workqueue: implement WQ_NON_REENTRANT
With gcwq managing all the workers and work->data pointing to the last
gcwq it was on, non-reentrance can be easily implemented by checking
whether the work is still running on the previous gcwq on queueing.
Implement it.
Signed-off-by: Tejun Heo <tj@kernel.org>
diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h
index 0a78141..07cf5e5 100644
--- a/include/linux/workqueue.h
+++ b/include/linux/workqueue.h
@@ -225,6 +225,7 @@
enum {
WQ_FREEZEABLE = 1 << 0, /* freeze during suspend */
WQ_SINGLE_CPU = 1 << 1, /* only single cpu at a time */
+ WQ_NON_REENTRANT = 1 << 2, /* guarantee non-reentrance */
};
extern struct workqueue_struct *