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workqueue: mark WQ_NON_REENTRANT deprecated

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dbf2576e37 ("workqueue: make all workqueues non-reentrant") made
WQ_NON_REENTRANT no-op but the following patches didn't remove the
flag or update the documentation.  Let's mark the flag deprecated and
update the documentation accordingly.

Signed-off-by: Tejun Heo <tj@kernel.org>
This commit is contained in:
Tejun Heo
2013-07-30 08:30:16 -04:00
parent ad81f0545e
commit 1207637304
2 changed files with 12 additions and 13 deletions
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18
Documentation/workqueue.txt
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@@ -100,8 +100,8 @@ Subsystems and drivers can create and queue work items through special
workqueue API functions as they see fit. They can influence some workqueue API functions as they see fit. They can influence some
aspects of the way the work items are executed by setting flags on the aspects of the way the work items are executed by setting flags on the
workqueue they are putting the work item on. These flags include workqueue they are putting the work item on. These flags include
things like CPU locality, reentrancy, concurrency limits, priority and things like CPU locality, concurrency limits, priority and more. To
more. To get a detailed overview refer to the API description of get a detailed overview refer to the API description of
alloc_workqueue() below. alloc_workqueue() below.
When a work item is queued to a workqueue, the target gcwq and When a work item is queued to a workqueue, the target gcwq and
@@ -166,16 +166,6 @@ resources, scheduled and executed.
@flags: @flags:
WQ_NON_REENTRANT
By default, a wq guarantees non-reentrance only on the same
CPU. A work item may not be executed concurrently on the same
CPU by multiple workers but is allowed to be executed
concurrently on multiple CPUs. This flag makes sure
non-reentrance is enforced across all CPUs. Work items queued
to a non-reentrant wq are guaranteed to be executed by at most
one worker system-wide at any given time.
WQ_UNBOUND WQ_UNBOUND
Work items queued to an unbound wq are served by a special Work items queued to an unbound wq are served by a special
@@ -233,6 +223,10 @@ resources, scheduled and executed.
This flag is meaningless for unbound wq. This flag is meaningless for unbound wq.
Note that the flag WQ_NON_REENTRANT no longer exists as all workqueues
are now non-reentrant - any work item is guaranteed to be executed by
at most one worker system-wide at any given time.
@max_active: @max_active:
@max_active determines the maximum number of execution contexts per @max_active determines the maximum number of execution contexts per

7
include/linux/workqueue.h
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@@ -295,7 +295,12 @@ static inline unsigned int work_static(struct work_struct *work) { return 0; }
* Documentation/workqueue.txt. * Documentation/workqueue.txt.
*/ */
enum { enum {
WQ_NON_REENTRANT = 1 << 0, /* guarantee non-reentrance */ /*
* All wqs are now non-reentrant making the following flag
* meaningless. Will be removed.
*/
WQ_NON_REENTRANT = 1 << 0, /* DEPRECATED */
WQ_UNBOUND = 1 << 1, /* not bound to any cpu */ WQ_UNBOUND = 1 << 1, /* not bound to any cpu */
WQ_FREEZABLE = 1 << 2, /* freeze during suspend */ WQ_FREEZABLE = 1 << 2, /* freeze during suspend */
WQ_MEM_RECLAIM = 1 << 3, /* may be used for memory reclaim */ WQ_MEM_RECLAIM = 1 << 3, /* may be used for memory reclaim */