kernel/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         char sbuf[STRERR_BUFSIZE];
  35
  36         threads = thread_map__new(-1, getpid(), UINT_MAX);
  37         if (threads == NULL) {
  38                 pr_debug("thread_map__new\n");
  39                 return -1;
  40         }
  41
  42         cpus = cpu_map__new(NULL);
  43         if (cpus == NULL) {
  44                 pr_debug("cpu_map__new\n");
  45                 goto out_free_threads;
  46         }
  47
  48         CPU_ZERO(&cpu_set);
  49         CPU_SET(cpus->map[0], &cpu_set);
  50         sched_setaffinity(0, sizeof(cpu_set), &cpu_set);
  51         if (sched_setaffinity(0, sizeof(cpu_set), &cpu_set) < 0) {
  52                 pr_debug("sched_setaffinity() failed on CPU %d: %s ",
  53                          cpus->map[0], strerror_r(errno, sbuf, sizeof(sbuf)));
  54                 goto out_free_cpus;
  55         }
  56
  57         evlist = perf_evlist__new();
  58         if (evlist == NULL) {
  59                 pr_debug("perf_evlist__new\n");
  60                 goto out_free_cpus;
  61         }
  62
  63         perf_evlist__set_maps(evlist, cpus, threads);
  64
  65         for (i = 0; i < nsyscalls; ++i) {
  66                 char name[64];
  67
  68                 snprintf(name, sizeof(name), "sys_enter_%s", syscall_names[i]);
  69                 evsels[i] = perf_evsel__newtp("syscalls", name);
  70                 if (evsels[i] == NULL) {
  71                         pr_debug("perf_evsel__new\n");
  72                         goto out_delete_evlist;
  73                 }
  74
  75                 evsels[i]->attr.wakeup_events = 1;
  76                 perf_evsel__set_sample_id(evsels[i], false);
  77
  78                 perf_evlist__add(evlist, evsels[i]);
  79
  80                 if (perf_evsel__open(evsels[i], cpus, threads) < 0) {
  81                         pr_debug("failed to open counter: %s, "
  82                                  "tweak /proc/sys/kernel/perf_event_paranoid?\n",
  83                                  strerror_r(errno, sbuf, sizeof(sbuf)));
  84                         goto out_delete_evlist;
  85                 }
  86
  87                 nr_events[i] = 0;
  88                 expected_nr_events[i] = 1 + rand() % 127;
  89         }
  90
  91         if (perf_evlist__mmap(evlist, 128, true) < 0) {
  92                 pr_debug("failed to mmap events: %d (%s)\n", errno,
  93                          strerror_r(errno, sbuf, sizeof(sbuf)));
  94                 goto out_delete_evlist;
  95         }
  96
  97         for (i = 0; i < nsyscalls; ++i)
  98                 for (j = 0; j < expected_nr_events[i]; ++j) {
  99                         int foo = syscalls[i]();
 100                         ++foo;
 101                 }
 102
 103         while ((event = perf_evlist__mmap_read(evlist, 0)) != NULL) {
 104                 struct perf_sample sample;
 105
 106                 if (event->header.type != PERF_RECORD_SAMPLE) {
 107                         pr_debug("unexpected %s event\n",
 108                                  perf_event__name(event->header.type));
 109                         goto out_delete_evlist;
 110                 }
 111
 112                 err = perf_evlist__parse_sample(evlist, event, &sample);
 113                 if (err) {
 114                         pr_err("Can't parse sample, err = %d\n", err);
 115                         goto out_delete_evlist;
 116                 }
 117
 118                 err = -1;
 119                 evsel = perf_evlist__id2evsel(evlist, sample.id);
 120                 if (evsel == NULL) {
 121                         pr_debug("event with id %" PRIu64
 122                                  " doesn't map to an evsel\n", sample.id);
 123                         goto out_delete_evlist;
 124                 }
 125                 nr_events[evsel->idx]++;
 126                 perf_evlist__mmap_consume(evlist, 0);
 127         }
 128
 129         err = 0;
 130         evlist__for_each(evlist, evsel) {
 131                 if (nr_events[evsel->idx] != expected_nr_events[evsel->idx]) {
 132                         pr_debug("expected %d %s events, got %d\n",
 133                                  expected_nr_events[evsel->idx],
 134                                  perf_evsel__name(evsel), nr_events[evsel->idx]);
 135                         err = -1;
 136                         goto out_delete_evlist;
 137                 }
 138         }
 139
 140 out_delete_evlist:
 141         perf_evlist__delete(evlist);
 142         cpus    = NULL;
 143         threads = NULL;
 144 out_free_cpus:
 145         cpu_map__delete(cpus);
 146 out_free_threads:
 147         thread_map__delete(threads);
 148         return err;
 149 }