From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Heffner Subject: Re: Possible BUG in IPv4 TCP window handling, all recent 2.4.x/2.6.x kernels Date: Fri, 2 Sep 2005 10:10:18 -0400 Message-ID: <6064b8272aa4562242eb60eb75c7cdae@psc.edu> References: <20050901.154300.118239765.davem@davemloft.net> <2d02c76a84655d212634a91002b3eccd@psc.edu> <20050901.232823.123760177.davem@davemloft.net> Mime-Version: 1.0 (Apple Message framework v622) Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Cc: "David S. Miller" , linux-net@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Return-path: In-Reply-To: To: lists@limebrokerage.com Sender: linux-net-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Sep 2, 2005, at 10:05 AM, lists@limebrokerage.com wrote: > This particular Win2k sender sends _only_ real-time data, it's not > capable of rewinding. So it's always sending small packets, from start > to finish, yet the problem still occurs. > > Note that even real-time data can end up generating a stream of > full-size packets occassionally. It's just very unlikely they would > occur at the start of the flow, as market data is very thin in the > pre-market open hours. The rcv_ssthresh growth can actually take place anywhere in the flow, not just at the beginning. >> But, that window clamping should fix the problem, as we recalculate >> the window to advertise. > > Patches for testing are very much welcome... Have you tried increasing the size of the receive buffer yet? -John