[Paraview] mpirun of paraview

[John Patchett]

It's probably MPICH, we have also witnessed the CPU spinning using 
MVAPICH.  We wrote some code that found nodes with open receives show 
high usage.  This makes sense that process 0 shows normal CPU usage 
while the rest of the nodes in the job have open receives while waiting 
for process 0 to tell them to do something.  I believe the behavior 
causing the high CPU usage is called polling and you can build MVAPICH 
(as well as MPICH??) with polling turned off.  I understand this will 
simply increase your latency.

-John

On Apr 18, 2006, at 12:22 PM, Sean Ziegeler, Contractor wrote:

>> I tried to run paraview which was compiled with mpich. I noticed that
>> cpu usage on paraview data servers (pvserver) is always around 99%
>> even though no data processing at all. Only the first pvdataserver's
>> cpu usage was reasonable(where I started the mpirun command).
>>
>> Why did that happen? Does that mean paraview is not working properly
>> on all paraivew data servers.
>
> That might be an MPI issue.  We use MVAPICH (a derivative of MPICH) and
> it also seems to peg-out the processors for all but the first process.
> This happens with any MPI run, not just Paraview.  I am guessing MPI is
> doing some sort of spin-wait on those processes.
>
> Anyway, to see if it truly is MPICH, you can try running some other MPI
> program that can idle for a certain amount of time and see if those
> processes behave similarly.
>
> -Sean
>
> _______________________________________________
> ParaView mailing list
> ParaView at paraview.org
> http://www.paraview.org/mailman/listinfo/paraview