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 <[email protected]>
---
mm/damon/tests/core-kunit.h | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)
diff --git a/mm/damon/tests/core-kunit.h b/mm/damon/tests/core-kunit.h
index 3041b8288ec26..0a1882ce6a081 100644
--- a/mm/damon/tests/core-kunit.h
+++ b/mm/damon/tests/core-kunit.h
@@ -619,6 +619,27 @@ 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 on 64 bit system doesn't cause
+ * overflow
+ */
+ if (ULONG_MAX > UINT_MAX) {
+ attrs.aggr_interval = (unsigned long)UINT_MAX + 1;
+ KUNIT_EXPECT_EQ(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 +1691,7 @@ 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
