Re: xennet slow under -current

[Chavdar Ivanov <ci4ic4%gmail.com@localhost>]

On Wed, 10 Mar 2021 at 21:11, Brian Marcotte <marcotte%panix.com@localhost> wrote:
>
> > What exactly do you use to test the performance?
> >
> > In my testing I found there to be a huge performance difference
> > between the two things I used for measuring, IIRC netcat and netio.
>
> Tests were done with iperf3 and TCP. iperf3 server is on FreeBSD running
> directly on hardware.
>
> I'll try some other tools as well.
>
> --
> - Brian

FWIW:
========
nbsd-w$ uname -a
NetBSD nbsd-w.lorien.lan 9.99.80 NetBSD 9.99.80 (GENERIC) #5: Tue Mar
2 17:15:22 GMT 2021
sysbuild@ymir:/home/sysbuild/amd64/obj/home/sysbuild/src/sys/arch/amd64/compile/GENERIC
amd64
nbsd-w$ ifconfig xennet0
xennet0: flags=0x8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        capabilities=0x3fc00<TCP4CSUM_Rx,TCP4CSUM_Tx,UDP4CSUM_Rx,UDP4CSUM_Tx>
        capabilities=0x3fc00<TCP6CSUM_Rx,TCP6CSUM_Tx,UDP6CSUM_Rx,UDP6CSUM_Tx>
        enabled=0
        ec_capabilities=0x5<VLAN_MTU,JUMBO_MTU>
        ec_enabled=0
        address: 1a:14:d1:b3:5a:46
        inet 192.168.0.36/24 broadcast 192.168.0.255 flags 0
        inet6 fe80::1814:d1ff:feb3:5a46%xennet0/64 flags 0 scopeid 0x1
nbsd-w$ iperf3 -s
-----------------------------------------------------------
Server listening on 5201
-----------------------------------------------------------
Accepted connection from 192.168.0.29, port 52709
[  5] local 192.168.0.36 port 5201 connected to 192.168.0.29 port 52708
[ ID] Interval           Transfer     Bitrate
[  5]   0.00-1.00   sec  31.9 MBytes   268 Mbits/sec
[  5]   1.00-2.00   sec  57.0 MBytes   478 Mbits/sec
[  5]   2.00-3.00   sec  74.1 MBytes   622 Mbits/sec
[  5]   3.00-4.00   sec  85.7 MBytes   719 Mbits/sec
[  5]   4.00-5.00   sec  86.3 MBytes   723 Mbits/sec
[  5]   5.00-6.00   sec  95.1 MBytes   798 Mbits/sec
[  5]   6.00-7.00   sec  94.4 MBytes   791 Mbits/sec
[  5]   7.00-8.00   sec  96.2 MBytes   807 Mbits/sec
[  5]   8.00-9.00   sec  91.8 MBytes   770 Mbits/sec
[  5]   9.00-10.00  sec  95.7 MBytes   804 Mbits/sec
[  5]  10.00-10.19  sec  16.3 MBytes   706 Mbits/sec
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate
[  5]   0.00-10.19  sec   824 MBytes   678 Mbits/sec                  receiver


The iperf3 server is GENERIC guest running under XCP-NG, obviously in
pvhvm mode. The client is an HP laptop running yesterday's -current as
well.

BTW if the server is a FreeBSD box (TrueNAS in this case) and the
client is the same pvhvm guest, I get somewhat better results, closer
to wire speeds:
....
^Ciperf3: interrupt - the server has terminated
nbsd-w$ iperf3 -c 192.168.0.34
Connecting to host 192.168.0.34, port 5201
[  5] local 192.168.0.36 port 65528 connected to 192.168.0.34 port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec   107 MBytes   898 Mbits/sec    0   4.00 MBytes
[  5]   1.00-2.00   sec   110 MBytes   921 Mbits/sec    0   4.00 MBytes
[  5]   2.00-3.00   sec   110 MBytes   925 Mbits/sec    0   4.00 MBytes
[  5]   3.00-4.00   sec   111 MBytes   927 Mbits/sec    0   4.00 MBytes
[  5]   4.00-5.00   sec   111 MBytes   931 Mbits/sec    0   4.00 MBytes
[  5]   5.00-6.00   sec   111 MBytes   929 Mbits/sec    0   4.00 MBytes
[  5]   6.00-7.00   sec   111 MBytes   930 Mbits/sec    0   4.00 MBytes
[  5]   7.00-8.00   sec   109 MBytes   912 Mbits/sec    0   4.00 MBytes
[  5]   8.00-9.00   sec   110 MBytes   925 Mbits/sec    0   4.00 MBytes
[  5]   9.00-10.00  sec   111 MBytes   931 Mbits/sec    0   4.00 MBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec  1.07 GBytes   923 Mbits/sec    0             sender
[  5]   0.00-10.07  sec  1.07 GBytes   916 Mbits/sec                  receiver

This is actually not too bad, it used to be worse last year (I mean
xennet performance as iperf3 server).


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