Date: Sat, 18 Jan 2014 16:32:10 -0500 From: Eric Dombroski <eric@edombroski.com> To: Adrian Chadd <adrian.chadd@gmail.com> Cc: FreeBSD Stable Mailing List <freebsd-stable@freebsd.org> Subject: Re: Major performance/stability regression in virtio network drivers between 9.2-RELEASE and 10.0-RC5 Message-ID: <CA%2B=CMd0ARvnE3FLN29uYARc9=c2K7BN=PpC7nf6hgt-6bx6Beg@mail.gmail.com> In-Reply-To: <CAJ-Vmo=ga-H5usiahWEXS8tu-RZJR0OXXcXiA-zEtJTNt99p5w@mail.gmail.com> References: <CA%2B=CMd3jeNevdzMQTCG5hEE91Tnmy=9VKfSOdsJaiqo7jYTvJg@mail.gmail.com> <CAJ-Vmo=ga-H5usiahWEXS8tu-RZJR0OXXcXiA-zEtJTNt99p5w@mail.gmail.com>
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Adrian:
Yes, no change.
-Eric
On Sat, Jan 18, 2014 at 4:06 PM, Adrian Chadd <adrian.chadd@gmail.com>wrote:
> Hi,
>
> Have you tried disabling tso?
>
> Adrian
> On Jan 18, 2014 1:52 PM, "Eric Dombroski" <eric@edombroski.com> 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
>> _______________________________________________
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>>
>
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