From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smartserver.smartsharesystems.com (smartserver.smartsharesystems.com [77.243.40.215]) by dpdk.org (Postfix) with ESMTP id 42DCE594B for ; Mon, 21 Dec 2015 17:09:00 +0100 (CET) X-MimeOLE: Produced By Microsoft Exchange V6.5 Content-class: urn:content-classes:message MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Date: Mon, 21 Dec 2015 17:08:53 +0100 Message-ID: <98CBD80474FA8B44BF855DF32C47DC358AF79A@smartserver.smartshare.dk> In-Reply-To: <20151221153945.GA12016@bricha3-MOBL3> X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: [dpdk-dev] tcpdump support in DPDK 2.3 Thread-Index: AdE8BdlKY0xFHr+nRs6X9TM8T1BbxQAAYjKw References: <98CBD80474FA8B44BF855DF32C47DC358AF758@smartserver.smartshare.dk> <20151214182931.GA17279@mhcomputing.net> <20151214223613.GC21163@mhcomputing.net> <20151216104502.GA10020@bricha3-MOBL3> <98CBD80474FA8B44BF855DF32C47DC358AF76F@smartserver.smartshare.dk> <20151216115611.GB10020@bricha3-MOBL3> <20151216181557.GA16963@mhcomputing.net> <20151221153945.GA12016@bricha3-MOBL3> From: =?iso-8859-1?Q?Morten_Br=F8rup?= To: "Bruce Richardson" Cc: dev@dpdk.org Subject: Re: [dpdk-dev] tcpdump support in DPDK 2.3 X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 21 Dec 2015 16:09:00 -0000 Bruce, Please reconsider your interpretation of the word "debuggability". = Debugging is not only something that R&D staff does in a lab. = Debuggability can also be interpreted as a network engineer's ability to = debug what is happening in a production network. Referring to the link you kindly provided (to the discussion on the OVF = mailing list), in my eyes the context of the itemized requirements is a = production environment, not a development environment. Daniele Di = Proietto wrote: >I think we can agree that there are a few rough spots that prevent it = from being easily deployed and used. >I was hoping to get some feedback from the community about those rough = spots, i.e. areas where OVS+DPDK can/needs to improve to become more = "production ready" and user-friendly. Med venlig hilsen / kind regards - Morten Br=F8rup -----Original Message----- From: Bruce Richardson [mailto:bruce.richardson@intel.com]=20 Sent: 21. december 2015 16:40 To: Matthew Hall Cc: Morten Br=F8rup; Kyle Larose; dev@dpdk.org Subject: Re: [dpdk-dev] tcpdump support in DPDK 2.3 On Wed, Dec 16, 2015 at 01:15:57PM -0500, Matthew Hall wrote: > On Wed, Dec 16, 2015 at 11:56:11AM +0000, Bruce Richardson wrote: > > Having this work with any application is one of our primary targets = here.=20 > > The app author should not have to worry too much about getting basic = > > debug support. Even if it doesn't work at 40G small packet rates,=20 > > you can get a lot of benefit from a scheme that provides functional = debugging for an app. >=20 > I think my issue is that I don't think I buy into this particular set=20 > of assumptions above. >=20 > I don't think a capture mechanism that doesn't work right in the real=20 > use cases of the apps actually buys us much. If all we care about is=20 > quickly dumping some frames to a pcap for occasional debugging, I=20 > already have some C code for that I can donate which is a lot less=20 > complicated than the trouble being proposed for "basic debug support". = > Or we could use libpcap's equivalent... but it's quite a lot more = complicated than the code I have. >=20 > If we're going to assign engineers to this it's costing somebody a lot = > of time and money. So I'd prefer to get them focused on something that = > will always work even with high loads, such as real bpfjit support. >=20 > Matthew. Hi, I think it basic boils down to the fact that we are trying to solve = different problems. Our current focus is the generic usability of all = DPDK applications, as discussed at the DPDK Userspace Summit. Our plan = is to provide some way to allow standard packet capture apps, such as = tcpdump, to be used easily with DPDK. This is something also being = looked for by folks such as those working on OVS e.g. called out at = http://openvswitch.org/pipermail/dev/2015-August/058814.html "- Insight into the system and debuggability: nothing beats tcpdump = for the kernel datapath. Can something similar be done for the userspace datapath? - Consistency of the tools: some commands are slightly different for = the userspace/kernel datapath. Ideally there shouldn't be any = difference." Providing libraries for packet capture at high packet rates is a = related, but different problem, that we'll maybe look to investigate in = the future - assuming that nobody else solves it first. /Bruce