As discussed in [1], damon_va_evenly_split_region() is called to size-evenly split a region into 'nr_pieces' small regions, when nr_pieces == 1, no actual split is required. Check that case for better code readability and add a simple kunit testcase. [1] https://lore.kernel.org/all/20241021163316.12443-1-sj@xxxxxxxxxx/ Signed-off-by: Zheng Yejian <zhengyejian@xxxxxxxxxxxxxxx> --- mm/damon/tests/vaddr-kunit.h | 1 + mm/damon/vaddr.c | 3 +++ 2 files changed, 4 insertions(+) diff --git a/mm/damon/tests/vaddr-kunit.h b/mm/damon/tests/vaddr-kunit.h index a149e354bb26..b9a03e4e29e5 100644 --- a/mm/damon/tests/vaddr-kunit.h +++ b/mm/damon/tests/vaddr-kunit.h @@ -300,6 +300,7 @@ static void damon_test_split_evenly(struct kunit *test) damon_test_split_evenly_fail(test, 0, 100, 0); damon_test_split_evenly_succ(test, 0, 100, 10); damon_test_split_evenly_succ(test, 5, 59, 5); + damon_test_split_evenly_succ(test, 4, 6, 1); damon_test_split_evenly_succ(test, 0, 3, 2); damon_test_split_evenly_fail(test, 5, 6, 2); } diff --git a/mm/damon/vaddr.c b/mm/damon/vaddr.c index dba3b2f4d758..25db0a582c27 100644 --- a/mm/damon/vaddr.c +++ b/mm/damon/vaddr.c @@ -72,6 +72,9 @@ static int damon_va_evenly_split_region(struct damon_target *t, if (!r || !nr_pieces) return -EINVAL; + if (nr_pieces == 1) + return 0; + orig_end = r->ar.end; sz_orig = damon_sz_region(r); sz_piece = ALIGN_DOWN(sz_orig / nr_pieces, DAMON_MIN_REGION); -- 2.25.1
