[mpich-discuss] thread MPI calls

[chong tan]

D,
sorry for the confusion.  In our application, the setting is different from the code
Pavan posted.  I will try to have them lined up here, (<--- is between thread,
<==== is between proc)

            proc 0                                                 proc 1

  main thread    recv thread

  do_work()     MPI_Irecv                               do_work()
                        MPI_Wait*()  <=======      MPI_Send()
  blocked     <--- unblock                                 do_very_litle_work()
  MPI_Send                         ==========>   MPI_Recv()


I don't know if the MPI_Recv call in Proc 1 is interferring with the MPI_Wait*() in Proc 1.  We
see heavy system activity in Proc 1.  

                     
tan


 



________________________________
From: Darius Buntinas <buntinas at mcs.anl.gov>
To: mpich-discuss at mcs.anl.gov
Sent: Thursday, July 30, 2009 11:17:52 AM
Subject: Re: [mpich-discuss] thread MPI calls

That sounds fishy.  If process 1 is doing a sleep(), you shouldn't see
any activity from that process!  Can you double check that?

-d

On 07/30/2009 01:05 PM, chong tan wrote:
> pavan,
> the behavior you described is the expected behavior.  However, using
> your example, we are also seeing
> a lot of system activity in process 1 in all of our experiments.  That
> contributes significantly
> to the negative gain.
>  



      
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