From owner-freebsd-hackers Mon Dec 31 10:49:22 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from swan.prod.itd.earthlink.net (swan.mail.pas.earthlink.net [207.217.120.123]) by hub.freebsd.org (Postfix) with ESMTP id 502D937B41B for ; Mon, 31 Dec 2001 10:49:20 -0800 (PST) Received: from pool0439.cvx21-bradley.dialup.earthlink.net ([209.179.193.184] helo=mindspring.com) by swan.prod.itd.earthlink.net with esmtp (Exim 3.33 #1) id 16L7UW-0000hj-00; Mon, 31 Dec 2001 10:48:57 -0800 Message-ID: <3C30B31C.FFD2363B@mindspring.com> Date: Mon, 31 Dec 2001 10:49:00 -0800 From: Terry Lambert X-Mailer: Mozilla 4.7 [en]C-CCK-MCD {Sony} (Win98; U) X-Accept-Language: en MIME-Version: 1.0 To: Matthew Dillon Cc: Mike Silbersack , Josef Karthauser , Tomas Svensson , freebsd-hackers@FreeBSD.ORG Subject: Re: FreeBSD performing worse than Linux? References: <200112310704.fBV74Wb18947@apollo.backplane.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit 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 Matthew Dillon wrote: > new-reno was artifically limiting the max number of in-transit > packets to 4. This is probably why the USB ethernet worked > with 4.3, but it destroyed TCP performance for everything else > and was removed. > > I don't think there is kernel solution to the USB problems, short > of fixing the driver (if that's even possible). The packets are > being sent from the server and the only thing the client has > control over is the receive window advertisement. You could artifically > reduce the window advertisement on the client to deal with lots of small > packets but it would destroy performance for larger packets / data > streams. Cap the window size via the driver. This will probably require another attribute on all drivers, indicating "max allowable window size" ("0" could mean "any", and be used as the default so that we don't end up flaking out someone talking to Mars). -- Terry To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message