<html><head><style type="text/css"><!-- DIV {margin:0px;} --></style></head><body><div style="font-family:times new roman, new york, times, serif;font-size:12pt"><DIV>D,</DIV>
<DIV>sorry for the confusion. In our application, the setting is different from the code</DIV>
<DIV>Pavan posted. I will try to have them lined up here, (<--- is between thread,</DIV>
<DIV><==== is between proc)</DIV>
<DIV> </DIV>
<DIV> proc 0 proc 1</DIV>
<DIV> </DIV>
<DIV> main thread recv thread</DIV>
<DIV> </DIV>
<DIV> do_work() MPI_Irecv do_work()</DIV>
<DIV> MPI_Wait*() <======= MPI_Send()</DIV>
<DIV> blocked <--- unblock do_very_litle_work()</DIV>
<DIV> MPI_Send ==========> MPI_Recv()</DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV>I don't know if the MPI_Recv call in Proc 1 is interferring with the MPI_Wait*() in Proc 1. We</DIV>
<DIV>see heavy system activity in Proc 1. </DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV>tan</DIV>
<DIV> </DIV>
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<B><SPAN style="FONT-WEIGHT: bold">From:</SPAN></B> Darius Buntinas <buntinas@mcs.anl.gov><BR><B><SPAN style="FONT-WEIGHT: bold">To:</SPAN></B> mpich-discuss@mcs.anl.gov<BR><B><SPAN style="FONT-WEIGHT: bold">Sent:</SPAN></B> Thursday, July 30, 2009 11:17:52 AM<BR><B><SPAN style="FONT-WEIGHT: bold">Subject:</SPAN></B> Re: [mpich-discuss] thread MPI calls<BR></FONT><BR>That sounds fishy. If process 1 is doing a sleep(), you shouldn't see<BR>any activity from that process! Can you double check that?<BR><BR>-d<BR><BR>On 07/30/2009 01:05 PM, chong tan wrote:<BR>> pavan,<BR>> the behavior you described is the expected behavior. However, using<BR>> your example, we are also seeing<BR>> a lot of system activity in process 1 in all of our experiments. That<BR>> contributes significantly<BR>> to the negative gain.<BR>> <BR></DIV></DIV></div><br>
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