tools/perf/tests/mmap-basic.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <errno.h>
   3 #include <inttypes.h>
   4 /* For the CLR_() macros */
   5 #include <pthread.h>
   6
   7 #include "evlist.h"
   8 #include "evsel.h"
   9 #include "thread_map.h"
  10 #include "cpumap.h"
  11 #include "tests.h"
  12 #include <linux/err.h>
  13 #include <linux/kernel.h>
  14
  15 /*
  16  * This test will generate random numbers of calls to some getpid syscalls,
  17  * then establish an mmap for a group of events that are created to monitor
  18  * the syscalls.
  19  *
  20  * It will receive the events, using mmap, use its PERF_SAMPLE_ID generated
  21  * sample.id field to map back to its respective perf_evsel instance.
  22  *
  23  * Then it checks if the number of syscalls reported as perf events by
  24  * the kernel corresponds to the number of syscalls made.
  25  */
  26 int test__basic_mmap(struct test *test __maybe_unused, int subtest __maybe_unused)
  27 {
  28         int err = -1;
  29         union perf_event *event;
  30         struct thread_map *threads;
  31         struct cpu_map *cpus;
  32         struct perf_evlist *evlist;
  33         cpu_set_t cpu_set;
  34         const char *syscall_names[] = { "getsid", "getppid", "getpgid", };
  35         pid_t (*syscalls[])(void) = { (void *)getsid, getppid, (void*)getpgid };
  36 #define nsyscalls ARRAY_SIZE(syscall_names)
  37         unsigned int nr_events[nsyscalls],
  38                      expected_nr_events[nsyscalls], i, j;
  39         struct perf_evsel *evsels[nsyscalls], *evsel;
  40         char sbuf[STRERR_BUFSIZE];
  41
  42         threads = thread_map__new(-1, getpid(), UINT_MAX);
  43         if (threads == NULL) {
  44                 pr_debug("thread_map__new\n");
  45                 return -1;
  46         }
  47
  48         cpus = cpu_map__new(NULL);
  49         if (cpus == NULL) {
  50                 pr_debug("cpu_map__new\n");
  51                 goto out_free_threads;
  52         }
  53
  54         CPU_ZERO(&cpu_set);
  55         CPU_SET(cpus->map[0], &cpu_set);
  56         sched_setaffinity(0, sizeof(cpu_set), &cpu_set);
  57         if (sched_setaffinity(0, sizeof(cpu_set), &cpu_set) < 0) {
  58                 pr_debug("sched_setaffinity() failed on CPU %d: %s ",
  59                          cpus->map[0], str_error_r(errno, sbuf, sizeof(sbuf)));
  60                 goto out_free_cpus;
  61         }
  62
  63         evlist = perf_evlist__new();
  64         if (evlist == NULL) {
  65                 pr_debug("perf_evlist__new\n");
  66                 goto out_free_cpus;
  67         }
  68
  69         perf_evlist__set_maps(evlist, cpus, threads);
  70
  71         for (i = 0; i < nsyscalls; ++i) {
  72                 char name[64];
  73
  74                 snprintf(name, sizeof(name), "sys_enter_%s", syscall_names[i]);
  75                 evsels[i] = perf_evsel__newtp("syscalls", name);
  76                 if (IS_ERR(evsels[i])) {
  77                         pr_debug("perf_evsel__new\n");
  78                         goto out_delete_evlist;
  79                 }
  80
  81                 evsels[i]->attr.wakeup_events = 1;
  82                 perf_evsel__set_sample_id(evsels[i], false);
  83
  84                 perf_evlist__add(evlist, evsels[i]);
  85
  86                 if (perf_evsel__open(evsels[i], cpus, threads) < 0) {
  87                         pr_debug("failed to open counter: %s, "
  88                                  "tweak /proc/sys/kernel/perf_event_paranoid?\n",
  89                                  str_error_r(errno, sbuf, sizeof(sbuf)));
  90                         goto out_delete_evlist;
  91                 }
  92
  93                 nr_events[i] = 0;
  94                 expected_nr_events[i] = 1 + rand() % 127;
  95         }
  96
  97         if (perf_evlist__mmap(evlist, 128, true) < 0) {
  98                 pr_debug("failed to mmap events: %d (%s)\n", errno,
  99                          str_error_r(errno, sbuf, sizeof(sbuf)));
 100                 goto out_delete_evlist;
 101         }
 102
 103         for (i = 0; i < nsyscalls; ++i)
 104                 for (j = 0; j < expected_nr_events[i]; ++j) {
 105                         int foo = syscalls[i]();
 106                         ++foo;
 107                 }
 108
 109         while ((event = perf_evlist__mmap_read(evlist, 0)) != NULL) {
 110                 struct perf_sample sample;
 111
 112                 if (event->header.type != PERF_RECORD_SAMPLE) {
 113                         pr_debug("unexpected %s event\n",
 114                                  perf_event__name(event->header.type));
 115                         goto out_delete_evlist;
 116                 }
 117
 118                 err = perf_evlist__parse_sample(evlist, event, &sample);
 119                 if (err) {
 120                         pr_err("Can't parse sample, err = %d\n", err);
 121                         goto out_delete_evlist;
 122                 }
 123
 124                 err = -1;
 125                 evsel = perf_evlist__id2evsel(evlist, sample.id);
 126                 if (evsel == NULL) {
 127                         pr_debug("event with id %" PRIu64
 128                                  " doesn't map to an evsel\n", sample.id);
 129                         goto out_delete_evlist;
 130                 }
 131                 nr_events[evsel->idx]++;
 132                 perf_evlist__mmap_consume(evlist, 0);
 133         }
 134
 135         err = 0;
 136         evlist__for_each_entry(evlist, evsel) {
 137                 if (nr_events[evsel->idx] != expected_nr_events[evsel->idx]) {
 138                         pr_debug("expected %d %s events, got %d\n",
 139                                  expected_nr_events[evsel->idx],
 140                                  perf_evsel__name(evsel), nr_events[evsel->idx]);
 141                         err = -1;
 142                         goto out_delete_evlist;
 143                 }
 144         }
 145
 146 out_delete_evlist:
 147         perf_evlist__delete(evlist);
 148         cpus    = NULL;
 149         threads = NULL;
 150 out_free_cpus:
 151         cpu_map__put(cpus);
 152 out_free_threads:
 153         thread_map__put(threads);
 154         return err;
 155 }