Back in February of this year, I reported some performance issues with
the ixgbe driver enabling XPS by default and instance network
performance in OpenStack:
http://www.spinics.net/lists/netdev/msg362915.html
I've now seen the same thing with be2net and Skyhawk. In this case, the
magnitude of the delta is even greater. Disabling XPS increased the
netperf single-stream performance out of the instance from an average of
4108 Mbit/s to 8888 Mbit/s or 116%.
Should drivers really be enabling XPS by default?
Instance To Outside World
Single-stream netperf
~30 Samples for Each Statistic
Mbit/s
Skyhawk BE3 #1 BE3 #2
XPS On XPS Off XPS On XPS Off XPS On XPS Off
Median 4192 8883 8930 8853 8917 8695
Average 4108 8888 8940 8859 8885 8671
happy benchmarking,
rick jones
The sample counts below may not fully support the additional statistics
but for the curious:
raj@tardy:/tmp$ ~/netperf2_trunk/doc/examples/parse_single_stream.py -r
6 waxon_performance.log -f 2
Field2,Min,P10,Median,Average,P90,P99,Max,Count
be3-1,8758.850,8811.600,8930.900,8940.555,9096.470,9175.839,9183.690,31
be3-2,8588.450,8736.967,8917.075,8885.322,9017.914,9075.735,9094.620,32
skyhawk,3326.760,3536.008,4192.780,4108.513,4651.164,4723.322,4724.320,27
0 too-short lines ignored.
raj@tardy:/tmp$ ~/netperf2_trunk/doc/examples/parse_single_stream.py -r
6 waxoff_performance.log -f 2
Field2,Min,P10,Median,Average,P90,P99,Max,Count
be3-1,8461.080,8634.690,8853.260,8859.870,9064.480,9247.770,9253.050,31
be3-2,7519.130,8368.564,8695.140,8671.241,9068.588,9200.719,9241.500,27
skyhawk,8071.180,8651.587,8883.340,8888.411,9135.603,9141.229,9142.010,32
0 too-short lines ignored.
"waxon" is with XPS enabled, "waxoff" is with XPS disabled. The servers
are the same models/config as in February.
stack@np-cp1-comp0013-mgmt:~$ sudo ethtool -i hed3
driver: be2net
version: 10.6.0.3
firmware-version: 10.7.110.45
