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
To build a kernel with TTM KUnit tests, first enable CONFIG_KUNIT,
and then
CONFIG_DRM_TTM_KUNIT_TEST.
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
v5:
- Drop unnecessary brackets in 2/3
- Rebase KConfig file on the top of drm-tip
v4:
- Test helpers have been changed to make the creation of init/fini
functions for each test suite easier:
+ Decouple device creation from test initialization by adding
helpers that initialize ttm_test_devices, a struct which stores
DRM/TTM devices, and can be used in test-specific init/finis
(see ttm_pool_tests.c for an example)
+ Introduce generic init/fini functions for tests that only need
devices
+ Add ttm_device field to ttm_test_devices (previously
ttm_test_devices_priv)
- Make TTM buffer object outlive its TT (Christian)
- Add a dedicated struct for ttm_pool_test (struct
ttm_pool_test_priv)
- Rename functions and structs:
+ struct ttm_test_devices_priv --> struct ttm_test_devices
+ ttm_kunit_helper_init_device() --> ttm_device_kunit_init()
+ ttm_kunit_helper_ttm_bo_init() --> ttm_bo_kunit_init()
- Split ttm_kunit_helper_init() into full config (with ttm_device
init) and basic (init only with device/drm_device) initialization
functions
v3:
- Rename ttm_kunit_helper_alloc_device() to
ttm_kunit_helper_init_device()
(Christian)
- Don't leak a full-blown drm_gem_object in
ttm_kunit_helper_ttm_bo_init().
(Christian). Create a small mock object just to get
ttm_tt_init_fields()
to init the right number of pages
- As a follow up to the change above, delete
ttm_kunit_helper_ttm_bo_fini()
and just use ttm_bo_put()
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
Karolina Stolarek (3):
drm/ttm: Introduce KUnit test
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 | 212 +++++++++
drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c | 115 +++++
drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.h | 41 ++
drivers/gpu/drm/ttm/tests/ttm_pool_test.c | 441
++++++++++++++++++
8 files changed, 835 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
