workqueue: Move pwq->max_active to wq->max_active

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[ Upstream commit a045a272d8 ]

max_active is a workqueue-wide setting and the configured value is stored in
wq->saved_max_active; however, the effective value was stored in
pwq->max_active. While this is harmless, it makes max_active update process
more complicated and gets in the way of the planned max_active semantic
updates for unbound workqueues.

This patches moves pwq->max_active to wq->max_active. This simplifies the
code and makes freezing and noop max_active updates cheaper too. No
user-visible behavior change is intended.

As wq->max_active is updated while holding wq mutex but read without any
locking, it now uses WRITE/READ_ONCE(). A new locking locking rule WO is
added for it.

v2: wq->max_active now uses WRITE/READ_ONCE() as suggested by Lai.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Lai Jiangshan <jiangshanlai@gmail.com>
Stable-dep-of: 5797b1c189 ("workqueue: Implement system-wide nr_active enforcement for unbound workqueues")
Signed-off-by: Sasha Levin <sashal@kernel.org>

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Tejun Heo 2024-01-29 08:11:24 -10:00 • committed by Sasha Levin

parent 43a181f8f4

commit 82e098f5be

1 changed files with 66 additions and 67 deletions

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kernel/workqueue.c

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