From mboxrd@z Thu Jan 1 00:00:00 1970 From: Baruch Even Subject: Re: Comparison of several congestion control algorithms Date: Fri, 03 Jun 2005 14:42:52 +0100 Message-ID: <42A05E5C.9050408@ev-en.org> References: <4298E045.9050009@ev-en.org> <20050602.163512.10298458.davem@davemloft.net> <429F9B2F.8030507@ev-en.org> <20050602.165341.63126720.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: netdev@oss.sgi.com, shemminger@osdl.org, doug.leith@nuim.ie Return-path: To: "David S. Miller" In-Reply-To: <20050602.165341.63126720.davem@davemloft.net> Sender: netdev-bounce@oss.sgi.com Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org David S. Miller wrote: > From: Baruch Even > Date: Fri, 03 Jun 2005 00:50:07 +0100 > > >>This is in part because of the start of the work that was based on 2.4 >>kernels and even as far as the 2.6.6 kernel which had disabled TSO once >>it saw SACKs. This made TSO unusable for our needs. >> >>AFAIK, the tests reported in that document used kernel 2.6.6. > > > Sure SACKs turn off TSO currently, but you'll have them enabled > at the beginning until the first loss and this affects how fast > the cwnd will grow. > > If you have e1000 cards, for example, you're getting TSO enabled > by default. > > You really need to look into this, as it has a real and very > non-trivial effect on all of the results you obtained. I checked that now and ethtool -k shows TSO to be disabled after boot. Since all the test scripts are not playing with ethtool I can be sure that TSO was off during all of our tests. Baruch