[GIT PULL] workqueue: Fixes for v6.9-rc6

[Tejun Heo]

The following changes since commit b1e6ec0a0fd0252af046e542f91234cd6c30b2cb:

  Merge tag 'docs-6.9-fixes' of git://git.lwn.net/linux (2024-04-02 12:44:09 -0700)

are available in the Git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq.git/ tags/wq-for-6.9-rc6-fixes

for you to fetch changes up to 91f098704c25106d88706fc9f8bcfce01fdb97df:

  workqueue: Fix divide error in wq_update_node_max_active() (2024-04-24 07:23:06 -1000)

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workqueue: Fixes for v6.9-rc6

Two doc update patches and the following three fixes:

- On single node systems, the default pool is used but the node_nr_active
  for the default pool was set to min_active. This effectively limited the
  max concurrency of unbound pools on single node systems to 8 causing
  performance regressions on some workloads. Fixed by setting the default
  pool's node_nr_active to max_active.

- wq_update_node_max_active() could trigger divide-by-zero if the
  intersection between the allowed CPUs for an unbound workqueue and online
  CPUs becomes empty.

- When kick_pool() was trying to repatriate a worker to a CPU in its pod by
  setting task->wake_cpu, it didn't consider whether the CPU being selected
  is online or not which obviously can lead to subobtimal behaviors. On
  s390, this triggered a crash in arch code. The workqueue patch removes the
  gross misbehavior but doesn't fix the crash completely as there's a race
  window in which CPUs can go down after wake_cpu is set. Need to decide
  whether the fix should be on the core or arch side.

----------------------------------------------------------------
Audra Mitchell (1):
      Documentation/core-api: Update events_freezable_power references.

Lai Jiangshan (1):
      workqueue: Fix divide error in wq_update_node_max_active()

Sven Schnelle (1):
      workqueue: Fix selection of wake_cpu in kick_pool()

Tejun Heo (1):
      workqueue: The default node_nr_active should have its max set to max_active

Xingyou Chen (1):
      docs/zh_CN: core-api: Update translation of workqueue.rst to 6.9-rc1

 Documentation/core-api/workqueue.rst               |   6 +-
 .../translations/zh_CN/core-api/workqueue.rst      | 398 +++++++++++++++++++--
 kernel/workqueue.c                                 |  19 +-
 3 files changed, 390 insertions(+), 33 deletions(-)