mm/damon/tests/core-kunit: add a test for damon_commit_ctx()

mm/damon/tests/core-kunit: add a test for damon_commit_ctx()

Patch series "mm/damon: test and document power-of-2 min_region_sz
requirement".

Since commit c80f46ac228b ("mm/damon/core: disallow non-power of two
min_region_sz"), min_region_sz is always restricted to be a power of two.
Add a kunit test to confirm the functionality.  Also, the change adds a
restriction to addr_unit parameter.  Clarify it on the document.

This patch (of 2):

Add a kunit test for confirming the change that is made on commit
c80f46ac228b ("mm/damon/core: disallow non-power of two min_region_sz")
functions as expected.

Link: https://lkml.kernel.org/r/20260307194222.202075-2-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: David Gow <davidgow@google.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes (Oracle) <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>