memcg_move_charge_at_immigrate in ubuntu_ltp_controller flaky with TBROK: timed out on memory.usage_in_bytes 0 0 405504

[Po-Hsu Lin]

Issue found on X-hwe-4.15.0-221.232~16.04.1 with openstack arm64.

It's failing with:
  TBROK: timed out on memory.usage_in_bytes 0 0 405504

Just like memcg_subgroup_charge (bug 1942426) and memcg_max_usage_in_bytes (bug 2037027). It appears to be flaky, test passed on thee second attempt.

Test log:
INFO: Test start time: Mon Jan 22 11:26:59 UTC 2024
COMMAND: /opt/ltp/bin/ltp-pan -q -e -S -a 15034 -n 15034 -f /tmp/ltp-xUVnruatjK/alltests -l /dev/null -C /dev/null -T /dev/null
LOG File: /dev/null
FAILED COMMAND File: /dev/null
TCONF COMMAND File: /dev/null
Running tests.......
memcg_move_charge_at_immigrate_test 1 TINFO: timeout per run is 0h 5m 0s
memcg_move_charge_at_immigrate_test 1 TINFO: set /sys/fs/cgroup/memory/memory.use_hierarchy to 0 failed
memcg_move_charge_at_immigrate_test 1 TINFO: Test disable moving charges
memcg_move_charge_at_immigrate_test 1 TINFO: Running memcg_process --mmap-anon -s 135168
memcg_move_charge_at_immigrate_test 1 TINFO: Warming up pid: 15128
memcg_move_charge_at_immigrate_test 1 TINFO: Process is still here after warm up: 15128
memcg_move_charge_at_immigrate_test 1 TPASS: rss is 0 as expected
memcg_move_charge_at_immigrate_test 1 TPASS: cache is 0 as expected
memcg_move_charge_at_immigrate_test 1 TPASS: rss is 135168 as expected
memcg_move_charge_at_immigrate_test 1 TPASS: cache is 0 as expected
memcg_move_charge_at_immigrate_test 2 TINFO: Test move anon
memcg_move_charge_at_immigrate_test 2 TINFO: Running memcg_process --mmap-anon --shm --mmap-file -s 135168
memcg_move_charge_at_immigrate_test 2 TINFO: Warming up pid: 15160
memcg_move_charge_at_immigrate_test 2 TINFO: Process is still here after warm up: 15160
memcg_move_charge_at_immigrate_test 2 TBROK: timed out on memory.usage_in_bytes 0 0 405504
memcg_move_charge_at_immigrate_test 2 TINFO: AppArmor enabled, this may affect test results
memcg_move_charge_at_immigrate_test 2 TINFO: it can be disabled with TST_DISABLE_APPARMOR=1 (requires super/root)
memcg_move_charge_at_immigrate_test 2 TINFO: loaded AppArmor profiles: none

Summary:
passed 4
failed 0
broken 1
skipped 0
warnings 0
INFO: ltp-pan reported some tests FAIL
LTP Version: 20230929
INFO: Test end time: Mon Jan 22 11:27:11 UTC 2024

[Manuel Diewald (diewald)]

Observed this issue with bionic:linux 4.15.0-223.235 on metal and openstack instances. memcg_stat failed in the same way in two cases.