[netperf-talk] CPU Usage

[Rick Jones]

chandramani wrote:
> Thanks for the info.
> 
> I am running netserver on windows XP and netperf on Soekris board
> with debian.
> 
> By the way when I run netperf several times, throughput remains
> almost invariant but I get large variation in "service demand" and
 > "utilization" values though I don't do anything with setup.
> 
> What could be the reason behind this? 
> How to get the true measure of "service demand" and "utilization". 


Configure/compile netperf to use "proper" CPU utilization measurment 
methods.

The "times" method is horribly bogus.  I thought I pulled it from the 
more recent versions of netperf2 but maybe I didn't.  Which version of 
netperf are you using?  Times only measures CPU time charged directly to 
the process, and "networking" is notorious for not being charged to the 
process.

Under Debian, netperf should be using the "procstat" method.

Under XP netperf should be using a method that reports with an 'N' IIRC.

rick

> regards
> chandra
>  
> 
> 
> 
> "Rick Jones"<rick.jones2 at hp.com> wrote:
> chandramani wrote:
> 
>>Hi all
>>
>>I am new to Netperf. Recently I installed netperf and ran it with following command
>>
>>netperf -H "remotehostip" -l 20 -c -C 
>>and got following result
>>
>>Recv Send Send Utilization Service Demand
>>Socket Socket Message Elapsed Send Recv Send Recv
>>Size Size Size Time Throughput local remote local remote
>>bytes bytes bytes secs. 10^6bits/s % T % L us/KB us/KB
>>
>>8192 16384 16384 20.01 23.03 42.67 17.45 151.773 62.056
>>
>>On net I got little information regarding 'service demand'
>>performence mesure. But I didn't get any thing regarding
>>'utilization'. Specifically what do symbols '%T' and '%L' mean?
> 
> 
> IIRC they may be described in the manual.
> 
> http://www.netperf.org/svn/netperf2/trunk/doc .
> 
> Basically they describe the method used to measure the CPU utilization. 
>   'L' means the "loopers" or CPU soaker processes.  'T' means that the 
> "times" method was used, and that is not a good thing - what are your 
> platforms?
> 
> 
>>Is there any relationship between 'utilization' and 'service
>>deamand'?
> 
> 
> Yes. Service demand is the normalization (as it were) of the CPU 
> utilization and the throughput.
> 
> rick jones
> 
> 
>>thanking in advance for any sort of help
>>
>>regards
>>chandra
>>
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