linux-toradex.git/include/linux/workqueue.h, branch v5.19-rc8

workqueue: Switch to new kerneldoc syntax for named variable macro argument

2022-06-12T00:16:42+00:00

The syntax without dots is available since commit 43756e347f21
("scripts/kernel-doc: Add support for named variable macro arguments").

The same HTML output is produced with and without this patch.

Signed-off-by: Jonathan Neuschäfer 
Acked-by: Tejun Heo 
Signed-off-by: Tejun Heo

workqueue: Wrap flush_workqueue() using a macro

2022-06-07T17:07:14+00:00

Since flush operation synchronously waits for completion, flushing
system-wide WQs (e.g. system_wq) might introduce possibility of deadlock
due to unexpected locking dependency. Tejun Heo commented at [1] that it
makes no sense at all to call flush_workqueue() on the shared WQs as the
caller has no idea what it's gonna end up waiting for.

Although there is flush_scheduled_work() which flushes system_wq WQ with
"Think twice before calling this function! It's very easy to get into
trouble if you don't take great care." warning message, syzbot found a
circular locking dependency caused by flushing system_wq WQ [2].

Therefore, let's change the direction to that developers had better use
their local WQs if flush_scheduled_work()/flush_workqueue(system_*_wq) is
inevitable.

Steps for converting system-wide WQs into local WQs are explained at [3],
and a conversion to stop flushing system-wide WQs is in progress. Now we
want some mechanism for preventing developers who are not aware of this
conversion from again start flushing system-wide WQs.

Since I found that WARN_ON() is complete but awkward approach for teaching
developers about this problem, let's use __compiletime_warning() for
incomplete but handy approach. For completeness, we will also insert
WARN_ON() into __flush_workqueue() after all in-tree users stopped calling
flush_scheduled_work().

Link: https://lore.kernel.org/all/YgnQGZWT%2Fn3VAITX@slm.duckdns.org/ [1]
Link: https://syzkaller.appspot.com/bug?extid=bde0f89deacca7c765b8 [2]
Link: https://lkml.kernel.org/r/49925af7-78a8-a3dd-bce6-cfc02e1a9236@I-love.SAKURA.ne.jp [3]
Signed-off-by: Tetsuo Handa 
Signed-off-by: Tejun Heo

workqueue: Introduce show_one_worker_pool and show_one_workqueue.

2021-10-20T16:19:03+00:00

Currently show_workqueue_state shows the state of all workqueues and of
all worker pools. In certain cases we may need to dump state of only a
specific workqueue or worker pool. For example in destroy_workqueue we
only need to show state of the workqueue which is getting destroyed.

So rename show_workqueue_state to show_all_workqueues(to signify it
dumps state of all busy workqueues) and divide it into more granular
functions (show_one_workqueue and show_one_worker_pool), that would show
states of individual workqueues and worker pools and can be used in
cases such as the one mentioned above.

Also, as mentioned earlier, make destroy_workqueue dump data pertaining
to only the workqueue that is being destroyed and make user(s) of
earlier interface(show_workqueue_state), use new interface
(show_all_workqueues).

Signed-off-by: Imran Khan 
Signed-off-by: Tejun Heo

workqueue: annotate alloc_workqueue() as printf

2021-09-13T17:53:27+00:00

This also enables checking of allows alloc_ordered_workqueue().

Signed-off-by: Rolf Eike Beer 
Signed-off-by: Tejun Heo

workqueue: Remove unused WORK_NO_COLOR

2021-08-17T17:49:10+00:00

WORK_NO_COLOR has no user now, just remove it.

Signed-off-by: Lai Jiangshan 
Signed-off-by: Tejun Heo

workqueue: Rename "delayed" (delayed by active management) to "inactive"

2021-08-17T17:49:09+00:00

There are two kinds of "delayed" work items in workqueue subsystem.

One is for timer-delayed work items which are visible to workqueue users.
The other kind is for work items delayed by active management which can
not be directly visible to workqueue users.  We mixed the word "delayed"
for both kinds and caused somewhat ambiguity.

This patch renames the later one (delayed by active management) to
"inactive", because it is used for workqueue active management and
most of its related symbols are named with "active" or "activate".

All "delayed" and "DELAYED" are carefully checked and renamed one by
one to avoid accidentally changing the name of the other kind for
timer-delayed.

No functional change intended.

Signed-off-by: Lai Jiangshan 
Signed-off-by: Tejun Heo

workqueue: Fix typo in comments

2021-08-09T22:31:03+00:00

Fix typo:
*assing  ==> assign
*alloced  ==> allocated
*Retun  ==> Return
*excute  ==> execute

v1->v2:
*reverse 'iff'
*update changelog

Signed-off-by: Cai Huoqing 
Signed-off-by: Tejun Heo

workqueue: fix annotation for WQ_SYSFS

2021-01-19T15:20:07+00:00

'wq_sysfs_register()' in annotation for 'WQ_SYSFS' is unavailable,
change it to 'workqueue_sysfs_register()'.

Signed-off-by: Menglong Dong 
Reviewed-by: Lai Jiangshan 
Signed-off-by: Tejun Heo

workqueue: fix a piece of comment about reserved bits for work flags

2020-06-01T15:02:28+00:00

8a2e8e5dec7e("workqueue: fix cwq->nr_active underflow")
allocated one more bit from the work flags, and it updated
partial of the comments (128 bytes -> 256 bytes), but it
failed to update the info about the number of reserved bits.

Signed-off-by: Lai Jiangshan 
Signed-off-by: Tejun Heo

Merge branch 'for-5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq

2020-04-03T19:27:36+00:00

Pull workqueue updates from Tejun Heo:
 "Nothing too interesting. Just two trivial patches"

* 'for-5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: Mark up unlocked access to wq->first_flusher
  workqueue: Make workqueue_init*() return void