[netperf-talk] global question concerning Netperf test and SMP support

[Simon Duboue]

>On 04/04/2012 03:15 AM, Simon Duboue wrote:
>>
>> Could the total throughput be considered as the sum of the two obtained
>> results?
>
>Maybe :)  There is no explicit synchronization in netperf.  There are a 
>few ways to address issues of skew error:
>
>http://www.netperf.org/svn/netperf2/trunk/doc/netperf.html#Using-Netperf-to-Measure-Aggregate-Performance

>
>The one I currently use the most is the "demo mode with post-processing" 
>path, though that has an issue with UDP_STREAM - the interim results 
>reported by netperf in a UDP_STREAM test will be sender side, not 
>receiver side.  In that case the (ab)use of confidence intervals path 
>may be better (though take longer).
>
>While the local CPU util in your pair of UDP_STREAM tests was the same, 
>the remote CPU util differed enough that I would not trust the results 
>to have low skew error.

Now I get the same version of netperf on both sides. The results seem to 
be in the same range as previously.
I come back on what you say before concerning the use of the -i option. As 
expected, I have a warning for the confidence intervals not reached.

netperf -i 10 -cC -p 17170 -l 30 -P 0 -H $1 -t TCP_STREAM -- -C &
netperf -i 10 -cC -p 17170 -l 30 -P 0 -H $1 -t TCP_STREAM -- -C &
netperf -i 10 -cC -p 17170 -l 30 -P 0 -H $1 -t TCP_STREAM -- -C &
netperf -i 10 -cC -p 17170 -l 30 -P 0 -H $1 -t TCP_STREAM -- -C 

!!! WARNING
!!! Desired confidence was not achieved within the specified iterations.
!!! This implies that there was variability in the test environment that
!!! must be investigated before going further.
!!! Confidence intervals: Throughput      : 11.9%
!!!                       Local CPU util  : 10.9%
!!!                       Remote CPU util : 70.5%

 87380  16384  16384    30.06       641.87   6.77     10.06    1.732 
10.306 
!!! WARNING
!!! Desired confidence was not achieved within the specified iterations.
!!! This implies that there was variability in the test environment that
!!! must be investigated before going further.
!!! Confidence intervals: Throughput      : 13.4%
!!!                       Local CPU util  : 11.5%
!!!                       Remote CPU util : 294.0%

 87380  16384  16384    30.08       668.97   6.79     7.66     1.668 7.879 
 
!!! WARNING
!!! Desired confidence was not achieved within the specified iterations.
!!! This implies that there was variability in the test environment that
!!! must be investigated before going further.
!!! Confidence intervals: Throughput      : 10.4%
!!!                       Local CPU util  : 12.7%
!!!                       Remote CPU util : 290.8%

 87380  16384  16384    30.10       683.27   6.79     7.68     1.631 7.436 
 
!!! WARNING
!!! Desired confidence was not achieved within the specified iterations.
!!! This implies that there was variability in the test environment that
!!! must be investigated before going further.
!!! Confidence intervals: Throughput      : 15.0%
!!!                       Local CPU util  : 11.4%
!!!                       Remote CPU util : 70.2%

 87380  16384  16384    30.12       643.66   6.79     10.14    1.735 
10.239

Considering the cpu utilization, can I consider that the test are running 
in parallel?

I increase the length of the test and the number of iterations and I still 
not achieve this interval but they decrease.
netperf -i 100 -cC -p 17170 -l 60 -P 0 -H $1 -t TCP_STREAM -- -C &
netperf -i 100 -cC -p 17170 -l 60 -P 0 -H $1 -t TCP_STREAM -- -C &
netperf -i 100 -cC -p 17170 -l 60 -P 0 -H $1 -t TCP_STREAM -- -C &
netperf -i 100 -cC -p 17170 -l 60 -P 0 -H $1 -t TCP_STREAM -- -C 
Second results:
!!! WARNING
!!! Desired confidence was not achieved within the specified iterations.
!!! This implies that there was variability in the test environment that
!!! must be investigated before going further.
!!! Confidence intervals: Throughput      :  4.2%
!!!                       Local CPU util  :  4.1%
!!!                       Remote CPU util :  9.1%

 87380  16384  16384    60.06       642.17   6.58     10.74    1.680 
10.985 
!!! WARNING
!!! Desired confidence was not achieved within the specified iterations.
!!! This implies that there was variability in the test environment that
!!! must be investigated before going further.
!!! Confidence intervals: Throughput      :  6.1%
!!!                       Local CPU util  :  4.0%
!!!                       Remote CPU util : 10.4%

 87380  16384  16384    60.08       643.44   6.57     10.73    1.679 
10.960 
!!! WARNING
!!! Desired confidence was not achieved within the specified iterations.
!!! This implies that there was variability in the test environment that
!!! must be investigated before going further.
!!! Confidence intervals: Throughput      :  5.1%
!!!                       Local CPU util  :  4.1%
!!!                       Remote CPU util :  9.0%

 87380  16384  16384    60.09       648.31   6.58     10.76    1.665 
10.896 
!!! WARNING
!!! Desired confidence was not achieved within the specified iterations.
!!! This implies that there was variability in the test environment that
!!! must be investigated before going further.
!!! Confidence intervals: Throughput      :  5.5%
!!!                       Local CPU util  :  4.0%
!!!                       Remote CPU util :  9.0%

 87380  16384  16384    60.09       651.78   6.57     10.73    1.657 
10.817 


For the -s -S and -m -M options, what scenario could be a good start in 
order to test their influence?


Have a nice day.

Simon Duboué

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