From f713ea62a9adc61ec3e5eba4151e2da8ce573cb9 Mon Sep 17 00:00:00 2001
From: Ted Unangst <tedu@cvs.openbsd.org>
Date: Fri, 14 Nov 2014 02:02:43 +0000
Subject: move the slowdown back up. it needs to take place after the allocated
 page has been added to the pool, else it doesn't help because the memory
 isn't available. lost in locking rework. tested blambert sthen

---
 sys/kern/subr_pool.c | 28 ++++++++++++++++++----------
 1 file changed, 18 insertions(+), 10 deletions(-)

(limited to 'sys/kern/subr_pool.c')

diff --git a/sys/kern/subr_pool.c b/sys/kern/subr_pool.c
index a82a4bbd785..9f379e370fc 100644
--- a/sys/kern/subr_pool.c
+++ b/sys/kern/subr_pool.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: subr_pool.c,v 1.165 2014/11/10 18:55:43 kettenis Exp $	*/
+/*	$OpenBSD: subr_pool.c,v 1.166 2014/11/14 02:02:42 tedu Exp $	*/
 /*	$NetBSD: subr_pool.c,v 1.61 2001/09/26 07:14:56 chs Exp $	*/
 
 /*-
@@ -105,7 +105,7 @@ int	pool_debug = 0;
 #define POOL_INPGHDR(pp) ((pp)->pr_phoffset != 0)
 
 struct pool_item_header *
-	 pool_p_alloc(struct pool *, int);
+	 pool_p_alloc(struct pool *, int, int *);
 void	 pool_p_insert(struct pool *, struct pool_item_header *);
 void	 pool_p_remove(struct pool *, struct pool_item_header *);
 void	 pool_p_free(struct pool *, struct pool_item_header *);
@@ -538,9 +538,12 @@ pool_do_get(struct pool *pp, int flags)
 	 */
 	pp->pr_nout++;
 
+again:
 	if (pp->pr_curpage == NULL) {
+		int slowdown = 0;
+
 		mtx_leave(&pp->pr_mtx);
-		ph = pool_p_alloc(pp, flags);
+		ph = pool_p_alloc(pp, flags, &slowdown);
 		mtx_enter(&pp->pr_mtx);
 
 		if (ph == NULL) {
@@ -549,6 +552,13 @@ pool_do_get(struct pool *pp, int flags)
 		}
 
 		pool_p_insert(pp, ph);
+
+		if (slowdown && ISSET(flags, PR_WAITOK)) {
+			mtx_leave(&pp->pr_mtx);
+			yield();
+			mtx_enter(&pp->pr_mtx);
+			goto again;
+		}
 	}
 
 	ph = pp->pr_curpage;
@@ -689,11 +699,12 @@ pool_prime(struct pool *pp, int n)
 	struct pool_pagelist pl = LIST_HEAD_INITIALIZER(pl);
 	struct pool_item_header *ph;
 	int newpages;
+	int slowdown = 0;
 
 	newpages = roundup(n, pp->pr_itemsperpage) / pp->pr_itemsperpage;
 
 	while (newpages-- > 0) {
-		ph = pool_p_alloc(pp, PR_NOWAIT);
+		ph = pool_p_alloc(pp, PR_NOWAIT, &slowdown);
 		if (ph == NULL)
 			break;
 
@@ -711,23 +722,20 @@ pool_prime(struct pool *pp, int n)
 }
 
 struct pool_item_header *
-pool_p_alloc(struct pool *pp, int flags)
+pool_p_alloc(struct pool *pp, int flags, int *slowdown)
 {
 	struct pool_item_header *ph;
 	struct pool_item *pi;
 	caddr_t addr;
-	int n, slowdown = 0;
+	int n; 
 
 	MUTEX_ASSERT_UNLOCKED(&pp->pr_mtx);
 	KASSERT(pp->pr_size >= sizeof(*pi));
 
-	addr = pool_allocator_alloc(pp, flags, &slowdown);
+	addr = pool_allocator_alloc(pp, flags, slowdown);
 	if (addr == NULL)
 		return (NULL);
 
-	if (slowdown && ISSET(flags, PR_WAITOK))
-		yield();
-
 	if (POOL_INPGHDR(pp))
 		ph = (struct pool_item_header *)(addr + pp->pr_phoffset);
 	else {
-- 
cgit v1.2.3