Date: Fri, 19 Apr 2019 18:45:43 +0200 (CEST) From: Wojciech Puchar <wojtek@puchar.net> To: Jim Thompson <jim@netgate.com> Cc: Eugene Grosbein <eugen@grosbein.net>, Wojciech Puchar <wojtek@puchar.net>, freebsd-hackers@freebsd.org Subject: Re: openvpn and system overhead Message-ID: <alpine.BSF.2.20.1904191842140.44949@puchar.net> In-Reply-To: <ACE6415A-549E-4349-BB70-E4C1ECA08BCB@netgate.com> References: <alpine.BSF.2.20.1904171707030.87502@puchar.net> <0cc6e0ac-a9a6-a462-3a1e-bfccfd41e138@grosbein.net> <ACE6415A-549E-4349-BB70-E4C1ECA08BCB@netgate.com>
next in thread | previous in thread | raw e-mail | index | archive | help
>> >> You need either some netmap-based solution or kernel-side vpn like IPsec (maybe with l2tp). >> For me, IKE daemon plus net/mpd5 work just fine. mpd5 is userland daemon too, >> but it processes only signalling traffic like session establishment packets >> and then it setups kernel structures (netgraph nodes) so that payload traffic is processed in-kernel only. > > > Addendum to previous message to freebsd-hackers: > > We have (also) considered a netmap-enhanced (enabled?) OpenVPN. You still have the problem that the ‘stack’ inside OpenVPN is single-threaded/single packet at a time. > > Also, you’ll need to multiplex > 1 instance of OpenVPN, maybe using the programability of VALE (aka ‘mswitch’). > there is no problem that openvpn is single threaded. i can easily divide things over multiple openvpn processes. The problem is CPU load it produces. It will not be smart to use up whole 8 core machine just to provide 3-4Gbps of VPN traffic with no spare power to do actual work. i found that most of time openvpn executes system call, encryption takes little time. if FreeBSD would be able to provide multiple packets per read/write call from/to tun device, as well as send/recv would have multipacket version - it would mean speeding it up at least 4 times. From owner-freebsd-hackers@freebsd.org Fri Apr 19 17:01:14 2019 Return-Path: <owner-freebsd-hackers@freebsd.org> Delivered-To: freebsd-hackers@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 393EC1572552 for <freebsd-hackers@mailman.ysv.freebsd.org>; Fri, 19 Apr 2019 17:01:14 +0000 (UTC) (envelope-from lidl@FreeBSD.org) Received: from hydra.pix.net (hydra.pix.net [IPv6:2001:470:e254:10::4]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "mail.pix.net", Issuer "Pix.Com Technologies LLC CA" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id E544087988 for <freebsd-hackers@freebsd.org>; Fri, 19 Apr 2019 17:01:13 +0000 (UTC) (envelope-from lidl@FreeBSD.org) Received: from torb.pix.net ([IPv6:2001:470:e254:10:fc26:6da6:2a7d:3ae5]) (authenticated bits=0) by hydra.pix.net (8.15.2/8.15.2) with ESMTPA id x3JH16iS002659; Fri, 19 Apr 2019 13:01:13 -0400 (EDT) (envelope-from lidl@FreeBSD.org) X-Authentication-Warning: hydra.pix.net: Host [IPv6:2001:470:e254:10:fc26:6da6:2a7d:3ae5] claimed to be torb.pix.net Subject: Re: openvpn and system overhead To: freebsd-hackers@freebsd.org References: <alpine.BSF.2.20.1904171707030.87502@puchar.net> <0cc6e0ac-a9a6-a462-3a1e-bfccfd41e138@grosbein.net> <ACE6415A-549E-4349-BB70-E4C1ECA08BCB@netgate.com> <alpine.BSF.2.20.1904191842140.44949@puchar.net> Reply-To: lidl@FreeBSD.org From: Kurt Lidl <lidl@FreeBSD.org> Message-ID: <8e238882-1779-41ed-92fd-33abf2667d18@FreeBSD.org> Date: Fri, 19 Apr 2019 13:01:06 -0400 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <alpine.BSF.2.20.1904191842140.44949@puchar.net> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Technical Discussions relating to FreeBSD <freebsd-hackers.freebsd.org> List-Unsubscribe: <https://lists.freebsd.org/mailman/options/freebsd-hackers>, <mailto:freebsd-hackers-request@freebsd.org?subject=unsubscribe> List-Archive: <http://lists.freebsd.org/pipermail/freebsd-hackers/>; List-Post: <mailto:freebsd-hackers@freebsd.org> List-Help: <mailto:freebsd-hackers-request@freebsd.org?subject=help> List-Subscribe: <https://lists.freebsd.org/mailman/listinfo/freebsd-hackers>, <mailto:freebsd-hackers-request@freebsd.org?subject=subscribe> X-List-Received-Date: Fri, 19 Apr 2019 17:01:14 -0000 On 4/19/19 12:45 PM, Wojciech Puchar wrote: >>> >>> You need either some netmap-based solution or kernel-side vpn like >>> IPsec (maybe with l2tp). >>> For me, IKE daemon plus net/mpd5 work just fine. mpd5 is userland >>> daemon too, >>> but it processes only signalling traffic like session establishment >>> packets >>> and then it setups kernel structures (netgraph nodes) so that payload >>> traffic is processed in-kernel only. >> >> >> Addendum to previous message to freebsd-hackers: >> >> We have (also) considered a netmap-enhanced (enabled?) OpenVPN. You >> still have the problem that the ‘stack’ inside OpenVPN is >> single-threaded/single packet at a time. >> >> Also, you’ll need to multiplex > 1 instance of OpenVPN, maybe using >> the programability of VALE (aka ‘mswitch’). >> > there is no problem that openvpn is single threaded. i can easily divide > things over multiple openvpn processes. > > The problem is CPU load it produces. It will not be smart to use up > whole 8 core machine just to provide 3-4Gbps of VPN traffic with no > spare power to do actual work. > > i found that most of time openvpn executes system call, encryption takes > little time. > > if FreeBSD would be able to provide multiple packets per read/write call > from/to tun device, as well as send/recv would have multipacket version > - it would mean speeding it up at least 4 times. Well, FreeBSD does have sendmmsg()/recvmmsg(), which allows for sending/receiving multiple packets per system call. I do not know if the "tun" device allows for send/recv type processing, or just read/write. Don't get me wrong -- having in-kernel processing, like ipsec does, is far superior to doing it as a userland daemon, IMHO. Just pointing out that there is a multi-packet system call that could be used, possibly, to make the userland solution less horrible. -Kurt
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?alpine.BSF.2.20.1904191842140.44949>