[GIT PULL] cgroup: Changes for v6.18

[Tejun Heo]

The following changes since commit 94a4acfec14615e971eb2c9e1fa6c992c85ff6c6:

  cgroup/psi: Set of->priv to NULL upon file release (2025-08-22 07:47:43 -1000)

are available in the Git repository at:

  https://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git tags/cgroup-for-6.18

for you to fetch changes up to 8f0fdbd4a06bf795c68bc9839d9c349ab592654f:

  cpuset: remove is_prs_invalid helper (2025-09-22 12:57:46 -1000)

----------------------------------------------------------------
cgroup: Changes for v6.18

- Extensive cpuset code cleanup and refactoring work with no functional
  changes: CPU mask computation logic refactoring, introducing new helpers,
  removing redundant code paths, and improving error handling for better
  maintainability.

- A few bug fixes to cpuset including fixes for partition creation failures
  when isolcpus is in use, missing error returns, and null pointer access
  prevention in free_tmpmasks().

- Core cgroup changes include replacing the global percpu_rwsem with
  per-threadgroup rwsem when writing to cgroup.procs for better scalability,
  workqueue conversions to use WQ_PERCPU and system_percpu_wq to prepare for
  workqueue default switching from percpu to unbound, and removal of unused
  code including the post_attach callback.

- New cgroup.stat.local time accounting feature that tracks frozen time
  duration.

- Misc changes including selftests updates (new freezer time tests and
  backward compatibility fixes), documentation sync, string function safety
  improvements, and 64-bit division fixes.

----------------------------------------------------------------
Bagas Sanjaya (1):
      Documentation: cgroup-v2: Sync manual toctree

Chen Ridong (21):
      cpuset: remove redundant CS_ONLINE flag
      cpuset: decouple tmpmasks and cpumasks freeing in cgroup
      cpuset: separate tmpmasks and cpuset allocation logic
      cpuset: add helpers for cpus read and cpuset_mutex locks
      cpuset: move the root cpuset write check earlier
      cpuset: remove unused assignment to trialcs->partition_root_state
      cpuset: change return type of is_partition_[in]valid to bool
      cpuset: Refactor exclusive CPU mask computation logic
      cpuset: refactor CPU mask buffer parsing logic
      cpuset: introduce cpus_excl_conflict and mems_excl_conflict helpers
      cpuset: refactor out validate_partition
      cpuset: refactor cpus_allowed_validate_change
      cpuset: introduce partition_cpus_change
      cpuset: use parse_cpulist for setting cpus.exclusive
      cpuset: use partition_cpus_change for setting exclusive cpus
      cpuset: fix failure to enable isolated partition when containing isolcpus
      cpuset: Use new excpus for nocpu error check when enabling root partition
      cpuset: fix missing error return in update_cpumask
      cpuset: remove redundant special case for null input in node mask update
      cpuset: remove impossible warning in update_parent_effective_cpumask
      cpuset: remove is_prs_invalid helper

Chuyi Zhou (3):
      cpuset: Don't always flush cpuset_migrate_mm_wq in cpuset_write_resmask
      cpuset: Defer flushing of the cpuset_migrate_mm_wq to task_work
      cgroup: Remove unused cgroup_subsys::post_attach

Marco Crivellari (2):
      cgroup: replace use of system_wq with system_percpu_wq
      cgroup: WQ_PERCPU added to alloc_workqueue users

Michal Koutný (1):
      selftests: cgroup: Make test_pids backwards compatible

Tejun Heo (2):
      cgroup: Remove unused local variables from cgroup_procs_write_finish()
      cgroup: Merge branch 'for-6.17-fixes' into for-6.18

Thorsten Blum (1):
      cgroup: Replace deprecated strcpy() with strscpy()

Tiffany Yang (3):
      cgroup: cgroup.stat.local time accounting
      cgroup: selftests: Add tests for freezer time
      cgroup: Fix 64-bit division in cgroup.stat.local

Waiman Long (1):
      cgroup/cpuset: Prevent NULL pointer access in free_tmpmasks()

Yi Tao (3):
      cgroup: refactor the cgroup_attach_lock code to make it clearer
      cgroup: relocate cgroup_attach_lock within cgroup_procs_write_start
      cgroup: replace global percpu_rwsem with per threadgroup resem when writing to cgroup.procs

pengdonglin (2):
      cgroup: Remove redundant rcu_read_lock/unlock() in spin_lock
      cgroup/cpuset: Remove redundant rcu_read_lock/unlock() in spin_lock

 Documentation/admin-guide/cgroup-v2.rst            |  33 +-
 include/linux/cgroup-defs.h                        |  43 +-
 include/linux/cgroup.h                             |   5 +
 include/linux/sched/signal.h                       |   4 +
 init/init_task.c                                   |   3 +
 kernel/cgroup/cgroup-internal.h                    |  11 +-
 kernel/cgroup/cgroup-v1.c                          |  19 +-
 kernel/cgroup/cgroup.c                             | 199 ++++--
 kernel/cgroup/cpuset-internal.h                    |   5 +-
 kernel/cgroup/cpuset-v1.c                          |  12 +-
 kernel/cgroup/cpuset.c                             | 752 +++++++++++----------
 kernel/cgroup/debug.c                              |   4 -
 kernel/cgroup/freezer.c                            |  16 +-
 kernel/fork.c                                      |   4 +
 tools/testing/selftests/cgroup/lib/cgroup_util.c   |  12 +
 .../selftests/cgroup/lib/include/cgroup_util.h     |   1 +
 tools/testing/selftests/cgroup/test_freezer.c      | 663 ++++++++++++++++++
 tools/testing/selftests/cgroup/test_pids.c         |   3 +
 18 files changed, 1355 insertions(+), 434 deletions(-)