mm/damon/dbgfs-test: add a unit test case for 'init_regions'

This adds another test case for the new feature, 'init_regions'.

Link: https://lkml.kernel.org/r/20211012205711.29216-3-sj@kernel.orgSigned-off-by: SeongJae Park <sj@kernel.org>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Cc: Amit Shah <amit@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rienjes <rientjes@google.com>
Cc: David Woodhouse <dwmw@amazon.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leonard Foerster <foersleo@amazon.de>
Cc: Marco Elver <elver@google.com>
Cc: Markus Boehme <markubo@amazon.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/damon/dbgfs-test.h

@@ -109,9 +109,63 @@ static void damon_dbgfs_test_set_targets(struct kunit *test)
 	dbgfs_destroy_ctx(ctx);
 }
 
+static void damon_dbgfs_test_set_init_regions(struct kunit *test)
+{
+	struct damon_ctx *ctx = damon_new_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);
+	damon_destroy_ctx(ctx);
+}
+
 static struct kunit_case damon_test_cases[] = {
 	KUNIT_CASE(damon_dbgfs_test_str_to_target_ids),
 	KUNIT_CASE(damon_dbgfs_test_set_targets),
+	KUNIT_CASE(damon_dbgfs_test_set_init_regions),
 	{},
 };