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