From owner-freebsd-hackers Fri Nov 30 13:43:33 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from ns.yogotech.com (ns.yogotech.com [206.127.123.66]) by hub.freebsd.org (Postfix) with ESMTP id D615937B405 for ; Fri, 30 Nov 2001 13:43:28 -0800 (PST) Received: from caddis.yogotech.com (caddis.yogotech.com [206.127.123.130]) by ns.yogotech.com (8.9.3/8.9.3) with ESMTP id OAA17564; Fri, 30 Nov 2001 14:43:21 -0700 (MST) (envelope-from nate@yogotech.com) Received: (from nate@localhost) by caddis.yogotech.com (8.11.6/8.11.6) id fAULhGi20686; Fri, 30 Nov 2001 14:43:16 -0700 (MST) (envelope-from nate) From: Nate Williams MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <15367.64883.390696.863120@caddis.yogotech.com> Date: Fri, 30 Nov 2001 14:43:15 -0700 To: Matthew Dillon Cc: Alexander Haderer , freebsd-hackers@FreeBSD.ORG Subject: Re: Found the problem, w/patch (was Re: FreeBSD performing worse than Linux?) In-Reply-To: <200111302130.fAULUU324648@apollo.backplane.com> 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> <200111302047.fAUKlT811090@apollo.backplane.com> <200111302130.fAULUU324648@apollo.backplane.com> X-Mailer: VM 6.96 under 21.1 (patch 14) "Cuyahoga Valley" XEmacs Lucid Reply-To: nate@yogotech.com (Nate Williams) 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 > I believe I have found the problem. The transmit side has a > maximum burst count imposed by newreno. As far as I can tell, if > this maxburst is hit (it defaults to 4 packets), the transmitter > just stops - presumably until it receives an ack. Note, my experiences (and John Capos) are showing degraded performance when *NOT* on a LAN segment. In other words, when packet loss enters the mix, performance tends to fall off rather quickly. This is with or without newreno (which should theoretically help with packet loss). John claims that disabling delayed_ack doesn't seem to affect his performance, and I've not been able to verify if delayed_ack helps/hurts in my situation, since the testers have been pressed for time so I can't get them to iterate through the different settings. I do however have some packet dumps, although I'm not sure they will tell anything. :( Nate To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message