *cpus;
  31         struct perf_evlist *evlist;
  32         cpu_set_t cpu_set;
  33         const char *syscall_names[] = { "getsid", "getppid", "getpgid", };
  34         pid_t (*syscalls[])(void) = { (void *)getsid, getppid, (void*)getpgid };
  35 #define nsyscalls ARRAY_SIZE(syscall_names)
  36         unsigned int nr_events[nsyscalls],
  37                      expected_nr_events[nsyscalls], i, j;
  38         struct perf_evsel *evsels[nsyscalls], *evsel;
  39         char sbuf[STRERR_BUFSIZE];
  40
  41         threads = thread_map__new(-1, getpid(), UINT_MAX);
  42         if (threads == NULL) {
  43                 pr_debug("thread_map__new\n");
  44                 return -1;
  45         }
  46
  47         cpus = cpu_map__new(NULL);
  48         if (cpus == NULL) {
  49                 pr_debug("cpu_map__new\n");
  50                 goto out_free_threads;
  51         }
  52
  53         CPU_ZERO(&cpu_set);
  54         CPU_SET(cpus->map[0], &cpu_set);
  55         sched_setaffinity(0, sizeof(cpu_set), &cpu_set);
  56         if (sched_setaffinity(0, sizeof(cpu_set), &cpu_set) < 0) {
  57                 pr_debug("sched_setaffinity() failed on CPU %d: %s ",
  58                          cpus->map[0], str_error_r(errno, sbuf, sizeof(sbuf)));
  59                 goto out_free_cpus;
  60         }
  61
  62         evlist = perf_evlist__new();
  63         if (evlist == NULL) {
  64                 pr_debug("perf_evlist__new\n");
  65                 goto out_free_cpus;
  66         }
  67
  68         perf_evlist__set_maps(evlist, cpus, threads);
  69
  70         for (i = 0; i < nsyscalls; ++i) {
  71                 char name[64];
  72
  73                 snprintf(name, sizeof(name), "sys_enter_%s", syscall_names[i]);
  74                 evsels[i] = perf_evsel__newtp("syscalls", name);
  75                 if (IS_ERR(evsels[i])) {
  76                         pr_debug("perf_evsel__new\n");
  77                         goto out_delete_evlist;
  78                 }
  79
  80                 evsels[i]->attr.wakeup_events = 1;
  81                 perf_evsel__set_sample_id(evsels[i], false);
  82
  83                 perf_evlist__add(evlist, evsels[i]);
  84
  85                 if (perf_evsel__open(evsels[i], cpus, threads) < 0) {
  86                         pr_debug("failed to open counter: %s, "
  87                                  "tweak /proc/sys/kernel/perf_event_paranoid?\n",
  88                                  str_error_r(errno, sbuf, sizeof(sbuf)));
  89                         goto out_delete_evlist;
  90                 }
  91
  92                 nr_events[i] = 0;
  93                 expected_nr_events[i] = 1 + rand() % 127;
  94         }
  95
  96         if (perf_evlist__mmap(evlist, 128, true) < 0) {
  97                 pr_debug("failed to mmap events: %d (%s)\n", errno,
  98                          str_error_r(errno, sbuf, sizeof(sbuf)));
  99                 goto out_delete_evlist;
 100         }
 101
 102         for (i = 0; i < nsyscalls; ++i)
 103                 for (j = 0; j < expected_nr_events[i]; ++j) {
 104                         int foo = syscalls[i]();
 105                         ++foo;
 106                 }
 107
 108         while ((event = perf_evlist__mmap_read(evlist, 0)) != NULL) {
 109                 struct perf_sample sample;
 110
 111                 if (event->header.type != PERF_RECORD_SAMPLE) {
 112                         pr_debug("unexpected %s event\n",
 113                                  perf_event__name(event->header.type));
 114                         goto out_delete_evlist;
 115                 }
 116
 117                 err = perf_evlist__parse_sample(evlist, event, &sample);
 118                 if (err) {
 119                         pr_err("Can't parse sample, err = %d\n", err);
 120                         goto out_delete_evlist;
 121                 }
 122
 123                 err = -1;
 124                 evsel = perf_evlist__id2evsel(evlist, sample.id);
 125                 if (evsel == NULL) {
 126                         pr_debug("event with id %" PRIu64
 127                                  " doesn't map to an evsel\n", sample.id);
 128                         goto out_delete_evlist;
 129                 }
 130                 nr_events[evsel->idx]++;
 131                 perf_evlist__mmap_consume(evlist, 0);
 132         }
 133
 134         err = 0;
 135         evlist__for_each_entry(evlist, evsel) {
 136                 if (nr_events[evsel->idx] != expected_nr_events[evsel->idx]) {
 137                         pr_debug("expected %d %s events, got %d\n",
 138                                  expected_nr_events[evsel->idx],
 139                                  perf_evsel__name(evsel), nr_events[evsel->idx]);
 140                         err = -1;
 141                         goto out_delete_evlist;
 142                 }
 143         }
 144
 145 out_delete_evlist:
 146         perf_evlist__delete(evlist);
 147         cpus    = NULL;
 148         threads = NULL;
 149 out_free_cpus:
 150         cpu_map__put(cpus);
 151 out_free_threads:
 152         thread_map__put(threads);
 153         return err;
 154 }