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         struct perf_mmap *md;
  42
  43         threads = thread_map__new(-1, getpid(), UINT_MAX);
  44         if (threads == NULL) {
  45                 pr_debug("thread_map__new\n");
  46                 return -1;
  47         }
  48
  49         cpus = cpu_map__new(NULL);
  50         if (cpus == NULL) {
  51                 pr_debug("cpu_map__new\n");
  52                 goto out_free_threads;
  53         }
  54
  55         CPU_ZERO(&cpu_set);
  56         CPU_SET(cpus->map[0], &cpu_set);
  57         sched_setaffinity(0, sizeof(cpu_set), &cpu_set);
  58         if (sched_setaffinity(0, sizeof(cpu_set), &cpu_set) < 0) {
  59                 pr_debug("sched_setaffinity() failed on CPU %d: %s ",
  60                          cpus->map[0], str_error_r(errno, sbuf, sizeof(sbuf)));
  61                 goto out_free_cpus;
  62         }
  63
  64         evlist = perf_evlist__new();
  65         if (evlist == NULL) {
  66                 pr_debug("perf_evlist__new\n");
  67                 goto out_free_cpus;
  68         }
  69
  70         perf_evlist__set_maps(evlist, cpus, threads);
  71
  72         for (i = 0; i < nsyscalls; ++i) {
  73                 char name[64];
  74
  75                 snprintf(name, sizeof(name), "sys_enter_%s", syscall_names[i]);
  76                 evsels[i] = perf_evsel__newtp("syscalls", name);
  77                 if (IS_ERR(evsels[i])) {
  78                         pr_debug("perf_evsel__new(%s)\n", name);
  79                         goto out_delete_evlist;
  80                 }
  81
  82                 evsels[i]->attr.wakeup_events = 1;
  83                 perf_evsel__set_sample_id(evsels[i], false);
  84
  85                 perf_evlist__add(evlist, evsels[i]);
  86
  87                 if (perf_evsel__open(evsels[i], cpus, threads) < 0) {
  88                         pr_debug("failed to open counter: %s, "
  89                                  "tweak /proc/sys/kernel/perf_event_paranoid?\n",
  90                                  str_error_r(errno, sbuf, sizeof(sbuf)));
  91                         goto out_delete_evlist;
  92                 }
  93
  94                 nr_events[i] = 0;
  95                 expected_nr_events[i] = 1 + rand() % 127;
  96         }
  97
  98         if (perf_evlist__mmap(evlist, 128) < 0) {
  99                 pr_debug("failed to mmap events: %d (%s)\n", errno,
 100                          str_error_r(errno, sbuf, sizeof(sbuf)));
 101                 goto out_delete_evlist;
 102         }
 103
 104         for (i = 0; i < nsyscalls; ++i)
 105                 for (j = 0; j < expected_nr_events[i]; ++j) {
 106                         int foo = syscalls[i]();
 107                         ++foo;
 108                 }
 109
 110         md = &evlist->mmap[0];
 111         if (perf_mmap__read_init(md) < 0)
 112                 goto out_init;
 113
 114         while ((event = perf_mmap__read_event(md)) != NULL) {
 115                 struct perf_sample sample;
 116
 117                 if (event->header.type != PERF_RECORD_SAMPLE) {
 118                         pr_debug("unexpected %s event\n",
 119                                  perf_event__name(event->header.type));
 120                         goto out_delete_evlist;
 121                 }
 122
 123                 err = perf_evlist__parse_sample(evlist, event, &sample);
 124                 if (err) {
 125                         pr_err("Can't parse sample, err = %d\n", err);
 126                         goto out_delete_evlist;
 127                 }
 128
 129                 err = -1;
 130                 evsel = perf_evlist__id2evsel(evlist, sample.id);
 131                 if (evsel == NULL) {
 132                         pr_debug("event with id %" PRIu64
 133                                  " doesn't map to an evsel\n", sample.id);
 134                         goto out_delete_evlist;
 135                 }
 136                 nr_events[evsel->idx]++;
 137                 perf_mmap__consume(md);
 138         }
 139         perf_mmap__read_done(md);
 140
 141 out_init:
 142         err = 0;
 143         evlist__for_each_entry(evlist, evsel) {
 144                 if (nr_events[evsel->idx] != expected_nr_events[evsel->idx]) {
 145                         pr_debug("expected %d %s events, got %d\n",
 146                                  expected_nr_events[evsel->idx],
 147                                  perf_evsel__name(evsel), nr_events[evsel->idx]);
 148                         err = -1;
 149                         goto out_delete_evlist;
 150                 }
 151         }
 152
 153 out_delete_evlist:
 154         perf_evlist__delete(evlist);
 155         cpus    = NULL;
 156         threads = NULL;
 157 out_free_cpus:
 158         cpu_map__put(cpus);
 159 out_free_threads:
 160         thread_map__put(threads);
 161         return err;
 162 }