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

   1 #include <api/fs/fs.h>
   2 #include "evsel.h"
   3 #include "tests.h"
   4 #include "thread_map.h"
   5 #include "cpumap.h"
   6 #include "debug.h"
   7 #include "stat.h"
   8
   9 int test__openat_syscall_event_on_all_cpus(void)
  10 {
  11         int err = -1, fd, cpu;
  12         struct cpu_map *cpus;
  13         struct perf_evsel *evsel;
  14         unsigned int nr_openat_calls = 111, i;
  15         cpu_set_t cpu_set;
  16         struct thread_map *threads = thread_map__new(-1, getpid(), UINT_MAX);
  17         char sbuf[STRERR_BUFSIZE];
  18
  19         if (threads == NULL) {
  20                 pr_debug("thread_map__new\n");
  21                 return -1;
  22         }
  23
  24         cpus = cpu_map__new(NULL);
  25         if (cpus == NULL) {
  26                 pr_debug("cpu_map__new\n");
  27                 goto out_thread_map_delete;
  28         }
  29
  30         CPU_ZERO(&cpu_set);
  31
  32         evsel = perf_evsel__newtp("syscalls", "sys_enter_openat");
  33         if (evsel == NULL) {
  34                 if (tracefs__configured())
  35                         pr_debug("is tracefs mounted on /sys/kernel/tracing?\n");
  36                 else if (debugfs__configured())
  37                         pr_debug("is debugfs mounted on /sys/kernel/debug?\n");
  38                 else
  39                         pr_debug("Neither tracefs or debugfs is enabled in this kernel\n");
  40                 goto out_thread_map_delete;
  41         }
  42
  43         if (perf_evsel__open(evsel, cpus, threads) < 0) {
  44                 pr_debug("failed to open counter: %s, "
  45                          "tweak /proc/sys/kernel/perf_event_paranoid?\n",
  46                          strerror_r(errno, sbuf, sizeof(sbuf)));
  47                 goto out_evsel_delete;
  48         }
  49
  50         for (cpu = 0; cpu < cpus->nr; ++cpu) {
  51                 unsigned int ncalls = nr_openat_calls + cpu;
  52                 /*
  53                  * XXX eventually lift this restriction in a way that
  54                  * keeps perf building on older glibc installations
  55                  * without CPU_ALLOC. 1024 cpus in 2010 still seems
  56                  * a reasonable upper limit tho :-)
  57                  */
  58                 if (cpus->map[cpu] >= CPU_SETSIZE) {
  59                         pr_debug("Ignoring CPU %d\n", cpus->map[cpu]);
  60                         continue;
  61                 }
  62
  63                 CPU_SET(cpus->map[cpu], &cpu_set);
  64                 if (sched_setaffinity(0, sizeof(cpu_set), &cpu_set) < 0) {
  65                         pr_debug("sched_setaffinity() failed on CPU %d: %s ",
  66                                  cpus->map[cpu],
  67                                  strerror_r(errno, sbuf, sizeof(sbuf)));
  68                         goto out_close_fd;
  69                 }
  70                 for (i = 0; i < ncalls; ++i) {
  71                         fd = openat(0, "/etc/passwd", O_RDONLY);
  72                         close(fd);
  73                 }
  74                 CPU_CLR(cpus->map[cpu], &cpu_set);
  75         }
  76
  77         /*
  78          * Here we need to explicitely preallocate the counts, as if
  79          * we use the auto allocation it will allocate just for 1 cpu,
  80          * as we start by cpu 0.
  81          */
  82         if (perf_evsel__alloc_counts(evsel, cpus->nr, 1) < 0) {
  83                 pr_debug("perf_evsel__alloc_counts(ncpus=%d)\n", cpus->nr);
  84                 goto out_close_fd;
  85         }
  86
  87         err = 0;
  88
  89         for (cpu = 0; cpu < cpus->nr; ++cpu) {
  90                 unsigned int expected;
  91
  92                 if (cpus->map[cpu] >= CPU_SETSIZE)
  93                         continue;
  94
  95                 if (perf_evsel__read_on_cpu(evsel, cpu, 0) < 0) {
  96                         pr_debug("perf_evsel__read_on_cpu\n");
  97                         err = -1;
  98                         break;
  99                 }
 100
 101                 expected = nr_openat_calls + cpu;
 102                 if (perf_counts(evsel->counts, cpu, 0)->val != expected) {
 103                         pr_debug("perf_evsel__read_on_cpu: expected to intercept %d calls on cpu %d, got %" PRIu64 "\n",
 104                                  expected, cpus->map[cpu], perf_counts(evsel->counts, cpu, 0)->val);
 105                         err = -1;
 106                 }
 107         }
 108
 109         perf_evsel__free_counts(evsel);
 110 out_close_fd:
 111         perf_evsel__close_fd(evsel, 1, threads->nr);
 112 out_evsel_delete:
 113         perf_evsel__delete(evsel);
 114 out_thread_map_delete:
 115         thread_map__put(threads);
 116         return err;
 117 }