[PATCH 0/6] workqueue: base pwq pool release and nr_active on the backing pool

[Breno Leitao <leitao@debian.org>]

The goal is to unify per-cpu and unbound workqueues onto one backend, so
an unbound workqueue can run on the concurrency-managed per-cpu pools and
WQ_PERCPU just requests that backend [1]. This series is preparation and
changes no behaviour on its own.

These changes also is a reasonable readability cleanup.

What will come later:

  * Introduce a concurrency-managed per-cpu affinity scope
    (WQ_AFFN_PERCPU_CM) — percpu as an affinity setting

  * Direct pool selection (fold the create-then-convert), and rename the
    helpers that are no longer unbound-specific: install_unbound_pwq(),
    unbound_pwq(), unbound_pwq_slot() (and alloc_unbound_pwq() -> alloc_pwq()).

  * Dynamic switching between per-cpu and unbound backing for CPU isolation.

Am I on the right path?

[1] https://lore.kernel.org/all/ak569WYSm3ygKl1-@slm.duckdns.org

Signed-off-by: Breno Leitao <leitao@debian.org>
---
Breno Leitao (6):
      workqueue: factor out get_percpu_pool()
      workqueue: factor out alloc_and_link_percpu_pwqs()
      workqueue: release pwq pools by pool type
      workqueue: account nr_active by the backing pool
      workqueue: add a per-cpu backend for unbound pwqs
      workqueue: install per-cpu pwqs at creation for __WQ_PERCPU_POOLS

 include/linux/workqueue.h |   1 +
 kernel/workqueue.c        | 143 +++++++++++++++++++++++++++++++++-------------
 2 files changed, 105 insertions(+), 39 deletions(-)
---
base-commit: dbff1ec23f68640a743512e8ada125795d1b72c7
change-id: 20260729-wq-pool-refactor-0fb28721f83f

Best regards,
--  
Breno Leitao <leitao@debian.org>