Re: [PATCH v2 2/2] drm/buddy: Add a testcase to verify the multiroot fini

[Jani Nikula <jani.nikula@linux.intel.com>]

On Thu, 26 Dec 2024, Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com> wrote:
> - Added a testcase to verify the multiroot force merge fini.
> - Added a new field in_use to track the mm freed status.
>
> v2:(Matthew)
>   - Add kunit_fail_current_test() when WARN_ON is true.

This i.e. commit 8cb3a1e2b350 ("drm/buddy: Add a testcase to verify the
multiroot fini") fails drm-tip build for me with:

In file included from ../drivers/gpu/drm/tests/drm_buddy_test.c:15:
../drivers/gpu/drm/tests/drm_buddy_test.c: In function ‘drm_test_buddy_alloc_clear’:
../drivers/gpu/drm/tests/drm_buddy_test.c:264:23: error: unused variable ‘prng’ [-Werror=unused-variable]
  264 |         DRM_RND_STATE(prng, random_seed);
      |                       ^~~~
../drivers/gpu/drm/tests/../lib/drm_random.h:18:26: note: in definition of macro ‘DRM_RND_STATE’
   18 |         struct rnd_state name__ = DRM_RND_STATE_INITIALIZER(seed__)
      |                          ^~~~~~
cc1: all warnings being treated as errors


BR,
Jani.


>
> Signed-off-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com>
> Signed-off-by: Lin.Cao <lincao12@amd.com>
> ---
>  drivers/gpu/drm/drm_buddy.c            |  6 +++++-
>  drivers/gpu/drm/tests/drm_buddy_test.c | 29 ++++++++++++++++++--------
>  2 files changed, 25 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_buddy.c b/drivers/gpu/drm/drm_buddy.c
> index ca42e6081d27..241c855f891f 100644
> --- a/drivers/gpu/drm/drm_buddy.c
> +++ b/drivers/gpu/drm/drm_buddy.c
> @@ -3,6 +3,8 @@
>   * Copyright © 2021 Intel Corporation
>   */
>  
> +#include <kunit/test-bug.h>
> +
>  #include <linux/kmemleak.h>
>  #include <linux/module.h>
>  #include <linux/sizes.h>
> @@ -335,7 +337,9 @@ void drm_buddy_fini(struct drm_buddy *mm)
>  		start = drm_buddy_block_offset(mm->roots[i]);
>  		__force_merge(mm, start, start + size, order);
>  
> -		WARN_ON(!drm_buddy_block_is_free(mm->roots[i]));
> +		if (WARN_ON(!drm_buddy_block_is_free(mm->roots[i])))
> +			kunit_fail_current_test("buddy_fini() root");
> +
>  		drm_block_free(mm, mm->roots[i]);
>  
>  		root_size = mm->chunk_size << order;
> diff --git a/drivers/gpu/drm/tests/drm_buddy_test.c b/drivers/gpu/drm/tests/drm_buddy_test.c
> index 9662c949d0e3..4b5818f9f2a9 100644
> --- a/drivers/gpu/drm/tests/drm_buddy_test.c
> +++ b/drivers/gpu/drm/tests/drm_buddy_test.c
> @@ -385,17 +385,28 @@ static void drm_test_buddy_alloc_clear(struct kunit *test)
>  	drm_buddy_fini(&mm);
>  
>  	/*
> -	 * Create a new mm with a non power-of-two size. Allocate a random size, free as
> -	 * cleared and then call fini. This will ensure the multi-root force merge during
> -	 * fini.
> +	 * Create a new mm with a non power-of-two size. Allocate a random size from each
> +	 * root, free as cleared and then call fini. This will ensure the multi-root
> +	 * force merge during fini.
>  	 */
> -	mm_size = 12 * SZ_4K;
> -	size = max(round_up(prandom_u32_state(&prng) % mm_size, ps), ps);
> +	mm_size = (SZ_4K << max_order) + (SZ_4K << (max_order - 2));
> +
>  	KUNIT_EXPECT_FALSE(test, drm_buddy_init(&mm, mm_size, ps));
> -	KUNIT_ASSERT_FALSE_MSG(test, drm_buddy_alloc_blocks(&mm, 0, mm_size,
> -							    size, ps, &allocated,
> -							    DRM_BUDDY_TOPDOWN_ALLOCATION),
> -				"buddy_alloc hit an error size=%u\n", size);
> +	KUNIT_EXPECT_EQ(test, mm.max_order, max_order);
> +	KUNIT_ASSERT_FALSE_MSG(test, drm_buddy_alloc_blocks(&mm, 0, SZ_4K << max_order,
> +							    4 * ps, ps, &allocated,
> +							    DRM_BUDDY_RANGE_ALLOCATION),
> +				"buddy_alloc hit an error size=%lu\n", 4 * ps);
> +	drm_buddy_free_list(&mm, &allocated, DRM_BUDDY_CLEARED);
> +	KUNIT_ASSERT_FALSE_MSG(test, drm_buddy_alloc_blocks(&mm, 0, SZ_4K << max_order,
> +							    2 * ps, ps, &allocated,
> +							    DRM_BUDDY_CLEAR_ALLOCATION),
> +				"buddy_alloc hit an error size=%lu\n", 2 * ps);
> +	drm_buddy_free_list(&mm, &allocated, DRM_BUDDY_CLEARED);
> +	KUNIT_ASSERT_FALSE_MSG(test, drm_buddy_alloc_blocks(&mm, SZ_4K << max_order, mm_size,
> +							    ps, ps, &allocated,
> +							    DRM_BUDDY_RANGE_ALLOCATION),
> +				"buddy_alloc hit an error size=%lu\n", ps);
>  	drm_buddy_free_list(&mm, &allocated, DRM_BUDDY_CLEARED);
>  	drm_buddy_fini(&mm);
>  }

-- 
Jani Nikula, Intel