Hi, thanks for your feedback. I'm sending updated solution that changes task iteration to be consistent with cgroup_is_populated() check and moving the responsibility to check PF_EXITING on the consumers of iterator API. Changes from v1 - v1: https://lore.kernel.org/lkml/20200117151533.12381-1-mkoutny@xxxxxxxx/ - Swap the fixing and refactoring patch (in order to make the fix easier for backport) - Don't introduce tasks lists array because of unnecessarily long access code - Fix comment in selftest - I leave the CC:stable on discretion of the maintainer Michal Koutný (2): cgroup: Iterate tasks that did not finish do_exit() cgroup: Clean up css_set task traversal Suren Baghdasaryan (1): kselftest/cgroup: add cgroup destruction test include/linux/cgroup.h | 4 +- kernel/cgroup/cgroup.c | 60 ++++++----- tools/testing/selftests/cgroup/test_core.c | 113 +++++++++++++++++++++ 3 files changed, 146 insertions(+), 31 deletions(-) -- 2.24.1