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                 if (tracefs_configured())
  33                         pr_debug("is tracefs mounted on /sys/kernel/tracing?\n");
  34                 else if (debugfs_configured())
  35                         pr_debug("is debugfs mounted on /sys/kernel/debug?\n");
  36                 else
  37                         pr_debug("Neither tracefs or debugfs is enabled in this kernel\n");
  38                 goto out_thread_map_delete;
  39         }
  40
  41         if (perf_evsel__open(evsel, cpus, threads) < 0) {
  42                 pr_debug("failed to open counter: %s, "
  43                          "tweak /proc/sys/kernel/perf_event_paranoid?\n",
  44                          strerror_r(errno, sbuf, sizeof(sbuf)));
  45                 goto out_evsel_delete;
  46         }
  47
  48         for (cpu = 0; cpu < cpus->nr; ++cpu) {
  49                 unsigned int ncalls = nr_open_calls + cpu;
  50                 /*
  51                  * XXX eventually lift this restriction in a way that
  52                  * keeps perf building on older glibc installations
  53                  * without CPU_ALLOC. 1024 cpus in 2010 still seems
  54                  * a reasonable upper limit tho :-)
  55                  */
  56                 if (cpus->map[cpu] >= CPU_SETSIZE) {
  57                         pr_debug("Ignoring CPU %d\n", cpus->map[cpu]);
  58                         continue;
  59                 }
  60
  61                 CPU_SET(cpus->map[cpu], &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[cpu],
  65                                  strerror_r(errno, sbuf, sizeof(sbuf)));
  66                         goto out_close_fd;
  67                 }
  68                 for (i = 0; i < ncalls; ++i) {
  69                         fd = open("/etc/passwd", O_RDONLY);
  70                         close(fd);
  71                 }
  72                 CPU_CLR(cpus->map[cpu], &cpu_set);
  73         }
  74
  75         /*
  76          * Here we need to explicitely preallocate the counts, as if
  77          * we use the auto allocation it will allocate just for 1 cpu,
  78          * as we start by cpu 0.
  79          */
  80         if (perf_evsel__alloc_counts(evsel, cpus->nr) < 0) {
  81                 pr_debug("perf_evsel__alloc_counts(ncpus=%d)\n", cpus->nr);
  82                 goto out_close_fd;
  83         }
  84
  85         err = 0;
  86
  87         for (cpu = 0; cpu < cpus->nr; ++cpu) {
  88                 unsigned int expected;
  89
  90                 if (cpus->map[cpu] >= CPU_SETSIZE)
  91                         continue;
  92
  93                 if (perf_evsel__read_on_cpu(evsel, cpu, 0) < 0) {
  94                         pr_debug("perf_evsel__read_on_cpu\n");
  95                         err = -1;
  96                         break;
  97                 }
  98
  99                 expected = nr_open_calls + cpu;
 100                 if (evsel->counts->cpu[cpu].val != expected) {
 101                         pr_debug("perf_evsel__read_on_cpu: expected to intercept %d calls on cpu %d, got %" PRIu64 "\n",
 102                                  expected, cpus->map[cpu], evsel->counts->cpu[cpu].val);
 103                         err = -1;
 104                 }
 105         }
 106
 107         perf_evsel__free_counts(evsel);
 108 out_close_fd:
 109         perf_evsel__close_fd(evsel, 1, threads->nr);
 110 out_evsel_delete:
 111         perf_evsel__delete(evsel);
 112 out_thread_map_delete:
 113         thread_map__delete(threads);
 114         return err;
 115 }