From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7EDA9C43603 for ; Tue, 10 Dec 2019 07:08:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5A87C20663 for ; Tue, 10 Dec 2019 07:08:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727306AbfLJHIu (ORCPT ); Tue, 10 Dec 2019 02:08:50 -0500 Received: from ivanoab7.miniserver.com ([37.128.132.42]:49998 "EHLO www.kot-begemot.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726819AbfLJHIt (ORCPT ); Tue, 10 Dec 2019 02:08:49 -0500 Received: from tun252.jain.kot-begemot.co.uk ([192.168.18.6] helo=jain.kot-begemot.co.uk) by www.kot-begemot.co.uk with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1ieZdT-0001M9-4T; Tue, 10 Dec 2019 07:08:43 +0000 Received: from sleer.kot-begemot.co.uk ([192.168.3.72]) by jain.kot-begemot.co.uk with esmtps (TLS1.3:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.92) (envelope-from ) id 1ieZdQ-0002j8-NY; Tue, 10 Dec 2019 07:08:42 +0000 Subject: Re: [RFC v1 1/2] um: drivers: remove support for UML_NET_PCAP To: Brendan Higgins Cc: johannes.berg@intel.com, Richard Weinberger , Jeff Dike , linux-um@lists.infradead.org, Linux Kernel Mailing List , David Gow References: <20191206020153.228283-1-brendanhiggins@google.com> <20191206020153.228283-2-brendanhiggins@google.com> <20191207012108.GA220741@google.com> <15f048d3-07ab-61c1-c6e0-0712e626dd33@cambridgegreys.com> From: Anton Ivanov Organization: Cambridge Greys Message-ID: <778d990f-5e07-b7af-498e-61f69c26f040@cambridgegreys.com> Date: Tue, 10 Dec 2019 07:08:40 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-Clacks-Overhead: GNU Terry Pratchett Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/12/2019 23:40, Brendan Higgins wrote: > On Sat, Dec 7, 2019 at 1:15 AM Anton Ivanov > wrote: >> On 07/12/2019 01:21, Brendan Higgins wrote: >>> On Fri, Dec 06, 2019 at 04:32:34PM -0800, Brendan Higgins wrote: >>>> On Thu, Dec 5, 2019 at 11:23 PM Anton Ivanov >>>> wrote: >>>> [...] >>>>> 1. There is a proposed patch for the build system to fix it. >>> So I just tried the patch you linked on the cover letter[1], and I am >>> still getting the build error described above: >>> >>> arch/um/drivers/pcap_user.c:35:12: error: conflicting types for ‘pcap_open’ >>> static int pcap_open(void *data) >>> ^~~~~~~~~ >>> In file included from /usr/include/pcap.h:43, >>> from arch/um/drivers/pcap_user.c:7: >>> /usr/include/pcap/pcap.h:859:18: note: previous declaration of ‘pcap_open’ was here >>> PCAP_API pcap_t *pcap_open(const char *source, int snaplen, int flags, >>> >>> Looking at the patch, I wouldn't expect it to solve this problem. >>> >>> Are there maybe different conflicting libpcap-dev libraries and I have >>> the wrong one? Or is this just still broken? >>> >>>>> 2. We should be removing all old drivers and replacing them with the >>>>> vector ones. >>>> Hmm...does this mean you would entertain a patch removing all the >>>> non-vector UML network drivers? I would be happy to see VDE go as >>>> well. >>>> >>>> In any event, it sounds like I should probably drop this patch as it >>>> is currently. >>>> >>>> Thanks! >>> [1] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=938962#79 >>> >>> _______________________________________________ >>> linux-um mailing list >>> linux-um@lists.infradead.org >>> http://lists.infradead.org/mailman/listinfo/linux-um >>> >> OK, looks like the pcap.h differs now as well. >> >> I will fix that too. It looks like you need both a pcap fix and a >> library linking fix for this to work. >> >> The patch fixes the issue with the build system which no longer provides >> the means for UML to specify extra libraries (I probably had an older >> pcap version on the machine where I tested this). >> >> IMHO frankly it is no longer necessary. >> >> 5.5-rc1 vector raw now has the facility to add/remove (including at >> runtime) filters compiled with pcap outside UML. It was merged this week. >> >> We now have the following line-up for vector drivers - EoGRE, EoL2TPv3, >> RAW (+/- BPF), TAP and BESS. Speeds are 2.5 to 9Gbit on my machine >> (mid-range Ryzen desktop). >> >> If I figure out a way to get hold of the underlying tap raw sockets the >> same way vhost does, TAP can probably go to 12Gbit or thereabouts. Same >> applies to getting zerocopy working with raw. >> >> As a basis for comparison I get 18Gbit on the same machine using vEth >> and containers. 50% of that is actually a very decent number. >> >> While vector drivers are not 1:1 replacements for the existing drivers, >> you can achieve the same topologies and the same connectivity at much >> higher performance - the old drivers test out in the 500Mbit range on >> the same hardware. >> >> IMHO we should at least mark them as "obsolete" and start preparing to >> remove them. > Alright, I will send a patch out which marks the other network drivers > as "obsolete". > > Clarification: Should I mark all UML network devices as "obsolete" > except for NET_VECTOR? Daemon and MCAST looked to me (I am not a > networking expert), like they might not be covered by vector. > They are not 1:1 replacements unfortunately. However, in order to fix daemon I have to rewrite the switch from uml-utilities too. It is beyond obsolete. MCAST for 2 UML instances can be replaced by either GRE or L2TPv3, for more than 2 you are better off introducing a proper switch. I am OK if all old drivers are marked as obsolete at this point, so please proceed with the patch. Brgds, -- Anton R. Ivanov Cambridgegreys Limited. Registered in England. Company Number 10273661 https://www.cambridgegreys.com/