tools/perf/tests/open-syscall-all-cpus.c

   1 #include "evsel.h"
   2 #include "tests.h"
   3 #include "thread_map.h"
   4 #include "cpumap.h"
   5 #include "debug.h"
   6
   7 int test__open_syscall_event_on_all_cpus(void)
   8 {
   9         int err = -1, fd, cpu;
  10         struct cpu_map *cpus;
  11         struct perf_evsel *evsel;
  12         unsigned int nr_open_calls = 111, i;
  13         cpu_set_t cpu_set;
  14         struct thread_map *threads = thread_map__new(-1, getpid(), UINT_MAX);
  15         char sbuf[STRERR_BUFSIZE];
  16
  17         if (threads == NULL) {
  18                 pr_debug("thread_map__new\n");
  19                 return -1;
  20         }
  21
  22         cpus = cpu_map__new(NULL);
  23         if (cpus == NULL) {
  24                 pr_debug("cpu_map__new\n");
  25                 goto out_thread_map_delete;
  26         }
  27
  28         CPU_ZERO(&cpu_set);
  29
  30         evsel = perf_evsel__newtp("syscalls", "sys_enter_open");
  31         if (evsel == NULL) {
  32                 pr_debug("is debugfs mounted on /sys/kernel/debug?\n");
  33                 goto out_thread_map_delete;
  34         }
  35
  36         if (perf_evsel__open(evsel, cpus, threads) < 0) {
  37                 pr_debug("failed to open counter: %s, "
  38                          "tweak /proc/sys/kernel/perf_event_paranoid?\n",
  39                          strerror_r(errno, sbuf, sizeof(sbuf)));
  40                 goto out_evsel_delete;
  41         }
  42
  43         for (cpu = 0; cpu < cpus->nr; ++cpu) {
  44                 unsigned int ncalls = nr_open_calls + cpu;
  45                 /*
  46                  * XXX eventually lift this restriction in a way that
  47                  * keeps perf building on older glibc installations
  48                  * without CPU_ALLOC. 1024 cpus in 2010 still seems
  49                  * a reasonable upper limit tho :-)
  50                  */
  51                 if (cpus->map[cpu] >= CPU_SETSIZE) {
  52                         pr_debug("Ignoring CPU %d\n", cpus->map[cpu]);
  53                         continue;
  54                 }
  55
  56                 CPU_SET(cpus->map[cpu], &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[cpu],
  60                                  strerror_r(errno, sbuf, sizeof(sbuf)));
  61                         goto out_close_fd;
  62                 }
  63                 for (i = 0; i < ncalls; ++i) {
  64                         fd = open("/etc/passwd", O_RDONLY);
  65                         close(fd);
  66                 }
  67                 CPU_CLR(cpus->map[cpu], &cpu_set);
  68         }
  69
  70         /*
  71          * Here we need to explicitely preallocate the counts, as if
  72          * we use the auto allocation it will allocate just for 1 cpu,
  73          * as we start by cpu 0.
  74          */
  75         if (perf_evsel__alloc_counts(evsel, cpus->nr) < 0) {
  76                 pr_debug("perf_evsel__alloc_counts(ncpus=%d)\n", cpus->nr);
  77                 goto out_close_fd;
  78         }
  79
  80         err = 0;
  81
  82         for (cpu = 0; cpu < cpus->nr; ++cpu) {
  83                 unsigned int expected;
  84
  85                 if (cpus->map[cpu] >= CPU_SETSIZE)
  86                         continue;
  87
  88                 if (perf_evsel__read_on_cpu(evsel, cpu, 0) < 0) {
  89                         pr_debug("perf_evsel__read_on_cpu\n");
  90                         err = -1;
  91                         break;
  92                 }
  93
  94                 expected = nr_open_calls + cpu;
  95                 if (evsel->counts->cpu[cpu].val != expected) {
  96                         pr_debug("perf_evsel__read_on_cpu: expected to intercept %d calls on cpu %d, got %" PRIu64 "\n",
  97                                  expected, cpus->map[cpu], evsel->counts->cpu[cpu].val);
  98                         err = -1;
  99                 }
 100         }
 101
 102         perf_evsel__free_counts(evsel);
 103 out_close_fd:
 104         perf_evsel__close_fd(evsel, 1, threads->nr);
 105 out_evsel_delete:
 106         perf_evsel__delete(evsel);
 107 out_thread_map_delete:
 108         thread_map__delete(threads);
 109         return err;
 110 }