[PerfSuite-users] monitoring the same process 3

[Giuseppe G. <gg9...@un...>]

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>
>Giuseppe,
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>  
>
>>> I am using perfsuite with PAPI, but I am not sure if multiplexing is 
>>> enabled. How to verify it? Is it necessary to install MPX?
>>> Variation that occurs are up to  100 % so unuseful for me, and I always 
>>> use the same intel compiler with the same option. Thanks, Giuseppe.
>>> 
>>    
>>
>
>It's not necessary to install MPX.  That's a software layer that was 
>developed by John May at Lawrence Livermore.  It's the basis for PAPI's 
>multiplexing and so comes with PAPI.  It's used when you are using 
>PerfSuite in counting (not profiling) mode, and you can tell when it has 
>been enabled by either looking in the "Statistics" section of psprocess 
>output or looking at the XML output files that psrun creates.
>
>If you have a program that runs for a very short time, it's possible that 
>you may see many event counts of zero, and typically that occurs because 
>the process is so short-lived, there is not enough time to cycle through 
>all the events.  You can force runs to happen without multiplexing by 
>creating your own configuration file; there is a short description of how 
>to do so here:
>
>http://perfsuite.ncsa.uiuc.edu/libpshwpc/sampleconfig.html
>
>Rick
>

Dear Rick,
I am testing a process that lasts tipically 30-40 seconds and it is not 
too short that many zeros appears. For this process I have variations up 
to 100 % in the number of total floating point operations.

I used perfsuite also to test a simple matrix-by-matrix multiplication 
that lasts between 0.5 an 1.0 seconds, but variation in this parameter 
are up to 20% and all counting parameters works.

Does the number of subroutines I call influences this parameter? What 
can I do to have a more precise test?
Thanks, Giuseppe.