Fix taskqueue_drain(9) to not have false negatives. For threaded

taskqueues, more than one task can be running simultaneously.

Also make taskqueue_run(9) static to the file, since there are no
consumers in the base kernel and the function signature needs to change
with this fix.

Remove mention of taskqueue_run(9) and taskqueue_run_fast(9) from the
taskqueue(9) man page.

Reviewed by:    jhb
Approved by:    zml (mentor)

2 files changed, 11 insertions, 6 deletions

diff --git a/sys/sys/_task.h b/sys/sys/_task.h
index 2a51e1b07b97..c3f94323ebd2 100644
--- a/sys/sys/_task.h
+++ b/sys/sys/_task.h
@@ -36,15 +36,20 @@
  * taskqueue_run().  The first argument is taken from the 'ta_context'
  * field of struct task and the second argument is a count of how many
  * times the task was enqueued before the call to taskqueue_run().
+ *
+ * List of locks	 
+ * (c)	const after init	 
+ * (q)	taskqueue lock
  */
 typedef void task_fn_t(void *context, int pending);
 
 struct task {
-	STAILQ_ENTRY(task) ta_link;	/* link for queue */
-	u_short	ta_pending;		/* count times queued */
-	u_short	ta_priority;		/* Priority */
-	task_fn_t *ta_func;		/* task handler */
-	void	*ta_context;		/* argument for handler */
+	struct task **ta_running;	/* (q) queue's running task pointer */
+	STAILQ_ENTRY(task) ta_link;	/* (q) link for queue */
+	u_short	ta_pending;		/* (q) count times queued */
+	u_short	ta_priority;		/* (c) Priority */
+	task_fn_t *ta_func;		/* (c) task handler */
+	void	*ta_context;		/* (c) argument for handler */
 };
 
 #endif /* !_SYS__TASK_H_ */
diff --git a/sys/sys/taskqueue.h b/sys/sys/taskqueue.h
index bf2e4ee31d0d..2490deb3c0f7 100644
--- a/sys/sys/taskqueue.h
+++ b/sys/sys/taskqueue.h
@@ -56,7 +56,6 @@ int	taskqueue_start_threads(struct taskqueue **tqp, int count, int pri,
 int	taskqueue_enqueue(struct taskqueue *queue, struct task *task);
 void	taskqueue_drain(struct taskqueue *queue, struct task *task);
 void	taskqueue_free(struct taskqueue *queue);
-void	taskqueue_run(struct taskqueue *queue);
 void	taskqueue_block(struct taskqueue *queue);
 void	taskqueue_unblock(struct taskqueue *queue);
 int	taskqueue_member(struct taskqueue *queue, struct thread *td);
@@ -75,6 +74,7 @@ void	taskqueue_thread_enqueue(void *context);
 	(task)->ta_priority = (priority);		\
 	(task)->ta_func = (func);			\
 	(task)->ta_context = (context);			\
+	(task)->ta_running = NULL;			\
 } while (0)
 
 /*