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authorLinus Torvalds <torvalds@linux-foundation.org>2017-09-06 21:59:31 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-09-06 21:59:31 -0700
commit9954d4892a813155cf808b1c29df50886b5672cf (patch)
tree7988449c499804aab0550a4e7381b417dbc6980e
parenta7cbfd05f427f8f1164bc53866971e89a0cbe103 (diff)
parentfbf1c41fc0f4d3574ac2377245efd666c1fa3075 (diff)
downloadlwn-9954d4892a813155cf808b1c29df50886b5672cf.tar.gz
lwn-9954d4892a813155cf808b1c29df50886b5672cf.zip
Merge branch 'for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue updates from Tejun Heo: "Nothing major. I introduced a flag collsion bug during v4.13 cycle which is fixed in this pull request. Fortunately, the flag is for debugging / verification and the bug isn't critical" * 'for-4.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: Fix flag collision workqueue: Use TASK_IDLE workqueue: fix path to documentation workqueue: doc change for ST behavior on NUMA systems
-rw-r--r--Documentation/core-api/workqueue.rst10
-rw-r--r--include/linux/workqueue.h2
-rw-r--r--kernel/workqueue.c6
3 files changed, 11 insertions, 7 deletions
diff --git a/Documentation/core-api/workqueue.rst b/Documentation/core-api/workqueue.rst
index ffdec94fbca1..3943b5bfa8cf 100644
--- a/Documentation/core-api/workqueue.rst
+++ b/Documentation/core-api/workqueue.rst
@@ -243,11 +243,15 @@ throttling the number of active work items, specifying '0' is
recommended.
Some users depend on the strict execution ordering of ST wq. The
-combination of ``@max_active`` of 1 and ``WQ_UNBOUND`` is used to
-achieve this behavior. Work items on such wq are always queued to the
-unbound worker-pools and only one work item can be active at any given
+combination of ``@max_active`` of 1 and ``WQ_UNBOUND`` used to
+achieve this behavior. Work items on such wq were always queued to the
+unbound worker-pools and only one work item could be active at any given
time thus achieving the same ordering property as ST wq.
+In the current implementation the above configuration only guarantees
+ST behavior within a given NUMA node. Instead alloc_ordered_queue should
+be used to achieve system wide ST behavior.
+
Example Execution Scenarios
===========================
diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h
index db6dc9dc0482..1c49431f3121 100644
--- a/include/linux/workqueue.h
+++ b/include/linux/workqueue.h
@@ -323,8 +323,8 @@ enum {
__WQ_DRAINING = 1 << 16, /* internal: workqueue is draining */
__WQ_ORDERED = 1 << 17, /* internal: workqueue is ordered */
- __WQ_ORDERED_EXPLICIT = 1 << 18, /* internal: alloc_ordered_workqueue() */
__WQ_LEGACY = 1 << 18, /* internal: create*_workqueue() */
+ __WQ_ORDERED_EXPLICIT = 1 << 19, /* internal: alloc_ordered_workqueue() */
WQ_MAX_ACTIVE = 512, /* I like 512, better ideas? */
WQ_MAX_UNBOUND_PER_CPU = 4, /* 4 * #cpus for unbound wq */
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index ab3c0dc8c7ed..64d0edf428f8 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -21,7 +21,7 @@
* pools for workqueues which are not bound to any specific CPU - the
* number of these backing pools is dynamic.
*
- * Please read Documentation/workqueue.txt for details.
+ * Please read Documentation/core-api/workqueue.rst for details.
*/
#include <linux/export.h>
@@ -2269,7 +2269,7 @@ sleep:
* event.
*/
worker_enter_idle(worker);
- __set_current_state(TASK_INTERRUPTIBLE);
+ __set_current_state(TASK_IDLE);
spin_unlock_irq(&pool->lock);
schedule();
goto woke_up;
@@ -2311,7 +2311,7 @@ static int rescuer_thread(void *__rescuer)
*/
rescuer->task->flags |= PF_WQ_WORKER;
repeat:
- set_current_state(TASK_INTERRUPTIBLE);
+ set_current_state(TASK_IDLE);
/*
* By the time the rescuer is requested to stop, the workqueue