From owner-freebsd-current@FreeBSD.ORG Mon Nov 12 17:45:59 2007 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 90DFB16A420 for ; Mon, 12 Nov 2007 17:45:59 +0000 (UTC) (envelope-from gwright@antiope.com) Received: from QMTA07.westchester.pa.mail.comcast.net (qmta07.westchester.pa.mail.comcast.net [76.96.62.64]) by mx1.freebsd.org (Postfix) with ESMTP id 3C63813C4D1 for ; Mon, 12 Nov 2007 17:45:59 +0000 (UTC) (envelope-from gwright@antiope.com) Received: from OMTA03.westchester.pa.mail.comcast.net ([76.96.62.27]) by QMTA07.westchester.pa.mail.comcast.net with smtp id Btl81Y00K0bG4ec0000W00; Mon, 12 Nov 2007 17:45:48 +0000 Received: from [192.168.2.42] ([72.88.201.27]) by OMTA03.westchester.pa.mail.comcast.net with comcast id Btlo1Y00N0byEVU0000000; Mon, 12 Nov 2007 17:45:48 +0000 X-Authority-Analysis: v=1.0 c=1 a=IJfJwvcmZ-LFclAhYWQA:9 a=HAQ9-HIdPFGBVTxcYboA:7 a=BaAXoKaL0Erw_FKE1DZ-Y-0nxyoA:4 a=WuK_CZDBSqoA:10 In-Reply-To: <473780DB.2040705@freebsd.org> References: <46B41421-3112-40C6-84D9-094FA771F93E@antiope.com> <4735CE3A.7020905@freebsd.org> <473780DB.2040705@freebsd.org> Mime-Version: 1.0 (Apple Message framework v752.2) Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed Message-Id: <17995F62-7E9B-42E3-A7FA-30143C704C34@antiope.com> Content-Transfer-Encoding: 7bit From: Gregory Wright Date: Mon, 12 Nov 2007 12:45:43 -0500 To: Andre Oppermann X-Mailer: Apple Mail (2.752.2) Cc: freebsd-current@freebsd.org Subject: Re: excessive TCP dulplicate acks revisted X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 12 Nov 2007 17:45:59 -0000 On Nov 11, 2007, at 5:23 PM, Andre Oppermann wrote: > Gregory Wright wrote: >> On Nov 10, 2007, at 10:28 AM, Andre Oppermann wrote: >>> >> Hi Andre, >> I also took a look at the bge (4) driver in 7.0-BETA2. As far as >> I can tell, >> it does not support TSO (there is no ioctl supporting TSO enable/ >> disable >> as there is for the em(4) driver). > >> Might the chip --- a BCM5704_B0 --- not be completely >> initialized? This >> might explain why the machine with the BCM5714_B3 chips works, while >> the other machine shows the duplicate ACK bug. > > Perhaps. Do you see the duplicate ACKs in a tcpdump on both the > sender > and the receiver? If you see it on the sender too, then it must be a > bug in our network stack or the driver (by requeuing the same packet > over and over again). > > -- > Andre The logs show that the duplicate ACKs are generated only by the receiver. I suspect a bug in the driver, perhaps the ACK packet is not being removed from the TX buffer ring. Examining the transmitted packets should be enough to rule out a network stack problem. Is there any debugging infrastructure I can use or do I just have to hack in on my own? Greg