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 #include <stdlib.h>
   7 #include <perf/cpumap.h>
   8
   9 #include "debug.h"
  10 #include "evlist.h"
  11 #include "evsel.h"
  12 #include "thread_map.h"
  13 #include "tests.h"
  14 #include <linux/err.h>
  15 #include <linux/kernel.h>
  16 #include <linux/string.h>
  17 #include <perf/evlist.h>
  18
  19 /*
  20  * This test will generate random numbers of calls to some getpid syscalls,
  21  * then establish an mmap for a group of events that are created to monitor
  22  * the syscalls.
  23  *
  24  * It will receive the events, using mmap, use its PERF_SAMPLE_ID generated
  25  * sample.id field to map back to its respective perf_evsel instance.
  26  *
  27  * Then it checks if the number of syscalls reported as perf events by
  28  * the kernel corresponds to the number of syscalls made.
  29  */
  30 int test__basic_mmap(struct test *test __maybe_unused, int subtest __maybe_unused)
  31 {
  32         int err = -1;
  33         union perf_event *event;
  34         struct perf_thread_map *threads;
  35         struct perf_cpu_map *cpus;
  36         struct evlist *evlist;
  37         cpu_set_t cpu_set;
  38         const char *syscall_names[] = { "getsid", "getppid", "getpgid", };
  39         pid_t (*syscalls[])(void) = { (void *)getsid, getppid, (void*)getpgid };
  40 #define nsyscalls ARRAY_SIZE(syscall_names)
  41         unsigned int nr_events[nsyscalls],
  42                      expected_nr_events[nsyscalls], i, j;
  43         struct evsel *evsels[nsyscalls], *evsel;
  44         char sbuf[STRERR_BUFSIZE];
  45         struct mmap *md;
  46
  47         threads = thread_map__new(-1, getpid(), UINT_MAX);
  48         if (threads == NULL) {
  49                 pr_debug("thread_map__new\n");
  50                 return -1;
  51         }
  52
  53         cpus = perf_cpu_map__new(NULL);
  54         if (cpus == NULL) {
  55                 pr_debug("perf_cpu_map__new\n");
  56                 goto out_free_threads;
  57         }
  58
  59         CPU_ZERO(&cpu_set);
  60         CPU_SET(cpus->map[0], &cpu_set);
  61         sched_setaffinity(0, sizeof(cpu_set), &cpu_set);
  62         if (sched_setaffinity(0, sizeof(cpu_set), &cpu_set) < 0) {
  63                 pr_debug("sched_setaffinity() failed on CPU %d: %s ",
  64                          cpus->map[0], str_error_r(errno, sbuf, sizeof(sbuf)));
  65                 goto out_free_cpus;
  66         }
  67
  68         evlist = evlist__new();
  69         if (evlist == NULL) {
  70                 pr_debug("perf_evlist__new\n");
  71                 goto out_free_cpus;
  72         }
  73
  74         perf_evlist__set_maps(&evlist->core, cpus, threads);
  75
  76         for (i = 0; i < nsyscalls; ++i) {
  77                 char name[64];
  78
  79                 snprintf(name, sizeof(name), "sys_enter_%s", syscall_names[i]);
  80                 evsels[i] = perf_evsel__newtp("syscalls", name);
  81                 if (IS_ERR(evsels[i])) {
  82                         pr_debug("perf_evsel__new(%s)\n", name);
  83                         goto out_delete_evlist;
  84                 }
  85
  86                 evsels[i]->core.attr.wakeup_events = 1;
  87                 perf_evsel__set_sample_id(evsels[i], false);
  88
  89                 evlist__add(evlist, evsels[i]);
  90
  91                 if (evsel__open(evsels[i], cpus, threads) < 0) {
  92                         pr_debug("failed to open counter: %s, "
  93                                  "tweak /proc/sys/kernel/perf_event_paranoid?\n",
  94                                  str_error_r(errno, sbuf, sizeof(sbuf)));
  95                         goto out_delete_evlist;
  96                 }
  97
  98                 nr_events[i] = 0;
  99                 expected_nr_events[i] = 1 + rand() % 127;
 100         }
 101
 102         if (evlist__mmap(evlist, 128) < 0) {
 103                 pr_debug("failed to mmap events: %d (%s)\n", errno,
 104                          str_error_r(errno, sbuf, sizeof(sbuf)));
 105                 goto out_delete_evlist;
 106         }
 107
 108         for (i = 0; i < nsyscalls; ++i)
 109                 for (j = 0; j < expected_nr_events[i]; ++j) {
 110                         int foo = syscalls[i]();
 111                         ++foo;
 112                 }
 113
 114         md = &evlist->mmap[0];
 115         if (perf_mmap__read_init(md) < 0)
 116                 goto out_init;
 117
 118         while ((event = perf_mmap__read_event(md)) != NULL) {
 119                 struct perf_sample sample;
 120
 121                 if (event->header.type != PERF_RECORD_SAMPLE) {
 122                         pr_debug("unexpected %s event\n",
 123                                  perf_event__name(event->header.type));
 124                         goto out_delete_evlist;
 125                 }
 126
 127                 err = perf_evlist__parse_sample(evlist, event, &sample);
 128                 if (err) {
 129                         pr_err("Can't parse sample, err = %d\n", err);
 130                         goto out_delete_evlist;
 131                 }
 132
 133                 err = -1;
 134                 evsel = perf_evlist__id2evsel(evlist, sample.id);
 135                 if (evsel == NULL) {
 136                         pr_debug("event with id %" PRIu64
 137                                  " doesn't map to an evsel\n", sample.id);
 138                         goto out_delete_evlist;
 139                 }
 140                 nr_events[evsel->idx]++;
 141                 perf_mmap__consume(md);
 142         }
 143         perf_mmap__read_done(md);
 144
 145 out_init:
 146         err = 0;
 147         evlist__for_each_entry(evlist, evsel) {
 148                 if (nr_events[evsel->idx] != expected_nr_events[evsel->idx]) {
 149                         pr_debug("expected %d %s events, got %d\n",
 150                                  expected_nr_events[evsel->idx],
 151                                  perf_evsel__name(evsel), nr_events[evsel->idx]);
 152                         err = -1;
 153                         goto out_delete_evlist;
 154                 }
 155         }
 156
 157 out_delete_evlist:
 158         evlist__delete(evlist);
 159         cpus    = NULL;
 160         threads = NULL;
 161 out_free_cpus:
 162         perf_cpu_map__put(cpus);
 163 out_free_threads:
 164         perf_thread_map__put(threads);
 165         return err;
 166 }