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

[Christian König]

Sorry for the delayed response, AMD had some mail server issues and I 
simply missed this through the web access interface.

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
>