From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: [PATCH 0/2] netem: trace enhancement Date: Wed, 12 Dec 2007 15:13:13 -0800 Message-ID: <20071212151313.6b668290@freepuppy.rosehill> References: <20071120231131.oqn4s5eda84k4csw@email.ee.ethz.ch> <474C2246.50205@ee.ethz.ch> <20071129134554.5c25a891@freepuppy.rosehill> <474F3719.30101@trash.net> <47503971.9080509@ee.ethz.ch> <4753B423.7030000@trash.net> <4753C874.80703@ee.ethz.ch> <47543E65.4060303@trash.net> <47544B1F.1010902@candelatech.com> <20071204154535.4eu35nfe9wks8kgg@email.ee.ethz.ch> <47556B20.2030700@trash.net> <4756A046.1070608@ee.ethz.ch> <4756A213.2060806@trash.net> <475D4DEE.2080308@ee.ethz.ch> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: Patrick McHardy , Ariane Keller , Ben Greear , netdev@vger.kernel.org, herbert@gondor.apana.org.au, Rainer Baumann To: Ariane Keller Return-path: Received: from smtp2.linux-foundation.org ([207.189.120.14]:57317 "EHLO smtp2.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751081AbXLLXPK (ORCPT ); Wed, 12 Dec 2007 18:15:10 -0500 In-Reply-To: <475D4DEE.2080308@ee.ethz.ch> Sender: netdev-owner@vger.kernel.org List-ID: On Mon, 10 Dec 2007 15:32:14 +0100 Ariane Keller wrote: > I finally managed to rewrite the netem trace extension to use rtnetlink > communication for the data transfer for user space to kernel space. > > The kernel patch is available here: > http://www.tcn.hypert.net/tcn_kernel_2_6_23_rtnetlink > > and the iproute patch is here: > http://www.tcn.hypert.net/tcn_iproute2_2_6_23_rtnetlink > > Whenever new data is needed the kernel module sends a notification to > the user space process. Thereupon the user space process sends a data > package to the kernel module. I wonder if it wouldn't be possible to enhance/extend netlink to use sendfile/splice to get the data. It is rather more work than needed for just this, but it would be useful for large configuration. > I had to write a new qdisc_notify function (qdisc_notify_pid) since the > other was acquiring a lock, which we already hold in this situation. > I hope everything works as expected and I'm looking forward for your > comments. > > Thanks! > Ariane -- Stephen Hemminger