damon_max_nr_accesses(), which is a previous version of damon_nr_samples_per_aggr() before the renaming, was wrongly returning zero or random overflowed values for extreme intervals setup. Commit 35d4a3cf70a8 ("mm/damon/ops-common: handle extreme intervals in damon_hot_score()") updated the function to return correct or more valid values. Add a kunit test to ensure it is working as expected. Signed-off-by: SJ Park --- mm/damon/tests/core-kunit.h | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/mm/damon/tests/core-kunit.h b/mm/damon/tests/core-kunit.h index 3041b8288ec26..511f2856d343c 100644 --- a/mm/damon/tests/core-kunit.h +++ b/mm/damon/tests/core-kunit.h @@ -619,6 +619,22 @@ static void damon_test_set_regions(struct kunit *test) (struct damon_addr_range[]){}, 0, -EINVAL); } +static void damon_test_nr_samples_per_aggr(struct kunit *test) +{ + struct damon_attrs attrs = { + .sample_interval = 0, + .aggr_interval = 0, + }; + + /* Zero aggregation interval doesn't cause division by zero */ + KUNIT_EXPECT_EQ(test, damon_nr_samples_per_aggr(&attrs), 1); + + /* Too large aggregation interval doesn't cause overflow */ + attrs.aggr_interval = (unsigned long)UINT_MAX + 1; + KUNIT_EXPECT_GE(test, damon_nr_samples_per_aggr(&attrs), 0); + KUNIT_EXPECT_LE(test, damon_nr_samples_per_aggr(&attrs), UINT_MAX); +} + static void damon_test_update_monitoring_result(struct kunit *test) { struct damon_attrs old_attrs = { @@ -1670,6 +1686,7 @@ static struct kunit_case damon_test_cases[] = { KUNIT_CASE(damon_test_split_above_half_progresses), KUNIT_CASE(damon_test_ops_registration), KUNIT_CASE(damon_test_set_regions), + KUNIT_CASE(damon_test_nr_samples_per_aggr), KUNIT_CASE(damon_test_update_monitoring_result), KUNIT_CASE(damon_test_set_attrs), KUNIT_CASE(damon_test_mvsum), -- 2.47.3