@@ -161,6 +161,58 @@ static void damon_test_set_recording(struct kunit *test)
 	KUNIT_EXPECT_STREQ(test, ctx->rfile_path, "foo");
 }
 
+static void damon_test_set_init_regions(struct kunit *test)
+{
+	struct damon_ctx *ctx = &damon_user_ctx;
+	unsigned long ids[] = {1, 2, 3};
+	/* Each line represents one region in ``<target id> <start> <end>`` */
+	char * const valid_inputs[] = {"2 10 20\n 2   20 30\n2 35 45",
+		"2 10 20\n",
+		"2 10 20\n1 39 59\n1 70 134\n  2  20 25\n",
+		""};
+	/* Reading the file again will show sorted, clean output */
+	char * const valid_expects[] = {"2 10 20\n2 20 30\n2 35 45\n",
+		"2 10 20\n",
+		"1 39 59\n1 70 134\n2 10 20\n2 20 25\n",
+		""};
+	char * const invalid_inputs[] = {"4 10 20\n",	/* target not exists */
+		"2 10 20\n 2 14 26\n",		/* regions overlap */
+		"1 10 20\n2 30 40\n 1 5 8"};	/* not sorted by address */
+	char *input, *expect;
+	int i, rc;
+	char buf[256];
+
+	damon_set_targets(ctx, ids, 3);
+
+	/* Put valid inputs and check the results */
+	for (i = 0; i < ARRAY_SIZE(valid_inputs); i++) {
+		input = valid_inputs[i];
+		expect = valid_expects[i];
+
+		rc = set_init_regions(ctx, input, strnlen(input, 256));
+		KUNIT_EXPECT_EQ(test, rc, 0);
+
+		memset(buf, 0, 256);
+		sprint_init_regions(ctx, buf, 256);
+
+		KUNIT_EXPECT_STREQ(test, (char *)buf, expect);
+	}
+	/* Put invlid inputs and check the return error code */
+	for (i = 0; i < ARRAY_SIZE(invalid_inputs); i++) {
+		input = invalid_inputs[i];
+		pr_info("input: %s\n", input);
+		rc = set_init_regions(ctx, input, strnlen(input, 256));
+		KUNIT_EXPECT_EQ(test, rc, -EINVAL);
+
+		memset(buf, 0, 256);
+		sprint_init_regions(ctx, buf, 256);
+
+		KUNIT_EXPECT_STREQ(test, (char *)buf, "");
+	}
+
+	damon_set_targets(ctx, NULL, 0);
+}
+
 static void __link_vmas(struct vm_area_struct *vmas, ssize_t nr_vmas)
 {
 	int i, j;

@@ -645,6 +697,7 @@ static struct kunit_case damon_test_cases[] = {
 	KUNIT_CASE(damon_test_regions),
 	KUNIT_CASE(damon_test_set_targets),
 	KUNIT_CASE(damon_test_set_recording),
+	KUNIT_CASE(damon_test_set_init_regions),
 	KUNIT_CASE(damon_test_three_regions_in_vmas),
 	KUNIT_CASE(damon_test_aggregate),
 	KUNIT_CASE(damon_test_write_rbuf),