[PATCH] selftests/cgroup: allow running a specific test with test_memcontrol

[Yosry Ahmed <yosryahmed@google.com>]

It is handy during testing and/or debugging to be able to run a single
test from test_memcontrol. Allow passing in a test name through a
command line argument (e.g. ./test_memcontrol -t test_memcg_recharge).

Change-Id: I0e0d74d81fdd9d997987389085a816715160467f
Signed-off-by: Yosry Ahmed <yosryahmed@google.com>
---
 .../selftests/cgroup/test_memcontrol.c        | 30 +++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/tools/testing/selftests/cgroup/test_memcontrol.c b/tools/testing/selftests/cgroup/test_memcontrol.c
index a2a90f4bfe9f..d8f8a13bc6c4 100644
--- a/tools/testing/selftests/cgroup/test_memcontrol.c
+++ b/tools/testing/selftests/cgroup/test_memcontrol.c
@@ -1308,9 +1308,36 @@ struct memcg_test {
 
 int main(int argc, char **argv)
 {
+	int opt;
 	char root[PATH_MAX];
+	int selected_test = -1;
 	int i, proc_status, ret = EXIT_SUCCESS;
 
+	while ((opt = getopt(argc, argv, "ht:")) != -1) {
+		switch (opt) {
+		case 't':
+			for (i = 0; i < ARRAY_SIZE(tests); i++) {
+				if (!strcmp(tests[i].name, optarg)) {
+					selected_test = i;
+					break;
+				}
+			}
+			if (selected_test >= 0)
+				break;
+			fprintf(stderr, "test %s not found\n", optarg);
+			return EXIT_FAILURE;
+		case 'h':
+			fprintf(stderr,
+				"Usage: %s [-h] [-t name]\n"
+				"\t-h       print help\n"
+				"\t-t name  run specific test\n"
+				, argv[0]);
+			return ret;
+		default:
+			break;
+		}
+	}
+
 	if (cg_find_unified_root(root, sizeof(root)))
 		ksft_exit_skip("cgroup v2 isn't mounted\n");
 
@@ -1336,6 +1363,9 @@ int main(int argc, char **argv)
 	has_localevents = proc_status;
 
 	for (i = 0; i < ARRAY_SIZE(tests); i++) {
+		if (selected_test >= 0 && selected_test != i)
+			continue;
+
 		switch (tests[i].fn(root)) {
 		case KSFT_PASS:
 			ksft_test_result_pass("%s\n", tests[i].name);
-- 
2.41.0.162.gfafddb0af9-goog