From owner-freebsd-ipfw@FreeBSD.ORG  Fri Aug 13 08:20:24 2004
Return-Path: <owner-freebsd-ipfw@FreeBSD.ORG>
Delivered-To: freebsd-ipfw@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id 47EB416A4CE
	for <ipfw@hub.freebsd.org>; Fri, 13 Aug 2004 08:20:24 +0000 (GMT)
Received: from freefall.freebsd.org (freefall.freebsd.org [216.136.204.21])
	by mx1.FreeBSD.org (Postfix) with ESMTP id 37BDE43D5C
	for <ipfw@hub.freebsd.org>; Fri, 13 Aug 2004 08:20:24 +0000 (GMT)
	(envelope-from gnats@FreeBSD.org)
Received: from freefall.freebsd.org (gnats@localhost [127.0.0.1])
	by freefall.freebsd.org (8.12.11/8.12.11) with ESMTP id i7D8KOgh062945
	for <ipfw@freefall.freebsd.org>; Fri, 13 Aug 2004 08:20:24 GMT
	(envelope-from gnats@freefall.freebsd.org)
Received: (from gnats@localhost)
	by freefall.freebsd.org (8.12.11/8.12.11/Submit) id i7D8KN21062944;
	Fri, 13 Aug 2004 08:20:23 GMT
	(envelope-from gnats)
Date: Fri, 13 Aug 2004 08:20:23 GMT
Message-Id: <200408130820.i7D8KN21062944@freefall.freebsd.org>
To: ipfw@FreeBSD.org
From: Pawel Malachowski <pawmal-posting@freebsd.lublin.pl>
Subject: Re: kern/46557: ipfw pipe show fails with lots of queues
X-BeenThere: freebsd-ipfw@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
Reply-To: Pawel Malachowski <pawmal-posting@freebsd.lublin.pl>
List-Id: IPFW Technical Discussions <freebsd-ipfw.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-ipfw>,
	<mailto:freebsd-ipfw-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-ipfw>
List-Post: <mailto:freebsd-ipfw@freebsd.org>
List-Help: <mailto:freebsd-ipfw-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-ipfw>,
	<mailto:freebsd-ipfw-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Fri, 13 Aug 2004 08:20:24 -0000

The following reply was made to PR kern/46557; it has been noted by GNATS.

From: Pawel Malachowski <pawmal-posting@freebsd.lublin.pl>
To: Pawel Malachowski <pawmal-posting@freebsd.lublin.pl>
Cc: freebsd-gnats-submit@FreeBSD.org
Subject: Re: kern/46557: ipfw pipe show fails with lots of queues
Date: Fri, 13 Aug 2004 10:13:35 +0200

 On Thu, Aug 12, 2004 at 07:30:25PM +0000, Pawel Malachowski wrote:
 
 >  Here are more details what is going on. I hope someone will look at this and
 >  explain why malloc() can fail here and what can be done to prevent this.
 
 Well, I will explain myself. First, a patch:
 
 *** ip_dummynet.c.orig  Fri Aug 13 09:51:54 2004
 --- ip_dummynet.c       Fri Aug 13 09:52:23 2004
 ***************
 *** 1833,1839 ****
       for (set = all_flow_sets ; set ; set = set->next )
         size += sizeof ( *set ) +
             set->rq_elements * sizeof(struct dn_flow_queue);
 !     buf = malloc(size, M_TEMP, M_NOWAIT);
       if (buf == 0) {
         splx(s);
         return ENOBUFS ;
 --- 1833,1839 ----
       for (set = all_flow_sets ; set ; set = set->next )
         size += sizeof ( *set ) +
             set->rq_elements * sizeof(struct dn_flow_queue);
 !     buf = malloc(size, M_TEMP, M_WAITOK);
       if (buf == 0) {
         splx(s);
         return ENOBUFS ;
 
 Since buf can be very big (on my system, up to 3MB), malloc typically
 consumes only 128k-512k buckets (as checked in vmstat -m). On heavy
 loaded system with huge number of pipes, there is a risk that first-fit
 strategy won't find memory because of fragmentation.
 We will change M_NOWAIT to M_WAITOK flag so malloc() will always succeed;
 dummynet_get() is called only when superuser runs `ipfw pipe show', so
 WAITOK is not a problem for us.
 
 
 -- 
 Paweł Małachowski