From mboxrd@z Thu Jan 1 00:00:00 1970 From: "David S. Miller" Subject: Re: [PATCH 0/9]: TCP: The Road to Super TSO Date: Wed, 08 Jun 2005 14:49:06 -0700 (PDT) Message-ID: <20050608.144906.77057282.davem@davemloft.net> References: <20050606.210846.07641049.davem@davemloft.net> <200506081740.11292.jheffner@psc.edu> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@oss.sgi.com, herbert@gondor.apana.org.au Return-path: To: jheffner@psc.edu In-Reply-To: <200506081740.11292.jheffner@psc.edu> Sender: netdev-bounce@oss.sgi.com Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org From: John Heffner Subject: Re: [PATCH 0/9]: TCP: The Road to Super TSO Date: Wed, 8 Jun 2005 17:40:10 -0400 > On Tuesday 07 June 2005 12:08 am, David S. Miller wrote: > > Some folks, notable the S2IO guys, get performance degradation > > from the Super TSO v2 patch (they get it from the first version > > as well). It's a real pain to spot what causes such things > > in such a huge patch... so I started splitting things up in > > a very fine grained manner so we can catch regressions more > > precisely. > > I'm curious about the details of this. Is there decreased performance > relative to current TSO? Relative to no TSO? Sending to just one receiver > or many, and is it receiver limited? The receiver is limited in their tests. No current generation systems can fill a 10gbit pipe fully, especially at 1500 byte MTU. Performance went down, with both TSO enabled and disabled, compared to not having the patches applied. That's why I'm going through this entire exercise of doing things one piece at a time.