From owner-freebsd-net@freebsd.org Tue Jun 25 12:08:19 2019 Return-Path: Delivered-To: freebsd-net@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 4D05F15CA99A; Tue, 25 Jun 2019 12:08:19 +0000 (UTC) (envelope-from eugen@grosbein.net) Received: from eg.sd.rdtc.ru (eg.sd.rdtc.ru [IPv6:2a03:3100:c:13::5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "eg.sd.rdtc.ru", Issuer "eg.sd.rdtc.ru" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id B2C5387841; Tue, 25 Jun 2019 12:08:07 +0000 (UTC) (envelope-from eugen@grosbein.net) X-Envelope-From: eugen@grosbein.net X-Envelope-To: freebsd-xen@freebsd.org Received: from [10.58.0.4] ([10.58.0.4]) by eg.sd.rdtc.ru (8.15.2/8.15.2) with ESMTPS id x5PC7tfl096801 (version=TLSv1.2 cipher=DHE-RSA-AES128-SHA bits=128 verify=NOT); Tue, 25 Jun 2019 19:07:55 +0700 (+07) (envelope-from eugen@grosbein.net) Subject: Re: Very slow and inconsistent internal network speed (between, VM's on the same host) for FreeBSD 11.0+ as guest on, XCP-ng/XenServer To: Christian M , freebsd-xen@freebsd.org, freebsd-net@freebsd.org References: <12994df1-f847-ec92-aae8-43a32e59385f@darco.dk> <20190625082103.qiiz2cikrauaqlas@MacBook-Air-de-Roger.local> From: Eugene Grosbein Message-ID: Date: Tue, 25 Jun 2019 19:07:47 +0700 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: B2C5387841 X-Spamd-Bar: / Authentication-Results: mx1.freebsd.org; spf=permerror (mx1.freebsd.org: domain of eugen@grosbein.net uses mechanism not recognized by this client) smtp.mailfrom=eugen@grosbein.net X-Spamd-Result: default: False [0.27 / 15.00]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-0.76)[-0.762,0]; MX_INVALID(0.50)[greylisted]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[3]; TO_DN_SOME(0.00)[]; NEURAL_HAM_LONG(-0.13)[-0.134,0]; TAGGED_RCPT(0.00)[]; MIME_GOOD(-0.10)[text/plain]; DMARC_NA(0.00)[grosbein.net]; NEURAL_SPAM_SHORT(0.71)[0.707,0]; TO_MATCH_ENVRCPT_SOME(0.00)[]; R_SPF_PERMFAIL(0.00)[]; IP_SCORE(0.06)[asn: 29072(0.27), country: RU(0.01)]; FREEMAIL_TO(0.00)[gmail.com]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:29072, ipnet:2a03:3100::/32, country:RU]; MID_RHS_MATCH_FROM(0.00)[]; RCVD_TLS_ALL(0.00)[]; RCVD_COUNT_TWO(0.00)[2] X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 25 Jun 2019 12:08:19 -0000 25.06.2019 18:55, Christian M wrote: > Please note the > extremely uneven throughput for test 2 below. It's almost like the > throughput increased when running tcpdump simultaneously. Generally this indicates broken "hardware" offload for some features like txcsum/rxcsum/vlan_hwcsum/vlan_hwtagging etc. Some of them may be automatically disabled while interface is put in promiscuous mode by running tcpdump and enabled back after tcpdump terminated. You should look at "options" line in the output of ifconfig for the interface and manually disable offloads (look for ifconfig(8) manual for details). They retry tests without tcpdump running.