Add the following to the taskqueue api:

taskqueue_start_threads(struct taskqueue **, int count, int pri,
			const char *name, ...);

This allows the creation of 1 or more threads that will service a single
taskqueue.  Also rework the taskqueue_create() API to remove the API change
that was introduced a while back.  Creating a taskqueue doesn't rely on
the presence of a process structure, and the proc mechanics are much better
encapsulated in taskqueue_start_threads().  Also clean up the
taskqueue_terminate() and taskqueue_free() functions to safely drain
pending tasks and remove all associated threads.

The TASKQUEUE_DEFINE and TASKQUEUE_DEFINE_THREAD macros have been changed
to use the new API, but drivers compiled against the old definitions will
still work.  Thus, recompiling drivers is not a strict requirement.

1 files changed, 11 insertions, 13 deletions

diff --git a/sys/sys/taskqueue.h b/sys/sys/taskqueue.h
index 59ac30988793..6d6d9ad6997e 100644
--- a/sys/sys/taskqueue.h
+++ b/sys/sys/taskqueue.h
@@ -50,7 +50,9 @@ typedef void (*taskqueue_enqueue_fn)(void *context);
 struct proc;
 struct taskqueue *taskqueue_create(const char *name, int mflags,
 				    taskqueue_enqueue_fn enqueue,
-				    void *context, struct proc **);
+				    void *context);
+int	taskqueue_start_threads(struct taskqueue **tqp, int count, int pri,
+				const char *name, ...) __printflike(4, 5);
 int	taskqueue_enqueue(struct taskqueue *queue, struct task *task);
 void	taskqueue_drain(struct taskqueue *queue, struct task *task);
 struct taskqueue *taskqueue_find(const char *name);
@@ -89,10 +91,8 @@ struct taskqueue *taskqueue_##name;					\
 static void								\
 taskqueue_define_##name(void *arg)					\
 {									\
-	static struct proc *taskqueue_##name##_proc;			\
 	taskqueue_##name =						\
-	    taskqueue_create(#name, M_NOWAIT, (enqueue), (context),	\
-	    &taskqueue_##name##_proc);					\
+	    taskqueue_create(#name, M_NOWAIT, (enqueue), (context));	\
 	init;								\
 }									\
 									\
@@ -102,8 +102,8 @@ SYSINIT(taskqueue_##name, SI_SUB_CONFIGURE, SI_ORDER_SECOND,		\
 struct __hack
 #define TASKQUEUE_DEFINE_THREAD(name)					\
 TASKQUEUE_DEFINE(name, taskqueue_thread_enqueue, &taskqueue_##name,	\
-	kthread_create(taskqueue_thread_loop, &taskqueue_##name,	\
-	&taskqueue_##name##_proc, 0, 0, #name " taskq"))
+	taskqueue_start_threads(&taskqueue_##name, 1, PWAIT,		\
+	"%s taskq", #name))
 
 /*
  * Define and initialise a global taskqueue that uses spin mutexes.
@@ -115,10 +115,9 @@ struct taskqueue *taskqueue_##name;					\
 static void								\
 taskqueue_define_##name(void *arg)					\
 {									\
-	static struct proc *taskqueue_##name##_proc;			\
 	taskqueue_##name =						\
-	    taskqueue_create_fast(#name, M_NOWAIT, (enqueue), (context),\
-	    &taskqueue_##name##_proc);					\
+	    taskqueue_create_fast(#name, M_NOWAIT, (enqueue),		\
+	    (context));							\
 	init;								\
 }									\
 									\
@@ -128,9 +127,8 @@ SYSINIT(taskqueue_##name, SI_SUB_CONFIGURE, SI_ORDER_SECOND,		\
 struct __hack
 #define TASKQUEUE_FAST_DEFINE_THREAD(name)				\
 TASKQUEUE_FAST_DEFINE(name, taskqueue_thread_enqueue,			\
-	&taskqueue_##name, kthread_create(taskqueue_thread_loop,	\
-	&taskqueue_##name, &taskqueue_##name##_proc, 0, 0,		\
-	#name " fast taskq"))
+	&taskqueue_##name, taskqueue_start_threads(&taskqueue_##name	\
+	1, PWAIT, "%s taskq", #name))
 
 /*
  * These queues are serviced by software interrupt handlers.  To enqueue
@@ -156,6 +154,6 @@ TASKQUEUE_DECLARE(fast);
 int	taskqueue_enqueue_fast(struct taskqueue *queue, struct task *task);
 struct taskqueue *taskqueue_create_fast(const char *name, int mflags,
 				    taskqueue_enqueue_fn enqueue,
-				    void *context, struct proc **);
+				    void *context);
 
 #endif /* !_SYS_TASKQUEUE_H_ */