Index: sys/pool.h
===================================================================
RCS file: /cvs/src/sys/sys/pool.h,v
retrieving revision 1.74
diff -u -p -r1.74 pool.h
--- sys/pool.h	13 Aug 2017 20:26:33 -0000	1.74
+++ sys/pool.h	19 Jan 2018 01:35:30 -0000
@@ -103,7 +103,7 @@ struct kinfo_pool_cache_cpu {
 struct pool;
 struct pool_request;
 struct pool_lock_ops;
-TAILQ_HEAD(pool_requests, pool_request);
+SIMPLEQ_HEAD(pool_requests, pool_request);
 
 struct pool_allocator {
 	void		*(*pa_alloc)(struct pool *, int, int *);
@@ -249,7 +249,7 @@ extern struct pool_allocator pool_alloca
 extern struct pool_allocator pool_allocator_multi;
 
 struct pool_request {
-	TAILQ_ENTRY(pool_request) pr_entry;
+	SIMPLEQ_ENTRY(pool_request) pr_entry;
 	void (*pr_handler)(struct pool *, void *, void *);
 	void *pr_cookie;
 	void *pr_item;
Index: kern/subr_pool.c
===================================================================
RCS file: /cvs/src/sys/kern/subr_pool.c,v
retrieving revision 1.221
diff -u -p -r1.221 subr_pool.c
--- kern/subr_pool.c	18 Jan 2018 18:08:51 -0000	1.221
+++ kern/subr_pool.c	19 Jan 2018 01:35:30 -0000
@@ -457,7 +457,7 @@ pool_init(struct pool *pp, size_t size, 
 
 	pl_init(pp, &pp->pr_lock);
 	pl_init(pp, &pp->pr_requests_lock);
-	TAILQ_INIT(&pp->pr_requests);
+	SIMPLEQ_INIT(&pp->pr_requests);
 
 	if (phpool.pr_size == 0) {
 		pool_init(&phpool, sizeof(struct pool_page_header), 0,
@@ -549,7 +549,7 @@ void
 pool_request(struct pool *pp, struct pool_request *pr)
 {
 	pl_enter(pp, &pp->pr_requests_lock);
-	TAILQ_INSERT_TAIL(&pp->pr_requests, pr, pr_entry);
+	SIMPLEQ_INSERT_TAIL(&pp->pr_requests, pr, pr_entry);
 	pool_runqueue(pp, PR_NOWAIT);
 	pl_leave(pp, &pp->pr_requests_lock);
 }
@@ -643,7 +643,7 @@ pool_get_done(struct pool *pp, void *xme
 void
 pool_runqueue(struct pool *pp, int flags)
 {
-	struct pool_requests prl = TAILQ_HEAD_INITIALIZER(prl);
+	struct pool_requests prl = SIMPLEQ_HEAD_INITIALIZER(prl);
 	struct pool_request *pr;
 
 	pl_assert_unlocked(pp, &pp->pr_lock);
@@ -655,18 +655,14 @@ pool_runqueue(struct pool *pp, int flags
 	do {
 		pp->pr_requesting = 1;
 
-		/* no TAILQ_JOIN? :( */
-		while ((pr = TAILQ_FIRST(&pp->pr_requests)) != NULL) {
-			TAILQ_REMOVE(&pp->pr_requests, pr, pr_entry);
-			TAILQ_INSERT_TAIL(&prl, pr, pr_entry);
-		}
-		if (TAILQ_EMPTY(&prl))
+		SIMPLEQ_CONCAT(&prl, &pp->pr_requests);
+		if (SIMPLEQ_EMPTY(&prl))
 			continue;
 
 		pl_leave(pp, &pp->pr_requests_lock);
 
 		pl_enter(pp, &pp->pr_lock);
-		pr = TAILQ_FIRST(&prl);
+		pr = SIMPLEQ_FIRST(&prl);
 		while (pr != NULL) {
 			int slowdown = 0;
 
@@ -677,24 +673,21 @@ pool_runqueue(struct pool *pp, int flags
 			if (pr->pr_item == NULL) /* || slowdown ? */
 				break;
 
-			pr = TAILQ_NEXT(pr, pr_entry);
+			pr = SIMPLEQ_NEXT(pr, pr_entry);
 		}
 		pl_leave(pp, &pp->pr_lock);
 
-		while ((pr = TAILQ_FIRST(&prl)) != NULL &&
+		while ((pr = SIMPLEQ_FIRST(&prl)) != NULL &&
 		    pr->pr_item != NULL) {
-			TAILQ_REMOVE(&prl, pr, pr_entry);
+			SIMPLEQ_REMOVE_HEAD(&prl, pr_entry);
 			(*pr->pr_handler)(pp, pr->pr_cookie, pr->pr_item);
 		}
 
 		pl_enter(pp, &pp->pr_requests_lock);
 	} while (--pp->pr_requesting);
 
-	/* no TAILQ_JOIN :( */
-	while ((pr = TAILQ_FIRST(&prl)) != NULL) {
-		TAILQ_REMOVE(&prl, pr, pr_entry);
-		TAILQ_INSERT_TAIL(&pp->pr_requests, pr, pr_entry);
-	}
+	SIMPLEQ_CONCAT(&prl, &pp->pr_requests);
+	SIMPLEQ_CONCAT(&pp->pr_requests, &prl);
 }
 
 void *
@@ -795,7 +788,7 @@ pool_put(struct pool *pp, void *v)
 #endif
 
 #ifdef MULTIPROCESSOR
-	if (pp->pr_cache != NULL && TAILQ_EMPTY(&pp->pr_requests)) {
+	if (pp->pr_cache != NULL && SIMPLEQ_EMPTY(&pp->pr_requests)) {
 		pool_cache_put(pp, v);
 		return;
 	}
@@ -821,7 +814,7 @@ pool_put(struct pool *pp, void *v)
 	if (freeph != NULL)
 		pool_p_free(pp, freeph);
 
-	if (!TAILQ_EMPTY(&pp->pr_requests)) {
+	if (!SIMPLEQ_EMPTY(&pp->pr_requests)) {
 		pl_enter(pp, &pp->pr_requests_lock);
 		pool_runqueue(pp, PR_NOWAIT);
 		pl_leave(pp, &pp->pr_requests_lock);