[GIT PULL] cgroup: Fixes for v7.1-rc2

[Tejun Heo <tj@kernel.org>]

Hello,

The following changes since commit 981cd338614c96070cf9854679014fd027c1fb1d:

  docs: cgroup: fix typo 'protetion' -> 'protection' (2026-04-27 07:55:40 -1000)

are available in the Git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git tags/cgroup-for-7.1-rc2-fixes

for you to fetch changes up to d8769544bde51b0ac980d10f8fe9f9fed6c95995:

  docs: cgroup-v1: Update charge-commit section (2026-05-04 11:02:12 -1000)

----------------------------------------------------------------
cgroup: Fixes for v7.1-rc2

- During v6.19, cgroup task unlink was moved from do_exit() to after the
  final task switch to satisfy a controller invariant. That left the kernel
  seeing tasks past exit_signals() longer than userspace expected, and
  several v7.0 follow-ups tried to bridge the gap by making rmdir wait for
  the kernel side. None held up. The latest is an A-A deadlock when rmdir
  is invoked by the reaper of zombies whose pidns teardown the rmdir itself
  is waiting on, which points at the synchronizing approach being
  fundamentally wrong:

  - Take a different approach: drop the wait, leave rmdir's user-visible
    side returning as soon as cgroup.procs is empty, and defer the css
    percpu_ref kill that drives ->css_offline() until the cgroup is fully
    depopulated.

  - Tagged for stable. Somewhat invasive but contained. The hope is that
    fixing forward sticks. If not, the fallback is to revert the entire
    chain and rework on the development branch.

  - Doesn't plug a pre-existing analogous race in
    cgroup_apply_control_disable() (controller disable via subtree_control).
    Not a regression. The development branch will do the more invasive
    restructuring needed for that.

- Documentation update for cgroup-v1 charge-commit section that still
  referenced functions removed when the memcg hugetlb try-commit-cancel
  protocol was retired.

----------------------------------------------------------------
T.J. Mercier (1):
      docs: cgroup-v1: Update charge-commit section

Tejun Heo (1):
      cgroup: Defer css percpu_ref kill on rmdir until cgroup is depopulated

 Documentation/admin-guide/cgroup-v1/memcg_test.rst |   6 +-
 include/linux/cgroup-defs.h                        |   4 +-
 kernel/cgroup/cgroup.c                             | 250 ++++++++++-----------
 3 files changed, 121 insertions(+), 139 deletions(-)

Thanks.

--
tejun