From owner-freebsd-hackers@FreeBSD.ORG Fri Apr 11 09:09:55 2003 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id C9F2E37B401; Fri, 11 Apr 2003 09:09:55 -0700 (PDT) Received: from bluejay.mail.pas.earthlink.net (bluejay.mail.pas.earthlink.net [207.217.120.218]) by mx1.FreeBSD.org (Postfix) with ESMTP id 587A043FBD; Fri, 11 Apr 2003 09:09:50 -0700 (PDT) (envelope-from tlambert2@mindspring.com) Received: from pool0023.cvx40-bradley.dialup.earthlink.net ([216.244.42.23] helo=mindspring.com) by bluejay.mail.pas.earthlink.net with asmtp (SSLv3:RC4-MD5:128) (Exim 3.33 #1) id 19415z-0007VY-00; Fri, 11 Apr 2003 09:09:44 -0700 Message-ID: <3E96E873.9CC19544@mindspring.com> Date: Fri, 11 Apr 2003 09:08:19 -0700 From: Terry Lambert X-Mailer: Mozilla 4.79 [en] (Win98; U) X-Accept-Language: en MIME-Version: 1.0 To: Mattias Pantzare References: <20030410171640.C44793B2@porter.dc.luth.se> <3E95E446.73B7E510@mindspring.com> <3E95E8E9.3080102@ludd.luth.se> <3E95F03C.2A01561D@mindspring.com> <3E96CA1F.4070000@ludd.luth.se> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-ELNK-Trace: b1a02af9316fbb217a47c185c03b154d40683398e744b8a45886caa052154494972ef95f061a06a7a2d4e88014a4647c350badd9bab72f9c350badd9bab72f9c cc: freebsd-hackers@freebsd.org cc: freebsd-performance@freebsd.org cc: "Jin Guojun \[DSD\]" cc: Eric Anderson cc: David Gilbert Subject: Re: tcp_output starving -- is due to mbuf get delay? X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 11 Apr 2003 16:09:56 -0000 Mattias Pantzare wrote: > Terry Lambert wrote: > > Latency = pool retention time = queue size > > Then explain this, FreeBSD to FreeBSD on that link uses all CPU on the > sender, the reciver is fine, but performance is not. NetBSD to FreeBSD > fills the link (1 Gbit/s). On the same computers. MTU 4470. Send and > receive maximum windows where tuned to the same values on NetBSD and > FreeBSD. I rather expect that the number of jumbogram buffers on FreeBSD is tiny and/or your MTU is not being properly negotiated between the endpoints, and you are fragging the bejesus out of your packets. A good thing to look at at this point would be: o Clean boot of FreeBSD target o Run NetBSD against it o Save statistics o Clean boot of FreeBSD target o Run FreeBSD against it o Save statistics o Compare saved statistics of NetBSD vs. FreeBSD against the target machine > And packet loss will affect the performance diffrently if you have a > large bandwith-latency product. You mean "bandwidth delay product". Yes, assuming you have packet loss. From your description of your setup, packet loss should not be possible, so we can discount it as a factor. You may want to disable fast restart on the FreeBSD sender. -- Terry