From owner-freebsd-fs@FreeBSD.ORG Sat Feb 27 22:16:23 2010 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 5923D1065678 for ; Sat, 27 Feb 2010 22:16:23 +0000 (UTC) (envelope-from jdc@koitsu.dyndns.org) Received: from qmta02.emeryville.ca.mail.comcast.net (qmta02.emeryville.ca.mail.comcast.net [76.96.30.24]) by mx1.freebsd.org (Postfix) with ESMTP id 376438FC2A for ; Sat, 27 Feb 2010 22:16:22 +0000 (UTC) Received: from omta08.emeryville.ca.mail.comcast.net ([76.96.30.12]) by qmta02.emeryville.ca.mail.comcast.net with comcast id n6Nh1d0030FhH24A2A3DJ4; Sat, 27 Feb 2010 22:03:13 +0000 Received: from koitsu.dyndns.org ([98.248.46.159]) by omta08.emeryville.ca.mail.comcast.net with comcast id nA3B1d00H3S48mS8UA3CbN; Sat, 27 Feb 2010 22:03:12 +0000 Received: by icarus.home.lan (Postfix, from userid 1000) id 992AE1E301A; Sat, 27 Feb 2010 14:03:10 -0800 (PST) Date: Sat, 27 Feb 2010 14:03:10 -0800 From: Jeremy Chadwick To: rwatson@freebsd.org Message-ID: <20100227220310.GA65110@icarus.home.lan> References: <20100226174021.8feadad9.gerrit@pmp.uni-hannover.de> <20100226224320.8c4259bf.gerrit@pmp.uni-hannover.de> <4B884757.9040001@digiware.nl> <20100227080220.ac6a2e4d.gerrit@pmp.uni-hannover.de> <4B892918.4080701@digiware.nl> <20100227202105.f31cbef7.gerrit@pmp.uni-hannover.de> <20100227193819.GA60576@icarus.home.lan> <4B89943C.70704@digiware.nl> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <4B89943C.70704@digiware.nl> User-Agent: Mutt/1.5.20 (2009-06-14) Cc: freebsd-fs@freebsd.org, stable@freebsd.org, Willem Jan Withagen , Eirik =?iso-8859-1?Q?=D8verby?= Subject: Re: mbuf leakage with nfs/zfs? X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 27 Feb 2010 22:16:23 -0000 On Sat, Feb 27, 2010 at 10:53:00PM +0100, Willem Jan Withagen wrote: > On 27-2-2010 21:32, Eirik Øverby wrote: > >I've had a discussion with some folks on this for a while. I can easily > >reproduce this situation by mounting a FreeBSD ZFS filesystem via > >NFS-UDP from an OpenBSD machine. Telling the OpenBSD machine to use TCP > >instead of UDP makes the problem go away. > > > >Other FreeBSD systems mounting the same share, either using UDP or TCP, > >does not cause the problem to show up. > > > >A patch was suggested by Rick Macklem, but that did not solve the issue: > >http://lists.freebsd.org/pipermail/freebsd-current/2009-December/014181.html > > I concur. > Everything in my network is now on TCP, and there is no mbuf leakage. > I just don't get over the 5500 mark, no matter what I throw at it. > > I do feel that TCP is not as well performing on a local net with Linux, > hence the choice for UDP. But TCP is workable as next best. I'm pulling in Robert Watson, who has some familiarity with the UDP stack/code in FreeBSD. I'm not sure he'll be a sufficient source of knowledge for this specific issue since it appears (?) to be specific to NFS; Rick Macklem would be a better choice, but as reported, he's MIA. Robert, are you aware of any changes or implementation issues which might cause excessive (read: leaking) mbuf use under UDP-based NFS? Do you know of a way folks could determine the source of the leak, either via DDB or while the system is live? -- | Jeremy Chadwick jdc@parodius.com | | Parodius Networking http://www.parodius.com/ | | UNIX Systems Administrator Mountain View, CA, USA | | Making life hard for others since 1977. PGP: 4BD6C0CB |