From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [ofa-general] Re: [PATCH 2/3][NET_BATCH] net core use batching Date: Wed, 10 Oct 2007 15:53:22 -0700 (PDT) Message-ID: <20071010.155322.43010360.davem@davemloft.net> References: <1191967006.5324.14.camel@localhost> <20071009.170435.43504422.davem@davemloft.net> <20071010120215.7ec19323.billfink@mindspring.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: hadi@cyberus.ca, shemminger@linux-foundation.org, andi@firstfloor.org, jeff@garzik.org, johnpol@2ka.mipt.ru, herbert@gondor.apana.org.au, gaagaan@gmail.com, Robert.Olsson@data.slu.se, netdev@vger.kernel.org, rdreier@cisco.com, peter.p.waskiewicz.jr@intel.com, mcarlson@broadcom.com, jagana@us.ibm.com, general@lists.openfabrics.org, mchan@broadcom.com, tgraf@suug.ch, randy.dunlap@oracle.com, sri@us.ibm.com, kaber@trash.net To: billfink@mindspring.com Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:56827 "EHLO sunset.davemloft.net" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1756538AbXJJWxU (ORCPT ); Wed, 10 Oct 2007 18:53:20 -0400 In-Reply-To: <20071010120215.7ec19323.billfink@mindspring.com> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org From: Bill Fink Date: Wed, 10 Oct 2007 12:02:15 -0400 > On Tue, 09 Oct 2007, David Miller wrote: > > > We have to keep in mind, however, that the sw queue right now is 1000 > > packets. I heavily discourage any driver author to try and use any > > single TX queue of that size. Which means that just dropping on back > > pressure might not work so well. > > > > Or it might be perfect and signal TCP to backoff, who knows! :-) > > I can't remember the details anymore, but for 10-GigE, I have encountered > cases where I was able to significantly increase TCP performance by > increasing the txqueuelen to 10000, which is the setting I now use for > any 10-GigE testing. For some reason this does not surprise me. We bumped the ethernet default up to 1000 for gigabit.