[RFC PATCH 02/13] mm/damon/tests/core-kunit: test damon_mvsum()

[SeongJae Park <sj@kernel.org>]

Add a simple unit test for damon_nr_accesses_mvsum()'s internal core
logic, damon_mvsum().  The test contains cases for just-started windows,
partially completed windows, and just-completed windows.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 mm/damon/tests/core-kunit.h | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/mm/damon/tests/core-kunit.h b/mm/damon/tests/core-kunit.h
index 4e448c08c724a..cdab14396250f 100644
--- a/mm/damon/tests/core-kunit.h
+++ b/mm/damon/tests/core-kunit.h
@@ -623,6 +623,30 @@ static void damon_test_moving_sum(struct kunit *test)
 	}
 }
 
+static void damon_test_mvsum(struct kunit *test)
+{
+	unsigned long input_expects[] = {
+		/* current value, last value, remaining window (bp) */
+		0, 49, 10000, 49,	/* 0 + 49 * 1 */
+		3, 10, 7000, 10,	/* 3 + 10 * 0.7 */
+		3, 10, 5000, 8,		/* 3 + 10 * 0.5 */
+		32, 100, 1000, 42,	/* 32 + 100 * 0.1 */
+		42, 49, 0, 42,		/* 42 + 49 * 0 */
+	};
+
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(input_expects); i += 4) {
+		unsigned long current_nr = input_expects[i];
+		unsigned long last_nr = input_expects[i + 1];
+		unsigned long left_window_bp = input_expects[i + 2];
+		unsigned long expect = input_expects[i + 3];
+
+		KUNIT_EXPECT_EQ(test, damon_mvsum(current_nr, last_nr,
+					left_window_bp), expect);
+	}
+}
+
 static void damos_test_new_filter(struct kunit *test)
 {
 	struct damos_filter *filter;
@@ -1501,6 +1525,7 @@ static struct kunit_case damon_test_cases[] = {
 	KUNIT_CASE(damon_test_update_monitoring_result),
 	KUNIT_CASE(damon_test_set_attrs),
 	KUNIT_CASE(damon_test_moving_sum),
+	KUNIT_CASE(damon_test_mvsum),
 	KUNIT_CASE(damos_test_new_filter),
 	KUNIT_CASE(damos_test_commit_quota_goal),
 	KUNIT_CASE(damos_test_commit_quota_goals),
-- 
2.47.3