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;
}