Revert taskqueue(9) related commits until mdf@ is approved and can

resolve issues.

This reverts commits r207439, r208623, r208624

2 files changed, 11 insertions, 23 deletions

diff --git a/sys/kern/subr_taskqueue.c b/sys/kern/subr_taskqueue.c
index b06678c..8405b3d 100644
--- a/sys/kern/subr_taskqueue.c
+++ b/sys/kern/subr_taskqueue.c
@@ -51,13 +51,12 @@ struct taskqueue {
 	const char		*tq_name;
 	taskqueue_enqueue_fn	tq_enqueue;
 	void			*tq_context;
+	struct task		*tq_running;
 	struct mtx		tq_mutex;
 	struct thread		**tq_threads;
 	int			tq_tcount;
 	int			tq_spin;
 	int			tq_flags;
-	int			tq_tasks_running;
-	int			tq_task_waiters;
 };
 
 #define	TQ_FLAGS_ACTIVE		(1 << 0)
@@ -234,15 +233,14 @@ taskqueue_run(struct taskqueue *queue)
 		STAILQ_REMOVE_HEAD(&queue->tq_queue, ta_link);
 		pending = task->ta_pending;
 		task->ta_pending = 0;
-		queue->tq_tasks_running++;
+		queue->tq_running = task;
 		TQ_UNLOCK(queue);
 
 		task->ta_func(task->ta_context, pending);
 
 		TQ_LOCK(queue);
-		queue->tq_tasks_running--;
-		if (queue->tq_task_waiters > 0)
-			wakeup(task);
+		queue->tq_running = NULL;
+		wakeup(task);
 	}
 
 	/*
@@ -258,21 +256,15 @@ taskqueue_drain(struct taskqueue *queue, struct task *task)
 {
 	if (queue->tq_spin) {		/* XXX */
 		mtx_lock_spin(&queue->tq_mutex);
-		while (task->ta_pending != 0 || queue->tq_tasks_running > 0) {
-			queue->tq_task_waiters++;
+		while (task->ta_pending != 0 || task == queue->tq_running)
 			msleep_spin(task, &queue->tq_mutex, "-", 0);
-			queue->tq_task_waiters--;
-		}
 		mtx_unlock_spin(&queue->tq_mutex);
 	} else {
 		WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, __func__);
 
 		mtx_lock(&queue->tq_mutex);
-		while (task->ta_pending != 0 || queue->tq_tasks_running > 0) {
-			queue->tq_task_waiters++;
+		while (task->ta_pending != 0 || task == queue->tq_running)
 			msleep(task, &queue->tq_mutex, PWAIT, "-", 0);
-			queue->tq_task_waiters--;
-		}
 		mtx_unlock(&queue->tq_mutex);
 	}
 }
diff --git a/sys/sys/_task.h b/sys/sys/_task.h
index 68e236f..2a51e1b 100644
--- a/sys/sys/_task.h
+++ b/sys/sys/_task.h
@@ -36,19 +36,15 @@
  * 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;	/* (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 */
+	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 */
 };
 
 #endif /* !_SYS__TASK_H_ */