LXR linux/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
  13int 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);
 111out_close_fd:
 112        perf_evsel__close_fd(evsel, 1, threads->nr);
 113out_evsel_delete:
 114        perf_evsel__delete(evsel);
 115out_thread_map_delete:
 116        thread_map__put(threads);
 117        return err;
 118}
 119