From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roland Dreier Subject: Re: Re: TSO and IPoIB performance degradation Date: Tue, 07 Mar 2006 17:34:34 -0800 Message-ID: References: <1141776697.6119.938.camel@localhost> <20060307.161808.60227862.davem@davemloft.net> <20060307.172336.107863253.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, openib-general@openib.org, shemminger@osdl.org Return-path: To: "David S. Miller" In-Reply-To: <20060307.172336.107863253.davem@davemloft.net> (David S. Miller's message of "Tue, 07 Mar 2006 17:23:36 -0800 (PST)") List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: openib-general-bounces@openib.org Errors-To: openib-general-bounces@openib.org List-Id: netdev.vger.kernel.org David> I wish you had started the thread by mentioning this David> specific patch, we wasted an enormous amount of precious David> developer time speculating and asking for arbitrary tests David> to be run in order to narrow down the problem, yet you knew David> the specific change that introduced the performance David> regression already... Sorry, you're right. I was a little confused because I had a memory of Michael's original email (http://lkml.org/lkml/2006/3/6/150) quoting a changelog entry, but looking back at the message, it was quoting something completely different and misleading. I think the most interesting email in the old thread is http://openib.org/pipermail/openib-general/2005-October/012482.html which shows that reverting 314324121 (the "stretch ACK performance killer" fix) gives ~400 Mbit/sec in extra IPoIB performance. - R.