From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH 1/2] improve netem reorder flexibility Date: Fri, 18 Dec 2009 19:59:07 -0800 (PST) Message-ID: <20091218.195907.189689401.davem@davemloft.net> References: <1261142318-26249-1-git-send-email-christian.samsel@rwth-aachen.de> <20091218093240.64ca7d88@nehalam> <200912181901.28542.christian.samsel@rwth-aachen.de> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: shemminger@vyatta.com, netdev@vger.kernel.org To: christian.samsel@rwth-aachen.de Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:42863 "EHLO sunset.davemloft.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753998AbZLSD7G (ORCPT ); Fri, 18 Dec 2009 22:59:06 -0500 In-Reply-To: <200912181901.28542.christian.samsel@rwth-aachen.de> Sender: netdev-owner@vger.kernel.org List-ID: From: Christian Samsel Date: Fri, 18 Dec 2009 19:01:28 +0100 > Am Freitag, 18. Dezember 2009 18:32:40 schrieb Stephen Hemminger: >> On Fri, 18 Dec 2009 14:18:37 +0100 >> >> Christian Samsel wrote: >> > This patch adds a new feature to netem: The newly introduced parameter >> > reorderdelay TIME is the time a reordered packet is delayed. It can be >> > used in a combination with delay TIME to enable netem to produce late >> > packets, which is not possible in the standard netem / iproute2. In the >> > standard version reordered packets are always sent immediately and >> > therefore are always early packets. >> >> I like the idea but is it binary compatible with older kernels/ older >> iproute2 utilities? >> > Thats a good point. I will test it. So far i think it should work. It won't work. If you change the size of the tc_netem_qopt, older kernels will reject because the size is different from what the kernel expects. So newer iproute2 will not work with older kernels. You can't change these structures, add new netlink attributes to pass the new data instead.