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

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