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