From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rainer Baumann Subject: Re: [PATCH 2.6.16.19 0/2] LARTC: trace control for netem Date: Wed, 02 Aug 2006 21:02:55 +0200 Message-ID: <44D0F6DF.9060408@tik.ee.ethz.ch> References: <44D0DF17.6060809@tik.ee.ethz.ch> <20060802111921.31906ea1@dxpl.pdx.osdl.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: netdev@VGER.KERNEL.ORG, netem@osdl.org Return-path: To: Stephen Hemminger In-Reply-To: <20060802111921.31906ea1@dxpl.pdx.osdl.net> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Thanx for your feedback! We will try to fix this. Rainer Stephen Hemminger wrote: > On Wed, 02 Aug 2006 19:21:27 +0200 > Rainer Baumann wrote: > > >> Hi, >> >> We developed an extension to the network emulator netem, that provides >> emulation of long term network properties such as long-range dependence >> and self-similarity of cross-traffic. It is not possible to emulate >> these properties with the statistical tables for the packet delay >> values used by the original netem. >> >> We read the values for the packet delay, drop, loss and corruption from >> a pre-generated trace file. This trace file is obtained by monitoring >> network traffic and writing all actions to a trace file. During the >> emulation the packets get processed according the values in such a trace >> file. Detailed information are available on our >> Webseitehttp://tcn.hypert.net >> >> A new option (trace) has been added to the netem command. If the trace >> option is used, the values for packet delay etc. are read from a trace >> file, afterwards the packets are processed by the normal netem functions. >> The packet action values are readout from the trace file in user space >> and sent to kernel space via procfs. >> >> The evaluation results show similar behavior for our enhancement and the >> original netem with respect to packet delay precision and packet loss at >> high load (e.g. 80'000 packets per second). >> It is possible to add, change or delete multiple netem qdiscs on-the-fly >> (original netem qdiscs and trace qdiscs mixed). >> >> We are looking forward for any comments, feedback and suggestions! >> >> Thanks, >> Rainer >> > > I like the idea and want to get it incorporated. > > Major things that need fixing: > * Don't extend size of tc_netem_qopt instead use a new netlink > payload. > + add type to TCA_NETEM_ enum > + new structure containing the payload > This allows for binary compatiablity. > > * Don't use proc for a interface to netem features. Use netlink. > Either add a new command (or option) to the iproute2 commands > to handle flow table, or add a new payload. > > > Minor stuff: > * the bzero macro in netem is a BSDism, just use memset > * bad indentation and style issues. > * minor whitespace damage in several places in patch > > - > To unsubscribe from this list: send the line "unsubscribe netdev" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >