int __perf_evsel__read_on_cpu(struct perf_evsel *evsel, int cpu, int thread, bool scale) { struct perf_counts_values count; size_t nv = scale ? 3 : 1; if (FD(evsel, cpu, thread) < 0) return -EINVAL; if (evsel->counts == NULL && perf_evsel__alloc_counts(evsel, cpu + 1) < 0) return -ENOMEM; if (readn(FD(evsel, cpu, thread), &count, nv * sizeof(u64)) < 0) return -errno; if (scale) { if (count.run == 0) count.val = 0; else if (count.run < count.ena) count.val = (u64)((double)count.val * count.ena / count.run + 0.5); } else count.ena = count.run = 0; evsel->counts->cpu[cpu] = count; return 0; }
static int perf_evsel__alloc_stats(struct perf_evsel *evsel, bool alloc_raw) { int ncpus = perf_evsel__nr_cpus(evsel); int nthreads = thread_map__nr(evsel->threads); if (perf_evsel__alloc_stat_priv(evsel) < 0 || perf_evsel__alloc_counts(evsel, ncpus, nthreads) < 0 || (alloc_raw && perf_evsel__alloc_prev_raw_counts(evsel, ncpus, nthreads) < 0)) return -ENOMEM; return 0; }
int test__openat_syscall_event_on_all_cpus(int subtest __maybe_unused) { int err = -1, fd, cpu; struct cpu_map *cpus; struct perf_evsel *evsel; unsigned int nr_openat_calls = 111, i; cpu_set_t cpu_set; struct thread_map *threads = thread_map__new(-1, getpid(), UINT_MAX); char sbuf[STRERR_BUFSIZE]; char errbuf[BUFSIZ]; if (threads == NULL) { pr_debug("thread_map__new\n"); return -1; } cpus = cpu_map__new(NULL); if (cpus == NULL) { pr_debug("cpu_map__new\n"); goto out_thread_map_delete; } CPU_ZERO(&cpu_set); evsel = perf_evsel__newtp("syscalls", "sys_enter_openat"); if (IS_ERR(evsel)) { tracing_path__strerror_open_tp(errno, errbuf, sizeof(errbuf), "syscalls", "sys_enter_openat"); pr_debug("%s\n", errbuf); goto out_thread_map_delete; } if (perf_evsel__open(evsel, cpus, threads) < 0) { pr_debug("failed to open counter: %s, " "tweak /proc/sys/kernel/perf_event_paranoid?\n", str_error_r(errno, sbuf, sizeof(sbuf))); goto out_evsel_delete; } for (cpu = 0; cpu < cpus->nr; ++cpu) { unsigned int ncalls = nr_openat_calls + cpu; /* * XXX eventually lift this restriction in a way that * keeps perf building on older glibc installations * without CPU_ALLOC. 1024 cpus in 2010 still seems * a reasonable upper limit tho :-) */ if (cpus->map[cpu] >= CPU_SETSIZE) { pr_debug("Ignoring CPU %d\n", cpus->map[cpu]); continue; } CPU_SET(cpus->map[cpu], &cpu_set); if (sched_setaffinity(0, sizeof(cpu_set), &cpu_set) < 0) { pr_debug("sched_setaffinity() failed on CPU %d: %s ", cpus->map[cpu], str_error_r(errno, sbuf, sizeof(sbuf))); goto out_close_fd; } for (i = 0; i < ncalls; ++i) { fd = openat(0, "/etc/passwd", O_RDONLY); close(fd); } CPU_CLR(cpus->map[cpu], &cpu_set); } /* * Here we need to explicitly preallocate the counts, as if * we use the auto allocation it will allocate just for 1 cpu, * as we start by cpu 0. */ if (perf_evsel__alloc_counts(evsel, cpus->nr, 1) < 0) { pr_debug("perf_evsel__alloc_counts(ncpus=%d)\n", cpus->nr); goto out_close_fd; } err = 0; for (cpu = 0; cpu < cpus->nr; ++cpu) { unsigned int expected; if (cpus->map[cpu] >= CPU_SETSIZE) continue; if (perf_evsel__read_on_cpu(evsel, cpu, 0) < 0) { pr_debug("perf_evsel__read_on_cpu\n"); err = -1; break; } expected = nr_openat_calls + cpu; if (perf_counts(evsel->counts, cpu, 0)->val != expected) { pr_debug("perf_evsel__read_on_cpu: expected to intercept %d calls on cpu %d, got %" PRIu64 "\n", expected, cpus->map[cpu], perf_counts(evsel->counts, cpu, 0)->val); err = -1; } } perf_evsel__free_counts(evsel); out_close_fd: perf_evsel__close_fd(evsel, 1, threads->nr); out_evsel_delete: perf_evsel__delete(evsel); out_thread_map_delete: thread_map__put(threads); return err; }