4023a2d950
[ Upstream commit 1c270b79ce0b8290f146255ea9057243f6dd3c17 ]
__queue_work(), pwq_dec_nr_in_flight() and wq_adjust_max_active() were
open-coding nr_active handling, which is fine given that the operations are
trivial. However, the planned unbound nr_active update will make them more
complicated, so let's move them into helpers.
- pwq_tryinc_nr_active() is added. It increments nr_active if under
max_active limit and return a boolean indicating whether inc was
successful. Note that the function is structured to accommodate future
changes. __queue_work() is updated to use the new helper.
- pwq_activate_first_inactive() is updated to use pwq_tryinc_nr_active() and
thus no longer assumes that nr_active is under max_active and returns a
boolean to indicate whether a work item has been activated.
- wq_adjust_max_active() no longer tests directly whether a work item can be
activated. Instead, it's updated to use the return value of
pwq_activate_first_inactive() to tell whether a work item has been
activated.
- nr_active decrement and activating the first inactive work item is
factored into pwq_dec_nr_active().
v3: - WARN_ON_ONCE(!WORK_STRUCT_INACTIVE) added to __pwq_activate_work() as
now we're calling the function unconditionally from
pwq_activate_first_inactive().
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: 5797b1c18919 ("workqueue: Implement system-wide nr_active enforcement for unbound workqueues")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.