From: David Vernet Subject: cgroup: account for memory_localevents in test_memcg_oom_group_leaf_events() The test_memcg_oom_group_leaf_events() testcase in the cgroup memcg tests validates that processes in a group that perform allocations exceeding memory.oom.group are killed. It also validates that the memory.events.oom_kill events are properly propagated in this case. Commit 06e11c907ea4 ("kselftests: memcg: update the oom group leaf events test") fixed test_memcg_oom_group_leaf_events() to account for the fact that the memory.events.oom_kill events in a child cgroup is propagated up to its parent. This behavior can actually be configured by the memory_localevents mount option, so this patch updates the testcase to properly account for the possible presence of this mount option. Link: https://lkml.kernel.org/r/20220423155619.3669555-4-void@manifault.com Signed-off-by: David Vernet Acked-by: Roman Gushchin Cc: Johannes Weiner Cc: Michal Hocko Cc: Shakeel Butt Cc: Tejun Heo Signed-off-by: Andrew Morton --- tools/testing/selftests/cgroup/test_memcontrol.c | 22 ++++++++++--- 1 file changed, 17 insertions(+), 5 deletions(-) --- a/tools/testing/selftests/cgroup/test_memcontrol.c~cgroup-account-for-memory_localevents-in-test_memcg_oom_group_leaf_events +++ a/tools/testing/selftests/cgroup/test_memcontrol.c @@ -21,6 +21,7 @@ #include "../kselftest.h" #include "cgroup_util.h" +static bool has_localevents; static bool has_recursiveprot; /* @@ -1153,6 +1154,7 @@ static int test_memcg_oom_group_parent_e { int ret = KSFT_FAIL; char *parent, *child; + long parent_oom_events; parent = cg_name(root, "memcg_test_0"); child = cg_name(root, "memcg_test_0/memcg_test_1"); @@ -1236,14 +1238,20 @@ static int test_memcg_oom_group_score_ev if (!cg_run(memcg, alloc_anon, (void *)MB(100))) goto cleanup; - if (cg_read_key_long(memcg, "memory.events", "oom_kill ") != 3) - goto cleanup; + parent_oom_events = cg_read_key_long( + parent, "memory.events", "oom_kill "); + /* + * If memory_localevents is not enabled (the default), the parent should + * count OOM events in its children groups. Otherwise, it should not + * have observed any events. + */ + if ((has_localevents && parent_oom_events == 0) || + parent_oom_events > 0) + ret = KSFT_PASS; if (kill(safe_pid, SIGKILL)) goto cleanup; - ret = KSFT_PASS; - cleanup: if (memcg) cg_destroy(memcg); @@ -1252,7 +1260,6 @@ cleanup: return ret; } - #define T(x) { x, #x } struct memcg_test { int (*fn)(const char *root); @@ -1298,6 +1305,11 @@ int main(int argc, char **argv) ksft_exit_skip("Failed to query cgroup mount option\n"); has_recursiveprot = proc_status; + proc_status = proc_mount_contains("memory_localevents"); + if (proc_status < 0) + ksft_exit_skip("Failed to query cgroup mount option\n"); + has_localevents = proc_status; + for (i = 0; i < ARRAY_SIZE(tests); i++) { switch (tests[i].fn(root)) { case KSFT_PASS: _