[PATCH v5 0/7] hugetlb_cgroup: Add hugetlb_cgroup reservation limits

[Mina Almasry]

Patch series implements hugetlb_cgroup reservation usage and limits, which
track hugetlb reservations rather than hugetlb memory faulted in. Details of
the approach is 1/7.

Changes in v5:
- Moved the bulk of the description to the first patch in the series.
- Clang formatted the entire series.
- Split off 'hugetlb: remove duplicated code' and 'hugetlb: region_chg provides
  only cache entry' into their own patch series.
- Added comments to HUGETLB_RES enum.
- Fixed bug in 'hugetlb: disable region_add file_region coalescing' calculating
  the wrong number of regions_needed in some cases.
- Changed sleeps in test to proper conditions.
- Misc fixes in test based on shuah@ review.

Changes in v4:
- Split up 'hugetlb_cgroup: add accounting for shared mappings' into 4 patches
  for better isolation and context on the indvidual changes:
  - hugetlb_cgroup: add accounting for shared mappings
  - hugetlb: disable region_add file_region coalescing
  - hugetlb: remove duplicated code
  - hugetlb: region_chg provides only cache entry
- Fixed resv->adds_in_progress accounting.
- Retained behavior that region_add never fails, in earlier patchsets region_add
  could return failure.
- Fixed libhugetlbfs failure.
- Minor fix to the added tests that was preventing them from running on some
  environments.

Changes in v3:
- Addressed comments of Hillf Danton:
  - Added docs.
  - cgroup_files now uses enum.
  - Various readability improvements.
- Addressed comments of Mike Kravetz.
  - region_* functions no longer coalesce file_region entries in the resv_map.
  - region_add() and region_chg() refactored to make them much easier to
    understand and remove duplicated code so this patch doesn't add too much
    complexity.
  - Refactored common functionality into helpers.

Changes in v2:
- Split the patch into a 5 patch series.
- Fixed patch subject.

Mina Almasry (7):
  hugetlb_cgroup: Add hugetlb_cgroup reservation counter
  hugetlb_cgroup: add interface for charge/uncharge hugetlb reservations
  hugetlb_cgroup: add reservation accounting for private mappings
  hugetlb: disable region_add file_region coalescing
  hugetlb_cgroup: add accounting for shared mappings
  hugetlb_cgroup: Add hugetlb_cgroup reservation tests
  hugetlb_cgroup: Add hugetlb_cgroup reservation docs

 .../admin-guide/cgroup-v1/hugetlb.rst         |  85 +++-
 include/linux/hugetlb.h                       |  31 +-
 include/linux/hugetlb_cgroup.h                |  33 +-
 mm/hugetlb.c                                  | 423 +++++++++++-----
 mm/hugetlb_cgroup.c                           | 190 ++++++--
 tools/testing/selftests/vm/.gitignore         |   1 +
 tools/testing/selftests/vm/Makefile           |   1 +
 .../selftests/vm/charge_reserved_hugetlb.sh   | 461 ++++++++++++++++++
 .../selftests/vm/write_hugetlb_memory.sh      |  22 +
 .../testing/selftests/vm/write_to_hugetlbfs.c | 250 ++++++++++
 10 files changed, 1306 insertions(+), 191 deletions(-)
 create mode 100755 tools/testing/selftests/vm/charge_reserved_hugetlb.sh
 create mode 100644 tools/testing/selftests/vm/write_hugetlb_memory.sh
 create mode 100644 tools/testing/selftests/vm/write_to_hugetlbfs.c

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2.23.0.351.gc4317032e6-goog