Re: [PerfSuite-users] monitoring the same process 3

[Rick K. <rk...@nc...>]

Giuseppe,

> 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.

OK, thanks for the further information about the extent of the variation 
in your experiments.  I am still putting inaccuracies due to multiplexing 
at the top of the list.

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

For aggregate counting with psrun it shouldn't matter.  Profiling is a 
different situation (as the comments forwarded by Harry M yesterday 
pointed out).

I'd suggest using a non-multiplexed configuration file first to see if 
your results vary less.  You can use an alternate config file with psrun 
through the "-c" option, for example:

psrun -c fp.xml a.out

Where "fp.xml" is an XML file that contains the following:

<?xml version="1.0" encoding="UTF-8" ?>
<ps_hwpc_eventlist class="PAPI">
  <ps_hwpc_event type="preset" name="PAPI_FP_INS" />
  <ps_hwpc_event type="preset" name="PAPI_TOT_CYC" />
</ps_hwpc_eventlist>

This file should count only floating point instructions and total cycles 
on your system.

Rick