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

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <errno.h>
   3 #include <inttypes.h>
   4 /* For the CPU_* macros */
   5 #include <pthread.h>
   6
   7 #include <sys/types.h>
   8 #include <sys/stat.h>
   9 #include <fcntl.h>
  10 #include <api/fs/fs.h>
  11 #include <linux/err.h>
  12 #include <linux/string.h>
  13 #include <api/fs/tracing_path.h>
  14 #include "evsel.h"
  15 #include "tests.h"
  16 #include "thread_map.h"
  17 #include <perf/cpumap.h>
  18 #include <internal/cpumap.h>
  19 #include "debug.h"
  20 #include "stat.h"
  21 #include "util/counts.h"
  22
  23 int test__openat_syscall_event_on_all_cpus(struct test *test __maybe_unused, int subtest __maybe_unused)
  24 {
  25         int err = -1, fd, cpu;
  26         struct perf_cpu_map *cpus;
  27         struct evsel *evsel;
  28         unsigned int nr_openat_calls = 111, i;
  29         cpu_set_t cpu_set;
  30         struct perf_thread_map *threads = thread_map__new(-1, getpid(), UINT_MAX);
  31         char sbuf[STRERR_BUFSIZE];
  32         char errbuf[BUFSIZ];
  33
  34         if (threads == NULL) {
  35                 pr_debug("thread_map__new\n");
  36                 return -1;
  37         }
  38
  39         cpus = perf_cpu_map__new(NULL);
  40         if (cpus == NULL) {
  41                 pr_debug("perf_cpu_map__new\n");
  42                 goto out_thread_map_delete;
  43         }
  44
  45         CPU_ZERO(&cpu_set);
  46
  47         evsel = evsel__newtp("syscalls", "sys_enter_openat");
  48         if (IS_ERR(evsel)) {
  49                 tracing_path__strerror_open_tp(errno, errbuf, sizeof(errbuf), "syscalls", "sys_enter_openat");
  50                 pr_debug("%s\n", errbuf);
  51                 goto out_cpu_map_delete;
  52         }
  53
  54         if (evsel__open(evsel, cpus, threads) < 0) {
  55                 pr_debug("failed to open counter: %s, "
  56                          "tweak /proc/sys/kernel/perf_event_paranoid?\n",
  57                          str_error_r(errno, sbuf, sizeof(sbuf)));
  58                 goto out_evsel_delete;
  59         }
  60
  61         for (cpu = 0; cpu < cpus->nr; ++cpu) {
  62                 unsigned int ncalls = nr_openat_calls + cpu;
  63                 /*
  64                  * XXX eventually lift this restriction in a way that
  65                  * keeps perf building on older glibc installations
  66                  * without CPU_ALLOC. 1024 cpus in 2010 still seems
  67                  * a reasonable upper limit tho :-)
  68                  */
  69                 if (cpus->map[cpu] >= CPU_SETSIZE) {
  70                         pr_debug("Ignoring CPU %d\n", cpus->map[cpu]);
  71                         continue;
  72                 }
  73
  74                 CPU_SET(cpus->map[cpu], &cpu_set);
  75                 if (sched_setaffinity(0, sizeof(cpu_set), &cpu_set) < 0) {
  76                         pr_debug("sched_setaffinity() failed on CPU %d: %s ",
  77                                  cpus->map[cpu],
  78                                  str_error_r(errno, sbuf, sizeof(sbuf)));
  79                         goto out_close_fd;
  80                 }
  81                 for (i = 0; i < ncalls; ++i) {
  82                         fd = openat(0, "/etc/passwd", O_RDONLY);
  83                         close(fd);
  84                 }
  85                 CPU_CLR(cpus->map[cpu], &cpu_set);
  86         }
  87
  88         /*
  89          * Here we need to explicitly preallocate the counts, as if
  90          * we use the auto allocation it will allocate just for 1 cpu,
  91          * as we start by cpu 0.
  92          */
  93         if (evsel__alloc_counts(evsel, cpus->nr, 1) < 0) {
  94                 pr_debug("evsel__alloc_counts(ncpus=%d)\n", cpus->nr);
  95                 goto out_close_fd;
  96         }
  97
  98         err = 0;
  99
 100         for (cpu = 0; cpu < cpus->nr; ++cpu) {
 101                 unsigned int expected;
 102
 103                 if (cpus->map[cpu] >= CPU_SETSIZE)
 104                         continue;
 105
 106                 if (evsel__read_on_cpu(evsel, cpu, 0) < 0) {
 107                         pr_debug("evsel__read_on_cpu\n");
 108                         err = -1;
 109                         break;
 110                 }
 111
 112                 expected = nr_openat_calls + cpu;
 113                 if (perf_counts(evsel->counts, cpu, 0)->val != expected) {
 114                         pr_debug("evsel__read_on_cpu: expected to intercept %d calls on cpu %d, got %" PRIu64 "\n",
 115                                  expected, cpus->map[cpu], perf_counts(evsel->counts, cpu, 0)->val);
 116                         err = -1;
 117                 }
 118         }
 119
 120         evsel__free_counts(evsel);
 121 out_close_fd:
 122         perf_evsel__close_fd(&evsel->core);
 123 out_evsel_delete:
 124         evsel__delete(evsel);
 125 out_cpu_map_delete:
 126         perf_cpu_map__put(cpus);
 127 out_thread_map_delete:
 128         perf_thread_map__put(threads);
 129         return err;
 130 }