From owner-freebsd-amd64@FreeBSD.ORG  Sat Nov 20 11:57:33 2004
Return-Path: <owner-freebsd-amd64@FreeBSD.ORG>
Delivered-To: freebsd-amd64@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP
	id C7B4116A4CE; Sat, 20 Nov 2004 11:57:33 +0000 (GMT)
Received: from mailout1.pacific.net.au (mailout1.pacific.net.au [61.8.0.84])
	by mx1.FreeBSD.org (Postfix) with ESMTP
	id 1F76343D4C; Sat, 20 Nov 2004 11:57:33 +0000 (GMT)
	(envelope-from bde@zeta.org.au)
Received: from mailproxy2.pacific.net.au (mailproxy2.pacific.net.au
	[61.8.0.87])iAKBvUGx009457;	Sat, 20 Nov 2004 22:57:30 +1100
Received: from katana.zip.com.au (katana.zip.com.au [61.8.7.246])
	iAKBvTgb009859;	Sat, 20 Nov 2004 22:57:29 +1100
Date: Sat, 20 Nov 2004 22:57:30 +1100 (EST)
From: Bruce Evans <bde@zeta.org.au>
X-X-Sender: bde@delplex.bde.org
To: Ruslan Ermilov <ru@FreeBSD.org>
In-Reply-To: <20041119204208.GA92096@ip.net.ua>
Message-ID: <20041120225023.V86199@delplex.bde.org>
References: <Pine.BSF.4.60.0411191757010.75856@mail.sbb.co.yu>
	<bf8d7e4904111912214a86a151@mail.gmail.com>
	<20041119204208.GA92096@ip.net.ua>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
cc: amd64@FreeBSD.org
Subject: Re: Too many mbufs
X-BeenThere: freebsd-amd64@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
List-Id: Porting FreeBSD to the AMD64 platform <freebsd-amd64.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-amd64>,
	<mailto:freebsd-amd64-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-amd64>
List-Post: <mailto:freebsd-amd64@freebsd.org>
List-Help: <mailto:freebsd-amd64-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-amd64>,
	<mailto:freebsd-amd64-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sat, 20 Nov 2004 11:57:33 -0000

On Fri, 19 Nov 2004, Ruslan Ermilov wrote:

> On Fri, Nov 19, 2004 at 03:21:44PM -0500, Chris McDermott wrote:
> ...
> > If I try and get the value with sysctlbyname() [copied from
> > netstat/mbuf.c], it returns negative values for mbstat->m_mbufs. This
> > negative value does fluctuate with network usage though...
> >
> > Test code:
> > ...
> > 	if (sysctlbyname("kern.ipc.mbstat", mbstat, &mlen, NULL, 0) < 0)
> > 		perror("sysctl: retrieving mbstat");
> >
> > 	printf("mbufs: %d \nclusters: %d\n", mbstat->m_mbufs, mbstat->m_mclusts);
> >
> > 	return 0;
> > }
> >
> Your code is broken.  Both m_mbufs and m_mclusts are of the type
> u_long, so they should be printed with "%lu" specifier.  Fix your
> program and try again.  (And you should see the same big number.)
>
> > Output:
> >
> > mbufs: -2240
> > clusters: -2686
> > ..
> > codefactory# netstat -m
> > 18446744073709549940 mbufs in use
> > 18446744073709549630/17152 mbuf clusters in use (current/max)

The value is obviously negative (since 1844mumble is nearly 2^64),
so the buggy program accidentally displays the correct value.

I can't see why the count would be decremented below 0 more on 64-bit
machines than on 32-bit ones.

Bruce