LXR linux/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
  19int 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);
 117out_close_fd:
 118        perf_evsel__close_fd(evsel, 1, threads->nr);
 119out_evsel_delete:
 120        perf_evsel__delete(evsel);
 121out_thread_map_delete:
 122        thread_map__put(threads);
 123        return err;
 124}
 125