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From:   Marco Elver <elver@google.com>
Date:   Wed, 26 Oct 2022 09:21:22 -0700
Message-ID: <CANpmjNMLuep71fz2P=9ZrYSaD_GwE6XDf69+auf=2G7FYqu4sw@mail.gmail.com>
Subject: Re: [PATCH] perf/hw_breakpoint: test: Skip the test if dependencies unmet
To:     David Gow <davidgow@google.com>
Cc:     Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org,
        kunit-dev@googlegroups.com,
        Brendan Higgins <brendanhiggins@google.com>,
        Daniel Latypov <dlatypov@google.com>,
        kasan-dev@googlegroups.com
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On Wed, 26 Oct 2022 at 07:10, David Gow <davidgow@google.com> wrote:
>
> Running the test currently fails on non-SMP systems, despite being
> enabled by default. This means that running the test with:
>
>  ./tools/testing/kunit/kunit.py run --arch x86_64 hw_breakpoint
>
> results in every hw_breakpoint test failing with:
>
>  # test_one_cpu: failed to initialize: -22
>  not ok 1 - test_one_cpu
>
> Instead, use kunit_skip(), which will mark the test as skipped, and give
> a more comprehensible message:
>
>  ok 1 - test_one_cpu # SKIP not enough cpus
>
> This makes it more obvious that the test is not suited to the test
> environment, and so wasn't run, rather than having run and failed.
>
> Signed-off-by: David Gow <davidgow@google.com>

Acked-by: Marco Elver <elver@google.com>

Although I still get confused by the fact that skipped tests say "ok"
and then need to double check the log that tests weren't skipped.

> ---
>  kernel/events/hw_breakpoint_test.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/events/hw_breakpoint_test.c b/kernel/events/hw_breakpoint_test.c
> index 5ced822df788..c57610f52bb4 100644
> --- a/kernel/events/hw_breakpoint_test.c
> +++ b/kernel/events/hw_breakpoint_test.c
> @@ -295,11 +295,11 @@ static int test_init(struct kunit *test)
>  {
>         /* Most test cases want 2 distinct CPUs. */
>         if (num_online_cpus() < 2)
> -               return -EINVAL;
> +               kunit_skip(test, "not enough cpus");
>
>         /* Want the system to not use breakpoints elsewhere. */
>         if (hw_breakpoint_is_used())
> -               return -EBUSY;
> +               kunit_skip(test, "hw breakpoint already in use");
>
>         return 0;
>  }
> --
> 2.38.0.135.g90850a2211-goog
>