Re: [PATCH 4/7] perf test: Basic mmap use skip

[Namhyung Kim <namhyung@kernel.org>]

On Thu, May 12, 2022 at 9:05 PM Ian Rogers <irogers@google.com> wrote:
>
> If opening the first event fails for basic mmap it is more likely
> permission related that a true error. Mark the test as skip in this
> case and add a skip reason.
>
> Signed-off-by: Ian Rogers <irogers@google.com>
> ---
>  tools/perf/tests/mmap-basic.c | 22 ++++++++++++++++++++--
>  1 file changed, 20 insertions(+), 2 deletions(-)
>
> diff --git a/tools/perf/tests/mmap-basic.c b/tools/perf/tests/mmap-basic.c
> index c3c17600f29c..32f0a63fa157 100644
> --- a/tools/perf/tests/mmap-basic.c
> +++ b/tools/perf/tests/mmap-basic.c
> @@ -31,7 +31,7 @@
>   */
>  static int test__basic_mmap(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
>  {
> -       int err = -1;
> +       int err = TEST_FAIL;
>         union perf_event *event;
>         struct perf_thread_map *threads;
>         struct perf_cpu_map *cpus;
> @@ -83,6 +83,14 @@ static int test__basic_mmap(struct test_suite *test __maybe_unused, int subtest
>                 evsels[i] = evsel__newtp("syscalls", name);
>                 if (IS_ERR(evsels[i])) {
>                         pr_debug("evsel__new(%s)\n", name);
> +                       if (i == 0) {
> +                               /*
> +                                * Failure to open first event is more likely
> +                                * related to permissions so flag the failure as
> +                                * a skip.
> +                                */
> +                               err = TEST_SKIP;

This is not about perf_event_open() but it accesses
tracefs to get the type number of the trace event.

The evsel__newtp() seems to return the errno in a
negative number.  It'd be better to check if it's
-EACCES actually.

Thanks,
Namhyung


> +                       }
>                         goto out_delete_evlist;
>                 }
>
> @@ -166,4 +174,14 @@ static int test__basic_mmap(struct test_suite *test __maybe_unused, int subtest
>         return err;
>  }
>
> -DEFINE_SUITE("Read samples using the mmap interface", basic_mmap);
> +static struct test_case tests__basic_mmap[] = {
> +       TEST_CASE_REASON("Read samples using the mmap interface",
> +                        basic_mmap,
> +                        "permissions"),
> +       {       .name = NULL, }
> +};
> +
> +struct test_suite suite__basic_mmap = {
> +       .desc = "Read samples using the mmap interface",
> +       .test_cases = tests__basic_mmap,
> +};
> --
> 2.36.0.550.gb090851708-goog
>