[RFC v2 0/3] Introduce KUnit tests for TTM subsystem

[Karolina Stolarek]

On 29.06.2023 09:39, Christian König wrote:
> Sorry for the delayed response, AMD had some mail server issues and I 
> simply missed this through the web access interface.

No worries, that gave me an opportunity to fix my series :)

All the best,
Karolina

> 
> Going to take a look at this now,
> Christian.
> 
> Am 27.06.23 um 10:32 schrieb Karolina Stolarek:
>> This series introduces KUnit[1] tests for TTM (Translation Table Manager)
>> subsystem, a memory manager used by graphics drivers to create and manage
>> memory buffers across different memory domains, such as system memory
>> or VRAM.
>>
>> Unit tests implemented here cover two data structures:
>>    - ttm_device -- referred as a buffer object device, which stores
>>      resource managers and page pools
>>    - ttm_pool -- a struct of pools (ttm_pool_type) of different page
>>      orders and caching attributes, with pages that can be reused on
>>      the next buffer allocation
>>
>> Use kunit_tool script to manually run the tests:
>>
>> $ ./tools/testing/kunit/kunit.py run 
>> --kunitconfig=drivers/gpu/drm/ttm/tests
>>
>> The kunit tool might not work with older python versions. To fix that,
>> apply [2] patch.
>>
>> To build a kernel with TTM KUnit tests, enable CONFIG_DRM_TTM_KUNIT_TEST
>> symbol.
>>
>> As for now, tests are architecture-agnostic (i.e. KUnit runner uses UML
>> kernel), which means that we have limited coverage in some places. For
>> example, we can't fully test the initialization of global page pools,
>> such as global_write_combined. It is to be decided if we want to stick
>> to UML or use CONFIG_X86 (at least to some extent).
>>
>> These patches are just a beginning of the work to improve the test
>> coverage of TTM. Feel free to suggest changes, test cases or priorities.
>>
>> Many thanks,
>> Karolina
>>
>> v2:
>>    - Add missing symbol exports in ttm_kunit_helpers.c
>>    - Update helpers include to fix compilation issues (didn't catch it as
>>      KUnit tests weren't enabled in the kernel I tested, an oversight
>>      on my part)
>>    - Add checks for ttm_pool fields in ttm_pool_alloc_basic(), 
>> including the
>>      one for NUMA node id
>>    - Rebase the changes on the top of drm-tip
>>
>> --------------------------------
>> [1] - https://www.kernel.org/doc/html/latest/dev-tools/kunit/index.html
>> [2] - 
>> https://lore.kernel.org/lkml/20230610175618.82271-1-sj@kernel.org/T/
>>
>> Karolina Stolarek (3):
>>    drm/ttm: Introduce KUnit tests
>>    drm/ttm/tests: Add tests for ttm_device
>>    drm/ttm/tests: Add tests for ttm_pool
>>
>>   drivers/gpu/drm/Kconfig                       |  15 +
>>   drivers/gpu/drm/ttm/Makefile                  |   1 +
>>   drivers/gpu/drm/ttm/tests/.kunitconfig        |   4 +
>>   drivers/gpu/drm/ttm/tests/Makefile            |   6 +
>>   drivers/gpu/drm/ttm/tests/ttm_device_test.c   | 213 +++++++++
>>   drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c |  88 ++++
>>   drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.h |  34 ++
>>   drivers/gpu/drm/ttm/tests/ttm_pool_test.c     | 406 ++++++++++++++++++
>>   8 files changed, 767 insertions(+)
>>   create mode 100644 drivers/gpu/drm/ttm/tests/.kunitconfig
>>   create mode 100644 drivers/gpu/drm/ttm/tests/Makefile
>>   create mode 100644 drivers/gpu/drm/ttm/tests/ttm_device_test.c
>>   create mode 100644 drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c
>>   create mode 100644 drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.h
>>   create mode 100644 drivers/gpu/drm/ttm/tests/ttm_pool_test.c
>>
>