[GIT PULL] cgroup: Fixes for v7.4

[GIT PULL] cgroup: Fixes for v7.4

[Tejun Heo]

Hello,

The following changes since commit 1850c669516cb8568150937497a9a16a7bfa1582:

  selftests/cgroup: test pids.events notification (2026-10-16 09:52:06 -1000)

are available in the Git repository at:

  https://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup.git tags/cgroup-for-7.4-fixes

for you to fetch changes up to 518cec2def9992192291f5028edc077fb2e475e9:

  cgroup/cpuset: Integrate compute_partition_effective_cpumask() into compute_effective_cpumask() (2026-10-26 07:44:43 -1000)

----------------------------------------------------------------
cgroup: Fixes for v7.4

- cgroup.kill did not kill a process whose thread group leader had exited
  while other threads still ran, nor those threads once moved to another
  cgroup, letting a process survive its container being killed.

- A cgroup.procs write under favordynmods could migrate a newly forked
  process before fork linked it to its cgroup, corrupting cgroup task lists.

- cpuset partition fixes for nested hierarchies: invalidation, revival,
  shrinking and switches between root and isolated could leak isolated CPUs,
  skip or miscompute the housekeeping check, or leave wrong effective CPUs.

  - A root partition can no longer be created under an isolated parent or
    stay valid under one, as disabling it could leave no housekeeping CPUs.

  - Enabling a partition failed when a grandchild held tasks, although the
    parent had none of its own.

  - Separately, an allocation racing with a cpuset.mems update could drop
    its mempolicy nodemask and land on the wrong node, and a memoryless node
    in cpuset.mems triggered a spurious "movable nodes only" warning.

  - Two no-functional-change cleanups of the effective CPU computation.

----------------------------------------------------------------
Daehyeon Ko (1):
      cgroup: serialize migrations of newly forked processes

Gregory Price (Meta) (2):
      cgroup/cpuset: use mems_allowed_seq when checking a policy nodemask
      cgroup/cpuset: check effective mems for a movable-only configuration

Guopeng Zhang (1):
      cgroup/cpuset: Fix task checking when enabling a partition

Kir Kolyshkin (2):
      cgroup: fix cgroup.kill for exited thread group leader
      selftests/cgroup: test cgroup.kill with an exited thread group leader

Sasha Levin (1):
      cgroup: don't kill migrated processes through their exiting threads

Waiman Long (20):
      cgroup/cpuset: Fix a missing isolated_cpus update in update_cpumasks_hier()
      cgroup/cpuset: Consolidate isolated_cpus_can_update() into prstate_housekeeping_conflict()
      cgroup/cpuset: Consider all the exclusive CPUs when doing housekeeping check
      cgroup/cpuset: Do housekeeping check before converting invalid partition to valid
      cgroup/cpuset: Properly disabling partition when partition state switching fails
      cgroup/cpuset: Don't allow a child root partition under an isolated parent
      selftests/cgroup: Add tests for isolcpus housekeeping check
      selftests/cgroup: Add tests for nohz_full housekeeping check
      selftests/cgroup: Skip test_cpuset_prs.sh test if some required CPUs are offline
      cgroup/cpuset: Find furthest isolated ancestor for invalidated isolated partition
      cgroup/cpuset: Properly compute effective xcpus in update_parent_effective_cpumask()
      cgroup/cpuset: Fix incorrect effective_cpus bug in update_cpumasks_hier()
      cgroup/cpuset: Minor fixes to prstate_housekeeping_conflict()
      selftests/cgroup: Check for a single range nohz_full CPUs before running test matrix
      cgroup/cpuset: Prevent recursive call of remote_cpus_update() via update_cpumasks_hier()
      cgroup/cpuset: Make sure compute_partition_effective_cpumask() is only called for valid partition
      cgroup/cpuset: Release invalid isolated CPUs in compute_partition_effective_cpumask()
      cgroup/cpuset: Release invalid isolated CPUs with a shrunk root partition parent
      cgroup/cpuset: Relocate compute_*effective_cpumask() and compute_effective_nodemask()
      cgroup/cpuset: Integrate compute_partition_effective_cpumask() into compute_effective_cpumask()

 Documentation/admin-guide/cgroup-v2.rst           |   4 +-
 kernel/cgroup/cgroup.c                            |  30 +-
 kernel/cgroup/cpuset-internal.h                   |   6 +
 kernel/cgroup/cpuset.c                            | 678 +++++++++++++---------
 tools/testing/selftests/cgroup/test_cpuset_prs.sh | 276 +++++++--
 tools/testing/selftests/cgroup/test_kill.c        | 158 +++++
 6 files changed, 823 insertions(+), 329 deletions(-)

-- 
tejun