Re: [PATCH] gpu/buddy: Introduce gpu_buddy_assert() for kunit-aware assertions

["Yadav, Sanjay Kumar" <sanjay.kumar.yadav@intel.com>]

On 25-02-2026 16:49, Arunpravin Paneer Selvam wrote:
> Reviewed-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com>

Thanks for your prompt review, Arun!

-Sanjay

>
> On 2/24/2026 6:55 PM, Sanjay Yadav wrote:
>> Introduce gpu_buddy_assert(), a small helper that wraps WARN_ON() and,
>> when CONFIG_KUNIT is enabled, also calls kunit_fail_current_test() so
>> that any active KUnit test is marked as failed. In non-KUnit builds
>> the macro reduces to WARN_ON(), preserving existing behaviour.
>>
>> Stringify the asserted condition in the failure message to make it easy
>> to identify which assertion fired. Leave the WARN_ON() in
>> gpu_buddy_block_trim() unchanged, as it returns -EINVAL and the caller
>> already observes the failure via the return code.
>>
>> Cc: Christian König <christian.koenig@amd.com>
>> Cc: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com>
>> Suggested-by: Matthew Auld <matthew.auld@intel.com>
>> Signed-off-by: Sanjay Yadav <sanjay.kumar.yadav@intel.com>
>> ---
>>   drivers/gpu/buddy.c | 36 ++++++++++++++++++++++++++++--------
>>   1 file changed, 28 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/gpu/buddy.c b/drivers/gpu/buddy.c
>> index b27761246d4b..da5a1222f46b 100644
>> --- a/drivers/gpu/buddy.c
>> +++ b/drivers/gpu/buddy.c
>> @@ -3,8 +3,7 @@
>>    * Copyright © 2021 Intel Corporation
>>    */
>>   -#include <kunit/test-bug.h>
>> -
>> +#include <linux/bug.h>
>>   #include <linux/export.h>
>>   #include <linux/kmemleak.h>
>>   #include <linux/module.h>
>> @@ -12,6 +11,28 @@
>>     #include <linux/gpu_buddy.h>
>>   +/**
>> + * gpu_buddy_assert - assert a condition in the buddy allocator
>> + * @condition: condition expected to be true
>> + *
>> + * When CONFIG_KUNIT is enabled, evaluates @condition and, if false, 
>> triggers
>> + * a WARN_ON() and also calls kunit_fail_current_test() so that any 
>> running
>> + * kunit test is properly marked as failed. The stringified 
>> condition is
>> + * included in the failure message for easy identification.
>> + *
>> + * When CONFIG_KUNIT is not enabled, this reduces to WARN_ON() so 
>> production
>> + * builds retain the same warning semantics as before.
>> + */
>> +#if IS_ENABLED(CONFIG_KUNIT)
>> +#include <kunit/test-bug.h>
>> +#define gpu_buddy_assert(condition) do { \
>> +    if (WARN_ON(!(condition)))                        \
>> +        kunit_fail_current_test("gpu_buddy_assert(" #condition 
>> ")");    \
>> +} while (0)
>> +#else
>> +#define gpu_buddy_assert(condition) WARN_ON(!(condition))
>> +#endif
>> +
>>   static struct kmem_cache *slab_blocks;
>>     static unsigned int
>> @@ -268,8 +289,8 @@ static int __force_merge(struct gpu_buddy *mm,
>>                   if (!gpu_buddy_block_is_free(buddy))
>>                       continue;
>>   -                WARN_ON(gpu_buddy_block_is_clear(block) ==
>> -                    gpu_buddy_block_is_clear(buddy));
>> + gpu_buddy_assert(gpu_buddy_block_is_clear(block) !=
>> +                         gpu_buddy_block_is_clear(buddy));
>>                     /*
>>                    * Advance to the next node when the current node 
>> is the buddy,
>> @@ -415,8 +436,7 @@ void gpu_buddy_fini(struct gpu_buddy *mm)
>>           start = gpu_buddy_block_offset(mm->roots[i]);
>>           __force_merge(mm, start, start + size, order);
>>   -        if (WARN_ON(!gpu_buddy_block_is_free(mm->roots[i])))
>> -            kunit_fail_current_test("buddy_fini() root");
>> + gpu_buddy_assert(gpu_buddy_block_is_free(mm->roots[i]));
>>             gpu_block_free(mm, mm->roots[i]);
>>   @@ -424,7 +444,7 @@ void gpu_buddy_fini(struct gpu_buddy *mm)
>>           size -= root_size;
>>       }
>>   -    WARN_ON(mm->avail != mm->size);
>> +    gpu_buddy_assert(mm->avail == mm->size);
>>         for_each_free_tree(i)
>>           kfree(mm->free_trees[i]);
>> @@ -541,7 +561,7 @@ static void __gpu_buddy_free_list(struct 
>> gpu_buddy *mm,
>>   {
>>       struct gpu_buddy_block *block, *on;
>>   -    WARN_ON(mark_dirty && mark_clear);
>> +    gpu_buddy_assert(!(mark_dirty && mark_clear));
>>         list_for_each_entry_safe(block, on, objects, link) {
>>           if (mark_clear)
>