From owner-freebsd-hackers Fri Nov 30 12:47:34 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from apollo.backplane.com (apollo.backplane.com [216.240.41.2]) by hub.freebsd.org (Postfix) with ESMTP id 4AEC237B416 for ; Fri, 30 Nov 2001 12:47:31 -0800 (PST) Received: (from dillon@localhost) by apollo.backplane.com (8.11.6/8.9.1) id fAUKlT811090; Fri, 30 Nov 2001 12:47:29 -0800 (PST) (envelope-from dillon) Date: Fri, 30 Nov 2001 12:47:29 -0800 (PST) From: Matthew Dillon Message-Id: <200111302047.fAUKlT811090@apollo.backplane.com> To: Alexander Haderer Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: FreeBSD performing worse than Linux? References: <20011128153817.T61580@monorchid.lemis.com> <15364.38174.938500.946169@caddis.yogotech.com> <20011128104629.A43642@walton.maths.tcd.ie> <5.1.0.14.1.20011130181236.00a80160@postamt1.charite.de> Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG Well, this is embarassing. I can reproduce this completely running 4.4-stable (Nov 17th kernel) on two machines. With newreno turned on, a TCP NFS mount only gets 80K/sec. With newreno turned off on the transmit side, a TCP NFS mount gets 7MB/sec. The state of the delayed-ack sysctl is irrelevant. This is without running any nfsiod's (which would mask the degredation of the synchronous messaging). I am tracking it down now. -Matt Matthew Dillon :> (I wrote) :> Hmm. I'll play with it a bit tomorrow. Er, later today. One thing :> I noticed recently with NFS/TCP is that I have to run 'nfsiod -n 4' :> on the client to get reasonable TCP performance. I don't think I :> had to do that before. It sure sounds similar... like a delayed-ack :> problem or improper transmit side backoff. :> :> It would be nice if someone able to reproduce the problem can test :> the TCP connection with newreno turned off (net.inet.tcp.newreno) :> and delayed acks turned off (net.inet.tcp.delayed_ack). If that :> fixes the proble it narrows down our search considerably. : :Hello, I am the submitter of PR 32141 mentioned above, : :I did check it with a 4.3 Release server and 4.2 Release client using :'mount_nfs -3 -T ...': :setting net.inet.tcp.newreno=0 gives fast performance (about 8 Mbyte/s, same :for udp mount), setting net.inet.tcp.newreno=1 gives 80kbyte/s. :Setting net.inet.tcp.delayed_ack=0 has no influence (I checked all 4 :combinations). :There is 'nfsiod -n 4' running at clientside (default setting if enabling :nfs via sysinstall). We did not play around with nfsiod settings so far. : :Hope that helps : : Alexander : :------------------------------------------------------------------ :Alexander Haderer Charite To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message