linux/tools/perf/tests/openat-syscall-all-cpus.c
Namhyung Kim 8719138318 perf test: Silence tracepoint event failures
Currently, when 'perf test' is run by a normal user, it'll fail to
access tracepoint events.  The output becomes somewhat messy because it
tries to be nice with long error messages and hints.

IMHO this is not needed for 'perf test' by default and AFAIK 'perf test'
uses pr_debug() rather than pr_err() for such messages so that one can
use -v option to see further details on failed testcases if needed.

Before:
  $ perf test
   1: vmlinux symtab matches kallsyms                          : FAILED!
   2: detect openat syscall event                              :Error:
  No permissions to read
  /sys/kernel/debug/tracing/events/syscalls/sys_enter_openat
  Hint:	Try 'sudo mount -o remount,mode=755 /sys/kernel/debug/tracing'
  FAILED!
   3: detect openat syscall event on all cpus                  :Error:
  No permissions to read
  /sys/kernel/debug/tracing/events/syscalls/sys_enter_openat
  Hint:	Try 'sudo mount -o remount,mode=755 /sys/kernel/debug/tracing'
  FAILED!
   ...

After:
  $ perf test
   1: vmlinux symtab matches kallsyms                          : FAILED!
   2: detect openat syscall event                              : FAILED!
   3: detect openat syscall event on all cpus                  : FAILED!
   ...

  $ perf test -v 2
   2: detect openat syscall event                              :
  --- start ---
  test child forked, pid 30575
  Error:	    No permissions to read
  /sys/kernel/debug/tracing/events/syscalls/sys_enter_openat
  Hint:  Try 'sudo mount -o remount,mode=755 /sys/kernel/debug/tracing'

  test child finished with -1
  ---- end ----
  detect openat syscall event: FAILED!

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1445268229-1601-1-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-10-19 14:57:49 -03:00

116 lines
2.9 KiB
C

#include <api/fs/fs.h>
#include <linux/err.h>
#include "evsel.h"
#include "tests.h"
#include "thread_map.h"
#include "cpumap.h"
#include "debug.h"
#include "stat.h"
int test__openat_syscall_event_on_all_cpus(void)
{
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",
strerror_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],
strerror_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 explicitely 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;
}