LXR linux/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 */
  18int 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", "getpgid", };
  27        pid_t (*syscalls[])(void) = { (void *)getsid, getppid, (void*)getpgid };
  28#define nsyscalls ARRAY_SIZE(syscall_names)
  29        unsigned int nr_events[nsyscalls],
  30                     expected_nr_events[nsyscalls], i, j;
  31        struct perf_evsel *evsels[nsyscalls], *evsel;
  32        char sbuf[STRERR_BUFSIZE];
  33
  34        threads = thread_map__new(-1, getpid(), UINT_MAX);
  35        if (threads == NULL) {
  36                pr_debug("thread_map__new\n");
  37                return -1;
  38        }
  39
  40        cpus = cpu_map__new(NULL);
  41        if (cpus == NULL) {
  42                pr_debug("cpu_map__new\n");
  43                goto out_free_threads;
  44        }
  45
  46        CPU_ZERO(&cpu_set);
  47        CPU_SET(cpus->map[0], &cpu_set);
  48        sched_setaffinity(0, sizeof(cpu_set), &cpu_set);
  49        if (sched_setaffinity(0, sizeof(cpu_set), &cpu_set) < 0) {
  50                pr_debug("sched_setaffinity() failed on CPU %d: %s ",
  51                         cpus->map[0], strerror_r(errno, sbuf, sizeof(sbuf)));
  52                goto out_free_cpus;
  53        }
  54
  55        evlist = perf_evlist__new();
  56        if (evlist == NULL) {
  57                pr_debug("perf_evlist__new\n");
  58                goto out_free_cpus;
  59        }
  60
  61        perf_evlist__set_maps(evlist, cpus, threads);
  62
  63        for (i = 0; i < nsyscalls; ++i) {
  64                char name[64];
  65
  66                snprintf(name, sizeof(name), "sys_enter_%s", syscall_names[i]);
  67                evsels[i] = perf_evsel__newtp("syscalls", name);
  68                if (evsels[i] == NULL) {
  69                        pr_debug("perf_evsel__new\n");
  70                        goto out_delete_evlist;
  71                }
  72
  73                evsels[i]->attr.wakeup_events = 1;
  74                perf_evsel__set_sample_id(evsels[i], false);
  75
  76                perf_evlist__add(evlist, evsels[i]);
  77
  78                if (perf_evsel__open(evsels[i], cpus, threads) < 0) {
  79                        pr_debug("failed to open counter: %s, "
  80                                 "tweak /proc/sys/kernel/perf_event_paranoid?\n",
  81                                 strerror_r(errno, sbuf, sizeof(sbuf)));
  82                        goto out_delete_evlist;
  83                }
  84
  85                nr_events[i] = 0;
  86                expected_nr_events[i] = 1 + rand() % 127;
  87        }
  88
  89        if (perf_evlist__mmap(evlist, 128, true) < 0) {
  90                pr_debug("failed to mmap events: %d (%s)\n", errno,
  91                         strerror_r(errno, sbuf, sizeof(sbuf)));
  92                goto out_delete_evlist;
  93        }
  94
  95        for (i = 0; i < nsyscalls; ++i)
  96                for (j = 0; j < expected_nr_events[i]; ++j) {
  97                        int foo = syscalls[i]();
  98                        ++foo;
  99                }
 100
 101        while ((event = perf_evlist__mmap_read(evlist, 0)) != NULL) {
 102                struct perf_sample sample;
 103
 104                if (event->header.type != PERF_RECORD_SAMPLE) {
 105                        pr_debug("unexpected %s event\n",
 106                                 perf_event__name(event->header.type));
 107                        goto out_delete_evlist;
 108                }
 109
 110                err = perf_evlist__parse_sample(evlist, event, &sample);
 111                if (err) {
 112                        pr_err("Can't parse sample, err = %d\n", err);
 113                        goto out_delete_evlist;
 114                }
 115
 116                err = -1;
 117                evsel = perf_evlist__id2evsel(evlist, sample.id);
 118                if (evsel == NULL) {
 119                        pr_debug("event with id %" PRIu64
 120                                 " doesn't map to an evsel\n", sample.id);
 121                        goto out_delete_evlist;
 122                }
 123                nr_events[evsel->idx]++;
 124                perf_evlist__mmap_consume(evlist, 0);
 125        }
 126
 127        err = 0;
 128        evlist__for_each(evlist, evsel) {
 129                if (nr_events[evsel->idx] != expected_nr_events[evsel->idx]) {
 130                        pr_debug("expected %d %s events, got %d\n",
 131                                 expected_nr_events[evsel->idx],
 132                                 perf_evsel__name(evsel), nr_events[evsel->idx]);
 133                        err = -1;
 134                        goto out_delete_evlist;
 135                }
 136        }
 137
 138out_delete_evlist:
 139        perf_evlist__delete(evlist);
 140        cpus    = NULL;
 141        threads = NULL;
 142out_free_cpus:
 143        cpu_map__put(cpus);
 144out_free_threads:
 145        thread_map__put(threads);
 146        return err;
 147}
 148