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

   1 #include <errno.h>
   2 #include <inttypes.h>
   3 /* For the CPU_* macros */
   4 #include <pthread.h>
   5
   6 #include <sys/types.h>
   7 #include <sys/stat.h>
   8 #include <fcntl.h>
   9 #include <api/fs/fs.h>
  10 #include <linux/err.h>
  11 #include <api/fs/tracing_path.h>
  12 #include "evsel.h"
  13 #include "tests.h"
  14 #include "thread_map.h"
  15 #include "cpumap.h"
  16 #include "debug.h"
  17 #include "stat.h"
  18
  19 int test__openat_syscall_event_on_all_cpus(int subtest __maybe_unused)
  20 {
  21         int err = -1, fd, cpu;
  22         struct cpu_map *cpus;
  23         struct perf_evsel *evsel;
  24         unsigned int nr_openat_calls = 111, i;
  25         cpu_set_t cpu_set;
  26         struct thread_map *threads = thread_map__new(-1, getpid(), UINT_MAX);
  27         char sbuf[STRERR_BUFSIZE];
  28         char errbuf[BUFSIZ];
  29
  30         if (threads == NULL) {
  31                 pr_debug("thread_map__new\n");
  32                 return -1;
  33         }
  34
  35         cpus = cpu_map__new(NULL);
  36         if (cpus == NULL) {
  37                 pr_debug("cpu_map__new\n");
  38                 goto out_thread_map_delete;
  39         }
  40
  41         CPU_ZERO(&cpu_set);
  42
  43         evsel = perf_evsel__newtp("syscalls", "sys_enter_openat");
  44         if (IS_ERR(evsel)) {
  45                 tracing_path__strerror_open_tp(errno, errbuf, sizeof(errbuf), "syscalls", "sys_enter_openat");
  46                 pr_debug("%s\n", errbuf);
  47                 goto out_thread_map_delete;
  48         }
  49
  50         if (perf_evsel__open(evsel, cpus, threads) < 0) {
  51                 pr_debug("failed to open counter: %s, "
  52                          "tweak /proc/sys/kernel/perf_event_paranoid?\n",
  53                          str_error_r(errno, sbuf, sizeof(sbuf)));
  54                 goto out_evsel_delete;
  55         }
  56
  57         for (cpu = 0; cpu < cpus->nr; ++cpu) {
  58                 unsigned int ncalls = nr_openat_calls + cpu;
  59                 /*
  60                  * XXX eventually lift this restriction in a way that
  61                  * keeps perf building on older glibc installations
  62                  * without CPU_ALLOC. 1024 cpus in 2010 still seems
  63                  * a reasonable upper limit tho :-)
  64                  */
  65                 if (cpus->map[cpu] >= CPU_SETSIZE) {
  66                         pr_debug("Ignoring CPU %d\n", cpus->map[cpu]);
  67                         continue;
  68                 }
  69
  70                 CPU_SET(cpus->map[cpu], &cpu_set);
  71                 if (sched_setaffinity(0, sizeof(cpu_set), &cpu_set) < 0) {
  72                         pr_debug("sched_setaffinity() failed on CPU %d: %s ",
  73                                  cpus->map[cpu],
  74                                  str_error_r(errno, sbuf, sizeof(sbuf)));
  75                         goto out_close_fd;
  76                 }
  77                 for (i = 0; i < ncalls; ++i) {
  78                         fd = openat(0, "/etc/passwd", O_RDONLY);
  79                         close(fd);
  80                 }
  81                 CPU_CLR(cpus->map[cpu], &cpu_set);
  82         }
  83
  84         /*
  85          * Here we need to explicitly preallocate the counts, as if
  86          * we use the auto allocation it will allocate just for 1 cpu,
  87          * as we start by cpu 0.
  88          */
  89         if (perf_evsel__alloc_counts(evsel, cpus->nr, 1) < 0) {
  90                 pr_debug("perf_evsel__alloc_counts(ncpus=%d)\n", cpus->nr);
  91                 goto out_close_fd;
  92         }
  93
  94         err = 0;
  95
  96         for (cpu = 0; cpu < cpus->nr; ++cpu) {
  97                 unsigned int expected;
  98
  99                 if (cpus->map[cpu] >= CPU_SETSIZE)
 100                         continue;
 101
 102                 if (perf_evsel__read_on_cpu(evsel, cpu, 0) < 0) {
 103                         pr_debug("perf_evsel__read_on_cpu\n");
 104                         err = -1;
 105                         break;
 106                 }
 107
 108                 expected = nr_openat_calls + cpu;
 109                 if (perf_counts(evsel->counts, cpu, 0)->val != expected) {
 110                         pr_debug("perf_evsel__read_on_cpu: expected to intercept %d calls on cpu %d, got %" PRIu64 "\n",
 111                                  expected, cpus->map[cpu], perf_counts(evsel->counts, cpu, 0)->val);
 112                         err = -1;
 113                 }
 114         }
 115
 116         perf_evsel__free_counts(evsel);
 117 out_close_fd:
 118         perf_evsel__close_fd(evsel, 1, threads->nr);
 119 out_evsel_delete:
 120         perf_evsel__delete(evsel);
 121 out_thread_map_delete:
 122         thread_map__put(threads);
 123         return err;
 124 }