1 files changed, 34 insertions, 55 deletions

diff --git a/freebsd/sys/kern/subr_gtaskqueue.c b/freebsd/sys/kern/subr_gtaskqueue.c
index 173cfa08..c061c6b0 100644
--- a/freebsd/sys/kern/subr_gtaskqueue.c
+++ b/freebsd/sys/kern/subr_gtaskqueue.c
@@ -63,26 +63,26 @@ TASKQGROUP_DEFINE(softirq, mp_ncpus, 1);
 TASKQGROUP_DEFINE(config, 1, 1);
 
 struct gtaskqueue_busy {
-	struct gtask	*tb_running;
-	TAILQ_ENTRY(gtaskqueue_busy) tb_link;
+	struct gtask		*tb_running;
+	u_int			 tb_seq;
+	LIST_ENTRY(gtaskqueue_busy) tb_link;
 };
 
-static struct gtask * const TB_DRAIN_WAITER = (struct gtask *)0x1;
-
 typedef void (*gtaskqueue_enqueue_fn)(void *context);
 
 struct gtaskqueue {
 	STAILQ_HEAD(, gtask)	tq_queue;
+	LIST_HEAD(, gtaskqueue_busy) tq_active;
+	u_int			tq_seq;
+	int			tq_callouts;
+	struct mtx_padalign	tq_mutex;
 	gtaskqueue_enqueue_fn	tq_enqueue;
 	void			*tq_context;
 	char			*tq_name;
-	TAILQ_HEAD(, gtaskqueue_busy) tq_active;
-	struct mtx		tq_mutex;
 	struct thread		**tq_threads;
 	int			tq_tcount;
 	int			tq_spin;
 	int			tq_flags;
-	int			tq_callouts;
 	taskqueue_callback_fn	tq_callbacks[TASKQUEUE_NUM_CALLBACKS];
 	void			*tq_cb_contexts[TASKQUEUE_NUM_CALLBACKS];
 };
@@ -121,12 +121,11 @@ gtask_dump(struct gtask *gtask)
 #endif
 
 static __inline int
-TQ_SLEEP(struct gtaskqueue *tq, void *p, struct mtx *m, int pri, const char *wm,
-    int t)
+TQ_SLEEP(struct gtaskqueue *tq, void *p, const char *wm)
 {
 	if (tq->tq_spin)
-		return (msleep_spin(p, m, wm, t));
-	return (msleep(p, m, pri, wm, t));
+		return (msleep_spin(p, (struct mtx *)&tq->tq_mutex, wm, 0));
+	return (msleep(p, &tq->tq_mutex, 0, wm, 0));
 }
 
 static struct gtaskqueue *
@@ -150,7 +149,7 @@ _gtaskqueue_create(const char *name, int mflags,
 	}
 
 	STAILQ_INIT(&queue->tq_queue);
-	TAILQ_INIT(&queue->tq_active);
+	LIST_INIT(&queue->tq_active);
 	queue->tq_enqueue = enqueue;
 	queue->tq_context = context;
 	queue->tq_name = tq_name;
@@ -173,7 +172,7 @@ gtaskqueue_terminate(struct thread **pp, struct gtaskqueue *tq)
 
 	while (tq->tq_tcount > 0 || tq->tq_callouts > 0) {
 		wakeup(tq);
-		TQ_SLEEP(tq, pp, &tq->tq_mutex, PWAIT, "taskqueue_destroy", 0);
+		TQ_SLEEP(tq, pp, "gtq_destroy");
 	}
 }
 
@@ -184,7 +183,7 @@ gtaskqueue_free(struct gtaskqueue *queue)
 	TQ_LOCK(queue);
 	queue->tq_flags &= ~TQ_FLAGS_ACTIVE;
 	gtaskqueue_terminate(queue->tq_threads, queue);
-	KASSERT(TAILQ_EMPTY(&queue->tq_active), ("Tasks still running?"));
+	KASSERT(LIST_EMPTY(&queue->tq_active), ("Tasks still running?"));
 	KASSERT(queue->tq_callouts == 0, ("Armed timeout tasks"));
 	mtx_destroy(&queue->tq_mutex);
 	free(queue->tq_threads, M_GTASKQUEUE);
@@ -291,7 +290,7 @@ gtaskqueue_drain_tq_queue(struct gtaskqueue *queue)
 	 * have completed or are currently executing.
 	 */
 	while (t_barrier.ta_flags & TASK_ENQUEUED)
-		TQ_SLEEP(queue, &t_barrier, &queue->tq_mutex, PWAIT, "-", 0);
+		TQ_SLEEP(queue, &t_barrier, "gtq_qdrain");
 }
 
 /*
@@ -302,31 +301,24 @@ gtaskqueue_drain_tq_queue(struct gtaskqueue *queue)
 static void
 gtaskqueue_drain_tq_active(struct gtaskqueue *queue)
 {
-	struct gtaskqueue_busy tb_marker, *tb_first;
+	struct gtaskqueue_busy *tb;
+	u_int seq;
 
-	if (TAILQ_EMPTY(&queue->tq_active))
+	if (LIST_EMPTY(&queue->tq_active))
 		return;
 
 	/* Block taskq_terminate().*/
 	queue->tq_callouts++;
 
-	/*
-	 * Wait for all currently executing taskqueue threads
-	 * to go idle.
-	 */
-	tb_marker.tb_running = TB_DRAIN_WAITER;
-	TAILQ_INSERT_TAIL(&queue->tq_active, &tb_marker, tb_link);
-	while (TAILQ_FIRST(&queue->tq_active) != &tb_marker)
-		TQ_SLEEP(queue, &tb_marker, &queue->tq_mutex, PWAIT, "-", 0);
-	TAILQ_REMOVE(&queue->tq_active, &tb_marker, tb_link);
-
-	/*
-	 * Wakeup any other drain waiter that happened to queue up
-	 * without any intervening active thread.
-	 */
-	tb_first = TAILQ_FIRST(&queue->tq_active);
-	if (tb_first != NULL && tb_first->tb_running == TB_DRAIN_WAITER)
-		wakeup(tb_first);
+	/* Wait for any active task with sequence from the past. */
+	seq = queue->tq_seq;
+restart:
+	LIST_FOREACH(tb, &queue->tq_active, tb_link) {
+		if ((int)(tb->tb_seq - seq) <= 0) {
+			TQ_SLEEP(queue, tb->tb_running, "gtq_adrain");
+			goto restart;
+		}
+	}
 
 	/* Release taskqueue_terminate(). */
 	queue->tq_callouts--;
@@ -358,40 +350,27 @@ static void
 gtaskqueue_run_locked(struct gtaskqueue *queue)
 {
 	struct gtaskqueue_busy tb;
-	struct gtaskqueue_busy *tb_first;
 	struct gtask *gtask;
 
 	KASSERT(queue != NULL, ("tq is NULL"));
 	TQ_ASSERT_LOCKED(queue);
 	tb.tb_running = NULL;
+	LIST_INSERT_HEAD(&queue->tq_active, &tb, tb_link);
 
-	while (STAILQ_FIRST(&queue->tq_queue)) {
-		TAILQ_INSERT_TAIL(&queue->tq_active, &tb, tb_link);
-
-		/*
-		 * Carefully remove the first task from the queue and
-		 * clear its TASK_ENQUEUED flag
-		 */
-		gtask = STAILQ_FIRST(&queue->tq_queue);
-		KASSERT(gtask != NULL, ("task is NULL"));
+	while ((gtask = STAILQ_FIRST(&queue->tq_queue)) != NULL) {
 		STAILQ_REMOVE_HEAD(&queue->tq_queue, ta_link);
 		gtask->ta_flags &= ~TASK_ENQUEUED;
 		tb.tb_running = gtask;
+		tb.tb_seq = ++queue->tq_seq;
 		TQ_UNLOCK(queue);
 
 		KASSERT(gtask->ta_func != NULL, ("task->ta_func is NULL"));
 		gtask->ta_func(gtask->ta_context);
 
 		TQ_LOCK(queue);
-		tb.tb_running = NULL;
 		wakeup(gtask);
-
-		TAILQ_REMOVE(&queue->tq_active, &tb, tb_link);
-		tb_first = TAILQ_FIRST(&queue->tq_active);
-		if (tb_first != NULL &&
-		    tb_first->tb_running == TB_DRAIN_WAITER)
-			wakeup(tb_first);
 	}
+	LIST_REMOVE(&tb, tb_link);
 }
 
 static int
@@ -400,7 +379,7 @@ task_is_running(struct gtaskqueue *queue, struct gtask *gtask)
 	struct gtaskqueue_busy *tb;
 
 	TQ_ASSERT_LOCKED(queue);
-	TAILQ_FOREACH(tb, &queue->tq_active, tb_link) {
+	LIST_FOREACH(tb, &queue->tq_active, tb_link) {
 		if (tb->tb_running == gtask)
 			return (1);
 	}
@@ -433,7 +412,7 @@ static void
 gtaskqueue_drain_locked(struct gtaskqueue *queue, struct gtask *gtask)
 {
 	while ((gtask->ta_flags & TASK_ENQUEUED) || task_is_running(queue, gtask))
-		TQ_SLEEP(queue, gtask, &queue->tq_mutex, PWAIT, "-", 0);
+		TQ_SLEEP(queue, gtask, "gtq_drain");
 }
 
 void
@@ -580,7 +559,7 @@ gtaskqueue_thread_loop(void *arg)
 		 */
 		if ((tq->tq_flags & TQ_FLAGS_ACTIVE) == 0)
 			break;
-		TQ_SLEEP(tq, tq, &tq->tq_mutex, 0, "-", 0);
+		TQ_SLEEP(tq, tq, "-");
 	}
 	gtaskqueue_run_locked(tq);
 	/*
@@ -606,7 +585,7 @@ gtaskqueue_thread_enqueue(void *context)
 
 	tqp = context;
 	tq = *tqp;
-	wakeup_one(tq);
+	wakeup_any(tq);
 }