The cgroup testing relys on the root cgroup's subtree_control setting, If the 'memory' controller isn't set, some test cases will be failed as following: $sudo ./test_core not ok 1 test_cgcore_internal_process_constraint ok 2 test_cgcore_top_down_constraint_enable not ok 3 test_cgcore_top_down_constraint_disable ... To correct this unexcepted failure, this patch write the 'memory' to subtree_control of root to get a right result. Signed-off-by: Alex Shi <alex.shi@xxxxxxxxxxxxxxxxx> Cc: Shuah Khan <shuah@xxxxxxxxxx> Cc: Tejun Heo <tj@xxxxxxxxxx> Cc: Roman Gushchin <guro@xxxxxx> Cc: Claudio Zumbo <claudioz@xxxxxx> Cc: Claudio <claudiozumbo@xxxxxxxxx> Cc: linux-kselftest@xxxxxxxxxxxxxxx Cc: linux-kernel@xxxxxxxxxxxxxxx --- tools/testing/selftests/cgroup/test_core.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/tools/testing/selftests/cgroup/test_core.c b/tools/testing/selftests/cgroup/test_core.c index be59f9c34ea2..b1a570d7c557 100644 --- a/tools/testing/selftests/cgroup/test_core.c +++ b/tools/testing/selftests/cgroup/test_core.c @@ -376,6 +376,11 @@ int main(int argc, char *argv[]) if (cg_find_unified_root(root, sizeof(root))) ksft_exit_skip("cgroup v2 isn't mounted\n"); + + if (cg_read_strstr(root, "cgroup.subtree_control", "memory")) + if (cg_write(root, "cgroup.subtree_control", "+memory")) + ksft_exit_skip("Failed to set root memory controller\n"); + for (i = 0; i < ARRAY_SIZE(tests); i++) { switch (tests[i].fn(root)) { case KSFT_PASS: -- 2.19.1.856.g8858448bb