tools/perf/tests/openat-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 #include "stat.h"
   7
   8 int test__openat_syscall_event_on_all_cpus(void)
   9 {
  10         int err = -1, fd, cpu;
  11         struct cpu_map *cpus;
  12         struct perf_evsel *evsel;
  13         unsigned int nr_openat_calls = 111, i;
  14         cpu_set_t cpu_set;
  15         struct thread_map *threads = thread_map__new(-1, getpid(), UINT_MAX);
  16         char sbuf[STRERR_BUFSIZE];
  17
  18         if (threads == NULL) {
  19                 pr_debug("thread_map__new\n");
  20                 return -1;
  21         }
  22
  23         cpus = cpu_map__new(NULL);
  24         if (cpus == NULL) {
  25                 pr_debug("cpu_map__new\n");
  26                 goto out_thread_map_delete;
  27         }
  28
  29         CPU_ZERO(&cpu_set);
  30
  31         evsel = perf_evsel__newtp("syscalls", "sys_enter_openat");
  32         if (evsel == NULL) {
  33                 if (tracefs_configured())
  34                         pr_debug("is tracefs mounted on /sys/kernel/tracing?\n");
  35                 else if (debugfs_configured())
  36                         pr_debug("is debugfs mounted on /sys/kernel/debug?\n");
  37                 else
  38                         pr_debug("Neither tracefs or debugfs is enabled in this kernel\n");
  39                 goto out_thread_map_delete;
  40         }
  41
  42         if (perf_evsel__open(evsel, cpus, threads) < 0) {
  43                 pr_debug("failed to open counter: %s, "
  44                          "tweak /proc/sys/kernel/perf_event_paranoid?\n",
  45                          strerror_r(errno, sbuf, sizeof(sbuf)));
  46                 goto out_evsel_delete;
  47         }
  48
  49         for (cpu = 0; cpu < cpus->nr; ++cpu) {
  50                 unsigned int ncalls = nr_openat_calls + cpu;
  51                 /*
  52                  * XXX eventually lift this restriction in a way that
  53                  * keeps perf building on older glibc installations
  54                  * without CPU_ALLOC. 1024 cpus in 2010 still seems
  55                  * a reasonable upper limit tho :-)
  56                  */
  57                 if (cpus->map[cpu] >= CPU_SETSIZE) {
  58                         pr_debug("Ignoring CPU %d\n", cpus->map[cpu]);
  59                         continue;
  60                 }
  61
  62                 CPU_SET(cpus->map[cpu], &cpu_set);
  63                 if (sched_setaffinity(0, sizeof(cpu_set), &cpu_set) < 0) {
  64                         pr_debug("sched_setaffinity() failed on CPU %d: %s ",
  65                                  cpus->map[cpu],
  66                                  strerror_r(errno, sbuf, sizeof(sbuf)));
  67                         goto out_close_fd;
  68                 }
  69                 for (i = 0; i < ncalls; ++i) {
  70                         fd = openat(0, "/etc/passwd", O_RDONLY);
  71                         close(fd);
  72                 }
  73                 CPU_CLR(cpus->map[cpu], &cpu_set);
  74         }
  75
  76         /*
  77          * Here we need to explicitely preallocate the counts, as if
  78          * we use the auto allocation it will allocate just for 1 cpu,
  79          * as we start by cpu 0.
  80          */
  81         if (perf_evsel__alloc_counts(evsel, cpus->nr, 1) < 0) {
  82                 pr_debug("perf_evsel__alloc_counts(ncpus=%d)\n", cpus->nr);
  83                 goto out_close_fd;
  84         }
  85
  86         err = 0;
  87
  88         for (cpu = 0; cpu < cpus->nr; ++cpu) {
  89                 unsigned int expected;
  90
  91                 if (cpus->map[cpu] >= CPU_SETSIZE)
  92                         continue;
  93
  94                 if (perf_evsel__read_on_cpu(evsel, cpu, 0) < 0) {
  95                         pr_debug("perf_evsel__read_on_cpu\n");
  96                         err = -1;
  97                         break;
  98                 }
  99
 100                 expected = nr_openat_calls + cpu;
 101                 if (perf_counts(evsel->counts, cpu, 0)->val != expected) {
 102                         pr_debug("perf_evsel__read_on_cpu: expected to intercept %d calls on cpu %d, got %" PRIu64 "\n",
 103                                  expected, cpus->map[cpu], perf_counts(evsel->counts, cpu, 0)->val);
 104                         err = -1;
 105                 }
 106         }
 107
 108         perf_evsel__free_counts(evsel);
 109 out_close_fd:
 110         perf_evsel__close_fd(evsel, 1, threads->nr);
 111 out_evsel_delete:
 112         perf_evsel__delete(evsel);
 113 out_thread_map_delete:
 114         thread_map__put(threads);
 115         return err;
 116 }