tools/perf/tests/mmap-basic.c

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