LXR linux/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
  23int 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);
 121out_close_fd:
 122        perf_evsel__close_fd(&evsel->core);
 123out_evsel_delete:
 124        evsel__delete(evsel);
 125out_cpu_map_delete:
 126        perf_cpu_map__put(cpus);
 127out_thread_map_delete:
 128        perf_thread_map__put(threads);
 129        return err;
 130}
 131