[GIT PULL] cgroup changes for v6.20

[Tejun Heo]

Hi Linus,

The following changes since commit 3309b63a2281efb72df7621d60cc1246b6286ad3:

  cgroup: rstat: use LOCK CMPXCHG in css_rstat_updated (2025-12-08 08:26:56 -1000)

are available in the Git repository at:

  https://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git tags/cgroup-for-6.20

for you to fetch changes up to 8b1f3c54f930c3aeda0b5bad97bc317fc80267fd:

  cpuset: fix overlap of partition effective CPUs (2026-02-01 06:49:52 -1000)

----------------------------------------------------------------
cgroup: Changes for v6.20

- cpuset changes:

  - Continue separating v1 and v2 implementations by moving more
    v1-specific logic into cpuset-v1.c.

  - Improve partition handling. Sibling partitions are no longer
    invalidated on cpuset.cpus conflict, cpuset.cpus changes no longer
    fail in v2, and effective_xcpus computation is made consistent.

  - Fix partition effective CPUs overlap that caused a warning on cpuset
    removal when sibling partitions shared CPUs.

- Increase the maximum cgroup subsystem count from 16 to 32 to
  accommodate future subsystem additions.

- Misc cleanups and selftest improvements including switching to
  css_is_online() helper, removing dead code and stale documentation
  references, using lockdep_assert_cpuset_lock_held() consistently,
  and adding polling helpers for asynchronously updated cgroup
  statistics.

----------------------------------------------------------------
Chen Ridong (11):
      cgroup: switch to css_is_online() helper
      cpuset: Remove unnecessary checks in rebuild_sched_domains_locked
      cpuset: add lockdep_assert_cpuset_lock_held helper
      cpuset: add cpuset1_online_css helper for v1-specific operations
      cpuset: add cpuset1_init helper for v1 initialization
      cpuset: move update_domain_attr_tree to cpuset_v1.c
      cpuset: separate generate_sched_domains for v1 and v2
      cpuset: remove v1-specific code from generate_sched_domains
      cpuset: remove dead code in cpuset-v1.c
      cgroup: increase maximum subsystem count from 16 to 32
      cpuset: fix overlap of partition effective CPUs

Guopeng Zhang (3):
      selftests: cgroup: Add cg_read_key_long_poll() to poll a cgroup key with retries
      selftests: cgroup: make test_memcg_sock robust against delayed sock stats
      selftests: cgroup: Replace sleep with cg_read_key_long_poll() for waiting on nr_dying_descendants

Tejun Heo (1):
      cgroup: Remove stale cpu.rt.max reference from documentation

Waiman Long (5):
      cgroup/cpuset: Streamline rm_siblings_excl_cpus()
      cgroup/cpuset: Consistently compute effective_xcpus in update_cpumasks_hier()
      cgroup/cpuset: Don't fail cpuset.cpus change in v2
      cgroup/cpuset: Don't invalidate sibling partitions on cpuset.cpus conflict
      cgroup/cpuset: Move the v1 empty cpus/mems check to cpuset1_validate_change()

Zhao Mengmeng (1):
      cpuset: replace direct lockdep_assert_held() with lockdep_assert_cpuset_lock_held()

 Documentation/admin-guide/cgroup-v2.rst            |  44 +-
 fs/fs-writeback.c                                  |   2 +-
 include/linux/cgroup-defs.h                        |   8 +-
 include/linux/cpuset.h                             |   2 +
 include/linux/memcontrol.h                         |   2 +-
 include/trace/events/cgroup.h                      |   2 +-
 kernel/cgroup/cgroup-internal.h                    |   8 +-
 kernel/cgroup/cgroup-v1.c                          |  12 +-
 kernel/cgroup/cgroup.c                             |  50 +--
 kernel/cgroup/cpuset-internal.h                    |  54 ++-
 kernel/cgroup/cpuset-v1.c                          | 271 ++++++++++-
 kernel/cgroup/cpuset.c                             | 499 +++++----------------
 kernel/cgroup/debug.c                              |   2 +-
 mm/memcontrol.c                                    |   2 +-
 mm/page_owner.c                                    |   2 +-
 tools/testing/selftests/cgroup/lib/cgroup_util.c   |  21 +
 .../selftests/cgroup/lib/include/cgroup_util.h     |   5 +
 tools/testing/selftests/cgroup/test_cpuset_prs.sh  |  29 +-
 tools/testing/selftests/cgroup/test_kmem.c         |  33 +-
 tools/testing/selftests/cgroup/test_memcontrol.c   |  20 +-
 20 files changed, 593 insertions(+), 475 deletions(-)

Thanks.

--
tejun