Message-ID: <CA+GJov6Xcn_X8iDz9wQhpSo_O+v4DyaqYfW8heQ_+q-DxdOK9Q@mail.gmail.com>
Date: Tue, 5 Aug 2025 11:19:16 -0400
From: Rae Moar <rmoar@...gle.com>
To: Marie Zhussupova <marievic@...gle.com>
Cc: davidgow@...gle.com, shuah@...nel.org, brendan.higgins@...ux.dev, 
	elver@...gle.com, dvyukov@...gle.com, lucas.demarchi@...el.com, 
	thomas.hellstrom@...ux.intel.com, rodrigo.vivi@...el.com, 
	linux-kselftest@...r.kernel.org, kunit-dev@...glegroups.com, 
	kasan-dev@...glegroups.com, intel-xe@...ts.freedesktop.org, 
	dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 8/9] kunit: Add example parameterized test with direct
 dynamic parameter array setup

On Tue, Jul 29, 2025 at 3:37 PM Marie Zhussupova <marievic@...gle.com> wrote:
>
> Introduce `example_params_test_with_init_dynamic_arr`. This new
> KUnit test demonstrates directly assigning a dynamic parameter
> array using the `kunit_register_params_array` macro. It highlights the
> use of `param_init` and `param_exit` for proper initialization and
> cleanup, and their registration to the test with
> `KUNIT_CASE_PARAM_WITH_INIT`.
>
> Signed-off-by: Marie Zhussupova <marievic@...gle.com>

Hello!

This test is interesting and complex. I am very happy to see this test
accepted. I think it is a good demonstration of the new parameterized
test features.

Reviewed-by: Rae Moar <rmoar@...gle.com>

Thanks!

-Rae

> ---
>  lib/kunit/kunit-example-test.c | 95 ++++++++++++++++++++++++++++++++++
>  1 file changed, 95 insertions(+)
>
> diff --git a/lib/kunit/kunit-example-test.c b/lib/kunit/kunit-example-test.c
> index 5bf559e243f6..3ab121d81bf6 100644
> --- a/lib/kunit/kunit-example-test.c
> +++ b/lib/kunit/kunit-example-test.c
> @@ -387,6 +387,98 @@ static void example_params_test_with_init(struct kunit *test)
>         kunit_put_resource(res);
>  }
>
> +/*
> + * Helper function to create a parameter array of Fibonacci numbers. This example
> + * highlights a parameter generation scenario that is:
> + * 1. Not feasible to fully pre-generate at compile time.
> + * 2. Challenging to implement with a standard 'generate_params' function,
> + * as it typically only provides the immediately 'prev' parameter, while
> + * Fibonacci requires access to two preceding values for calculation.
> + */
> +static void *make_fibonacci_params(int seq_size)
> +{
> +       int *seq;
> +
> +       if (seq_size <= 0)
> +               return NULL;
> +
> +       seq = kmalloc_array(seq_size, sizeof(int), GFP_KERNEL);
> +
> +       if (!seq)
> +               return NULL;
> +
> +       if (seq_size >= 1)
> +               seq[0] = 0;
> +       if (seq_size >= 2)
> +               seq[1] = 1;
> +       for (int i = 2; i < seq_size; i++)
> +               seq[i] = seq[i - 1] + seq[i - 2];
> +       return seq;
> +}
> +
> +/*
> + * This is an example of a function that provides a description for each of the
> + * parameters.
> + */
> +static void example_param_dynamic_arr_get_desc(const void *p, char *desc)
> +{
> +       const int *fib_num = p;
> +
> +       snprintf(desc, KUNIT_PARAM_DESC_SIZE, "fibonacci param: %d", *fib_num);
> +}
> +
> +/*
> + * Example of a parameterized test init function that registers a dynamic array.
> + */
> +static int example_param_init_dynamic_arr(struct kunit *test)
> +{
> +       int seq_size = 6;
> +       int *fibonacci_params = make_fibonacci_params(seq_size);
> +
> +       if (!fibonacci_params)
> +               return -ENOMEM;
> +
> +       /*
> +        * Passes the dynamic parameter array information to the parent struct kunit.
> +        * The array and its metadata will be stored in test->parent->params_data.
> +        * The array itself will be located in params_data.params.
> +        */
> +       kunit_register_params_array(test, fibonacci_params, seq_size,
> +                                   example_param_dynamic_arr_get_desc);
> +       return 0;
> +}
> +
> +/**
> + * Function to clean up the parameterized test's parent kunit struct if
> + * there were custom allocations.
> + */
> +static void example_param_exit_dynamic_arr(struct kunit *test)
> +{
> +       /*
> +        * We allocated this array, so we need to free it.
> +        * Since the parent parameter instance is passed here,
> +        * we can directly access the array via `test->params_data.params`
> +        * instead of `test->parent->params_data.params`.
> +        */
> +       kfree(test->params_data.params);
> +}
> +
> +/*
> + * Example of test that uses the registered dynamic array to perform assertions
> + * and expectations.
> + */
> +static void example_params_test_with_init_dynamic_arr(struct kunit *test)
> +{
> +       const int *param = test->param_value;
> +       int param_val;
> +
> +       /* By design, param pointer will not be NULL. */
> +       KUNIT_ASSERT_NOT_NULL(test, param);
> +
> +       param_val = *param;
> +       KUNIT_EXPECT_EQ(test, param_val - param_val, 0);
> +}
> +
>  /*
>   * Here we make a list of all the test cases we want to add to the test suite
>   * below.
> @@ -408,6 +500,9 @@ static struct kunit_case example_test_cases[] = {
>         KUNIT_CASE_PARAM(example_params_test, example_gen_params),
>         KUNIT_CASE_PARAM_WITH_INIT(example_params_test_with_init, NULL,
>                                    example_param_init, NULL),
> +       KUNIT_CASE_PARAM_WITH_INIT(example_params_test_with_init_dynamic_arr, NULL,
> +                                  example_param_init_dynamic_arr,
> +                                  example_param_exit_dynamic_arr),
>         KUNIT_CASE_SLOW(example_slow_test),
>         {}
>  };
> --
> 2.50.1.552.g942d659e1b-goog
>

Powered by blists - more mailing lists