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