From mboxrd@z Thu Jan 1 00:00:00 1970 From: Patrick McManus Subject: RE: 2.6.27 problem with shaping using netem/ifb (regression?) [TSO] Date: Thu, 02 Oct 2008 11:49:20 -0400 Message-ID: <1222962561.7392.7.camel@tng> References: <1222902286.6395.22.camel@tng> <36D9DB17C6DE9E40B059440DB8D95F52064FB007@orsmsx418.amr.corp.intel.com> <1222912542.6395.30.camel@tng> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: "Brandeburg, Jesse" , herbert@gondor.apana.org.au, davem@davemloft.net Return-path: Received: from linode.ducksong.com ([64.22.125.164]:40573 "EHLO linode.ducksong.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753268AbYJBPt0 (ORCPT ); Thu, 2 Oct 2008 11:49:26 -0400 In-Reply-To: <1222912542.6395.30.camel@tng> Sender: netdev-owner@vger.kernel.org List-ID: Testing a little further, the key element is tso on loopback. It is off by default for 23->26, and on by default in 27. My script is always broken whenever I turn tso on for lo regardless of version. So maybe just a lo/tso interaction problem not a regression. The change that turned it on by default went into 27-rc4: commit f22f8567cb0a530d8958d177e0f268783bd0d894 Author: Herbert Xu Date: Fri Aug 15 14:52:08 2008 -0700 loopback: Enable TSO This patch enables TSO since the loopback device is naturally capable of handling packets of any size. This also means that we won't enable GSO on lo which is good until GSO is fixed to preserve netfilter state as netfilter treats loopback packets in a special way. Signed-off-by: Herbert Xu Signed-off-by: David S. Miller