From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: Re: TSO and IPoIB performance degradation Date: Tue, 7 Mar 2006 13:49:07 -0800 Message-ID: <20060307134907.733d3d27@localhost.localdomain> References: <1141767891.6119.903.camel@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, Linux Kernel Mailing List , openib-general@openib.org, "David S. Miller" Return-path: To: Matt Leininger In-Reply-To: <1141767891.6119.903.camel@localhost> 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 On Tue, 07 Mar 2006 13:44:51 -0800 Matt Leininger wrote: > On Mon, 2006-03-06 at 19:13 -0800, Shirley Ma wrote: > > > > > More likely you are getting hit by the fact that TSO prevents the > > congestion > > window from increasing properly. This was fixed in 2.6.15 (around mid > > of Nov 2005). > > > > Yep, I noticed the same problem. After updating to the new kernel, the > > performance are much better, but it's still lower than before. > > Here is an updated version of OpenIB IPoIB performance for various > kernels with and without one of the TSO patches. The netperf > performance for the latest kernels has not improved the TSO performance > drop. > > Any comments or suggestions would be appreciated. > > - Matt Configuration information? like did you increase the tcp_rmem, tcp_wmem? Tcpdump traces of what is being sent and available window? Is IB using NAPI or just doing netif_rx()?