From owner-freebsd-stable@FreeBSD.ORG Sat Jan 18 19:04:28 2014 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 2B761EF for ; Sat, 18 Jan 2014 19:04:28 +0000 (UTC) Received: from mail-wi0-f171.google.com (mail-wi0-f171.google.com [209.85.212.171]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id AB0141821 for ; Sat, 18 Jan 2014 19:04:27 +0000 (UTC) Received: by mail-wi0-f171.google.com with SMTP id cc10so1931776wib.16 for ; Sat, 18 Jan 2014 11:04:20 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:date :message-id:subject:from:to:content-type; bh=bIIazh6+E5S2lEALEXD30H7sZhh0nrVQJRSgjZqnf9c=; b=bisnchWvhgvnitF0TU7Qt6FWjG2BkoTCrOXjlCTmbL8jQJr5cAENFgF9ORaJRW3aUY s91lG/LCEgrdnNqFPuy/TDwwswsmI3X/OP18/7Zon8hyg4cAzTKqkk11acDKDGVLMRVQ PDTC3QffVGAuDUUTybIXCsk1hxKEw0/E/i5y5B+6Dk1c+hw6jNEnIFYkt78kzZ+KUlO6 WdP8AS/KAren3UuEr+dF2/qc6248WH2s/br1SMSTBikjgQdzOq/CrnW614ftZ25e7+Yn twMvYRBk+cNTAEYNXMIOufRydI/94SU0GGBdK7t469ZrUnb32V7o53oRq75ZzZoAy/SB ASQA== X-Gm-Message-State: ALoCoQnmQAx4pZYCUZq2ifBg+Mpw54dCXcJ4H1kHBwtcdBqDGBFiYkd/xxRV0MuwlfeTHgL5wJK0 MIME-Version: 1.0 X-Received: by 10.194.173.163 with SMTP id bl3mr7522812wjc.10.1390071860174; Sat, 18 Jan 2014 11:04:20 -0800 (PST) Received: by 10.216.182.71 with HTTP; Sat, 18 Jan 2014 11:04:20 -0800 (PST) In-Reply-To: References: Date: Sat, 18 Jan 2014 14:04:20 -0500 Message-ID: Subject: Re: Major performance/stability regression in virtio network drivers between 9.2-RELEASE and 10.0-RC5 From: Eric Dombroski To: freebsd-stable@freebsd.org Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.17 X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 18 Jan 2014 19:04:28 -0000 PR: http://www.freebsd.org/cgi/query-pr.cgi?pr=185864 On Sat, Jan 18, 2014 at 1:51 PM, Eric Dombroski wrote: > Hello: > > I believe there is a major performance regression between FreeBSD > 9.2-RELEASE and 10.0-RC5 involving the virtio network drivers (vtnet) and > handling incoming traffic. Below are the results of some iperf tests and > large dd operations over NFS. Write throughput goes from ~40Gbps to > ~2.4Gbps from 9.2 to 10.0RC5, and over time the connection becomes unstable > ("no buffer space available"), requiring the interface to be taken down/up. > > > These results are on fresh installs of 9.2 and 10.0RC5, no sysctl tweaks > on either system. > > I can't reproduce this using an Intel 1Gbps ethernet through PCIe > passthrough, although I suspect the problem manifests itself over 1Gbps > speeds anyway. > > Tests: > > Client (host): > root@gogo:~# uname -a > Linux gogo 3.2.0-4-amd64 #1 SMP Debian 3.2.51-1 x86_64 GNU/Linux > root@gogo:~# kvm -version > QEMU emulator version 1.1.2 (qemu-kvm-1.1.2+dfsg-6, Debian), Copyright > (c) 2003-2008 Fabrice Bellard > root@gogo:~# lsmod | grep vhost > vhost_net 27436 3 > tun 18337 8 vhost_net > macvtap 17633 1 vhost_net > > > Command: iperf -c 192.168.100.x -t 60 > > > Server (FreeBSD 9.2 VM): > > root@umarotest:~ # uname -a > FreeBSD umarotest 9.2-RELEASE-p3 FreeBSD 9.2-RELEASE-p3 #0: Sat Jan > 11 03:25:02 UTC 2014 root@amd64-builder.daemonology.net:/usr/obj/usr/src/sys/GENERIC > amd64 > root@umarotest:~ # iperf -s > ------------------------------------------------------------ > Server listening on TCP port 5001 > TCP window size: 64.0 KByte (default) > ------------------------------------------------------------ > [ 4] local 192.168.100.44 port 5001 connected with 192.168.100.1 > port 58996 > [ ID] Interval Transfer Bandwidth > [ 4] 0.0-60.0 sec 293 GBytes 41.9 Gbits/sec > [ 5] local 192.168.100.44 port 5001 connected with 192.168.100.1 > port 58997 > [ 5] 0.0-60.0 sec 297 GBytes 42.5 Gbits/sec > [ 4] local 192.168.100.44 port 5001 connected with 192.168.100.1 > port 58998 > [ 4] 0.0-60.0 sec 291 GBytes 41.6 Gbits/sec > [ 5] local 192.168.100.44 port 5001 connected with 192.168.100.1 > port 58999 > [ 5] 0.0-60.0 sec 297 GBytes 42.6 Gbits/sec > [ 4] local 192.168.100.44 port 5001 connected with 192.168.100.1 > port 59000 > [ 4] 0.0-60.0 sec 297 GBytes 42.5 Gbits/sec > > While pinging out from the server to the client, I do not get any > errors. > > > root@umaro:~ # uname -a FreeBSD umaro 10.0-RC5 FreeBSD 10.0-RC5 #0 > r260430: Wed Jan 8 05:10:04 UTC 2014 root@snap.freebsd.org:/usr/obj/usr/src/sys/GENERIC > amd64 > root@umaro:~ # iperf -s > ------------------------------------------------------------ > Server listening on TCP port 5001 > TCP window size: 64.0 KByte (default) > ------------------------------------------------------------ > [ 4] local 192.168.100.5 port 5001 connected with 192.168.100.1 > port 50264 > [ ID] Interval Transfer Bandwidth > [ 4] 0.0-60.0 sec 16.7 GBytes 2.39 Gbits/sec > [ 5] local 192.168.100.5 port 5001 connected with 192.168.100.1 > port 50265 > [ 5] 0.0-60.0 sec 18.3 GBytes 2.62 Gbits/sec > [ 4] local 192.168.100.5 port 5001 connected with 192.168.100.1 > port 50266 > [ 4] 0.0-60.0 sec 16.8 GBytes 2.40 Gbits/sec > [ 5] local 192.168.100.5 port 5001 connected with 192.168.100.1 > port 50267 > [ 5] 0.0-60.0 sec 16.8 GBytes 2.40 Gbits/sec > [ 4] local 192.168.100.5 port 5001 connected with 192.168.100.1 > port 50268 > [ 4] 0.0-60.0 sec 16.8 GBytes 2.41 Gbits/sec > > *** While pinging out from the server to client, frequent "ping: > sendto: No space left on device" errors *** > > > After a while, I can also reliably re-produce more egregious "ping: > sendto: No buffer space available" errors after doing a large sequential > write over NFS: > > mount -t nfs -o rsize=65536,wsize=65536 192.168.100.5:/storage/shared > /mnt/nfs > dd if=/dev/zero of=/mnt/nfs/testfile bs=1M count=30000 > > I am going to file a freebsd bug report as well. > > Thanks, > Eric >