Changelog: v2: * Add a cgroup mount option to enable/disable the new hugetlb memcg accounting behavior (patch 1) (suggested by Johannes Weiner). * Add a couple more ksft_print_msg() on error to aid debugging when the selftest fails. (patch 2) Currently, hugetlb memory usage is not acounted for in the memory controller, which could lead to memory overprotection for cgroups with hugetlb-backed memory. This has been observed in our production system. This patch series rectifies this issue by charging the memcg when the hugetlb folio is allocated, and uncharging when the folio is freed. In addition, a new selftest is added to demonstrate and verify this new behavior. Nhat Pham (2): hugetlb: memcg: account hugetlb-backed memory in memory controller selftests: add a selftest to verify hugetlb usage in memcg Documentation/admin-guide/cgroup-v2.rst | 9 + MAINTAINERS | 2 + fs/hugetlbfs/inode.c | 2 +- include/linux/cgroup-defs.h | 5 + include/linux/hugetlb.h | 6 +- include/linux/memcontrol.h | 8 + kernel/cgroup/cgroup.c | 15 +- mm/hugetlb.c | 23 +- mm/memcontrol.c | 41 +++ tools/testing/selftests/cgroup/.gitignore | 1 + tools/testing/selftests/cgroup/Makefile | 2 + .../selftests/cgroup/test_hugetlb_memcg.c | 234 ++++++++++++++++++ 12 files changed, 338 insertions(+), 10 deletions(-) create mode 100644 tools/testing/selftests/cgroup/test_hugetlb_memcg.c -- 2.34.1
